Updated on 2026-08-14

.gitignore

@@ -1,20 +1,22 @@
 *.iml
-.gradle
-/local.properties
-/.idea/libraries
-/.idea/modules.xml
-/.idea/workspace.xml
-.DS_Store
+
+# Built application files
 /build
-/captures
-.externalNativeBuild
-.idea/vcs.xml
-.idea/caches
-.idea/dictionaries
-.idea/runConfigurations.xml
-.idea/encodings.xml
-.idea/codeStyles/codeStyleConfig.xml
-.idea/assetWizardSettings.xml
+
+# Local configuration file (sdk path, etc)
+local.properties
+
+# Gradle generated files
+.gradle
+
+# User-specific configurations
+.idea/caches/
+.idea/libraries/
+.idea/*.xml
+
+# OS-specific files
+.DS_Store
+.DS_Store?
 
 # fastlane files
 **/fastlane/report.xml

.idea/gradle.xml

@@ -11,6 +11,7 @@
           <set>
             <option value="$PROJECT_DIR$" />
             <option value="$PROJECT_DIR$/app" />
+            <option value="$PROJECT_DIR$/blockchain" />
             <option value="$PROJECT_DIR$/server-android" />
             <option value="$PROJECT_DIR$/tangem-card-old" />
             <option value="$PROJECT_DIR$/tangem-core" />

app/build.gradle

@@ -125,7 +125,7 @@ dependencies {
     implementation 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0'
     implementation "com.orhanobut:hawk:2.0.1"
     implementation 'co.nstant.in:cbor:0.8'
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$versions.kotlin"
     implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.2.2'
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.2.2"
 //    implementation 'org.bitcoinj:bitcoinj-parent:0.14.7' //TODO: is this needed?

app/src/main/AndroidManifest.xml

@@ -66,6 +66,16 @@
                     android:host="app.tangem.com"
                     android:scheme="https" />
             </intent-filter>
+
+            <intent-filter>
+                <action android:name="android.nfc.action.NDEF_DISCOVERED" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data
+                    android:scheme="vnd.android.nfc"
+                    android:host="ext"
+                    android:pathPrefix="/android.com:pkg"/>
+            </intent-filter>
+
             <intent-filter>
                 <action android:name="android.nfc.action.TECH_DISCOVERED" />
             </intent-filter>

app/src/main/java/com/tangem/data/Blockchain.java

@@ -9,6 +9,7 @@ public enum Blockchain {
     Unknown("", "", 1.0, R.drawable.ic_logo_unknown, ""),
     Bitcoin("BTC", "BTC", 100000000.0, R.drawable.ic_logo_bitcoin, "Bitcoin"),
     BitcoinTestNet("BTC/test", "BTC", 100000000.0, R.drawable.ic_logo_bitcoin_testnet, "Bitcoin Testnet"),
+    BitcoinDual("BTC/dual", "BTC", 100000000.0, R.drawable.ic_logo_bitcoin, "Bitcoin"),
     Ethereum("ETH", "ETH", 1.0, R.drawable.ic_logo_ethereum, "Ethereum"),
     EthereumId("ETH/ID", "ETH", 1.0, R.drawable.ic_logo_ethereum, "Ethereum ID"),
     EthereumTestNet("ETH/test", "ETH", 1.0, R.drawable.ic_logo_ethereum_testnet, "Ethereum Testnet"),

app/src/main/java/com/tangem/data/network/BlockchainInfoApi.java

@@ -14,7 +14,7 @@ import retrofit2.http.Query;
 
 public interface BlockchainInfoApi {
     @GET(Server.ApiBlockchainInfo.Method.ADDRESS)
-    Single<BlockchainInfoAddress> blockchainInfoAddress(@Path("address") String address);
+    Single<BlockchainInfoAddress> blockchainInfoAddress(@Path("address") String address, @Query("offset") Integer offset);
 
     @GET(Server.ApiBlockchainInfo.Method.UTXO)
     Single<BlockchainInfoUnspents> blockchainInfoUnspents(@Query("active") String address);

app/src/main/java/com/tangem/data/network/BlockcypherApi.java

@@ -15,13 +15,13 @@ import retrofit2.http.Query;
 
 public interface BlockcypherApi {
     @GET(Server.ApiBlockcypher.Method.MAIN)
-    Call<BlockcypherFee> blockcypherMain(@Path("blockchain") String blockchain, @Path("network") String network);
+    Call<BlockcypherFee> blockcypherMain(@Path("blockchain") String blockchain, @Path("network") String network, @Query("token") String token);
 
     @GET(Server.ApiBlockcypher.Method.ADDRESS)
-    Call<BlockcypherResponse> blockcypherAddress(@Path("blockchain") String blockchain, @Path("network") String network, @Path("address") String address);
+    Call<BlockcypherResponse> blockcypherAddress(@Path("blockchain") String blockchain, @Path("network") String network, @Path("address") String address, @Query("token") String token);
 
     @GET(Server.ApiBlockcypher.Method.TXS)
-    Call<BlockcypherTx> blockcypherTxs(@Path("blockchain") String blockchain, @Path("network") String network, @Path("txHash") String txHash);
+    Call<BlockcypherTx> blockcypherTxs(@Path("blockchain") String blockchain, @Path("network") String network, @Path("txHash") String txHash, @Query("token") String token);
 
     @Headers("Content-Type: application/json")
     @POST(Server.ApiBlockcypher.Method.PUSH)

app/src/main/java/com/tangem/data/network/Server.java

@@ -113,7 +113,7 @@ public class Server {
 
         public static class Method {
             static final String MAIN = URL_BLOCKCYPHER + V1_MAIN;
-            static final String ADDRESS = MAIN + "/addrs/{address}?unspentOnly=true&includeScript=true";
+            static final String ADDRESS = MAIN + "/addrs/{address}?includeScript=true&limit=2000";
             static final String TXS = MAIN + "/txs/{txHash}?includeHex=true";
             static final String PUSH = MAIN + "/txs/push";
         }
@@ -123,7 +123,7 @@ public class Server {
         public static final String URL_BLOCKCHAININFO = ServerURL.API_BLOCKCHAIN_INFO;
 
         public static class Method {
-            static final String ADDRESS = URL_BLOCKCHAININFO + "rawaddr/{address}?limit=5";
+            static final String ADDRESS = URL_BLOCKCHAININFO + "rawaddr/{address}";
             static final String UTXO = URL_BLOCKCHAININFO + "unspent";
 //            static final String TX = URL_BLOCKCHAININFO + "rawtx/{txHash}";
             static final String PUSH = URL_BLOCKCHAININFO + "pushtx";

app/src/main/java/com/tangem/data/network/ServerApiBlockchainInfo.java

@@ -5,9 +5,11 @@ import android.util.Log;
 import com.tangem.App;
 import com.tangem.data.network.model.BlockchainInfoAddress;
 import com.tangem.data.network.model.BlockchainInfoAddressAndUnspents;
+import com.tangem.data.network.model.BlockchainInfoTransaction;
 import com.tangem.data.network.model.BlockchainInfoUnspents;
 
 import java.util.ArrayList;
+import java.util.List;
 
 import io.reactivex.Single;
 import io.reactivex.SingleObserver;
@@ -17,12 +19,13 @@ import okhttp3.ResponseBody;
 
 public class ServerApiBlockchainInfo {
     private static String TAG = ServerApiBlockchainInfo.class.getSimpleName();
+    private int page = 1;
 
     public void getAddressAndUnspents(String wallet, SingleObserver<BlockchainInfoAddressAndUnspents> addressAndUnspentsObserver) {
         Log.i(TAG, "new getAddressAndUnspents request");
         BlockchainInfoApi api = App.Companion.getNetworkComponent().getRetrofitBlockchainInfo().create(BlockchainInfoApi.class);
 
-        Single<BlockchainInfoAddress> addressObservable = api.blockchainInfoAddress(wallet);
+        Single<BlockchainInfoAddress> addressObservable = api.blockchainInfoAddress(wallet, null);
 
         Single<BlockchainInfoUnspents> unspentsObservable = api.blockchainInfoUnspents(wallet)
                 .onErrorReturnItem(new BlockchainInfoUnspents(new ArrayList<>()));
@@ -43,4 +46,17 @@ public class ServerApiBlockchainInfo {
 
         sendObservable.subscribe(sendObserver);
     }
+
+    public Single<List<BlockchainInfoTransaction>> getMoreAddressTxs(String wallet) {
+        Log.i(TAG, "new getAddress request");
+        BlockchainInfoApi api = App.Companion.getNetworkComponent().getRetrofitBlockchainInfo().create(BlockchainInfoApi.class);
+
+        Single<List<BlockchainInfoTransaction>> addressObservable = api.blockchainInfoAddress(wallet, page * 50)
+                .map(BlockchainInfoAddress::getTxs)
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread());
+
+        page++;
+        return addressObservable;
+    }
 }

app/src/main/java/com/tangem/data/network/ServerApiBlockcypher.java

@@ -32,8 +32,9 @@ public class ServerApiBlockcypher {
         return requestsCount <= 0;
     }
 
-    private ResponseListener responseListener;
+    private String apiKey = null;
 
+    private ResponseListener responseListener;
     private TxResponseListener txResponseListener;
 
     public interface ResponseListener {
@@ -68,20 +69,29 @@ public class ServerApiBlockcypher {
             blockchain = "btc";
             network = "test3";
         }
+        if (blockchainID.equals(Blockchain.Token.getID())) blockchain = "eth";
+        if (blockchainID.equals(Blockchain.BitcoinDual.getID())) blockchain = "btc";
 
         switch (method) {
             case BLOCKCYPHER_ADDRESS:
-                Call<BlockcypherResponse> addressCall = blockcypherApi.blockcypherAddress(blockchain, network, wallet);
+                Call<BlockcypherResponse> addressCall = blockcypherApi.blockcypherAddress(blockchain, network, wallet, apiKey);
                 addressCall.enqueue(new Callback<BlockcypherResponse>() {
                     @Override
                     public void onResponse(@NonNull Call<BlockcypherResponse> call, @NonNull Response<BlockcypherResponse> response) {
                         requestsCount--;
-                        if (response.code() == 200) {
-                            responseListener.onSuccess(method, response.body());
-                            Log.i(TAG, "requestData " + method + " onResponse " + response.code());
-                        } else {
-                            responseListener.onFail(method, String.valueOf(response.code()));
-                            Log.e(TAG, "requestData " + method + " onResponse " + response.code());
+                        switch (response.code()) {
+                            case 200:
+                                responseListener.onSuccess(method, response.body());
+                                Log.i(TAG, "requestData " + method + " onResponse " + response.code());
+                                break;
+                            case 429:
+                                apiKey = getRandomApiKey();
+                                requestData(blockchainID, method, wallet, tx);
+                                break;
+                            default:
+                                responseListener.onFail(method, String.valueOf(response.code()));
+                                Log.e(TAG, "requestData " + method + " onResponse " + response.code());
+                                break;
                         }
                     }
 
@@ -95,17 +105,24 @@ public class ServerApiBlockcypher {
                 break;
 
             case BLOCKCYPHER_FEE:
-                Call<BlockcypherFee> feeCall = blockcypherApi.blockcypherMain(blockchain, network);
+                Call<BlockcypherFee> feeCall = blockcypherApi.blockcypherMain(blockchain, network, apiKey);
                 feeCall.enqueue(new Callback<BlockcypherFee>() {
                     @Override
                     public void onResponse(@NonNull Call<BlockcypherFee> call, @NonNull Response<BlockcypherFee> response) {
                         requestsCount--;
-                        if (response.code() == 200) {
-                            responseListener.onSuccess(method, response.body());
-                            Log.i(TAG, "requestData " + method + " onResponse " + response.code());
-                        } else {
-                            responseListener.onFail(method, String.valueOf(response.code()));
-                            Log.e(TAG, "requestData " + method + " onResponse " + response.code());
+                        switch (response.code()) {
+                            case 200:
+                                responseListener.onSuccess(method, response.body());
+                                Log.i(TAG, "requestData " + method + " onResponse " + response.code());
+                                break;
+                            case 429:
+                                apiKey = getRandomApiKey();
+                                requestData(blockchainID, method, wallet, tx);
+                                break;
+                            default:
+                                responseListener.onFail(method, String.valueOf(response.code()));
+                                Log.e(TAG, "requestData " + method + " onResponse " + response.code());
+                                break;
                         }
                     }
 
@@ -119,17 +136,24 @@ public class ServerApiBlockcypher {
                 break;
 
             case BLOCKCYPHER_TXS:
-                Call<BlockcypherTx> txsCall = blockcypherApi.blockcypherTxs(blockchain, network, tx);
+                Call<BlockcypherTx> txsCall = blockcypherApi.blockcypherTxs(blockchain, network, tx, apiKey);
                 txsCall.enqueue(new Callback<BlockcypherTx>() {
                     @Override
                     public void onResponse(@NonNull Call<BlockcypherTx> call,@NonNull Response<BlockcypherTx> response) {
                         requestsCount--;
-                        if (response.code() == 200) {
-                            txResponseListener.onSuccess(response.body());
-                            Log.i(TAG, "requestData " + method + " onResponse " + response.code());
-                        } else {
-                            txResponseListener.onFail(String.valueOf(response.code()));
-                            Log.e(TAG, "requestData " + method + " onResponse " + response.code());
+                        switch (response.code()) {
+                            case 200:
+                                txResponseListener.onSuccess(response.body());
+                                Log.i(TAG, "requestData " + method + " onResponse " + response.code());
+                                break;
+                            case 429:
+                                apiKey = getRandomApiKey();
+                                requestData(blockchainID, method, wallet, tx);
+                                break;
+                            default:
+                                txResponseListener.onFail(String.valueOf(response.code()));
+                                Log.e(TAG, "requestData " + method + " onResponse " + response.code());
+                                break;
                         }
                     }
 
@@ -143,19 +167,24 @@ public class ServerApiBlockcypher {
                 break;
 
             case BLOCKCYPHER_SEND:
-                BlockcypherToken blockcypherToken = BlockcypherToken.values()[new Random().nextInt(BlockcypherToken.values().length)];
-
-                Call<BlockcypherResponse> sendCall = blockcypherApi.blockcypherPush(blockchain, network, new BlockcypherBody(tx), blockcypherToken.getToken());
+                Call<BlockcypherResponse> sendCall = blockcypherApi.blockcypherPush(blockchain, network, new BlockcypherBody(tx), apiKey);
                 sendCall.enqueue(new Callback<BlockcypherResponse>() {
                     @Override
                     public void onResponse(@NonNull Call<BlockcypherResponse> call, @NonNull Response<BlockcypherResponse> response) {
                         requestsCount--;
-                        if (response.code() == 201) {
-                            responseListener.onSuccess(method, response.body());
-                            Log.i(TAG, "requestData " + method + " onResponse " + response.code());
-                        } else {
-                            responseListener.onFail(method, String.valueOf(response.code()));
-                            Log.e(TAG, "requestData " + method + " onResponse " + response.code());
+                        switch (response.code()) {
+                            case 201:
+                                responseListener.onSuccess(method, response.body());
+                                Log.i(TAG, "requestData " + method + " onResponse " + response.code());
+                                break;
+                            case 429:
+                                apiKey = getRandomApiKey();
+                                requestData(blockchainID, method, wallet, tx);
+                                break;
+                            default:
+                                responseListener.onFail(method, String.valueOf(response.code()));
+                                Log.e(TAG, "requestData " + method + " onResponse " + response.code());
+                                break;
                         }
                     }
 
@@ -175,4 +204,9 @@ public class ServerApiBlockcypher {
                 break;
         }
     }
+
+    private String getRandomApiKey() {
+        return BlockcypherToken
+                .values()[new Random().nextInt(BlockcypherToken.values().length)].getToken();
+    }
 }

app/src/main/java/com/tangem/data/network/StellarRequest.java

@@ -4,11 +4,16 @@ import org.stellar.sdk.KeyPair;
 import org.stellar.sdk.Server;
 import org.stellar.sdk.Transaction;
 import org.stellar.sdk.requests.ErrorResponse;
+import org.stellar.sdk.requests.RequestBuilder;
 import org.stellar.sdk.responses.AccountResponse;
 import org.stellar.sdk.responses.LedgerResponse;
+import org.stellar.sdk.responses.Page;
 import org.stellar.sdk.responses.SubmitTransactionResponse;
+import org.stellar.sdk.responses.operations.OperationResponse;
 
 import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.List;
 
 /**
  * Created by dvol on 7.01.2019.
@@ -72,13 +77,37 @@ public class StellarRequest {
     public static class Ledgers extends Base {
         public LedgerResponse ledgerResponse;
 
-        public Ledgers() {};
+        public Ledgers() {
+        }
 
         @Override
         public void process(Server server) throws IOException {
-            int latestLedger = server.root().getCoreLatestLedger();
+            int latestLedger = server.root().getHistoryLatestLedger();
             ledgerResponse = server.ledgers().ledger(latestLedger);
         }
     }
 
+    public static class Operations extends Base {
+        KeyPair accountKeyPair;
+        public List<OperationResponse> operationsList;
+        int limit = 200;
+
+        public Operations(String walletAddress) {
+            accountKeyPair = KeyPair.fromAccountId(walletAddress);
+        }
+
+        @Override
+        public void process(Server server) throws IOException {
+            Page<OperationResponse> operationsResponse = server.operations().forAccount(accountKeyPair).limit(limit).order(RequestBuilder.Order.DESC).execute();
+            operationsList = operationsResponse.getRecords();
+            while (operationsResponse.getRecords().size() == limit) {
+                try {
+                    operationsResponse = operationsResponse.getNextPage(server.getHttpClient());
+                    operationsList.addAll(operationsResponse.getRecords());
+                } catch (URISyntaxException e) {
+                    break;
+                }
+            }
+        }
+    }
 }

app/src/main/java/com/tangem/data/network/model/BlockchainInfoResponse.kt

@@ -15,7 +15,10 @@ data class BlockchainInfoTransaction(
         var hash: String? = null,
 
         @SerializedName("block_height")
-        var block_height: Long? = null
+        var block_height: Long? = null,
+
+        @SerializedName("inputs")
+        var inputs: List<BlockchainInfoInput>
 )
 
 data class BlockchainInfoUnspents(
@@ -37,6 +40,16 @@ data class BlockchainInfoUtxo(
         var script: String? = null
 )
 
+data class BlockchainInfoInput(
+        @SerializedName("prev_out")
+        var prev_out: BlockchainInfoOutput
+)
+
+data class BlockchainInfoOutput(
+        @SerializedName("addr")
+        var addr: String? = null
+)
+
 data class BlockchainInfoAddressAndUnspents(
         var address: BlockchainInfoAddress,
         var unspents: BlockchainInfoUnspents

app/src/main/java/com/tangem/data/network/model/BlockcypherResponse.kt

@@ -13,13 +13,22 @@ data class BlockcypherResponse(
         var unconfirmed_balance: Long? = null,
 
         @SerializedName("txrefs")
-        var txrefs: List<BlockcypherTxref>? = null
+        var txrefs: List<BlockcypherTxref>? = null,
+
+        @SerializedName("unconfirmed_txrefs")
+        var unconfirmed_txrefs: List<BlockcypherTxref>? = null,
+
+        @SerializedName("hasMore")
+        var hasMore: Boolean? = null
 )
 
 data class BlockcypherTxref(
         @SerializedName("tx_hash")
         var tx_hash: String? = null,
 
+        @SerializedName("tx_input_n")
+        var tx_input_n: Int? = null,
+
         @SerializedName("tx_output_n")
         var tx_output_n: Int? = null,
 
@@ -30,7 +39,10 @@ data class BlockcypherTxref(
         var confirmations: Long? = null,
 
         @SerializedName("script")
-        var script: String? = null
+        var script: String? = null,
+
+        @SerializedName("spent")
+        var spent: Boolean? = null
 )
 
 data class BlockcypherTx(

app/src/main/java/com/tangem/ui/activity/MainActivity.kt

@@ -32,8 +32,6 @@ class MainActivity : AppCompatActivity(), NfcAdapter.ReaderCallback {
     lateinit var viewModel: GlobalViewModel
     lateinit var nfcManager: NfcManager
 
-//    private var onNfcReaderCallback: NfcAdapter.ReaderCallback? = null
-
     override fun onNewIntent(intent: Intent?) {
         super.onNewIntent(intent)
         if (intent != null && (NfcAdapter.ACTION_TECH_DISCOVERED == intent.action || NfcAdapter.ACTION_NDEF_DISCOVERED == intent.action)) {
@@ -68,15 +66,6 @@ class MainActivity : AppCompatActivity(), NfcAdapter.ReaderCallback {
         nfcManager = NfcManager(this, this)
         lifecycle.addObserver(NfcLifecycleObserver(nfcManager))
 
-//        // NFC
-//        val intent = intent
-//        if (intent != null && (NfcAdapter.ACTION_TECH_DISCOVERED == intent.action || NfcAdapter.ACTION_NDEF_DISCOVERED == intent.action)) {
-//            val tag = intent.getParcelableExtra<Tag>(NfcAdapter.EXTRA_TAG)
-//            if (tag != null && onNfcReaderCallback != null) {
-//                onNfcReaderCallback?.onTagDiscovered(tag)
-//            }
-//        }
-
         // check if root device
         val rootBeer = RootBeer(this)
         if (rootBeer.isRootedWithoutBusyBoxCheck && !BuildConfig.DEBUG)

app/src/main/java/com/tangem/ui/fragment/id/IdFragment.kt

@@ -364,7 +364,7 @@ class IdFragment : BaseFragment(), NfcAdapter.ReaderCallback,
         updateViews()
 
         // Bitcoin, Litecoin, BitcoinCash, Stellar
-        if (ctx.blockchain == Blockchain.Bitcoin || ctx.blockchain == Blockchain.BitcoinTestNet ||
+        if (ctx.blockchain == Blockchain.Bitcoin || ctx.blockchain == Blockchain.BitcoinTestNet || ctx.blockchain == Blockchain.BitcoinDual ||
                 ctx.blockchain == Blockchain.Litecoin || ctx.blockchain == Blockchain.BitcoinCash ||
                 ctx.blockchain == Blockchain.Stellar || ctx.blockchain == Blockchain.StellarTestNet || ctx.blockchain == Blockchain.StellarAsset) {
             ctx.coinData.setIsBalanceEqual(true)

app/src/main/java/com/tangem/wallet/CoinData.java

@@ -54,6 +54,10 @@ public abstract class CoinData {
             rate = B.getFloat("rate");
         if (B.containsKey("rateAlter"))
             rateAlter = B.getFloat("rateAlter");
+
+        if (B.containsKey("sentTransactionsCount")) {
+            sentTransactionsCount = B.getInt("sentTransactionsCount");
+        }
     }
 
     public void saveToBundle(Bundle B) {
@@ -70,6 +74,8 @@ public abstract class CoinData {
 
             B.putBoolean("balanceReceived", balanceReceived);
             B.putString("validationNodeDescription", validationNodeDescription);
+
+            B.putInt("sentTransactionsCount", sentTransactionsCount);
         } catch (Exception e) {
             Log.e("Can't save to bundle ", e.getMessage());
         }
@@ -83,8 +89,8 @@ public abstract class CoinData {
     }
 
     public static CoinData fromBundle(Blockchain blockchain, Bundle bundle) {
-        CoinEngine engine= CoinEngineFactory.INSTANCE.create(blockchain);
-        if( engine==null ) return null;
+        CoinEngine engine = CoinEngineFactory.INSTANCE.create(blockchain);
+        if (engine == null) return null;
         CoinData result = engine.createCoinData();
         result.loadFromBundle(bundle);
         return result;
@@ -143,11 +149,12 @@ public abstract class CoinData {
         setIsBalanceEqual(false);
         setBalanceReceived(false);
         setValidationNodeDescription("");
-        minFee=null;
-        maxFee=null;
-        normalFee=null;
-        rate=0f;
-        rateAlter=0f;
+        minFee = null;
+        maxFee = null;
+        normalFee = null;
+        rate = 0f;
+        rateAlter = 0f;
+        sentTransactionsCount = 0;
     }
 
 //    private AtomicInteger failedBalanceRequestCounter;
@@ -191,4 +198,14 @@ public abstract class CoinData {
     public CoinEngine.Amount minFee = null;
     public CoinEngine.Amount normalFee = null;
     public CoinEngine.Amount maxFee = null;
+
+    private int sentTransactionsCount = 0;
+
+    public int getSentTransactionsCount() {
+        return sentTransactionsCount;
+    }
+
+    public void incSentTransactionsCount() {
+        sentTransactionsCount++;
+    }
 }

app/src/main/java/com/tangem/wallet/CoinEngineFactory.kt

@@ -5,6 +5,7 @@ import com.tangem.data.Blockchain
 import com.tangem.wallet.bch.BtcCashEngine
 import com.tangem.wallet.binance.BinanceEngine
 import com.tangem.wallet.btc.BtcEngine
+import com.tangem.wallet.btcmultisig.BtcMultisigEngine
 import com.tangem.wallet.cardano.CardanoData
 import com.tangem.wallet.cardano.CardanoEngine
 import com.tangem.wallet.ducatus.DucatusEngine
@@ -56,6 +57,7 @@ object CoinEngineFactory {
             Blockchain.Eos -> EosEngine()
             Blockchain.Ducatus -> DucatusEngine()
             Blockchain.Tezos -> TezosEngine()
+            Blockchain.BitcoinDual -> BtcMultisigEngine()
             else -> null
         }
     }
@@ -101,6 +103,8 @@ object CoinEngineFactory {
                 DucatusEngine(context)
             else if (Blockchain.Tezos == context.blockchain)
                 TezosEngine(context)
+            else if (Blockchain.BitcoinDual == context.blockchain)
+                BtcMultisigEngine(context)
             else
                 return null
         } catch (e: Exception) {

app/src/main/java/com/tangem/wallet/btc/BtcEngine.java

@@ -13,6 +13,7 @@ import com.tangem.data.network.ServerApiBlockcypher;
 import com.tangem.data.network.ServerApiCommon;
 import com.tangem.data.network.model.BlockchainInfoAddress;
 import com.tangem.data.network.model.BlockchainInfoAddressAndUnspents;
+import com.tangem.data.network.model.BlockchainInfoInput;
 import com.tangem.data.network.model.BlockchainInfoTransaction;
 import com.tangem.data.network.model.BlockchainInfoUnspents;
 import com.tangem.data.network.model.BlockchainInfoUtxo;
@@ -53,6 +54,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import io.reactivex.Single;
 import io.reactivex.SingleObserver;
 import io.reactivex.observers.DisposableSingleObserver;
 import okhttp3.ResponseBody;
@@ -179,7 +181,7 @@ public class BtcEngine extends CoinEngine {
                     return false;
             }
 
-            if (ctx.getBlockchain() != Blockchain.BitcoinTestNet && ctx.getBlockchain() != Blockchain.Bitcoin) {
+            if (ctx.getBlockchain() != Blockchain.BitcoinTestNet && ctx.getBlockchain() != Blockchain.Bitcoin && ctx.getBlockchain() != Blockchain.BitcoinDual) {
                 return false;
             }
 
@@ -188,7 +190,7 @@ public class BtcEngine extends CoinEngine {
             }
         } else {
             try {
-                if (ctx.getBlockchain() == Blockchain.Bitcoin) {
+                if (ctx.getBlockchain() == Blockchain.Bitcoin || ctx.getBlockchain() == Blockchain.BitcoinDual) {
                     SegwitAddress.fromBech32(new MainNetParams(), address);
                 } else if (ctx.getBlockchain() == Blockchain.BitcoinTestNet) {
                     SegwitAddress.fromBech32(new TestNet3Params(), address);
@@ -211,7 +213,7 @@ public class BtcEngine extends CoinEngine {
 
     @Override
     public Uri getWalletExplorerUri() {
-        return Uri.parse((ctx.getBlockchain() == Blockchain.Bitcoin ? "https://www.blockchain.com/btc/address/" : "https://live.blockcypher.com/btc-testnet/address/") + ctx.getCoinData().getWallet());
+        return Uri.parse((ctx.getBlockchain() == Blockchain.Bitcoin || ctx.getBlockchain() == Blockchain.BitcoinDual ? "https://www.blockchain.com/btc/address/" : "https://live.blockcypher.com/btc-testnet/address/") + ctx.getCoinData().getWallet());
     }
 
     @Override
@@ -576,30 +578,6 @@ public class BtcEngine extends CoinEngine {
                     BlockchainInfoAddress blockchainInfoAddress = blockchainInfoAddressAndUnspents.getAddress();
                     BlockchainInfoUnspents blockchainInfoUnspents = blockchainInfoAddressAndUnspents.getUnspents();
 
-                    if (blockchainInfoAddress.getFinal_balance() != null) {
-                        coinData.setBalanceReceived(true);
-                        coinData.setBalanceConfirmed(blockchainInfoAddress.getFinal_balance());
-                        coinData.setBalanceUnconfirmed(0L);
-                        coinData.setValidationNodeDescription(Server.ApiBlockchainInfo.URL_BLOCKCHAININFO);
-
-                        for (BlockchainInfoTransaction tx : blockchainInfoAddress.getTxs()) {
-                            if (tx.getBlock_height() == null) {
-                                coinData.setHasUnconfirmed(true);
-                            }
-                        }
-
-                        if (App.pendingTransactionsStorage.hasTransactions(ctx.getCard())) {
-                            for (PendingTransactionsStorage.TransactionInfo pendingTx : App.pendingTransactionsStorage.getTransactions(ctx.getCard()).getTransactions()) {
-                                String pendingTxId = BTCUtils.toHex(BTCUtils.reverse(CryptoUtil.doubleSha256(BTCUtils.fromHex(pendingTx.getTx()))));
-                                for (BlockchainInfoTransaction responseTx : blockchainInfoAddress.getTxs()) {
-                                    if (responseTx.getHash().equals(pendingTxId)) {
-                                        App.pendingTransactionsStorage.removeTransaction(ctx.getCard(), pendingTx.getTx());
-                                    }
-                                }
-                            }
-                        }
-                    }
-
                     for (BlockchainInfoUtxo utxo : blockchainInfoUnspents.getUnspent_outputs()) {
                         BtcData.UnspentTransaction trUnspent = new BtcData.UnspentTransaction();
                         trUnspent.txID = utxo.getTx_hash_big_endian();
@@ -609,7 +587,18 @@ public class BtcEngine extends CoinEngine {
                         coinData.getUnspentTransactions().add(trUnspent);
                     }
 
-                    blockchainRequestsCallbacks.onComplete(true);
+                    if (blockchainInfoAddress.getFinal_balance() != null) {
+                        coinData.setBalanceReceived(true);
+                        coinData.setBalanceConfirmed(blockchainInfoAddress.getFinal_balance());
+                        coinData.setBalanceUnconfirmed(0L);
+                        coinData.setValidationNodeDescription(Server.ApiBlockchainInfo.URL_BLOCKCHAININFO);
+                    }
+
+                    if (blockchainInfoAddress.getTxs() != null) {
+                        checkTransactionsBlockchainInfo(Single.just(blockchainInfoAddress.getTxs()), serverApiBlockchainInfo, blockchainRequestsCallbacks);
+                    } else {
+                        blockchainRequestsCallbacks.onComplete(true);
+                    }
                 }
 
                 @Override
@@ -648,14 +637,29 @@ public class BtcEngine extends CoinEngine {
                         coinData.setValidationNodeDescription(Server.ApiBlockcypher.URL_BLOCKCYPHER);
 
                         coinData.getUnspentTransactions().clear();
+                        //TODO: change request logic, 2000 tx max
                         if (blockcypherResponse.getTxrefs() != null) {
                             for (BlockcypherTxref txref : blockcypherResponse.getTxrefs()) {
-                                BtcData.UnspentTransaction trUnspent = new BtcData.UnspentTransaction();
-                                trUnspent.txID = txref.getTx_hash();
-                                trUnspent.amount = txref.getValue();
-                                trUnspent.outputN = txref.getTx_output_n();
-                                trUnspent.script = txref.getScript();
-                                coinData.getUnspentTransactions().add(trUnspent);
+                                if (txref.getTx_input_n() == -1) { //recieved only
+                                    if (!txref.getSpent()) {
+                                        BtcData.UnspentTransaction trUnspent = new BtcData.UnspentTransaction();
+                                        trUnspent.txID = txref.getTx_hash();
+                                        trUnspent.amount = txref.getValue();
+                                        trUnspent.outputN = txref.getTx_output_n();
+                                        trUnspent.script = txref.getScript();
+                                        coinData.getUnspentTransactions().add(trUnspent);
+                                    }
+                                } else { //sent only
+                                    coinData.incSentTransactionsCount();
+                                }
+                            }
+                        }
+
+                        if (blockcypherResponse.getUnconfirmed_txrefs() != null) {
+                            for (BlockcypherTxref unconfirmedTxref : blockcypherResponse.getUnconfirmed_txrefs()) {
+                                if (unconfirmedTxref.getTx_input_n() != -1) {
+                                    coinData.incSentTransactionsCount();
+                                }
                             }
                         }
                     } catch (Exception e) {
@@ -663,7 +667,7 @@ public class BtcEngine extends CoinEngine {
                         Log.e(TAG, "FAIL BLOCKCYPHER_ADDRESS Exception");
                     }
 
-                    checkPending(blockchainRequestsCallbacks);
+                    checkPendingBlockcypher(blockchainRequestsCallbacks);
                 }
 
                 public void onSuccess(String method, BlockcypherFee blockcypherFee) {
@@ -686,7 +690,59 @@ public class BtcEngine extends CoinEngine {
         }
     }
 
-    private void checkPending(BlockchainRequestsCallbacks blockchainRequestsCallbacks) {
+    private void checkTransactionsBlockchainInfo(Single<List<BlockchainInfoTransaction>> txsSingle, ServerApiBlockchainInfo serverApiBlockchainInfo, BlockchainRequestsCallbacks blockchainRequestsCallbacks) {
+        SingleObserver<List<BlockchainInfoTransaction>> txsObserver = new DisposableSingleObserver<List<BlockchainInfoTransaction>>() {
+            @Override
+            public void onSuccess(List<BlockchainInfoTransaction> txs) {
+                if (App.pendingTransactionsStorage.hasTransactions(ctx.getCard())) {
+                    for (PendingTransactionsStorage.TransactionInfo pendingTx : App.pendingTransactionsStorage.getTransactions(ctx.getCard()).getTransactions()) {
+                        String pendingTxId = BTCUtils.toHex(BTCUtils.reverse(CryptoUtil.doubleSha256(BTCUtils.fromHex(pendingTx.getTx()))));
+                        for (BlockchainInfoTransaction responseTx : txs) {
+                            if (pendingTxId.equals(responseTx.getHash())) {
+                                App.pendingTransactionsStorage.removeTransaction(ctx.getCard(), pendingTx.getTx());
+                            }
+                        }
+                    }
+                }
+
+                for (BlockchainInfoTransaction tx : txs) {
+                    if (tx.getBlock_height() == null) {
+                        coinData.setHasUnconfirmed(true);
+                    }
+
+                    for (BlockchainInfoInput input : tx.getInputs()) {
+                        String inputAddress = input.getPrev_out().getAddr();
+                        if (coinData.getWallet().equals(inputAddress)) {
+                            coinData.incSentTransactionsCount();
+                        }
+                    }
+                }
+
+                if (txs.size() == 50) {
+                    final ServerApiBlockchainInfo serverApiBlockchainInfo = new ServerApiBlockchainInfo();
+                    checkTransactionsBlockchainInfo(serverApiBlockchainInfo.getMoreAddressTxs(coinData.getWallet()), serverApiBlockchainInfo, blockchainRequestsCallbacks);
+                } else {
+                    blockchainRequestsCallbacks.onComplete(true);
+                }
+            }
+
+            @Override
+            public void onError(Throwable e) {
+                Log.i(TAG, "onError: getMoreAddressTxs" + e.getMessage());
+                coinData.setUseBlockcypher(true);
+                try {
+                    requestBalanceAndUnspentTransactions(blockchainRequestsCallbacks);
+                } catch (Exception ex) {
+                    ctx.setError(ex.getMessage());
+                    blockchainRequestsCallbacks.onComplete(false);
+                }
+            }
+        };
+
+        txsSingle.subscribe(txsObserver);
+    }
+
+    private void checkPendingBlockcypher(BlockchainRequestsCallbacks blockchainRequestsCallbacks) {
         if (App.pendingTransactionsStorage.hasTransactions(ctx.getCard())) {
             ServerApiBlockcypher serverApiBlockcypher = new ServerApiBlockcypher();
 

app/src/main/java/com/tangem/wallet/btcmultisig/BtcMultisigEngine.kt

@@ -0,0 +1,137 @@
+package com.tangem.wallet.btcmultisig
+
+import com.google.common.primitives.UnsignedBytes
+import com.tangem.tangem_card.data.TangemCard
+import com.tangem.tangem_card.reader.CardProtocol.TangemException
+import com.tangem.tangem_card.tasks.SignTask
+import com.tangem.tangem_card.util.Util
+import com.tangem.wallet.TangemContext
+import com.tangem.wallet.btc.BtcEngine
+import org.bitcoinj.core.*
+import org.bitcoinj.crypto.TransactionSignature
+import org.bitcoinj.params.MainNetParams
+import org.bitcoinj.script.Script
+import org.bitcoinj.script.ScriptBuilder
+import java.math.BigInteger
+
+class BtcMultisigEngine : BtcEngine {
+    val networkParameters = MainNetParams.get()
+
+    constructor(): super()
+
+    constructor(context: TangemContext): super(context)
+
+    override fun defineWallet() {
+        try {
+            val wallet = calculateAddress(ctx.card.walletPublicKeyRar)
+            ctx.coinData.wallet = wallet
+        } catch (e: Exception) {
+            ctx.coinData.wallet = "ERROR"
+            throw TangemException("Can't define wallet address")
+        }
+    }
+
+    override fun calculateAddress(compressedPublicKey: ByteArray): String? {
+        if (ctx.card.issuerData != null && ctx.card.issuerData.size == 33) {
+            val script = createMultisigOutputScript()
+            val scriptHash = Utils.sha256hash160(script.program)
+            val address = LegacyAddress.fromScriptHash(networkParameters, scriptHash)
+            return address.toBase58()
+        } else {
+            return Util.byteArrayToHexString(compressedPublicKey)
+        }
+    }
+
+    override fun constructTransaction(amountValue: Amount, feeValue: Amount, IncFee: Boolean, targetAddress: String): SignTask.TransactionToSign {
+        val fee = convertToInternalAmount(feeValue).longValueExact()
+        var amount = convertToInternalAmount(amountValue).longValueExact()
+        var change = coinData.balanceInInternalUnits.longValueExact() - amount
+
+        if (IncFee) {
+            amount -= fee
+        } else {
+            change -= fee
+        }
+
+        val transaction = Transaction(networkParameters)
+
+        for (utxo in coinData.unspentTransactions) {
+            transaction.addInput(
+                    Sha256Hash.wrap(utxo.txID),
+                    utxo.outputN.toLong(),
+                    Script(Util.hexToBytes(utxo.script))
+            )
+        }
+
+        transaction.addOutput(
+                Coin.valueOf(amount),
+                Address.fromString(networkParameters, targetAddress)
+        )
+        if (change != 0L) {
+            transaction.addOutput(
+                    Coin.valueOf(change),
+                    Address.fromString(networkParameters, coinData.wallet)
+            )
+        }
+
+        return object : SignTask.TransactionToSign {
+            override fun isSigningMethodSupported(signingMethod: TangemCard.SigningMethod): Boolean {
+                return signingMethod == TangemCard.SigningMethod.Sign_Hash
+            }
+
+            override fun getHashesToSign(): Array<ByteArray> {
+                val hashesForSign: MutableList<ByteArray> = MutableList(transaction.inputs.size) { byteArrayOf() }
+                for (input in transaction.inputs) {
+                    val index = input.index
+                    val outputScript = createMultisigOutputScript()
+                    hashesForSign[index] = transaction.hashForSignature(index, outputScript, Transaction.SigHash.ALL, false).bytes
+                }
+                return hashesForSign.toTypedArray()
+            }
+
+            @Throws(java.lang.Exception::class)
+            override fun getRawDataToSign(): ByteArray {
+                throw java.lang.Exception("Signing of raw transaction not supported for " + this.javaClass.simpleName)
+            }
+
+            override fun getHashAlgToSign(): String {
+                return "sha-256x2"
+            }
+
+            @Throws(java.lang.Exception::class)
+            override fun getIssuerTransactionSignature(dataToSignByIssuer: ByteArray): ByteArray {
+                throw java.lang.Exception("Issuer validation not supported!")
+            }
+
+
+            override fun onSignCompleted(signFromCard: ByteArray): ByteArray {
+                for (index in transaction.inputs.indices) {
+                    transaction.inputs[index].scriptSig =
+                            createMultisigInputScript(index, signFromCard)
+                }
+                val txForSend = transaction.bitcoinSerialize()
+                notifyOnNeedSendTransaction(txForSend)
+                return txForSend
+            }
+        }
+    }
+
+    private fun createMultisigInputScript(index: Int, signedTransaction: ByteArray): Script {
+        val r = BigInteger(1, signedTransaction.copyOfRange(index * 64, 32 + index * 64))
+        val s = BigInteger(1, signedTransaction.copyOfRange(32 + index * 64, 64 + index * 64))
+        val canonicalS = ECKey.ECDSASignature(r, s).toCanonicalised().s
+        val signature = TransactionSignature(r, canonicalS)
+
+        val outputScript = createMultisigOutputScript()
+        return ScriptBuilder.createP2SHMultiSigInputScript(mutableListOf(signature), outputScript)
+    }
+
+    private fun createMultisigOutputScript(): Script {
+        val publicKeys =  mutableListOf(ctx.card.walletPublicKeyRar, ctx.card.issuerData)
+        publicKeys.sortWith(UnsignedBytes.lexicographicalComparator())
+        val publicEcKeys =
+                MutableList(publicKeys.size) { i -> ECKey.fromPublicOnly(publicKeys[i]) }
+
+        return Script(Script.createMultiSigOutputScript(1, publicEcKeys))
+    }
+}

app/src/main/java/com/tangem/wallet/eth/EthEngine.java

@@ -7,7 +7,11 @@ import android.util.Log;
 import com.tangem.App;
 import com.tangem.Constant;
 import com.tangem.data.Blockchain;
+import com.tangem.data.network.ServerApiBlockcypher;
 import com.tangem.data.network.ServerApiInfura;
+import com.tangem.data.network.model.BlockcypherFee;
+import com.tangem.data.network.model.BlockcypherResponse;
+import com.tangem.data.network.model.BlockcypherTxref;
 import com.tangem.data.network.model.InfuraResponse;
 import com.tangem.tangem_card.data.TangemCard;
 import com.tangem.tangem_card.tasks.SignTask;
@@ -463,7 +467,8 @@ public class EthEngine extends CoinEngine {
     @Override
     public void requestBalanceAndUnspentTransactions(BlockchainRequestsCallbacks blockchainRequestsCallbacks) {
         final ServerApiInfura serverApiInfura = new ServerApiInfura();
-        // request requestData listener
+        final ServerApiBlockcypher serverApiBlockcypher = new ServerApiBlockcypher();
+
         ServerApiInfura.ResponseListener responseListener = new ServerApiInfura.ResponseListener() {
             @Override
             public void onSuccess(String method, InfuraResponse infuraResponse) {
@@ -501,7 +506,7 @@ public class EthEngine extends CoinEngine {
                     break;
                 }
 
-                if (serverApiInfura.isRequestsSequenceCompleted()) {
+                if (serverApiInfura.isRequestsSequenceCompleted()&& serverApiBlockcypher.isRequestsSequenceCompleted()) {
                     blockchainRequestsCallbacks.onComplete(!ctx.hasError());
                 } else {
                     blockchainRequestsCallbacks.onProgress();
@@ -512,7 +517,7 @@ public class EthEngine extends CoinEngine {
             public void onFail(String method, String message) {
                 Log.e(TAG, "onFail: " + method + " " + message);
                 ctx.setError(message);
-                if (serverApiInfura.isRequestsSequenceCompleted()) {
+                if (serverApiInfura.isRequestsSequenceCompleted()&& serverApiBlockcypher.isRequestsSequenceCompleted()) {
                     blockchainRequestsCallbacks.onComplete(false);
                 } else {
                     blockchainRequestsCallbacks.onProgress();
@@ -521,9 +526,55 @@ public class EthEngine extends CoinEngine {
         };
         serverApiInfura.setResponseListener(responseListener);
 
+        ServerApiBlockcypher.ResponseListener blockcypherListener = new ServerApiBlockcypher.ResponseListener() {
+            @Override
+            public void onSuccess(String method, BlockcypherResponse blockcypherResponse) {
+                Log.i(TAG, "onSuccess: " + method);
+                try {
+                    //TODO: change request logic, 2000 tx max
+                    if (blockcypherResponse.getTxrefs() != null) {
+                        for (BlockcypherTxref txref : blockcypherResponse.getTxrefs()) {
+                            if (txref.getTx_input_n() != -1) { //sent only
+                                coinData.incSentTransactionsCount();
+                            }
+                        }
+                    }
+
+                    if (blockcypherResponse.getUnconfirmed_txrefs() != null) {
+                        for (BlockcypherTxref unconfirmedTxref : blockcypherResponse.getUnconfirmed_txrefs()) {
+                            if (unconfirmedTxref.getTx_input_n() != -1) {
+                                coinData.incSentTransactionsCount();
+                            }
+                        }
+                    }
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    Log.e(TAG, "FAIL BLOCKCYPHER_ADDRESS Exception");
+                }
+
+                if (serverApiInfura.isRequestsSequenceCompleted()&& serverApiBlockcypher.isRequestsSequenceCompleted()) {
+                    blockchainRequestsCallbacks.onComplete(!ctx.hasError());
+                } else {
+                    blockchainRequestsCallbacks.onProgress();
+                }
+            }
+
+            public void onSuccess(String method, BlockcypherFee blockcypherFee) {
+                Log.e(TAG, "Wrong response type for requestBalanceAndUnspentTransactions");
+            }
+
+            @Override
+            public void onFail(String method, String message) {
+                Log.i(TAG, "onFail: " + method + " " + message);
+            }
+        };
+        serverApiBlockcypher.setResponseListener(blockcypherListener);
+
         serverApiInfura.requestData(ServerApiInfura.INFURA_ETH_GET_BALANCE, 67, coinData.getWallet(), "", "");
         serverApiInfura.requestData(ServerApiInfura.INFURA_ETH_GET_TRANSACTION_COUNT, 67, coinData.getWallet(), "", "");
         serverApiInfura.requestData(ServerApiInfura.INFURA_ETH_GET_PENDING_COUNT, 67, coinData.getWallet(), "", "");
+
+        serverApiBlockcypher.requestData(ctx.getBlockchain().getID(), ServerApiBlockcypher.BLOCKCYPHER_ADDRESS, ctx.getCoinData().getWallet(), "");
     }
 
     @Override

app/src/main/java/com/tangem/wallet/token/TokenEngine.java

@@ -8,7 +8,11 @@ import android.util.Log;
 import com.google.common.base.Strings;
 import com.tangem.App;
 import com.tangem.data.Blockchain;
+import com.tangem.data.network.ServerApiBlockcypher;
 import com.tangem.data.network.ServerApiInfura;
+import com.tangem.data.network.model.BlockcypherFee;
+import com.tangem.data.network.model.BlockcypherResponse;
+import com.tangem.data.network.model.BlockcypherTxref;
 import com.tangem.data.network.model.InfuraResponse;
 import com.tangem.tangem_card.data.TangemCard;
 import com.tangem.tangem_card.tasks.SignTask;
@@ -542,7 +546,7 @@ public class TokenEngine extends CoinEngine {
 
 
         int gasLimitInt = 60000;
-        if (amountValue.getCurrency().equals("DGX")) {
+        if (amountValue.getCurrency().equals("DGX") || amountValue.getCurrency().equals("CGT")) {
             gasLimitInt = 300000;
         }
 
@@ -639,7 +643,8 @@ public class TokenEngine extends CoinEngine {
     @Override
     public void requestBalanceAndUnspentTransactions(BlockchainRequestsCallbacks blockchainRequestsCallbacks) {
         final ServerApiInfura serverApiInfura = new ServerApiInfura();
-        // request requestData listener
+        final ServerApiBlockcypher serverApiBlockcypher = new ServerApiBlockcypher();
+
         ServerApiInfura.ResponseListener responseListener = new ServerApiInfura.ResponseListener() {
             @Override
             public void onSuccess(String method, InfuraResponse infuraResponse) {
@@ -701,7 +706,7 @@ public class TokenEngine extends CoinEngine {
                     break;
 
                 }
-                if (serverApiInfura.isRequestsSequenceCompleted()) {
+                if (serverApiInfura.isRequestsSequenceCompleted()&& serverApiBlockcypher.isRequestsSequenceCompleted()) {
                     blockchainRequestsCallbacks.onComplete(!ctx.hasError());
                 } else {
                     blockchainRequestsCallbacks.onProgress();
@@ -712,7 +717,7 @@ public class TokenEngine extends CoinEngine {
             public void onFail(String method, String message) {
                 Log.e(TAG, "onFail: " + method + " " + message);
                 ctx.setError(message);
-                if (serverApiInfura.isRequestsSequenceCompleted()) {
+                if (serverApiInfura.isRequestsSequenceCompleted()&& serverApiBlockcypher.isRequestsSequenceCompleted()) {
                     blockchainRequestsCallbacks.onComplete(false);
                 } else {
                     blockchainRequestsCallbacks.onProgress();
@@ -721,12 +726,58 @@ public class TokenEngine extends CoinEngine {
         };
         serverApiInfura.setResponseListener(responseListener);
 
+        ServerApiBlockcypher.ResponseListener blockcypherListener = new ServerApiBlockcypher.ResponseListener() {
+            @Override
+            public void onSuccess(String method, BlockcypherResponse blockcypherResponse) {
+                Log.i(TAG, "onSuccess: " + method);
+                try {
+                    //TODO: change request logic, 2000 tx max
+                    if (blockcypherResponse.getTxrefs() != null) {
+                        for (BlockcypherTxref txref : blockcypherResponse.getTxrefs()) {
+                            if (txref.getTx_input_n() != -1) { //sent only
+                                coinData.incSentTransactionsCount();
+                            }
+                        }
+                    }
+
+                    if (blockcypherResponse.getUnconfirmed_txrefs() != null) {
+                        for (BlockcypherTxref unconfirmedTxref : blockcypherResponse.getUnconfirmed_txrefs()) {
+                            if (unconfirmedTxref.getTx_input_n() != -1) {
+                                coinData.incSentTransactionsCount();
+                            }
+                        }
+                    }
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    Log.e(TAG, "FAIL BLOCKCYPHER_ADDRESS Exception");
+                }
+
+                if (serverApiInfura.isRequestsSequenceCompleted()&& serverApiBlockcypher.isRequestsSequenceCompleted()) {
+                    blockchainRequestsCallbacks.onComplete(!ctx.hasError());
+                } else {
+                    blockchainRequestsCallbacks.onProgress();
+                }
+            }
+
+            public void onSuccess(String method, BlockcypherFee blockcypherFee) {
+                Log.e(TAG, "Wrong response type for requestBalanceAndUnspentTransactions");
+            }
+
+            @Override
+            public void onFail(String method, String message) {
+                Log.i(TAG, "onFail: " + method + " " + message);
+            }
+        };
+        serverApiBlockcypher.setResponseListener(blockcypherListener);
+
         if (validateAddress(getContractAddress(ctx.getCard()))) {
             serverApiInfura.requestData(ServerApiInfura.INFURA_ETH_CALL, 67, coinData.getWallet(), getContractAddress(ctx.getCard()), "");
         } else {
             ctx.setError("Smart contract address not defined");
             blockchainRequestsCallbacks.onComplete(false);
         }
+
+        serverApiBlockcypher.requestData(ctx.getBlockchain().getID(), ServerApiBlockcypher.BLOCKCYPHER_ADDRESS, ctx.getCoinData().getWallet(), "");
     }
 
     @Override
@@ -745,7 +796,7 @@ public class TokenEngine extends CoinEngine {
                 Log.i(TAG, "Infura gas price: " + gasPrice + " (" + l.toString() + ")");
                 BigInteger m;
                 if (!amount.getCurrency().equals(Blockchain.Ethereum.getCurrency()))
-                    if (amount.getCurrency().equals("DGX")) {
+                    if (amount.getCurrency().equals("DGX") || amount.getCurrency().equals("CGT")) {
                         m = BigInteger.valueOf(300000);
                     } else {
                         m = BigInteger.valueOf(60000);

app/src/main/java/com/tangem/wallet/xlm/XlmAssetData.java

@@ -30,7 +30,7 @@ public class XlmAssetData extends CoinData {
     private Long sequenceNumber = 0L;
     private CoinEngine.Amount baseReserve = new CoinEngine.Amount("0.5", "XLM");
     private CoinEngine.Amount baseFee = new CoinEngine.Amount("0.00001", "XLM");
-    private boolean error404 = false;
+    private boolean error404, targetAccountCreated = false;
 
     @Override
     public void clearInfo() {
@@ -38,6 +38,7 @@ public class XlmAssetData extends CoinData {
         xlmBalance = null;
         assetBalance = null;
         error404 = false;
+        targetAccountCreated = false;
     }
 
     CoinEngine.Amount getXlmBalance() {
@@ -101,6 +102,14 @@ public class XlmAssetData extends CoinData {
             return true;
     }
 
+    public boolean isTargetAccountCreated() {
+        return targetAccountCreated;
+    }
+
+    public void setTargetAccountCreated(boolean targetAccountCreated) {
+        this.targetAccountCreated = targetAccountCreated;
+    }
+
     @Override
     public void loadFromBundle(Bundle B) {
         super.loadFromBundle(B);
@@ -137,6 +146,10 @@ public class XlmAssetData extends CoinData {
 
         if (B.containsKey("Error404")) error404 = B.getBoolean("Error404");
         else error404 = false;
+
+        if (B.containsKey("TargetAccountCreated"))
+            targetAccountCreated = B.getBoolean("TargetAccountCreated");
+        else targetAccountCreated = false;
     }
 
     @Override
@@ -169,6 +182,8 @@ public class XlmAssetData extends CoinData {
 
             if (error404) B.putBoolean("Error404", true);
 
+            if (targetAccountCreated) B.putBoolean("TargetAccountCreated", true);
+
         } catch (Exception e) {
             Log.e("Can't save to bundle ", e.getMessage());
         }

app/src/main/java/com/tangem/wallet/xlm/XlmAssetEngine.java

@@ -1,12 +1,10 @@
 package com.tangem.wallet.xlm;
 
 import android.net.Uri;
-import android.os.StrictMode;
 import android.text.InputFilter;
 import android.util.Log;
 
 import com.tangem.App;
-import com.tangem.data.Blockchain;
 import com.tangem.data.network.ServerApiStellar;
 import com.tangem.data.network.StellarRequest;
 import com.tangem.tangem_card.data.TangemCard;
@@ -28,6 +26,7 @@ import org.stellar.sdk.Operation;
 import org.stellar.sdk.PaymentOperation;
 import org.stellar.sdk.Transaction;
 import org.stellar.sdk.TransactionEx;
+import org.stellar.sdk.responses.operations.OperationResponse;
 
 import java.io.IOException;
 import java.math.BigDecimal;
@@ -90,7 +89,7 @@ public class XlmAssetEngine extends CoinEngine {
 
         if (balance != null) {
             if (!coinData.isAssetBalanceZero()) {
-                return " " + assetBalance.toDescriptionString(getDecimals()) + "<br><small><small>"+ balance.toDescriptionString(getDecimals()) + " for fee + " + coinData.getReserve().toDescriptionString(getDecimals()) + " reserve</small></small>";
+                return " " + assetBalance.toDescriptionString(getDecimals()) + "<br><small><small>" + balance.toDescriptionString(getDecimals()) + " for fee + " + coinData.getReserve().toDescriptionString(getDecimals()) + " reserve</small></small>";
             }
             return " " + balance.toDescriptionString(getDecimals()) + "<br><small><small>+ " + coinData.getReserve().toDescriptionString(getDecimals()) + " reserve</small></small>";
         } else {
@@ -171,7 +170,7 @@ public class XlmAssetEngine extends CoinEngine {
 //        if (ctx.getCard().getDenomination() != null) {
 //            return Uri.parse(ctx.getCoinData().getWallet() + "?amount=" + convertToAmount(convertToInternalAmount(ctx.getCard().getDenomination())).toValueString());
 //        } else {
-            return Uri.parse(ctx.getCoinData().getWallet());
+        return Uri.parse(ctx.getCoinData().getWallet());
 //        }
     }
 
@@ -186,7 +185,7 @@ public class XlmAssetEngine extends CoinEngine {
 
         Amount balance;
         if (!coinData.isAssetBalanceZero()) {
-             balance = coinData.getAssetBalance();
+            balance = coinData.getAssetBalance();
         } else {
             balance = coinData.getXlmBalance();
         }
@@ -377,9 +376,6 @@ public class XlmAssetEngine extends CoinEngine {
     @Override
     public SignTask.TransactionToSign constructTransaction(Amount amountValue, Amount feeValue, boolean IncFee, String targetAddress) throws Exception {
         checkBlockchainDataExists();
-        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
-
-        StrictMode.setThreadPolicy(policy);
 
         if (coinData.isAssetBalanceZero() && IncFee) {
             amountValue = new Amount(amountValue.subtract(feeValue), amountValue.getCurrency());
@@ -392,13 +388,13 @@ public class XlmAssetEngine extends CoinEngine {
             if (!coinData.isAssetBalanceZero()) {
                 operation = new PaymentOperation.Builder(KeyPair.fromAccountId(targetAddress), Asset.createNonNativeAsset(ctx.getCard().getTokenSymbol(), KeyPair.fromAccountId(ctx.getCard().getContractAddress())), amountValue.toValueString()).build();
             } else {
-                if (isAccountCreated(targetAddress))
+                if (coinData.isTargetAccountCreated())
                     operation = new PaymentOperation.Builder(KeyPair.fromAccountId(targetAddress), new AssetTypeNative(), amountValue.toValueString()).build();
                 else
                     operation = new CreateAccountOperation.Builder(KeyPair.fromAccountId(targetAddress), amountValue.toValueString()).build();
             }
         }
-        TransactionEx transaction = TransactionEx.buildEx(60, coinData.getAccountResponse(), operation);
+        TransactionEx transaction = TransactionEx.buildEx(120, coinData.getAccountResponse(), operation);
 
 
         if (transaction.getFee() != convertToInternalAmount(feeValue).intValueExact()) {
@@ -447,23 +443,40 @@ public class XlmAssetEngine extends CoinEngine {
     }
 
 
-    // network call inside, don't use on main thread
-    private boolean isAccountCreated(String address) {
+    private void checkTargetAccountCreated(BlockchainRequestsCallbacks blockchainRequestsCallbacks, String targetAddress, Amount amount) {
         final ServerApiStellar serverApi = new ServerApiStellar(ctx.getBlockchain());
 
-        StellarRequest.Balance request = new StellarRequest.Balance(address);
+        ServerApiStellar.Listener listener = new ServerApiStellar.Listener() {
+            @Override
+            public void onSuccess(StellarRequest.Base request) {
+                coinData.setTargetAccountCreated(true);
+                blockchainRequestsCallbacks.onComplete(true);
+            }
 
-        try {
-            serverApi.doStellarRequest(ctx, request);
-        } catch (IOException e) {
-            Log.e(TAG, e.getMessage());
-            return true; // suppose account is created if anything goes wrong TODO:check
-        }
 
-        if (request.errorResponse != null && request.errorResponse.getCode() == 404)
-            return false;
-        else
-            return true;
+            @Override
+            public void onFail(StellarRequest.Base request) {
+                Log.i(TAG, "onFail: " + request.getClass().getSimpleName() + " " + request.getError());
+
+                if (request.errorResponse != null && request.errorResponse.getCode() == 404) {
+                    coinData.setTargetAccountCreated(false);
+
+                    if (amount.compareTo(coinData.getReserve()) >= 0) { //TODO: take fee inclusion in account, now 1 XLM with fee included will fail after transaction is sent
+                        blockchainRequestsCallbacks.onComplete(true);
+                    } else {
+                        ctx.setError(R.string.confirm_transaction_error_not_enough_xlm_for_create);
+                        blockchainRequestsCallbacks.onComplete(false);
+                    }
+                } else { // suppose account is created if anything goes wrong
+                    coinData.setTargetAccountCreated(true);
+                    blockchainRequestsCallbacks.onComplete(true);
+                }
+            }
+        };
+
+        serverApi.setListener(listener);
+
+        serverApi.requestData(ctx, new StellarRequest.Balance(targetAddress));
     }
 
     @Override
@@ -496,6 +509,21 @@ public class XlmAssetEngine extends CoinEngine {
                     } else {
                         blockchainRequestsCallbacks.onProgress();
                     }
+                } else if (request instanceof StellarRequest.Operations) {
+                    StellarRequest.Operations operationsRequest = (StellarRequest.Operations) request;
+
+                    for (OperationResponse operationResponse : operationsRequest.operationsList) {
+                        if (operationResponse.getSourceAccount().getAccountId().equals(coinData.getWallet())) {
+                            coinData.incSentTransactionsCount();
+                        }
+                    }
+
+                    if (serverApi.isRequestsSequenceCompleted()) {
+                        blockchainRequestsCallbacks.onComplete(!ctx.hasError());
+                    } else {
+                        blockchainRequestsCallbacks.onProgress();
+                    }
+
                 } else {
                     ctx.setError("Invalid request logic");
                     blockchainRequestsCallbacks.onComplete(false);
@@ -529,13 +557,14 @@ public class XlmAssetEngine extends CoinEngine {
 
         serverApi.requestData(ctx, new StellarRequest.Balance(coinData.getWallet()));
         serverApi.requestData(ctx, new StellarRequest.Ledgers());
+        serverApi.requestData(ctx, new StellarRequest.Operations(coinData.getWallet()));
     }
 
     @Override
     public void requestFee(BlockchainRequestsCallbacks blockchainRequestsCallbacks, String targetAddress, Amount amount) throws Exception {
         // TODO: get fee stats?
         coinData.minFee = coinData.normalFee = coinData.maxFee = coinData.getBaseFee();
-        blockchainRequestsCallbacks.onComplete(true);
+        checkTargetAccountCreated(blockchainRequestsCallbacks, targetAddress, amount);
     }
 
     @Override

app/src/main/java/com/tangem/wallet/xlm/XlmEngine.java

@@ -26,6 +26,7 @@ import org.stellar.sdk.Operation;
 import org.stellar.sdk.PaymentOperation;
 import org.stellar.sdk.Transaction;
 import org.stellar.sdk.TransactionEx;
+import org.stellar.sdk.responses.operations.OperationResponse;
 
 import java.io.IOException;
 import java.math.BigDecimal;
@@ -97,7 +98,7 @@ public class XlmEngine extends CoinEngine {
     @Override
     public boolean hasBalanceInfo() {
         if (coinData == null) return false;
-        return (coinData.getBalance() != null) || (coinData.isError404()) ;
+        return (coinData.getBalance() != null) || (coinData.isError404());
     }
 
 
@@ -365,7 +366,7 @@ public class XlmEngine extends CoinEngine {
         else
             operation = new CreateAccountOperation.Builder(KeyPair.fromAccountId(targetAddress), amountValue.toValueString()).build();
 
-        TransactionEx transaction = TransactionEx.buildEx(60, coinData.getAccountResponse(), operation);
+        TransactionEx transaction = TransactionEx.buildEx(120, coinData.getAccountResponse(), operation);
 
 
         if (transaction.getFee() != convertToInternalAmount(feeValue).intValueExact()) {
@@ -470,6 +471,7 @@ public class XlmEngine extends CoinEngine {
                     } else {
                         blockchainRequestsCallbacks.onProgress();
                     }
+
                 } else if (request instanceof StellarRequest.Ledgers) {
                     StellarRequest.Ledgers ledgersRequest = (StellarRequest.Ledgers) request;
 
@@ -480,6 +482,22 @@ public class XlmEngine extends CoinEngine {
                     } else {
                         blockchainRequestsCallbacks.onProgress();
                     }
+
+                } else if (request instanceof StellarRequest.Operations) {
+                    StellarRequest.Operations operationsRequest = (StellarRequest.Operations) request;
+
+                    for (OperationResponse operationResponse : operationsRequest.operationsList) {
+                        if (operationResponse.getSourceAccount().getAccountId().equals(coinData.getWallet())) {
+                            coinData.incSentTransactionsCount();
+                        }
+                    }
+
+                    if (serverApi.isRequestsSequenceCompleted()) {
+                        blockchainRequestsCallbacks.onComplete(!ctx.hasError());
+                    } else {
+                        blockchainRequestsCallbacks.onProgress();
+                    }
+
                 } else {
                     ctx.setError("Invalid request logic");
                     blockchainRequestsCallbacks.onComplete(false);
@@ -513,6 +531,7 @@ public class XlmEngine extends CoinEngine {
 
         serverApi.requestData(ctx, new StellarRequest.Balance(coinData.getWallet()));
         serverApi.requestData(ctx, new StellarRequest.Ledgers());
+        serverApi.requestData(ctx, new StellarRequest.Operations(coinData.getWallet()));
     }
 
     @Override

blockchain/.gitignore

@@ -0,0 +1 @@
+/build

blockchain/build.gradle

@@ -0,0 +1,78 @@
+apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
+apply plugin: 'kotlin-android-extensions'
+apply plugin: 'kotlin-kapt'
+android {
+    compileSdkVersion 29
+    buildToolsVersion "29.0.2"
+
+
+    defaultConfig {
+        minSdkVersion 21
+        targetSdkVersion 29
+        versionCode 1
+        versionName "1.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+        consumerProguardFiles 'consumer-rules.pro'
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+
+}
+
+dependencies {
+//    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation project(':tangem-core')
+    implementation project(':tangem-sdk')
+
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$versions.kotlin"
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.core:core-ktx:1.1.0'
+
+    implementation 'com.squareup.retrofit2:retrofit:2.7.0'
+    implementation 'com.squareup.retrofit2:converter-moshi:2.6.0'
+    implementation 'com.squareup.moshi:moshi:1.9.2'
+    kapt("com.squareup.moshi:moshi-kotlin-codegen:1.9.2")
+    implementation 'com.squareup.okhttp3:logging-interceptor:4.2.2'
+
+    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.3'
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.3.3"
+
+    implementation 'org.bitcoinj:bitcoinj-core:0.15.2'
+    implementation 'com.github.stellar:java-stellar-sdk:0.13.0'
+
+    implementation "com.madgag.spongycastle:core:1.58.0.0"
+    implementation "com.madgag.spongycastle:prov:1.58.0.0"
+
+    ext.kethereum_version = '0.79.5'
+    implementation "com.github.walleth.kethereum:functions:$kethereum_version"
+    implementation "com.github.walleth.kethereum:keccak_shortcut:$kethereum_version"
+    implementation "com.github.walleth.kethereum:wallet:$kethereum_version"
+    implementation "com.github.walleth.kethereum:crypto_impl_spongycastle:$kethereum_version"
+    implementation "com.github.walleth.kethereum:crypto:$kethereum_version"
+    implementation "com.github.walleth.kethereum:crypto_api:$kethereum_version"
+    implementation "com.github.walleth.kethereum:model:$kethereum_version"
+    implementation 'com.github.komputing.khex:core:1.0.0-RC6'
+    implementation 'com.github.komputing.khex:extensions:1.0.0-RC6'
+
+    implementation 'co.nstant.in:cbor:0.8'
+
+    implementation files('libs/ripple-core-0.0.1.jar')
+    //4 dependencies for ripple-core
+    implementation 'net.i2p.crypto:eddsa:0.3.0'
+    implementation 'org.bouncycastle:bcprov-jdk15on:1.61'
+    //noinspection DuplicatePlatformClasses
+    implementation 'org.json:json:20180813'
+    implementation 'com.fasterxml.jackson.core:jackson-databind:2.9.8'
+
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.5.2'
+    testImplementation "com.google.truth:truth:1.0"
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+}

blockchain/proguard-rules.pro

@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

blockchain/src/main/AndroidManifest.xml

@@ -0,0 +1 @@
+<manifest package="com.tangem.blockchain" />

blockchain/src/main/java/com/tangem/blockchain/bitcoin/BitcoinAddress.kt

@@ -0,0 +1,72 @@
+package com.tangem.blockchain.bitcoin
+
+
+import com.tangem.common.extensions.calculateRipemd160
+import com.tangem.common.extensions.calculateSha256
+import org.bitcoinj.core.AddressFormatException
+import org.bitcoinj.core.Base58
+import org.bitcoinj.core.SegwitAddress
+import org.bitcoinj.params.MainNetParams
+import org.bitcoinj.params.TestNet3Params
+import java.security.MessageDigest
+
+class BitcoinAddressFactory {
+    companion object {
+        fun makeAddress(walletPublicKey: ByteArray, testNet: Boolean = false): String {
+            val netSelectionByte = if (testNet) 0x6f.toByte() else 0x00.toByte()
+            val hash1 = walletPublicKey.calculateSha256().calculateRipemd160()
+            val hash2 = byteArrayOf(netSelectionByte).plus(hash1).calculateSha256().calculateSha256()
+            val result = byteArrayOf(netSelectionByte) + hash1 + hash2[0] + hash2[1] + hash2[2] + hash2[3]
+            return Base58.encode(result)
+        }
+    }
+}
+
+class BitcoinAddressValidator {
+    companion object {
+
+        private const val firstLetters = "123nm"
+        private const val firstLettersNonTestNet = "13"
+
+        fun validate(address: String, testNet: Boolean = false): Boolean {
+            if (firstLetters.contains(address.first())) {
+                if (testNet && firstLettersNonTestNet.contains(address.first())) return false
+                if (address.length !in 26..35) return false
+                val decoded = address.decodeBase58() ?: return false
+                val hash = recursiveSha256(decoded, 0, 21, 2)
+                return hash.sliceArray(0..3).contentEquals(decoded.sliceArray(21..24))
+            } else {
+                return validateSegwitAddress(address, testNet)
+            }
+        }
+
+        private fun recursiveSha256(data: ByteArray, start: Int, len: Int, recursion: Int): ByteArray {
+            if (recursion == 0) return data
+            val md = MessageDigest.getInstance("SHA-256")
+            md.update(data.sliceArray(start until start + len))
+            return recursiveSha256(md.digest(), 0, 32, recursion - 1)
+        }
+
+        private fun String.decodeBase58(): ByteArray? {
+            return try {
+                Base58.decode(this)
+            } catch (exception: AddressFormatException) {
+                null
+            }
+        }
+
+        private fun validateSegwitAddress(address: String, testNet: Boolean): Boolean {
+            return try {
+                if (testNet) {
+                    SegwitAddress.fromBech32(TestNet3Params(), address)
+                    true
+                } else {
+                    SegwitAddress.fromBech32(MainNetParams(), address)
+                    true
+                }
+            } catch (e: Exception) {
+                false
+            }
+        }
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/bitcoin/BitcoinTransactionBuilder.kt

@@ -0,0 +1,99 @@
+package com.tangem.blockchain.bitcoin
+
+import com.tangem.blockchain.common.TransactionData
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.toCanonicalised
+import org.bitcoinj.core.*
+import org.bitcoinj.crypto.TransactionSignature
+import org.bitcoinj.script.Script
+import org.bitcoinj.script.ScriptBuilder
+import java.math.BigDecimal
+import java.math.BigInteger
+
+class BitcoinTransactionBuilder(private val testNet: Boolean) {
+
+    private lateinit var transaction: Transaction
+    private var networkParameters: NetworkParameters? = null
+    var unspentOutputs: List<UnspentTransaction>? = null
+
+    fun buildToSign(
+            transactionData: TransactionData): Result<List<ByteArray>> {
+
+        if (unspentOutputs == null) return Result.Failure(Exception("Currently there's an unconfirmed transaction"))
+
+        val change: BigDecimal = calculateChange(transactionData)
+
+        networkParameters = if (testNet) {
+            NetworkParameters.fromID(NetworkParameters.ID_TESTNET)
+        } else {
+            NetworkParameters.fromID(NetworkParameters.ID_MAINNET)
+        }
+        transaction = transactionData.toBitcoinJTransaction(networkParameters, unspentOutputs!!, change)
+
+        val hashesForSign: MutableList<ByteArray> = MutableList(transaction.inputs.size) { byteArrayOf() }
+        for (input in transaction.inputs) {
+            val index = input.index
+            hashesForSign[index] = transaction.hashForSignature(index, input.scriptBytes, Transaction.SigHash.ALL, false).bytes
+        }
+        return Result.Success(hashesForSign)
+    }
+
+    private fun calculateChange(transactionData: TransactionData): BigDecimal {
+        val fullAmount = unspentOutputs!!.map { it.amount }.reduce { acc, number -> acc + number }
+        return fullAmount - (transactionData.amount.value!! + (transactionData.fee?.value
+                ?: 0.toBigDecimal()))
+    }
+
+    fun buildToSend(signedTransaction: ByteArray, publicKey: ByteArray): ByteArray {
+        for (index in transaction.inputs.indices) {
+            transaction.inputs[index].scriptSig = createScript(index, signedTransaction, publicKey)
+        }
+        return transaction.bitcoinSerialize()
+    }
+
+    private fun createScript(index: Int, signedTransaction: ByteArray, publicKey: ByteArray): Script {
+        val r = BigInteger(1, signedTransaction.copyOfRange(index * 64, 32 + index * 64))
+        val s = BigInteger(1, signedTransaction.copyOfRange(32 + index * 64, 64 + index * 64))
+        val canonicalS = ECKey.ECDSASignature(r, s).toCanonicalised().s
+        val signature = TransactionSignature(r, canonicalS)
+        return ScriptBuilder.createInputScript(signature, ECKey.fromPublicOnly(publicKey))
+    }
+
+    fun getEstimateSize(transactionData: TransactionData, walletPublicKey: ByteArray): Result<Int> {
+        val buildTransactionResult = buildToSign(transactionData)
+        when (buildTransactionResult) {
+            is Result.Failure -> return buildTransactionResult
+            is Result.Success -> {
+                val hashes = buildTransactionResult.data
+                val finalTransaction = buildToSend(ByteArray(64 * hashes.size) { 1 }, walletPublicKey)
+                return Result.Success(finalTransaction.size)
+            }
+        }
+    }
+}
+
+internal fun TransactionData.toBitcoinJTransaction(networkParameters: NetworkParameters?,
+                                                   unspentOutputs: List<UnspentTransaction>,
+                                                   change: BigDecimal): Transaction {
+    val transaction = Transaction(networkParameters)
+    for (utxo in unspentOutputs) {
+        transaction.addInput(Sha256Hash.wrap(utxo.hash), utxo.outputIndex, Script(utxo.outputScript))
+    }
+    transaction.addOutput(
+            Coin.parseCoin(this.amount.value!!.toPlainString()),
+            Address.fromString(networkParameters, this.destinationAddress))
+    if (change != 0.toBigDecimal()) {
+        transaction.addOutput(
+                Coin.parseCoin(change.toPlainString()),
+                Address.fromString(networkParameters,
+                        this.sourceAddress))
+    }
+    return transaction
+}
+
+class UnspentTransaction(
+        val amount: BigDecimal,
+        val outputIndex: Long,
+        val hash: ByteArray,
+        val outputScript: ByteArray
+)

blockchain/src/main/java/com/tangem/blockchain/bitcoin/BitcoinWalletManager.kt

@@ -0,0 +1,109 @@
+package com.tangem.blockchain.bitcoin
+
+import android.util.Log
+import com.tangem.blockchain.bitcoin.network.BitcoinAddressResponse
+import com.tangem.blockchain.bitcoin.network.BitcoinNetworkManager
+import com.tangem.blockchain.bitcoin.network.BitcoinNetworkManager.Companion.SATOSHI_IN_BTC
+import com.tangem.blockchain.common.*
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.wallets.CurrencyWallet
+import com.tangem.common.extensions.toHexString
+import com.tangem.tasks.TaskEvent
+import java.math.BigDecimal
+
+class BitcoinWalletManager(
+        private val cardId: String,
+        private val walletPublicKey: ByteArray,
+        walletConfig: WalletConfig,
+        isTestNet: Boolean = false
+) : WalletManager,
+        TransactionSender,
+        FeeProvider {
+
+    override val blockchain = if (isTestNet) Blockchain.BitcoinTestnet else Blockchain.Bitcoin
+    private val address = blockchain.makeAddress(walletPublicKey)
+    private val currencyWallet = CurrencyWallet(walletConfig, address)
+    override var wallet: Wallet = currencyWallet
+    private val transactionBuilder = BitcoinTransactionBuilder(isTestNet)
+    private val networkManager = BitcoinNetworkManager(isTestNet)
+
+    override suspend fun update() {
+        val response = networkManager.getInfo(address)
+        when (response) {
+            is Result.Success -> updateWallet(response.data)
+            is Result.Failure -> updateError(response.error)
+        }
+    }
+
+    private fun updateWallet(response: BitcoinAddressResponse) {
+        Log.d(this::class.java.simpleName, "Balance is ${response.balance}")
+        currencyWallet.balances[AmountType.Coin]?.value = response.balance
+        transactionBuilder.unspentOutputs = response.unspentTransactions
+        if (response.hasUnconfirmed) {
+            if (currencyWallet.pendingTransactions.isEmpty()) {
+                currencyWallet.pendingTransactions.add(TransactionData(
+                        Amount(blockchain.currency, decimals = blockchain.decimals),
+                        null,
+                        "unknown",
+                        currencyWallet.address))
+            }
+        } else {
+            currencyWallet.pendingTransactions.clear()
+        }
+    }
+
+    private fun updateError(error: Throwable?) {
+        Log.e(this::class.java.simpleName, error?.message ?: "")
+    }
+
+    override suspend fun send(transactionData: TransactionData, signer: TransactionSigner): SimpleResult {
+        val buildTransactionResult = transactionBuilder.buildToSign(transactionData)
+        when (buildTransactionResult) {
+            is Result.Failure -> return SimpleResult.Failure(buildTransactionResult.error)
+            is Result.Success -> {
+                when (val signerResponse = signer.sign(buildTransactionResult.data.toTypedArray(), cardId)) {
+                    is TaskEvent.Event -> {
+                        val transactionToSend = transactionBuilder.buildToSend(signerResponse.data.signature, walletPublicKey)
+                        return networkManager.sendTransaction(transactionToSend.toHexString())
+                    }
+                    is TaskEvent.Completion -> return SimpleResult.Failure(signerResponse.error)
+                }
+            }
+        }
+    }
+
+    override suspend fun getFee(amount: Amount, source: String, destination: String): Result<List<Amount>> {
+        when (val result = networkManager.getFee()) {
+            is Result.Failure -> return result
+            is Result.Success -> {
+                val sizeResult = transactionBuilder.getEstimateSize(
+                        TransactionData(amount,
+                                Amount(1.toBigDecimal().divide(SATOSHI_IN_BTC), blockchain),
+                                address, destination),
+                        walletPublicKey
+                )
+                when (sizeResult) {
+                    is Result.Failure -> return sizeResult
+                    is Result.Success -> {
+                        val transactionSize = sizeResult.data.toBigDecimal()
+                        val minFee = result.data.minimalPerKb.calculateFee(transactionSize)
+                        val normalFee = result.data.normalPerKb.calculateFee(transactionSize)
+                        val priorityFee = result.data.priorityPerKb.calculateFee(transactionSize)
+                        return Result.Success(
+                                listOf(Amount(minFee, blockchain),
+                                        Amount(normalFee, blockchain),
+                                        Amount(priorityFee, blockchain))
+                        )
+                    }
+                }
+            }
+        }
+    }
+
+    private fun BigDecimal.calculateFee(transactionSize: BigDecimal): BigDecimal {
+        val bytesInKb = BigDecimal(1024)
+        return this.divide(bytesInKb).multiply(transactionSize)
+                .setScale(8, blockchain.roundingMode())
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/bitcoin/network/BitcoinNetworkManager.kt

@@ -0,0 +1,104 @@
+package com.tangem.blockchain.bitcoin.network
+
+import com.tangem.blockchain.bitcoin.UnspentTransaction
+import com.tangem.blockchain.bitcoin.network.api.BlockchainInfoApi
+import com.tangem.blockchain.bitcoin.network.api.BlockcypherApi
+import com.tangem.blockchain.bitcoin.network.api.EstimatefeeApi
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.network.API_BLOCKCHAIN_INFO
+import com.tangem.blockchain.common.network.API_BLOCKCYPHER
+import com.tangem.blockchain.common.network.API_ESTIMATEFEE
+import com.tangem.blockchain.common.network.createRetrofitInstance
+import retrofit2.HttpException
+import java.io.IOException
+import java.math.BigDecimal
+
+
+class BitcoinNetworkManager(private val isTestNet: Boolean) : BitcoinProvider {
+
+    private val blockcypherProvider by lazy {
+        val api = createRetrofitInstance(API_BLOCKCYPHER)
+                .create(BlockcypherApi::class.java)
+        BlockcypherProvider(api, isTestNet)
+    }
+
+    private val blockchainInfoProvider by lazy {
+        val api = createRetrofitInstance(API_BLOCKCHAIN_INFO)
+                .create(BlockchainInfoApi::class.java)
+        val estimateFeeApi = createRetrofitInstance(API_ESTIMATEFEE)
+                .create(EstimatefeeApi::class.java)
+        BlockchainInfoProvider(api, estimateFeeApi)
+    }
+
+    private var bitcoinProvider: BitcoinProvider = blockchainInfoProvider
+
+    private fun changeProvider() {
+        bitcoinProvider = if (bitcoinProvider == blockchainInfoProvider) {
+            blockcypherProvider
+        } else {
+            blockchainInfoProvider
+        }
+    }
+
+    override suspend fun getInfo(address: String): Result<BitcoinAddressResponse> {
+        val result = bitcoinProvider.getInfo(address)
+        when (result) {
+            is Result.Success -> return result
+            is Result.Failure -> {
+                if (result.error is IOException || result.error is HttpException) {
+                    changeProvider()
+                    return bitcoinProvider.getInfo(address)
+                } else {
+                    return result
+                }
+            }
+        }
+    }
+
+    override suspend fun getFee(): Result<BitcoinFee> {
+        val result = bitcoinProvider.getFee()
+        when (result) {
+            is Result.Success -> return result
+            is Result.Failure -> {
+                if (result.error is IOException || result.error is HttpException) {
+                    changeProvider()
+                    return bitcoinProvider.getFee()
+                } else {
+                    return result
+                }
+            }
+        }
+    }
+
+    override suspend fun sendTransaction(transaction: String): SimpleResult {
+        val result = bitcoinProvider.sendTransaction(transaction)
+        when (result) {
+            is SimpleResult.Success -> return result
+            is SimpleResult.Failure -> {
+                if (result.error is IOException || result.error is HttpException) {
+                    changeProvider()
+                    return bitcoinProvider.sendTransaction(transaction)
+                } else {
+                    return result
+                }
+            }
+        }
+    }
+
+    companion object {
+        val SATOSHI_IN_BTC = 100000000.toBigDecimal()
+    }
+}
+
+data class BitcoinAddressResponse(
+        val balance: BigDecimal,
+        val hasUnconfirmed: Boolean,
+        val unspentTransactions: List<UnspentTransaction>?
+)
+
+data class BitcoinFee(
+        val minimalPerKb: BigDecimal,
+        val normalPerKb: BigDecimal,
+        val priorityPerKb: BigDecimal
+)

blockchain/src/main/java/com/tangem/blockchain/bitcoin/network/BitcoinProvider.kt

@@ -0,0 +1,10 @@
+package com.tangem.blockchain.bitcoin.network
+
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+
+interface BitcoinProvider {
+    suspend fun getInfo(address: String): Result<BitcoinAddressResponse>
+    suspend fun getFee(): Result<BitcoinFee>
+    suspend fun sendTransaction(transaction: String): SimpleResult
+}

blockchain/src/main/java/com/tangem/blockchain/bitcoin/network/BlockchainInfoProvider.kt

@@ -0,0 +1,80 @@
+package com.tangem.blockchain.bitcoin.network
+
+import com.tangem.blockchain.bitcoin.UnspentTransaction
+import com.tangem.blockchain.bitcoin.network.BitcoinNetworkManager.Companion.SATOSHI_IN_BTC
+import com.tangem.blockchain.bitcoin.network.api.BlockchainInfoApi
+import com.tangem.blockchain.bitcoin.network.api.EstimatefeeApi
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.extensions.retryIO
+import com.tangem.common.extensions.hexToBytes
+import kotlinx.coroutines.async
+import kotlinx.coroutines.coroutineScope
+
+
+class BlockchainInfoProvider(
+        private val blockchainApi: BlockchainInfoApi,
+        private val estimatefeeApi: EstimatefeeApi
+) : BitcoinProvider {
+
+    override suspend fun getInfo(address: String): Result<BitcoinAddressResponse> {
+        return try {
+            coroutineScope {
+                val addressDeferred = retryIO { async { blockchainApi.getAddress(address) } }
+                val unspentsDeferred = retryIO { async { blockchainApi.getUnspents(address) } }
+
+                val addressData = addressDeferred.await()
+                val unspents = unspentsDeferred.await()
+                val unconfirmedTransactions = addressData.transactions?.find { it.blockHeight == 0L } != null
+
+                val bitcoinUnspents = unspents.unspentOutputs.map {
+                    UnspentTransaction(
+                            it.amount!!.toBigDecimal().divide(SATOSHI_IN_BTC),
+                            it.outputIndex!!.toLong(),
+                            it.hash!!.hexToBytes(),
+                            it.outputScript!!.hexToBytes())
+                }
+
+                Result.Success(
+                        BitcoinAddressResponse(
+                                addressData.finalBalance?.toBigDecimal()?.divide(SATOSHI_IN_BTC)
+                                        ?: 0.toBigDecimal(), unconfirmedTransactions, bitcoinUnspents))
+            }
+        } catch (exception: Exception) {
+            Result.Failure(exception)
+        }
+    }
+
+    override suspend fun getFee(): Result<BitcoinFee> {
+        return try {
+            coroutineScope {
+                val minFeeDeferred = retryIO { async { estimatefeeApi.getEstimateFeeMinimal() } }
+                val normalFeeDeferred = retryIO { async { estimatefeeApi.getEstimateFeeNormal() } }
+                val priorityFeeDeferred = retryIO { async { estimatefeeApi.getEstimateFeePriority() } }
+
+                val minFee = minFeeDeferred.await()
+                val normalFee = normalFeeDeferred.await()
+                val priorityFee = priorityFeeDeferred.await()
+
+                Result.Success(BitcoinFee(
+                        minFee.toBigDecimal(),
+                        normalFee.toBigDecimal(),
+                        priorityFee.toBigDecimal()))
+            }
+        } catch (exception: Exception) {
+            Result.Failure(exception)
+        }
+    }
+
+
+    override suspend fun sendTransaction(transaction: String): SimpleResult {
+        return try {
+            retryIO { blockchainApi.sendTransaction(transaction) }
+            SimpleResult.Success
+        } catch (exception: Exception) {
+            SimpleResult.Failure(exception)
+        }
+    }
+
+
+}

blockchain/src/main/java/com/tangem/blockchain/bitcoin/network/BlockcypherProvider.kt

@@ -0,0 +1,83 @@
+package com.tangem.blockchain.bitcoin.network
+
+import com.tangem.blockchain.bitcoin.UnspentTransaction
+import com.tangem.blockchain.bitcoin.network.BitcoinNetworkManager.Companion.SATOSHI_IN_BTC
+import com.tangem.blockchain.bitcoin.network.api.BlockcypherApi
+import com.tangem.blockchain.bitcoin.network.api.BlockcypherBody
+import com.tangem.blockchain.bitcoin.network.response.BlockcypherFee
+import com.tangem.blockchain.bitcoin.network.response.BlockcypherResponse
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.extensions.retryIO
+import com.tangem.common.extensions.hexToBytes
+
+class BlockcypherProvider(private val api: BlockcypherApi, isTestNet: Boolean) : BitcoinProvider {
+
+    private val blockchain = "btc"
+
+    private val network = if (isTestNet) {
+        BlockcypherNetwork.Test.network
+    } else {
+        BlockcypherNetwork.Main.network
+    }
+
+    override suspend fun getInfo(address: String): Result<BitcoinAddressResponse> {
+        try {
+            val addressData: BlockcypherResponse = retryIO { api.getAddressData(blockchain, network, address) }
+            val unspents = addressData.txrefs?.map {
+                UnspentTransaction(
+                        it.amount!!.toBigDecimal().divide(SATOSHI_IN_BTC),
+                        it.outputIndex!!.toLong(),
+                        it.hash!!.hexToBytes(),
+                        it.outputScript!!.hexToBytes()
+                )
+            }
+            return Result.Success(BitcoinAddressResponse(
+                    addressData.balance!!.toBigDecimal().divide(SATOSHI_IN_BTC),
+                    addressData.unconfirmedBalance != 0L,
+                    unspents))
+
+        } catch (error: Exception) {
+            return Result.Failure(error)
+        }
+    }
+
+    override suspend fun getFee(): Result<BitcoinFee> {
+        try {
+            val receivedFee: BlockcypherFee = retryIO { api.getFee(blockchain, network) }
+            return Result.Success(
+                    BitcoinFee(receivedFee.minFeePerKb!!.toBigDecimal().divide(SATOSHI_IN_BTC),
+                            receivedFee.normalFeePerKb!!.toBigDecimal().divide(SATOSHI_IN_BTC),
+                            receivedFee.priorityFeePerKb!!.toBigDecimal().divide(SATOSHI_IN_BTC))
+            )
+        } catch (error: Exception) {
+            return Result.Failure(error)
+        }
+    }
+
+    override suspend fun sendTransaction(transaction: String): SimpleResult {
+        try {
+            retryIO {
+                api.sendTransaction(
+                        blockchain, network, BlockcypherBody(transaction), BlockcypherToken.getToken())
+            }
+            return SimpleResult.Success
+        } catch (error: Exception) {
+            return SimpleResult.Failure(error)
+        }
+    }
+}
+
+private object BlockcypherToken {
+    private val tokens = listOf(
+            "aa8184b0e0894b88a5688e01b3dc1e82",
+            "56c4ca23c6484c8f8864c32fde4def8d",
+            "66a8a37c5e9d4d2c9bb191acfe7f93aa")
+
+    fun getToken(): String = tokens.random()
+}
+
+private enum class BlockcypherNetwork(val network: String) {
+    Main("main"),
+    Test("test3")
+}

blockchain/src/main/java/com/tangem/blockchain/bitcoin/network/api/BlockchainInfoApi.kt

@@ -0,0 +1,18 @@
+package com.tangem.blockchain.bitcoin.network.api
+
+import com.tangem.blockchain.bitcoin.network.response.BlockchainInfoAddress
+import com.tangem.blockchain.bitcoin.network.response.BlockchainInfoUnspents
+import okhttp3.ResponseBody
+import retrofit2.http.*
+
+interface BlockchainInfoApi {
+    @GET("rawaddr/{address}?limit=5")
+    suspend fun getAddress(@Path("address") address: String): BlockchainInfoAddress
+
+    @GET("unspent")
+    suspend fun getUnspents(@Query("active") address: String): BlockchainInfoUnspents
+
+    @FormUrlEncoded
+    @POST("pushtx")
+    suspend fun sendTransaction(@Field("tx") transaction: String): ResponseBody
+}

blockchain/src/main/java/com/tangem/blockchain/bitcoin/network/api/BlockcypherApi.kt

@@ -0,0 +1,41 @@
+package com.tangem.blockchain.bitcoin.network.api
+
+import com.squareup.moshi.JsonClass
+import com.tangem.blockchain.bitcoin.network.response.BlockcypherFee
+import com.tangem.blockchain.bitcoin.network.response.BlockcypherResponse
+import com.tangem.blockchain.bitcoin.network.response.BlockcypherTx
+import retrofit2.http.*
+
+interface BlockcypherApi {
+    @GET("v1/{blockchain}/{network}")
+    suspend fun getFee(
+            @Path("blockchain") blockchain: String,
+            @Path("network") network: String
+    ): BlockcypherFee
+
+    @GET("v1/{blockchain}/{network}/addrs/{address}?unspentOnly=true&includeScript=true")
+    suspend fun getAddressData(
+            @Path("blockchain") blockchain: String,
+            @Path("network") network: String,
+            @Path("address") address: String
+    ): BlockcypherResponse
+
+    @GET("v1/{blockchain}/{network}/txs/{txHash}?includeHex=true")
+    suspend fun getTransactions(
+            @Path("blockchain") blockchain: String,
+            @Path("network") network: String,
+            @Path("txHash") txHash: String
+    ): BlockcypherTx
+
+    @Headers("Content-Type: application/json")
+    @POST("v1/{blockchain}/{network}/txs/push")
+    suspend fun sendTransaction(
+            @Path("blockchain") blockchain: String,
+            @Path("network") network: String,
+            @Body blockcypherBody: BlockcypherBody,
+            @Query("token") token: String
+    ): BlockcypherTx
+}
+
+@JsonClass(generateAdapter = true)
+data class BlockcypherBody(val tx: String)

blockchain/src/main/java/com/tangem/blockchain/bitcoin/network/api/EstimateFeeApi.kt

@@ -0,0 +1,16 @@
+package com.tangem.blockchain.bitcoin.network.api
+
+import retrofit2.http.GET
+
+interface EstimatefeeApi {
+    @GET(ESTIMATE_FEE_URL + "n/2")
+    suspend fun getEstimateFeePriority(): String
+
+    @GET(ESTIMATE_FEE_URL + "n/3")
+    suspend fun getEstimateFeeNormal(): String
+
+    @GET(ESTIMATE_FEE_URL + "n/6")
+    suspend fun getEstimateFeeMinimal(): String
+}
+
+const val ESTIMATE_FEE_URL = "https://estimatefee.com/"

blockchain/src/main/java/com/tangem/blockchain/bitcoin/network/response/BlockchainInfoResponse.kt

@@ -0,0 +1,43 @@
+package com.tangem.blockchain.bitcoin.network.response
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+data class BlockchainInfoAddress(
+        @Json(name = "final_balance")
+        val finalBalance: Long? = null,
+
+        @Json(name = "txs")
+        val transactions: List<BlockchainInfoTransaction>? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class BlockchainInfoTransaction(
+        @Json(name = "hash")
+        val hash: String? = null,
+
+        @Json(name = "block_height")
+        val blockHeight: Long? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class BlockchainInfoUnspents(
+        @Json(name = "unspent_outputs")
+        val unspentOutputs: List<BlockchainInfoUtxo>
+)
+
+@JsonClass(generateAdapter = true)
+data class BlockchainInfoUtxo(
+        @Json(name = "tx_hash_big_endian")
+        val hash: String? = null,
+
+        @Json(name = "tx_output_n")
+        val outputIndex: Int? = null,
+
+        @Json(name = "value")
+        val amount: Long? = null,
+
+        @Json(name = "script")
+        val outputScript: String? = null
+)

blockchain/src/main/java/com/tangem/blockchain/bitcoin/network/response/BlockcypherResponse.kt

@@ -0,0 +1,55 @@
+package com.tangem.blockchain.bitcoin.network.response
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+data class BlockcypherResponse(
+        @Json(name = "address")
+        val address: String? = null,
+
+        @Json(name = "balance")
+        val balance: Long? = null,
+
+        @Json(name = "unconfirmed_balance")
+        val unconfirmedBalance: Long? = null,
+
+        @Json(name = "txrefs")
+        val txrefs: List<BlockcypherTxref>? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class BlockcypherTxref(
+        @Json(name = "tx_hash")
+        val hash: String? = null,
+
+        @Json(name = "tx_output_n")
+        val outputIndex: Int? = null,
+
+        @Json(name = "value")
+        val amount: Long? = null,
+
+        @Json(name = "confirmations")
+        val confirmations: Long? = null,
+
+        @Json(name = "script")
+        val outputScript: String? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class BlockcypherTx(
+        @Json(name = "hex")
+        val hex: String? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class BlockcypherFee(
+        @Json(name = "low_fee_per_kb")
+        val minFeePerKb: Long? = null,
+
+        @Json(name = "medium_fee_per_kb")
+        val normalFeePerKb: Long? = null,
+
+        @Json(name = "high_fee_per_kb")
+        val priorityFeePerKb: Long? = null
+)

blockchain/src/main/java/com/tangem/blockchain/cardano/CardanoAddress.kt

@@ -0,0 +1,105 @@
+package com.tangem.blockchain.cardano
+
+import co.nstant.`in`.cbor.CborBuilder
+import co.nstant.`in`.cbor.CborDecoder
+import co.nstant.`in`.cbor.CborEncoder
+import co.nstant.`in`.cbor.model.Array
+import co.nstant.`in`.cbor.model.ByteString
+import co.nstant.`in`.cbor.model.UnsignedInteger
+import com.tangem.blockchain.cardano.crypto.Blake2b
+import com.tangem.blockchain.common.extensions.decodeBase58
+import com.tangem.blockchain.common.extensions.encodeBase58
+import org.spongycastle.crypto.util.DigestFactory
+import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
+import java.util.zip.CRC32
+
+class CardanoAddressFactory {
+    companion object {
+        fun makeAddress(cardPublicKey: ByteArray, testNet: Boolean = false): String {
+            val extendedPublicKey = extendPublicKey(cardPublicKey)
+
+            val pubKeyWithAttributesBaos = ByteArrayOutputStream()
+            CborEncoder(pubKeyWithAttributesBaos).encode(CborBuilder()
+                    .addArray()
+                        .add(0)
+                            .addArray()
+                                .add(0)
+                                .add(extendedPublicKey)
+                            .end()
+                        .addMap()
+                        .end()
+                    .end()
+                    .build())
+            val pubKeyWithAttributes = pubKeyWithAttributesBaos.toByteArray()
+
+            val sha3Digest = DigestFactory.createSHA3_256()
+            sha3Digest.update(pubKeyWithAttributes, 0, pubKeyWithAttributes.size)
+            val sha3Hash = ByteArray(32)
+            sha3Digest.doFinal(sha3Hash, 0)
+
+            val blake2b = Blake2b.Digest.newInstance(28)
+            val blakeHash = blake2b.digest(sha3Hash)
+
+            val hashWithAttributesBaos = ByteArrayOutputStream()
+            CborEncoder(hashWithAttributesBaos).encode(CborBuilder()
+                    .addArray()
+                        .add(blakeHash)
+                        .addMap() //additional attributes
+                        .end()
+                        .add(0) //address type
+                    .end()
+                    .build())
+            val hashWithAttributes = hashWithAttributesBaos.toByteArray()
+
+            val crc32 = CRC32()
+            crc32.update(hashWithAttributes)
+            val checksum = crc32.value
+
+            val addressItem = CborBuilder().add(hashWithAttributes).build().get(0)
+            addressItem.setTag(24)
+
+            //addr + checksum
+            val addressBaos = ByteArrayOutputStream()
+            CborEncoder(addressBaos).encode(CborBuilder()
+                    .addArray()
+                        .add(addressItem)
+                        .add(checksum)
+                    .end()
+                    .build())
+
+            val hexAddress = addressBaos.toByteArray()
+            return hexAddress.encodeBase58()
+        }
+
+        fun extendPublicKey(publicKey: ByteArray): ByteArray {
+            val zeroBytes = ByteArray(32)
+            zeroBytes.fill(0)
+            return publicKey + zeroBytes
+        }
+    }
+}
+
+class CardanoAddressValidator {
+    companion object {
+        fun validate(address: String): Boolean {
+            val decoded = address.decodeBase58() ?: return false
+
+            return try {
+                val bais = ByteArrayInputStream(decoded)
+                val addressList =
+                        (CborDecoder(bais).decode()[0] as Array).dataItems
+                val addressItemBytes = (addressList[0] as ByteString).bytes
+                val checksum = (addressList[1] as UnsignedInteger).value.toLong()
+
+                val crc32 = CRC32()
+                crc32.update(addressItemBytes)
+                val calculatedChecksum = crc32.value
+
+                checksum == calculatedChecksum
+            } catch (e: Exception) {
+                false
+            }
+        }
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/cardano/CardanoTransactionBuilder.kt

@@ -0,0 +1,171 @@
+package com.tangem.blockchain.cardano
+
+import co.nstant.`in`.cbor.CborBuilder
+import co.nstant.`in`.cbor.CborDecoder
+import co.nstant.`in`.cbor.CborEncoder
+import co.nstant.`in`.cbor.builder.ArrayBuilder
+import com.tangem.blockchain.cardano.crypto.Blake2b
+import com.tangem.blockchain.common.TransactionData
+import com.tangem.blockchain.common.extensions.decodeBase58
+import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
+import java.math.BigDecimal
+
+class CardanoTransactionBuilder() {
+    var unspentOutputs: List<UnspentOutput> = listOf()
+    var transactionBody: ByteArray = ByteArray(0)
+
+    fun buildToSign(transactionData: TransactionData): ByteArray {
+        val transactionBuilder = CborBuilder()
+
+        val transactionArray = transactionBuilder.addArray()
+        transactionArray.addInputArray()
+        transactionArray.addOutputArray(transactionData)
+        transactionArray.addMap().end()
+
+        val transactionBaos = ByteArrayOutputStream()
+        CborEncoder(transactionBaos).encode(transactionBuilder.build())
+        transactionBody = transactionBaos.toByteArray()
+
+        val blake2b = Blake2b.Digest.newInstance(32)
+        val transactionBodyHash = blake2b.digest(transactionBody)
+
+        val magicBaos = ByteArrayOutputStream()
+        CborEncoder(magicBaos).encode(CborBuilder().add(PROTOCOL_MAGIC).build())
+        val magic = magicBaos.toByteArray()
+
+        //dataToSign prefix
+        val prefixedHashBaos = ByteArrayOutputStream()
+        prefixedHashBaos.write(byteArrayOf(0x01.toByte()))
+        prefixedHashBaos.write(magic)
+        prefixedHashBaos.write(byteArrayOf(0x58.toByte(), 0x20.toByte()))
+        prefixedHashBaos.write(transactionBodyHash)
+        return prefixedHashBaos.toByteArray()
+    }
+
+    fun buildToSend(signature: ByteArray, publicKey: ByteArray): ByteArray {
+        val extendedPublicKey = CardanoAddressFactory.extendPublicKey(publicKey)
+
+        //pubkey + signature
+        val witnessBodyBaos = ByteArrayOutputStream()
+        CborEncoder(witnessBodyBaos).encode(CborBuilder()
+                .addArray()
+                    .add(extendedPublicKey)
+                    .add(signature)
+                .end()
+                .build())
+        val witnessBody = witnessBodyBaos.toByteArray()
+        val witnessBodyItem = CborBuilder().add(witnessBody).build()[0]
+        witnessBodyItem.setTag(24)
+
+        val witnessBuilder = CborBuilder()
+        val witnessArrayBuilder = witnessBuilder.addArray()
+
+        //witness type + witness body
+        for (utxo in unspentOutputs) {
+            witnessArrayBuilder
+                    .addArray()
+                        .add(0)
+                        .add(witnessBodyItem)
+                    .end()
+        }
+
+        val witnessBaos = ByteArrayOutputStream()
+        CborEncoder(witnessBaos).encode(witnessBuilder.build())
+        val witness = witnessBaos.toByteArray()
+
+        val transactionBaos = ByteArrayOutputStream()
+        transactionBaos.write(byteArrayOf(0x82.toByte()))
+        transactionBaos.write(transactionBody)
+        transactionBaos.write(witness)
+        return transactionBaos.toByteArray()
+    }
+
+    private fun ArrayBuilder<CborBuilder>.addInputArray() {
+        val inputArray = this.startArray()
+
+        for (utxo in unspentOutputs) {
+            val inputBaos = ByteArrayOutputStream()
+            CborEncoder(inputBaos).encode(CborBuilder()
+                    .addArray()
+                        .add(utxo.hash)
+                        .add(utxo.outputIndex)
+                    .end()
+                    .build())
+            val input = inputBaos.toByteArray()
+
+            val inputItem = CborBuilder().add(input).build().get(0)
+            inputItem.setTag(24)
+            //input type + input
+            inputArray
+                    .addArray()
+                        .add(0)
+                        .add(inputItem)
+                    .end()
+        }
+        inputArray.end()
+    }
+
+    private fun ArrayBuilder<CborBuilder>.addOutputArray(transactionData: TransactionData) {
+        val amount = transactionData.amount.value!!
+                .movePointRight(transactionData.amount.decimals.toInt()).toLong()
+        val fee = transactionData.fee!!.value!!
+                .movePointRight(transactionData.fee.decimals.toInt()).toLong()
+        val change = calculateChange(amount, fee)
+
+        val outputArray = this.startArray()
+
+        //1st output
+        val targetAddressItem =
+                CborDecoder(ByteArrayInputStream(transactionData.destinationAddress.decodeBase58()))
+                        .decode()[0]
+        outputArray
+                .addArray()
+                    .add(targetAddressItem)
+                    .add(amount)
+                .end()
+
+        //2nd output (optional)
+        if (change > 0) {
+            val myAddressItem =
+                    CborDecoder(ByteArrayInputStream(transactionData.sourceAddress.decodeBase58()))
+                            .decode()[0]
+            outputArray
+                    .addArray()
+                        .add(myAddressItem)
+                        .add(change)
+                    .end()
+        }
+        outputArray.end()
+    }
+
+    private fun calculateChange(amount: Long, fee: Long): Long {
+        val fullAmount = unspentOutputs.map { it.amount }.sum()
+        return fullAmount - (amount + fee)
+    }
+
+    fun getEstimateSize(transactionData: TransactionData, walletPublicKey: ByteArray): Int {
+        val dummyFeeValue = BigDecimal.valueOf(0.1)
+
+        val dummyFee = transactionData.amount.copy(value = dummyFeeValue)
+        val dummyAmount =
+                transactionData.amount.copy(value = transactionData.amount.value!! - dummyFeeValue)
+
+        val dummyTransactionData = transactionData.copy(
+                amount = dummyAmount,
+                fee = dummyFee
+        )
+        buildToSign(dummyTransactionData)
+        return buildToSend(ByteArray(64), walletPublicKey).size
+    }
+
+    companion object {
+        private const val PROTOCOL_MAGIC: Long = 764824073
+    }
+}
+
+class UnspentOutput(
+        val amount: Long,
+        val outputIndex: Long,
+        val hash: ByteArray
+)

blockchain/src/main/java/com/tangem/blockchain/cardano/CardanoWalletManager.kt

@@ -0,0 +1,70 @@
+package com.tangem.blockchain.cardano
+
+import android.util.Base64
+import android.util.Log
+import com.tangem.blockchain.cardano.network.CardanoAddressResponse
+import com.tangem.blockchain.cardano.network.CardanoNetworkManager
+import com.tangem.blockchain.common.*
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.extensions.encodeBase64NoWrap
+import com.tangem.blockchain.wallets.CurrencyWallet
+import com.tangem.tasks.TaskEvent
+import java.math.BigDecimal
+
+class CardanoWalletManager(
+        private val cardId: String,
+        private val walletPublicKey: ByteArray,
+        walletConfig: WalletConfig
+) : WalletManager,
+        TransactionSender,
+        FeeProvider {
+
+    override val blockchain = Blockchain.Cardano
+    private val address = blockchain.makeAddress(walletPublicKey)
+    private val currencyWallet = CurrencyWallet(walletConfig, address)
+    override var wallet: Wallet = currencyWallet
+    private val transactionBuilder = CardanoTransactionBuilder()
+    private val networkManager = CardanoNetworkManager()
+
+    override suspend fun update() {
+        val response = networkManager.getInfo(address)
+        when (response) {
+            is Result.Success -> updateWallet(response.data)
+            is Result.Failure -> updateError(response.error)
+        }
+    }
+
+    private fun updateWallet(response: CardanoAddressResponse) {
+        Log.d(this::class.java.simpleName, "Balance is ${response.balance.toString()}")
+        currencyWallet.balances[AmountType.Coin]?.value =
+                response.balance.toBigDecimal().movePointLeft(blockchain.decimals.toInt())
+        transactionBuilder.unspentOutputs = response.unspentOutputs
+    }
+
+    private fun updateError(error: Throwable?) {
+        Log.e(this::class.java.simpleName, error?.message ?: "")
+    }
+
+    override suspend fun send(transactionData: TransactionData, signer: TransactionSigner): SimpleResult {
+        val transactionHash = transactionBuilder.buildToSign(transactionData)
+
+        when (val signerResponse = signer.sign(arrayOf(transactionHash), cardId)) {
+            is TaskEvent.Event -> {
+                val transactionToSend = transactionBuilder.buildToSend(signerResponse.data.signature, walletPublicKey)
+                return networkManager.sendTransaction(transactionToSend.encodeBase64NoWrap())
+            }
+            is TaskEvent.Completion -> return SimpleResult.Failure(signerResponse.error)
+        }
+    }
+
+    override suspend fun getFee(amount: Amount, source: String, destination: String): Result<List<Amount>> {
+        val a = 0.155381
+        val b = 0.000043946
+        val size = transactionBuilder.getEstimateSize(
+                TransactionData(amount, null, source, destination), walletPublicKey
+        )
+        val fee = (a + b * size).toBigDecimal()
+        return Result.Success(listOf(Amount(blockchain.currency, fee, source, blockchain.decimals)))
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/cardano/network/CardanoNetworkManager.kt

@@ -0,0 +1,67 @@
+package com.tangem.blockchain.cardano.network
+
+import com.tangem.blockchain.cardano.UnspentOutput
+import com.tangem.blockchain.cardano.network.adalite.AdaliteProvider
+import com.tangem.blockchain.cardano.network.api.AdaliteApi
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.network.API_ADALITE
+import com.tangem.blockchain.common.network.API_ADALITE_RESERVE
+import com.tangem.blockchain.common.network.createRetrofitInstance
+import retrofit2.HttpException
+import java.io.IOException
+
+class CardanoNetworkManager {
+    private val adaliteProvider by lazy {
+        val api = createRetrofitInstance(API_ADALITE)
+                .create(AdaliteApi::class.java)
+        AdaliteProvider(api)
+    }
+
+    private val adaliteReserveProvider by lazy {
+        val api = createRetrofitInstance(API_ADALITE_RESERVE)
+                .create(AdaliteApi::class.java)
+        AdaliteProvider(api)
+    }
+
+    private var provider = adaliteProvider
+
+    private fun changeProvider() {
+        provider = if (provider == adaliteProvider) adaliteReserveProvider else adaliteProvider
+    }
+
+    suspend fun getInfo(address: String): Result<CardanoAddressResponse> {
+        val result = provider.getInfo(address)
+        when (result) {
+            is Result.Success -> return result
+            is Result.Failure -> {
+                if (result.error is IOException || result.error is HttpException) {
+                    changeProvider()
+                    return provider.getInfo(address)
+                } else {
+                    return result
+                }
+            }
+        }
+    }
+
+    suspend fun sendTransaction(transaction: String): SimpleResult {
+        val result = provider.sendTransaction(transaction)
+        when (result) {
+            is SimpleResult.Success -> return result
+            is SimpleResult.Failure -> {
+                if (result.error is IOException || result.error is HttpException) {
+                    changeProvider()
+                    return provider.sendTransaction(transaction)
+                } else {
+                    return result
+                }
+            }
+        }
+    }
+}
+
+data class CardanoAddressResponse(
+        val balance: Long,
+        val unspentOutputs: List<UnspentOutput>
+)

blockchain/src/main/java/com/tangem/blockchain/cardano/network/adalite/AdaliteApi.kt

@@ -0,0 +1,20 @@
+package com.tangem.blockchain.cardano.network.api
+
+import com.tangem.blockchain.cardano.network.adalite.AdaliteAddress
+import com.tangem.blockchain.cardano.network.adalite.AdaliteSendBody
+import com.tangem.blockchain.cardano.network.adalite.AdaliteUnspents
+import retrofit2.http.*
+import shadow.okhttp3.ResponseBody
+
+interface AdaliteApi {
+    @GET("/api/addresses/summary/{address}")
+    suspend fun getAddress(@Path("address") address: String): AdaliteAddress
+
+    @Headers("Content-Type: application/json")
+    @POST("/api/bulk/addresses/utxo")
+    suspend fun getUnspents(@Body address: String): AdaliteUnspents
+
+    @Headers("Content-Type: application/json")
+    @POST("/api/v2/txs/signed")
+    suspend fun sendTransaction(@Body adaliteBody: AdaliteSendBody): ResponseBody // List<Any>?
+}

blockchain/src/main/java/com/tangem/blockchain/cardano/network/adalite/AdaliteProvider.kt

@@ -0,0 +1,53 @@
+package com.tangem.blockchain.cardano.network.adalite
+
+import com.tangem.blockchain.cardano.network.CardanoAddressResponse
+import com.tangem.blockchain.cardano.UnspentOutput
+import com.tangem.blockchain.cardano.network.api.AdaliteApi
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.extensions.retryIO
+import kotlinx.coroutines.async
+import kotlinx.coroutines.coroutineScope
+
+class AdaliteProvider(private val api: AdaliteApi) {
+
+    suspend fun getInfo(address: String): Result<CardanoAddressResponse> {
+        return try {
+            coroutineScope {
+                val addressDeferred = retryIO { async { api.getAddress(address) } }
+                val unspentsDeferred = retryIO { async { api.getUnspents(address) } }
+
+                val addressData = addressDeferred.await()
+                val unspents = unspentsDeferred.await()
+
+                val cardanoUnspents = unspents.data.map {
+                    UnspentOutput(
+                            it.amountData!!.amount!!,
+                            it.outputIndex!!.toLong(),
+                            it.hash!!.toByteArray()
+                    )
+                }
+
+                Result.Success(
+                        CardanoAddressResponse(
+                                addressData.data!!.balanceData!!.amount!!,
+                                cardanoUnspents
+                        )
+                )
+            }
+        } catch (exception: Exception) {
+            Result.Failure(exception)
+        }
+    }
+
+    suspend fun sendTransaction(transaction: String): SimpleResult {
+        return try {
+            retryIO { api.sendTransaction(AdaliteSendBody(transaction)) }
+            SimpleResult.Success
+        } catch (exception: Exception) {
+            SimpleResult.Failure(exception)
+        }
+    }
+}
+
+data class AdaliteSendBody(val signedTransaction: String)

blockchain/src/main/java/com/tangem/blockchain/cardano/network/adalite/AdaliteResponse.kt

@@ -0,0 +1,49 @@
+package com.tangem.blockchain.cardano.network.adalite
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+data class AdaliteAddress(
+        @Json(name = "final_balance")
+        var data: AdaliteAddressData? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class AdaliteAddressData(
+        @Json(name = "caBalance")
+        var balanceData: BalanceData? = null
+
+//        @Json(name = "caTxList")
+//        var transactions: List<AdaliteTransaction>
+)
+
+@JsonClass(generateAdapter = true)
+data class BalanceData(
+        @Json(name = "getCoin")
+        var amount: Long? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class AdaliteUnspents(
+        @Json(name = "Right")
+        var data: List<AdaliteUtxo>
+)
+
+@JsonClass(generateAdapter = true)
+data class AdaliteUtxo(
+        @Json(name = "cuId")
+        var hash: String? = null,
+
+        @Json(name = "cuOutIndex")
+        var outputIndex: Int? = null,
+
+        @Json(name = "cuCoins")
+        var amountData: BalanceData? = null
+)
+
+//@JsonClass(generateAdapter = true)
+//data class AdaliteTransaction(
+//        @Json(name = "ctbId")
+//        var hash: String? = null
+//)

blockchain/src/main/java/com/tangem/blockchain/common/Blockchain.kt

@@ -0,0 +1,74 @@
+package com.tangem.blockchain.common
+
+import com.tangem.blockchain.bitcoin.BitcoinAddressFactory
+import com.tangem.blockchain.bitcoin.BitcoinAddressValidator
+import com.tangem.blockchain.ethereum.EthereumAddressFactory
+import com.tangem.blockchain.ethereum.EthereumAddressValidator
+import com.tangem.blockchain.cardano.CardanoAddressFactory
+import com.tangem.blockchain.cardano.CardanoAddressValidator
+import com.tangem.blockchain.stellar.StellarAddressFactory
+import com.tangem.blockchain.xrp.XrpAddressFactory
+import com.tangem.blockchain.xrp.XrpAddressValidator
+import java.math.BigDecimal
+
+enum class Blockchain(
+        val id: String,
+        val currency: String,
+        val decimals: Byte,
+        val fullName: String,
+        val pendingTransactionTimeout: Int
+) {
+    Unknown("", "", 0, "", 0),
+    Bitcoin("BTC", "BTC", 8, "Bitcoin", 0),
+    BitcoinTestnet("BTC", "BTC", 8, "Bitcoin Testnet", 0),
+    Ethereum("ETH", "ETH", 18, "Ethereum", 0),
+    Rootstock("", "", 18, "", 0),
+    Cardano("CARDANO", "ADA", 6, "Cardano", 0),
+    XRP("", "XRP", 6, "XRP Ledger", 0),
+    Binance("", "", 8, "", 0),
+    Stellar("XLM", "XLM", 7, "Stellar", 0);
+
+    fun roundingMode(): Int = when (this) {
+        Bitcoin, Ethereum, Rootstock, Binance -> BigDecimal.ROUND_DOWN
+        Cardano -> BigDecimal.ROUND_UP
+        else -> BigDecimal.ROUND_HALF_UP
+    }
+
+    fun makeAddress(walletPublicKey: ByteArray): String {
+        return when (this) {
+            Unknown -> throw Exception("unsupported blockchain")
+            Bitcoin -> BitcoinAddressFactory.makeAddress(walletPublicKey)
+            BitcoinTestnet -> BitcoinAddressFactory.makeAddress(walletPublicKey, testNet = true)
+            Ethereum -> EthereumAddressFactory.makeAddress(walletPublicKey)
+//            Rootstock -> RootstockAddressFactory.makeAddress(cardPublicKey)
+            Cardano -> CardanoAddressFactory.makeAddress(walletPublicKey)
+            XRP -> XrpAddressFactory.makeAddress(walletPublicKey)
+//            Binance -> BinanceAddressFactory.makeAddress(cardPublicKey)
+            Stellar -> StellarAddressFactory.makeAddress(walletPublicKey)
+            else -> throw Exception("unsupported blockchain")
+        }
+    }
+
+    fun validateAddress(address: String): Boolean {
+        return when (this) {
+            Unknown -> throw Exception("unsupported blockchain")
+            Bitcoin -> BitcoinAddressValidator.validate(address)
+            BitcoinTestnet -> BitcoinAddressValidator.validate(address, testNet = true)
+            Ethereum -> EthereumAddressValidator.validate(address)
+//            Rootstock -> RootstockAddressValidator.validate(address)
+            Cardano -> CardanoAddressValidator.validate(address)
+            XRP -> XrpAddressValidator.validate(address)
+//            Binance -> BinanceAddressValidator.validate(address)
+//            Stellar -> StellarAddressValidator.validate(address)
+            else -> throw Exception("unsupported blockchain")
+        }
+    }
+
+    companion object {
+        private val values = values()
+        fun fromId(id: String): Blockchain = values.find { it.id == id } ?: Unknown
+        fun fromName(name: String): Blockchain = values.find { it.name == name } ?: Unknown
+        fun fromCurrency(currency: String): Blockchain = values.find { it.currency == currency }
+                ?: Unknown
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/common/Wallet.kt

@@ -0,0 +1,52 @@
+package com.tangem.blockchain.common
+
+import java.math.BigDecimal
+import java.util.*
+
+interface Wallet {
+    val config: WalletConfig
+    val address: String
+    val exploreUrl: String?
+    val shareUrl: String?
+}
+
+class WalletConfig(
+        val allowFeeSelection: Boolean,
+        val allowFeeInclusion: Boolean,
+        var allowExtract: Boolean = false,
+        var allowLoad: Boolean = false
+)
+
+data class Amount(
+        val currencySymbol: String,
+        var value: BigDecimal? = null,
+        val address: String? = null,
+        val decimals: Byte,
+        val type: AmountType = AmountType.Coin
+) {
+    constructor(
+            value: BigDecimal?,
+            blockchain: Blockchain,
+            address: String? = null,
+            type: AmountType = AmountType.Coin
+    ) : this(blockchain.currency, value, address, blockchain.decimals, type)
+}
+
+data class TransactionData(
+        val amount: Amount,
+        val fee: Amount?,
+        val sourceAddress: String,
+        val destinationAddress: String,
+        var status: TransactionStatus = TransactionStatus.Unconfirmed,
+        var date: Calendar? = null
+)
+
+enum class AmountType { Coin, Token, Reserve }
+
+enum class TransactionStatus { Confirmed, Unconfirmed }
+
+enum class ValidationError { WrongAmount, WrongFee, WrongTotal }
+
+interface TransactionValidator {
+    fun validateTransaction(amount: Amount, fee: Amount?): EnumSet<ValidationError>
+}

blockchain/src/main/java/com/tangem/blockchain/common/WalletManager.kt

@@ -0,0 +1,26 @@
+package com.tangem.blockchain.common
+
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.commands.SignResponse
+import com.tangem.tasks.TaskEvent
+import kotlinx.coroutines.flow.Flow
+
+interface WalletManager {
+    var wallet: Wallet
+    val blockchain: Blockchain
+
+    suspend fun update()
+}
+
+interface TransactionSender {
+    suspend fun send(transactionData: TransactionData, signer: TransactionSigner) : SimpleResult
+}
+
+interface TransactionSigner {
+    suspend fun sign(hashes: Array<ByteArray>, cardId: String): TaskEvent<SignResponse>
+}
+
+interface FeeProvider {
+    suspend fun getFee(amount: Amount, source: String, destination: String): Result<List<Amount>>
+}

blockchain/src/main/java/com/tangem/blockchain/common/WalletManagerFactory.kt

@@ -0,0 +1,82 @@
+package com.tangem.blockchain.common
+
+import com.tangem.blockchain.bitcoin.BitcoinWalletManager
+import com.tangem.blockchain.ethereum.Chain
+import com.tangem.blockchain.ethereum.EthereumWalletManager
+import com.tangem.blockchain.cardano.CardanoWalletManager
+import com.tangem.blockchain.stellar.StellarWalletManager
+import com.tangem.blockchain.xrp.XrpWalletManager
+import com.tangem.commands.Card
+
+object WalletManagerFactory {
+
+    fun makeWalletManager(card: Card): WalletManager? {
+        val walletPublicKey: ByteArray = card.walletPublicKey ?: return null
+        val blockchainName: String = card.cardData?.blockchainName ?: return null
+
+        when {
+            blockchainName == Blockchain.Bitcoin.id -> {
+                return BitcoinWalletManager(
+                        cardId = card.cardId,
+                        walletPublicKey = walletPublicKey,
+                        walletConfig = WalletConfig(true, true)
+                )
+            }
+            blockchainName == Blockchain.BitcoinTestnet.id -> {
+                return BitcoinWalletManager(
+                        cardId = card.cardId,
+                        walletPublicKey = walletPublicKey,
+                        walletConfig = WalletConfig(true, true),
+                        isTestNet = true
+                )
+            }
+            blockchainName == Blockchain.Ethereum.id -> {
+                val chain = Chain.Mainnet
+                return EthereumWalletManager(
+                        cardId = card.cardId,
+                        walletPublicKey = walletPublicKey,
+                        walletConfig = WalletConfig(true, true),
+                        chain = chain
+                )
+            }
+            blockchainName == Blockchain.Stellar.id -> {
+                val token = getToken(card)
+                return StellarWalletManager(
+                        cardId = card.cardId,
+                        walletPublicKey = walletPublicKey,
+                        walletConfig = WalletConfig(true, token == null),
+                        token = token
+                )
+            }
+            blockchainName == Blockchain.Cardano.id -> {
+                return CardanoWalletManager(
+                        cardId = card.cardId,
+                        walletPublicKey = walletPublicKey,
+                        walletConfig = WalletConfig(false, true)
+                )
+            }
+            blockchainName == Blockchain.XRP.id -> {
+                return XrpWalletManager(
+                        cardId = card.cardId,
+                        walletPublicKey = walletPublicKey,
+                        walletConfig = WalletConfig(true, true)
+                )
+            }
+            else -> return null
+        }
+    }
+
+    private fun getToken(card: Card): Token? {
+        val symbol = card.cardData?.tokenSymbol ?: return null
+        val contractAddress = card.cardData?.tokenContractAddress ?: return null
+        val decimals = card.cardData?.tokenDecimal ?: return null
+        return Token(symbol, contractAddress, decimals.toByte())
+    }
+}
+
+
+data class Token(
+        val symbol: String,
+        val contractAddress: String,
+        val decimals: Byte
+)

blockchain/src/main/java/com/tangem/blockchain/common/extensions/Amount.kt

@@ -0,0 +1,8 @@
+package com.tangem.blockchain.common.extensions
+
+import com.tangem.blockchain.common.Amount
+import java.math.BigInteger
+
+fun Amount.bigIntegerValue(): BigInteger? {
+    return this.value?.movePointRight(this.decimals.toInt())?.toBigInteger()
+}

blockchain/src/main/java/com/tangem/blockchain/common/extensions/BitInteger.kt

@@ -0,0 +1,11 @@
+package com.tangem.blockchain.common.extensions
+
+import org.bitcoinj.core.ECKey
+import java.math.BigInteger
+
+fun BigInteger.toCanonicalised(): BigInteger {
+    if (!this.isCanonical()) ECKey.CURVE.n - this
+    return this
+}
+
+fun BigInteger.isCanonical(): Boolean = this <= ECKey.HALF_CURVE_ORDER

blockchain/src/main/java/com/tangem/blockchain/common/extensions/ByteArray.kt

@@ -0,0 +1,12 @@
+package com.tangem.blockchain.common.extensions
+
+import android.util.Base64
+import org.bitcoinj.core.Base58
+
+fun ByteArray.encodeBase58(): String {
+    return Base58.encode(this)
+}
+
+fun ByteArray.encodeBase64NoWrap(): String {
+    return Base64.encodeToString(this, Base64.NO_WRAP)
+}

blockchain/src/main/java/com/tangem/blockchain/common/extensions/Coroutines.kt

@@ -0,0 +1,66 @@
+package com.tangem.blockchain.common.extensions
+
+import com.tangem.CardManager
+import com.tangem.blockchain.common.TransactionSigner
+import com.tangem.commands.SignResponse
+import com.tangem.tasks.TaskEvent
+import kotlinx.coroutines.*
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import java.io.IOException
+import kotlin.coroutines.resume
+import kotlin.coroutines.suspendCoroutine
+
+suspend fun <T> retryIO(
+        times: Int = 3,
+        initialDelay: Long = 100,
+        maxDelay: Long = 1000,
+        factor: Double = 2.0,
+        block: suspend () -> T
+): T {
+    var currentDelay = initialDelay
+    repeat(times - 1) {
+        try {
+            return block()
+        } catch (e: IOException) {
+
+
+        }
+        delay(currentDelay)
+        currentDelay = (currentDelay * factor).toLong().coerceAtMost(maxDelay)
+    }
+    return block() // last attempt
+}
+
+
+//suspend fun <T: Any> handleRequest(requestFunc: suspend () -> T): Result<T> {
+//    return try {
+//        Result.success(requestFunc.invoke())
+//    } catch (he: HttpException) {
+//        Result.failure(he)
+////        HttpException
+////        SocketTimeoutException
+////        IOException
+//    }
+//}
+
+
+sealed class Result<out T : Any> {
+    data class Success<out T : Any>(val data: T) : Result<T>()
+    data class Failure(val error: Throwable?) : Result<Nothing>()
+}
+
+sealed class SimpleResult {
+    object Success : SimpleResult()
+    data class Failure(val error: Throwable?) : SimpleResult()
+}
+
+class Signer(private val cardManager: CardManager) : TransactionSigner {
+    override suspend fun sign(hashes: Array<ByteArray>, cardId: String): TaskEvent<SignResponse> = coroutineScope {
+        async {
+            suspendCancellableCoroutine<TaskEvent<SignResponse>> { continuation ->
+                cardManager.sign(hashes, cardId) { if (continuation.isActive) continuation.resume(it) }
+            }
+        }.await()
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/common/extensions/String.kt

@@ -0,0 +1,12 @@
+package com.tangem.blockchain.common.extensions
+
+import org.bitcoinj.core.AddressFormatException
+import org.bitcoinj.core.Base58
+
+fun String.decodeBase58(): ByteArray? {
+    return try {
+        Base58.decode(this)
+    } catch (exception: AddressFormatException) {
+        null
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/common/network/RetrofitBuilder.kt

@@ -0,0 +1,48 @@
+package com.tangem.blockchain.common.network
+
+import com.tangem.blockchain.BuildConfig
+import okhttp3.OkHttpClient
+import okhttp3.logging.HttpLoggingInterceptor
+import retrofit2.Retrofit
+import retrofit2.converter.moshi.MoshiConverterFactory
+
+private val okHttpClient: OkHttpClient by lazy {
+    OkHttpClient.Builder().apply {
+        if (BuildConfig.DEBUG) addInterceptor(createHttpLoggingInterceptor())
+    }.build()
+}
+
+private fun createHttpLoggingInterceptor(): HttpLoggingInterceptor {
+    val logging = HttpLoggingInterceptor()
+    logging.level = HttpLoggingInterceptor.Level.BODY
+    return logging
+}
+
+
+fun createRetrofitInstance(baseUrl: String): Retrofit =
+        Retrofit.Builder()
+                .baseUrl(baseUrl)
+                .addConverterFactory(MoshiConverterFactory.create())
+                .client(okHttpClient)
+                .build()
+
+
+const val API_TANGEM = "https://verify.tangem.com/"
+const val API_COINMARKETCAP = "https://pro-api.coinmarketcap.com/"
+const val API_INFURA = "https://mainnet.infura.io/"
+const val API_SOCHAIN_V2 = "https://chain.so/"
+const val API_ESTIMATEFEE = "https://estimatefee.com/"
+const val API_UPDATE_VERSION = "https://raw.githubusercontent.com/"
+const val API_ROOTSTOCK = "https://public-node.rsk.co/"
+const val API_BLOCKCYPHER = "https://api.blockcypher.com/"
+const val API_BINANCE = "https://dex.binance.org/"
+const val API_BINANCE_TESTNET = "https://testnet-dex.binance.org/"
+const val API_MATIC_TESTNET = "https://testnet2.matic.network/"
+const val API_STELLAR = "https://horizon.stellar.org/"
+const val API_STELLAR_RESERVE = "https://horizon.sui.li/"
+const val API_STELLAR_TESTNET = "https://horizon-testnet.stellar.org/"
+const val API_BLOCKCHAIN_INFO = "https://blockchain.info/"
+const val API_ADALITE = "https://explorer2.adalite.io"
+const val API_ADALITE_RESERVE = "https://nodes.southeastasia.cloudapp.azure.com"
+const val API_RIPPLED = "https://s1.ripple.com:51234"
+const val API_RIPPLED_RESERVE = "https://s2.ripple.com:51234"

blockchain/src/main/java/com/tangem/blockchain/ethereum/EthereumAddress.kt

@@ -0,0 +1,33 @@
+package com.tangem.blockchain.ethereum
+
+import org.kethereum.crypto.toAddress
+import org.kethereum.functions.isValid
+import org.kethereum.model.Address
+import org.kethereum.model.PublicKey
+
+class EthereumAddressFactory {
+    companion object {
+        fun makeAddress(walletPublicKey: ByteArray): String =
+                PublicKey(walletPublicKey.sliceArray(1..64)).toAddress().hex
+    }
+}
+
+class EthereumAddressValidator {
+    companion object {
+        fun validate(address: String): Boolean = Address(address).isValid()
+    }
+}
+
+enum class Chain(val id: Int) {
+    Mainnet(1),
+    Morden(2),
+    Ropsten(3),
+    Rinkeby(4),
+    RootstockMainnet(30),
+    RootstockTestnet(31),
+    Kovan(42),
+    EthereumClassicMainnet(61),
+    EthereumClassicTestnet(62),
+    Geth_private_chains(1337),
+    MaticTestnet(8995);
+}

blockchain/src/main/java/com/tangem/blockchain/ethereum/EthereumWalletManager.kt

@@ -0,0 +1,144 @@
+package com.tangem.blockchain.ethereum
+
+import com.tangem.blockchain.common.*
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.ethereum.network.EthereumNetworkManager
+import com.tangem.blockchain.ethereum.network.EthereumResponse
+import com.tangem.blockchain.wallets.CurrencyWallet
+import com.tangem.common.extensions.toHexString
+import com.tangem.tasks.TaskEvent
+import org.kethereum.DEFAULT_GAS_LIMIT
+import org.kethereum.crypto.api.ec.ECDSASignature
+import org.kethereum.crypto.determineRecId
+import org.kethereum.crypto.impl.ec.canonicalise
+import org.kethereum.functions.encodeRLP
+import org.kethereum.keccakshortcut.keccak
+import org.kethereum.model.*
+import java.math.BigDecimal
+import java.math.BigInteger
+
+class EthereumWalletManager(
+        private val cardId: String,
+        private val walletPublicKey: ByteArray,
+        chain: Chain,
+        walletConfig: WalletConfig
+) : WalletManager,
+        TransactionSender,
+        FeeProvider {
+
+    override val blockchain: Blockchain = Blockchain.Ethereum
+    private val address = blockchain.makeAddress(walletPublicKey)
+    private val currencyWallet = CurrencyWallet(walletConfig, address)
+    override var wallet: Wallet = currencyWallet
+    private val builder = EthereumTransactionBuilder(chain)
+    private val networkManager = EthereumNetworkManager()
+    private var pendingTxCount = -1L
+    private var txCount = -1L
+
+    override suspend fun update() {
+        val result = networkManager.getInfo(address, currencyWallet.balances[AmountType.Token]?.address)
+        when (result) {
+            is Result.Failure -> updateError(result.error)
+            is Result.Success -> updateWallet(result.data)
+        }
+    }
+
+    private fun updateWallet(data: EthereumResponse) {
+        currencyWallet.balances[AmountType.Coin]?.value = data.balance
+        currencyWallet.balances[AmountType.Token]?.value = data.tokenBalance
+        txCount = data.txCount
+        pendingTxCount = data.pendingTxCount
+        if (txCount == pendingTxCount) {
+            currencyWallet.pendingTransactions.forEach { it.status = TransactionStatus.Confirmed }
+        } else if (currencyWallet.pendingTransactions.isEmpty()) {
+            currencyWallet.pendingTransactions.add(TransactionData(
+                    Amount(blockchain.currency, decimals = blockchain.decimals),
+                    null,
+                    "unknown",
+                    currencyWallet.address))
+        }
+    }
+
+    private fun updateError(error: Throwable?) {
+
+    }
+
+    override suspend fun send(transactionData: TransactionData, signer: TransactionSigner): SimpleResult {
+        val transactionToSign = builder.buildToSign(transactionData, txCount.toBigInteger())
+                ?: return SimpleResult.Failure(Exception("Not enough data"))
+        when (val signerResponse = signer.sign(transactionToSign.hashes.toTypedArray(), cardId)) {
+            is TaskEvent.Event -> {
+                val transactionToSend = builder.buildToSend(signerResponse.data.signature, transactionToSign, walletPublicKey)
+                return networkManager.sendTransaction(String.format("0x%s", transactionToSend.toHexString()))
+            }
+            is TaskEvent.Completion -> return SimpleResult.Failure(signerResponse.error)
+        }
+    }
+
+    override suspend fun getFee(amount: Amount, source: String, destination: String): Result<List<Amount>> {
+        val result = networkManager.getFee(getGasLimit(amount).value)
+        when (result) {
+            is Result.Success -> {
+                val feeValues: List<BigDecimal> = result.data
+                return Result.Success(
+                        feeValues.map { Amount(blockchain.currency, it, address, blockchain.decimals) })
+            }
+            is Result.Failure -> return result
+        }
+    }
+}
+
+private class EthereumTransactionBuilder(private val chain: Chain) {
+
+    fun buildToSign(transactionData: TransactionData, nonce: BigInteger?): TransactionToSign? {
+
+        val amount: BigDecimal = transactionData.amount.value ?: return null
+        val transactionFee: BigDecimal = transactionData.fee?.value ?: return null
+
+        val value = amount.movePointRight(transactionData.amount.decimals.toInt()).toBigInteger()
+        val fee = transactionFee.movePointRight(transactionData.fee.decimals.toInt()).toBigInteger()
+
+        val transaction = createTransactionWithDefaults(
+                from = Address(transactionData.sourceAddress),
+                to = Address(transactionData.destinationAddress),
+                value = value,
+                gasPrice = fee.divide(DEFAULT_GAS_LIMIT),
+                gasLimit = DEFAULT_GAS_LIMIT,
+                nonce = nonce,
+                chain = ChainId(chain.id.toLong())
+        )
+        val hash = transaction.encodeRLP(SignatureData(v = chain.id.toBigInteger())).keccak()
+        return TransactionToSign(transaction, listOf(hash))
+    }
+
+    fun buildToSend(signature: ByteArray, transactionToSign: TransactionToSign, walletPublicKey: ByteArray): ByteArray {
+        val r = BigInteger(1, signature.copyOfRange(0, 32))
+        val s = BigInteger(1, signature.copyOfRange(32, 64))
+
+        val ecdsaSignature = ECDSASignature(r, s).canonicalise()
+
+        val recId = ecdsaSignature.determineRecId(transactionToSign.hashes[0], PublicKey(walletPublicKey.sliceArray(1..64)))
+        val v = (recId + 27 + 8 + (chain.id * 2)).toBigInteger()
+        val signatureData = SignatureData(ecdsaSignature.r, ecdsaSignature.s, v)
+
+        return transactionToSign.transaction.encodeRLP(signatureData)
+    }
+}
+
+private class TransactionToSign(val transaction: Transaction, val hashes: List<ByteArray>)
+
+enum class GasLimit(val value: Long) {
+    Default(21000),
+    Token(60000),
+    High(300000)
+}
+
+private fun getGasLimit(amount: Amount): GasLimit {
+    return when (amount.currencySymbol) {
+        Blockchain.Ethereum.currency -> GasLimit.Default
+        "DGX" -> GasLimit.High
+        "CGT" -> GasLimit.High
+        else -> GasLimit.Token
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/ethereum/network/EthereumNetworkManager.kt

@@ -0,0 +1,100 @@
+package com.tangem.blockchain.ethereum.network
+
+import com.tangem.blockchain.common.Blockchain
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.extensions.retryIO
+import com.tangem.blockchain.common.network.API_INFURA
+import com.tangem.blockchain.common.network.createRetrofitInstance
+import kotlinx.coroutines.Deferred
+import kotlinx.coroutines.async
+import kotlinx.coroutines.coroutineScope
+import org.kethereum.ETH_IN_WEI
+import java.math.BigDecimal
+import java.math.BigInteger
+import java.math.RoundingMode
+
+
+class EthereumNetworkManager {
+
+    private val api: InfuraApi by lazy {
+        createRetrofitInstance(API_INFURA).create(InfuraApi::class.java)
+    }
+
+    private val provider: InfuraProvider by lazy { InfuraProvider(api) }
+
+    suspend fun sendTransaction(transaction: String): SimpleResult {
+        return try {
+            val response = retryIO { provider.sendTransaction(transaction) }
+            if (response.error == null) {
+                SimpleResult.Success
+            } else {
+                SimpleResult.Failure(Exception("Code: ${(response.error.code)}, ${(response.error.message)}"))
+            }
+        } catch (error: Exception) {
+            SimpleResult.Failure(error)
+        }
+    }
+
+    suspend fun getFee(gasLimit: Long): Result<List<BigDecimal>> {
+        return try {
+            Result.Success(
+                    provider.getGasPrice().result!!.parseFee(gasLimit)
+            )
+        } catch (error: Exception) {
+            Result.Failure(error)
+        }
+    }
+
+    suspend fun getInfo(address: String, contractAddress: String? = null): Result<EthereumResponse> {
+        return try {
+            coroutineScope {
+                val balanceResponse = retryIO { async { provider.getBalance(address) } }
+                val txCountResponse = retryIO { async { provider.getTxCount(address) } }
+                val pendingTxCountResponse = retryIO { async { provider.getPendingTxCount(address) } }
+                var tokenBalanceResponse: Deferred<InfuraResponse>? = null
+                if (contractAddress != null) {
+                    tokenBalanceResponse = retryIO { async { provider.getTokenBalance(address, contractAddress) } }
+                }
+                Result.Success(EthereumResponse(
+                        balanceResponse.await().result!!.parseAmount(),
+                        tokenBalanceResponse?.await()?.result?.parseAmount(),
+                        txCountResponse.await().result?.responseToNumber()?.toLong() ?: 0,
+                        pendingTxCountResponse.await().result?.responseToNumber()?.toLong() ?: 0
+                ))
+            }
+        } catch (error: Exception) {
+            Result.Failure(error)
+        }
+    }
+
+    private fun String.parseFee(gasLimit: Long): List<BigDecimal> {
+        val gasPrice = this.responseToNumber().toBigDecimal()
+        val minFee = gasPrice.multiply(gasLimit.toBigDecimal())
+        val normalFee = minFee.multiply(BigDecimal(1.2))
+        val priorityFee = minFee.multiply(BigDecimal(1.5))
+        return listOf(
+                minFee.convertFeeToEth(),
+                normalFee.convertFeeToEth(),
+                priorityFee.convertFeeToEth()
+        )
+    }
+
+    private fun String.responseToNumber(): BigInteger = this.substring(2).toBigInteger(16)
+
+    private fun String.parseAmount(): BigDecimal =
+            this.responseToNumber().toBigDecimal().divide(ETH_IN_WEI.toBigDecimal())
+
+    private fun BigDecimal.convertFeeToEth(): BigDecimal {
+        return this.divide(ETH_IN_WEI.toBigDecimal())
+                .setScale(12, Blockchain.Ethereum.roundingMode()).stripTrailingZeros()
+    }
+
+}
+
+data class EthereumResponse(
+        val balance: BigDecimal,
+        val tokenBalance: BigDecimal?,
+        val txCount: Long,
+        val pendingTxCount: Long
+)

blockchain/src/main/java/com/tangem/blockchain/ethereum/network/InfuraApi.kt

@@ -0,0 +1,31 @@
+package com.tangem.blockchain.ethereum.network
+
+import com.squareup.moshi.JsonClass
+import retrofit2.http.Body
+import retrofit2.http.Headers
+import retrofit2.http.POST
+
+interface InfuraApi {
+    @Headers("Content-Type: application/json")
+    @POST("v3/613a0b14833145968b1f656240c7d245")
+    suspend fun postToInfura(@Body body: InfuraBody?): InfuraResponse
+}
+
+@JsonClass(generateAdapter = true)
+data class InfuraBody(
+        val jsonrpc: String = "2.0",
+        val id: Int = 67,
+        val method: String? = null,
+        val params: List<Any> = listOf()
+)
+
+data class EthCallParams(private val data: String, private val to: String)
+
+enum class InfuraMethod(val value: String) {
+    GET_BALANCE("eth_getBalance"),
+    GET_TRANSACTION_COUNT("eth_getTransactionCount"),
+    GET_PENDING_COUNT("eth_getPendingCount"),
+    CALL("eth_call"),
+    SEND_RAW_TRANSACTION("eth_sendRawTransaction"),
+    GAS_PRICE("eth_gasPrice")
+}

blockchain/src/main/java/com/tangem/blockchain/ethereum/network/InfuraProvider.kt

@@ -0,0 +1,39 @@
+package com.tangem.blockchain.ethereum.network
+
+class InfuraProvider(private val api: InfuraApi) {
+    suspend fun getBalance(address: String) = api.postToInfura(createInfuraBody(InfuraMethod.GET_BALANCE, address))
+    suspend fun getTokenBalance(address: String, contractAddress: String) = api.postToInfura(createInfuraBody(InfuraMethod.CALL, address, contractAddress))
+    suspend fun getTxCount(address: String) = api.postToInfura(createInfuraBody(InfuraMethod.GET_TRANSACTION_COUNT, address))
+    suspend fun getPendingTxCount(address: String) = api.postToInfura(createInfuraBody(InfuraMethod.GET_PENDING_COUNT, address))
+    suspend fun getGasPrice() = api.postToInfura(createInfuraBody(InfuraMethod.GAS_PRICE))
+    suspend fun sendTransaction(transaction: String) = api.postToInfura(createInfuraBody(InfuraMethod.SEND_RAW_TRANSACTION, transaction = transaction))
+}
+
+private fun createInfuraBody(
+        method: InfuraMethod,
+        address: String? = null,
+        contractAddress: String? = null,
+        transaction: String? = null): InfuraBody {
+
+    return when (method) {
+        InfuraMethod.GET_BALANCE ->
+            InfuraBody(method = InfuraMethod.GET_BALANCE.value, params = listOf(address ?: "", "latest"))
+        InfuraMethod.GET_TRANSACTION_COUNT ->
+            InfuraBody(method = InfuraMethod.GET_TRANSACTION_COUNT.value, params = listOf(address ?: "", "latest"))
+        InfuraMethod.GET_PENDING_COUNT ->
+            InfuraBody(method = InfuraMethod.GET_TRANSACTION_COUNT.value, params = listOf(address ?: "", "pending"))
+        InfuraMethod.GAS_PRICE ->
+            InfuraBody(method = InfuraMethod.GAS_PRICE.value)
+        InfuraMethod.SEND_RAW_TRANSACTION ->
+            InfuraBody(method = InfuraMethod.SEND_RAW_TRANSACTION.value, params = listOf(transaction ?: ""))
+        InfuraMethod.CALL -> {
+            InfuraBody(
+                    method = InfuraMethod.CALL.value,
+                    params = listOf(EthCallParams(
+                            "0x70a08231000000000000000000000000" + address?.substring(2), contractAddress
+                            ?: ""),
+                            "latest"
+                    ))
+        }
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/ethereum/network/InfuraResponse.kt

@@ -0,0 +1,30 @@
+package com.tangem.blockchain.ethereum.network
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+data class InfuraResponse(
+        @Json(name = "jsonrpc")
+        val jsonrpc: String = "",
+
+        @Json(name = "id")
+        val id: Int? = null,
+
+        @Json(name = "result")
+        val result: String? = null,
+
+        @Json(name = "error")
+        val error: InfuraError? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class InfuraError(
+        @Json(name = "code")
+        val code: Int? = null,
+
+        @Json(name = "message")
+        val message: String? = null
+)
+
+

blockchain/src/main/java/com/tangem/blockchain/stellar/StellarAddress.kt

@@ -0,0 +1,24 @@
+package com.tangem.blockchain.stellar
+
+import org.stellar.sdk.KeyPair
+
+class StellarAddressFactory {
+    companion object {
+        fun makeAddress(cardPublicKey: ByteArray): String {
+            val kp = KeyPair.fromPublicKey(cardPublicKey)
+            return kp.accountId
+        }
+    }
+}
+
+class StellarAddressValidator {
+    companion object {
+        fun validate(address: String): Boolean {
+            return try {
+                KeyPair.fromAccountId(address) != null
+            } catch (exception: IllegalArgumentException) {
+                false
+            }
+        }
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/stellar/StellarNetworkManager.kt

@@ -0,0 +1,100 @@
+package com.tangem.blockchain.stellar
+
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.network.API_STELLAR
+import com.tangem.blockchain.common.network.API_STELLAR_TESTNET
+import com.tangem.blockchain.stellar.StellarWalletManager.Companion.STROOPS_IN_XLM
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.async
+import kotlinx.coroutines.coroutineScope
+import org.stellar.sdk.Network
+import org.stellar.sdk.Server
+import org.stellar.sdk.Transaction
+import org.stellar.sdk.requests.ErrorResponse
+import java.io.IOException
+import java.math.BigDecimal
+
+class StellarNetworkManager(isTestNet: Boolean) {
+
+    val network: Network = if (isTestNet) Network.TESTNET else Network.PUBLIC
+    private val stellarServer by lazy {
+        Server(if (isTestNet) API_STELLAR_TESTNET else API_STELLAR)
+    }
+
+    suspend fun sendTransaction(transaction: String): SimpleResult {
+        return try {
+            val response = stellarServer.submitTransaction(Transaction.fromEnvelopeXdr(transaction, network))
+            if (response.isSuccess) {
+                SimpleResult.Success
+            } else {
+                val trResult: String? = response.extras?.resultCodes?.transactionResultCode +
+                        (response.extras?.resultCodes?.operationsResultCodes?.getOrNull(0) ?: "")
+                SimpleResult.Failure(Exception(trResult ?: "transaction failed"))
+            }
+        } catch (error: Exception) {
+            SimpleResult.Failure(error)
+        }
+    }
+
+    suspend fun checkIsAccountCreated(address: String): Boolean {
+        try {
+            stellarServer.accounts().account(address)
+            return true
+        } catch (errorResponse: ErrorResponse) {
+            if (errorResponse.code == 404) return false
+            return false
+        } catch (exception: IOException) {
+            return false
+        }
+    }
+
+    suspend fun getInfo(accountId: String, assetCode: String? = null): Result<StellarResponse> {
+        return try {
+            coroutineScope {
+                val accountResponseDefered = async(Dispatchers.IO) { stellarServer.accounts().account(accountId) }
+                val ledgerResponseDeferred = async(Dispatchers.IO) {
+                    val latestLedger: Int = stellarServer.root().coreLatestLedger
+                    stellarServer.ledgers().ledger(latestLedger.toLong())
+                }
+
+                val accountResponse = accountResponseDefered.await()
+                val balance = accountResponse.balances
+                        .find { it.assetType == "native" }
+                        ?.balance?.toBigDecimal()
+                        ?: return@coroutineScope Result.Failure(Exception("Stellar Balance not found"))
+                val assetBalance = if (assetCode == null) {
+                    null
+                } else {
+                    accountResponse.balances
+                            .find { it.assetType != "native" && it.assetCode == assetCode }
+                            ?.balance?.toBigDecimal()
+                            ?: return@coroutineScope Result.Failure(Exception("Stellar Balance not found"))
+                }
+                val sequence = accountResponse.sequenceNumber
+
+                val ledgerResponse = ledgerResponseDeferred.await()
+                val baseFee = ledgerResponse.baseFeeInStroops.toBigDecimal().divide(STROOPS_IN_XLM)
+                val baseReserve = ledgerResponse.baseReserveInStroops.toBigDecimal().divide(STROOPS_IN_XLM)
+
+                Result.Success(StellarResponse(
+                        baseFee,
+                        baseReserve,
+                        assetBalance,
+                        balance,
+                        sequence
+                ))
+            }
+        } catch (error: Exception) {
+            Result.Failure(error)
+        }
+    }
+}
+
+data class StellarResponse(
+        val baseFee: BigDecimal,
+        val baseReserve: BigDecimal,
+        val assetBalance: BigDecimal?,
+        val balance: BigDecimal,
+        val sequence: Long
+)

blockchain/src/main/java/com/tangem/blockchain/stellar/StellarTransactionBuilder.kt

@@ -0,0 +1,84 @@
+package com.tangem.blockchain.stellar
+
+import com.tangem.blockchain.common.AmountType
+import com.tangem.blockchain.common.TransactionData
+import com.tangem.blockchain.stellar.StellarWalletManager.Companion.BASE_FEE
+import com.tangem.blockchain.stellar.StellarWalletManager.Companion.STROOPS_IN_XLM
+import com.tangem.common.extensions.hexToBytes
+import org.stellar.sdk.*
+import org.stellar.sdk.xdr.AccountID
+import org.stellar.sdk.xdr.DecoratedSignature
+import org.stellar.sdk.xdr.Signature
+import org.stellar.sdk.xdr.SignatureHint
+import java.util.*
+
+class StellarTransactionBuilder(private val newtorkManager: StellarNetworkManager, private val publicKey: ByteArray) {
+
+    private lateinit var transaction: Transaction
+
+    suspend fun buildToSign(transactionData: TransactionData, sequence: Long, fee: Int): List<ByteArray> {
+
+        val destinationKeyPair = KeyPair.fromAccountId(transactionData.destinationAddress)
+        val sourceKeyPair = KeyPair.fromAccountId(transactionData.sourceAddress)
+
+        if (transactionData.amount.type == AmountType.Coin) {
+            val operation = if (newtorkManager.checkIsAccountCreated(transactionData.sourceAddress)) {
+                PaymentOperation.Builder(destinationKeyPair.accountId,
+                        AssetTypeNative(),
+                        transactionData.amount.value.toString())
+                        .build()
+            } else {
+                CreateAccountOperation.Builder(destinationKeyPair.accountId, transactionData.amount.value.toString()).build()
+            }
+            return serializeOperation(operation, sourceKeyPair, sequence, fee)
+
+        } else if (transactionData.amount.type == AmountType.Token) {
+            val keyPair = KeyPair.fromAccountId(transactionData.amount.address)
+            val asset = Asset.createNonNativeAsset(transactionData.amount.currencySymbol, keyPair.accountId)
+            val operation: Operation = if (transactionData.amount.value != null) {
+                PaymentOperation.Builder(
+                        destinationKeyPair.accountId,
+                        asset,
+                        transactionData.amount.value!!.toPlainString())
+                        .build()
+            } else {
+                ChangeTrustOperation.Builder(asset, "900000000000.0000000")
+                        .setSourceAccount(sourceKeyPair.accountId)
+                        .build()
+            }
+            return serializeOperation(operation, sourceKeyPair, sequence, fee)
+        } else {
+            return emptyList()
+        }
+    }
+
+    private fun serializeOperation(
+            operation: Operation, sourceKeyPair: KeyPair,
+            sequence: Long, fee: Int
+    ): List<ByteArray> {
+
+        val accountID = AccountID()
+        accountID.accountID = sourceKeyPair.xdrPublicKey
+        val currentTime = Calendar.getInstance().timeInMillis / 1000
+        val minTime = 0L
+        val maxTime = currentTime + 120
+
+        transaction = Transaction.Builder(
+                Account(sourceKeyPair.accountId, sequence), newtorkManager.network)
+                .addOperation(operation)
+                .addTimeBounds(TimeBounds(minTime, maxTime))
+                .setOperationFee(fee)
+                .build()
+        return listOf<ByteArray>(transaction.hash())
+    }
+
+    fun buildToSend(signature: ByteArray): String {
+        val hint = publicKey.takeLast(4).toByteArray()
+        val decoratedSignature = DecoratedSignature().apply {
+            this.hint = SignatureHint().apply { signatureHint = hint }
+            this.signature = Signature().apply { this.signature = signature }
+        }
+        transaction.signatures.add(decoratedSignature)
+        return transaction.toEnvelopeXdrBase64()
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/stellar/StellarWalletManager.kt

@@ -0,0 +1,95 @@
+package com.tangem.blockchain.stellar
+
+import com.tangem.blockchain.common.*
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.wallets.CurrencyWallet
+import com.tangem.tasks.TaskEvent
+import java.math.BigDecimal
+import java.util.*
+
+class StellarWalletManager(
+        private val cardId: String,
+        walletPublicKey: ByteArray,
+        walletConfig: WalletConfig,
+        token: Token? = null,
+        isTestNet: Boolean = false
+) : WalletManager,
+        TransactionSender,
+        FeeProvider {
+
+    override val blockchain: Blockchain = Blockchain.Stellar
+    private val address = blockchain.makeAddress(walletPublicKey)
+    private val currencyWallet = CurrencyWallet(walletConfig, address)
+    override var wallet: Wallet = currencyWallet
+    private val networkManager = StellarNetworkManager(isTestNet)
+    private val builder = StellarTransactionBuilder(networkManager, walletPublicKey)
+    private var baseFee = BASE_FEE
+    private var baseReserve = BASE_RESERVE
+    private var sequence = 0L
+
+    init {
+        if (token != null) currencyWallet.balances[AmountType.Token] =
+                Amount(
+                        token.symbol,
+                        null,
+                        token.contractAddress,
+                        token.decimals,
+                        AmountType.Token)
+    }
+
+    override suspend fun update() {
+        val result = networkManager.getInfo(address, currencyWallet.balances[AmountType.Token]?.address)
+        when (result) {
+            is Result.Failure -> updateError(result.error)
+            is Result.Success -> updateWallet(result.data)
+        }
+    }
+
+    private fun updateWallet(data: StellarResponse) {
+        currencyWallet.balances[AmountType.Coin]?.value = data.balance
+        currencyWallet.balances[AmountType.Token]?.value = data.assetBalance
+        currencyWallet.balances[AmountType.Reserve]?.value = data.baseReserve
+        sequence = data.sequence
+        baseFee = data.baseFee
+        baseReserve = data.baseReserve
+
+        val currentTime = Calendar.getInstance().timeInMillis
+        currencyWallet.pendingTransactions.forEach { transaction ->
+            if (transaction.date?.timeInMillis ?: 0 - currentTime > 10) {
+                transaction.status = TransactionStatus.Confirmed
+            }
+        }
+    }
+
+    private fun updateError(error: Throwable?) {
+
+    }
+
+    override suspend fun send(transactionData: TransactionData, signer: TransactionSigner): SimpleResult {
+        val hashes = builder.buildToSign(transactionData, sequence, baseFee.toStroops())
+        when (val signerResponse = signer.sign(hashes.toTypedArray(), cardId)) {
+            is TaskEvent.Event -> {
+                val transactionToSend = builder.buildToSend(signerResponse.data.signature)
+                return networkManager.sendTransaction(transactionToSend)
+            }
+            is TaskEvent.Completion -> return SimpleResult.Failure(signerResponse.error)
+        }
+    }
+
+    override suspend fun getFee(amount: Amount, source: String, destination: String): Result<List<Amount>> {
+        return Result.Success(listOf(
+                Amount(baseFee, blockchain)
+        ))
+    }
+
+    private fun BigDecimal.toStroops(): Int {
+        return this.multiply(STROOPS_IN_XLM).toInt()
+    }
+
+    companion object {
+        val STROOPS_IN_XLM = 10000000.toBigDecimal()
+        val BASE_FEE = 0.00001.toBigDecimal()
+        val BASE_RESERVE = 0.5.toBigDecimal()
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/wallets/CurrencyWallet.kt

@@ -0,0 +1,20 @@
+package com.tangem.blockchain.wallets
+
+import com.tangem.blockchain.common.*
+import java.util.*
+
+class CurrencyWallet(
+        override val config: WalletConfig,
+        override val address: String,
+        override val exploreUrl: String? = null,
+        override val shareUrl: String? = null,
+        val pendingTransactions: MutableList<TransactionData> = mutableListOf(),
+        val balances: MutableMap<AmountType, Amount> = mutableMapOf(),
+        val isTestnet: Boolean = false
+) : Wallet, TransactionValidator {
+
+
+    override fun validateTransaction(amount: Amount, fee: Amount?): EnumSet<ValidationError> {
+        TODO("not implemented")
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/xrp/XrpAddress.kt

@@ -0,0 +1,38 @@
+package com.tangem.blockchain.xrp
+
+import com.ripple.encodings.addresses.Addresses
+import com.tangem.common.extensions.calculateRipemd160
+import com.tangem.common.extensions.calculateSha256
+import com.tangem.common.extensions.toCompressedPublicKey
+
+class XrpAddressFactory {
+    companion object {
+        fun makeAddress(walletPublicKey: ByteArray): String {
+            val canonicalPublicKey = canonizePublicKey(walletPublicKey)
+            val publicKeyHash = canonicalPublicKey.calculateSha256().calculateRipemd160()
+            return Addresses.encodeAccountID(publicKeyHash)
+        }
+
+        fun canonizePublicKey(publicKey: ByteArray): ByteArray {
+            val compressedPublicKey = publicKey.toCompressedPublicKey()
+            return if (compressedPublicKey.size == 32) {
+                byteArrayOf(0xED.toByte()) + compressedPublicKey
+            } else {
+                compressedPublicKey
+            }
+        }
+    }
+}
+
+class XrpAddressValidator {
+    companion object {
+        fun validate(address: String): Boolean {
+            return try {
+                Addresses.decodeAccountID(address)
+                address.startsWith("r")
+            } catch (excpetion: Exception) {
+                false
+            }
+        }
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/xrp/XrpTransactionBuilder.kt

@@ -0,0 +1,54 @@
+package com.tangem.blockchain.xrp
+
+import com.ripple.core.coretypes.AccountID
+import com.ripple.core.coretypes.Amount
+import com.ripple.core.coretypes.uint.UInt32
+import com.ripple.crypto.ecdsa.ECDSASignature
+import com.ripple.utils.HashUtils
+import com.tangem.blockchain.common.TransactionData
+import com.tangem.blockchain.common.extensions.bigIntegerValue
+import com.tangem.blockchain.xrp.override.XrpPayment
+import com.tangem.blockchain.xrp.override.XrpSignedTransaction
+import org.bitcoinj.core.ECKey
+import java.math.BigInteger
+
+class XrpTransactionBuilder(walletPublicKey: ByteArray) {
+    private val canonicalPublicKey = XrpAddressFactory.canonizePublicKey(walletPublicKey)
+    var sequence: Long? = null
+    private var transaction: XrpSignedTransaction? = null
+
+    fun buildToSign(transactionData: TransactionData): ByteArray {
+        val payment = XrpPayment()
+        payment.putTranslated(AccountID.Account, transactionData.sourceAddress)
+        payment.putTranslated(AccountID.Destination, transactionData.destinationAddress)
+        payment.putTranslated(Amount.Amount, transactionData.amount.bigIntegerValue().toString())
+        payment.putTranslated(UInt32.Sequence, sequence)
+        payment.putTranslated(Amount.Fee, transactionData.fee!!.bigIntegerValue().toString())
+
+        transaction = payment.prepare(canonicalPublicKey)
+
+        return if (canonicalPublicKey[0] == 0xED.toByte()) {
+            transaction!!.signingData
+        } else {
+            HashUtils.halfSha512(transaction!!.signingData)
+        }
+    }
+
+    fun buildToSend(signature: ByteArray): String {
+        if (canonicalPublicKey[0] == 0xED.toByte()) {
+            transaction!!.addSign(signature)
+        } else {
+            val derSignature = encodeDerSignature(signature)
+            transaction!!.addSign(derSignature)
+        }
+        return transaction!!.tx_blob
+    }
+
+    private fun encodeDerSignature(signature: ByteArray): ByteArray {
+        val r = BigInteger(1, signature.copyOfRange(0, 32))
+        val s = BigInteger(1, signature.copyOfRange(32, 64))
+        val canonicalS = ECKey.ECDSASignature(r, s).toCanonicalised().s
+        val ecdsaSignature = ECDSASignature(r, canonicalS)
+        return ecdsaSignature.encodeToDER()
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/xrp/XrpWalletManager.kt

@@ -0,0 +1,86 @@
+package com.tangem.blockchain.xrp
+
+import android.util.Log
+import com.tangem.blockchain.common.*
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.wallets.CurrencyWallet
+import com.tangem.blockchain.xrp.network.XrpInfoResponse
+import com.tangem.blockchain.xrp.network.XrpNetworkManager
+import com.tangem.tasks.TaskEvent
+
+class XrpWalletManager(
+        private val cardId: String,
+        private val walletPublicKey: ByteArray,
+        walletConfig: WalletConfig
+) : WalletManager,
+        TransactionSender,
+        FeeProvider {
+
+    override val blockchain = Blockchain.XRP
+    private val address = blockchain.makeAddress(walletPublicKey)
+    private val currencyWallet = CurrencyWallet(walletConfig, address)
+    override var wallet: Wallet = currencyWallet
+    private val transactionBuilder = XrpTransactionBuilder(walletPublicKey)
+    private val networkManager = XrpNetworkManager()
+
+    override suspend fun update() {
+        val result = networkManager.getInfo(address)
+        when (result) {
+            is Result.Success -> updateWallet(result.data)
+            is Result.Failure -> updateError(result.error)
+        }
+    }
+
+    private fun updateWallet(response: XrpInfoResponse) {
+        Log.d(this::class.java.simpleName, "Balance is ${response.balance}")
+        currencyWallet.balances[AmountType.Reserve]?.value = response.reserveBase
+
+        if (!response.accountFound) {
+            updateError(Exception("Account not found")) //TODO rework, add reserve
+            return
+        }
+        currencyWallet.balances[AmountType.Coin]?.value = response.balance - response.reserveBase
+        transactionBuilder.sequence = response.sequence
+
+        if (response.hasUnconfirmed) {
+            if (currencyWallet.pendingTransactions.isEmpty()) {
+                currencyWallet.pendingTransactions.add(TransactionData(
+                        Amount(blockchain.currency, decimals = blockchain.decimals),
+                        null,
+                        "unknown",
+                        currencyWallet.address))
+            }
+        } else {
+            currencyWallet.pendingTransactions.clear()
+        }
+    }
+
+    private fun updateError(error: Throwable?) {
+        Log.e(this::class.java.simpleName, error?.message ?: "")
+    }
+
+    override suspend fun send(transactionData: TransactionData, signer: TransactionSigner): SimpleResult {
+        val transactionHash = transactionBuilder.buildToSign(transactionData)
+
+        when (val signerResponse = signer.sign(arrayOf(transactionHash), cardId)) {
+            is TaskEvent.Event -> {
+                val transactionToSend = transactionBuilder.buildToSend(signerResponse.data.signature)
+                return networkManager.sendTransaction(transactionToSend)
+            }
+            is TaskEvent.Completion -> return SimpleResult.Failure(signerResponse.error)
+        }
+    }
+
+    override suspend fun getFee(amount: Amount, source: String, destination: String): Result<List<Amount>> {
+        val result = networkManager.getFee()
+        when (result) {
+            is Result.Failure -> return result
+            is Result.Success -> return Result.Success(listOf(
+                    Amount(result.data.minimalFee, blockchain),
+                    Amount(result.data.normalFee, blockchain),
+                    Amount(result.data.priorityFee, blockchain)
+            ))
+        }
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/xrp/network/XrpNetworkManager.kt

@@ -0,0 +1,92 @@
+package com.tangem.blockchain.xrp.network
+
+import com.tangem.blockchain.bitcoin.network.BitcoinFee
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.network.API_RIPPLED
+import com.tangem.blockchain.common.network.API_RIPPLED_RESERVE
+import com.tangem.blockchain.common.network.createRetrofitInstance
+import com.tangem.blockchain.xrp.network.rippled.RippledApi
+import com.tangem.blockchain.xrp.network.rippled.RippledProvider
+import retrofit2.HttpException
+import java.io.IOException
+import java.math.BigDecimal
+
+class XrpNetworkManager {
+    private val rippledProvider by lazy {
+        val api = createRetrofitInstance(API_RIPPLED)
+                .create(RippledApi::class.java)
+        RippledProvider(api)
+    }
+
+    private val rippledReserveProvider by lazy {
+        val api = createRetrofitInstance(API_RIPPLED_RESERVE)
+                .create(RippledApi::class.java)
+        RippledProvider(api)
+    }
+
+    var provider = rippledProvider
+
+    private fun changeProvider() {
+        provider = if (provider == rippledProvider) rippledReserveProvider else rippledProvider
+    }
+
+    suspend fun getInfo(address: String): Result<XrpInfoResponse> {
+        val result = provider.getInfo(address)
+        when (result) {
+            is Result.Success -> return result
+            is Result.Failure -> {
+                if (result.error is IOException || result.error is HttpException) {
+                    changeProvider()
+                    return provider.getInfo(address)
+                } else {
+                    return result
+                }
+            }
+        }
+    }
+
+    suspend fun sendTransaction(transaction: String): SimpleResult {
+        val result = provider.sendTransaction(transaction)
+        when (result) {
+            is SimpleResult.Success -> return result
+            is SimpleResult.Failure -> {
+                if (result.error is IOException || result.error is HttpException) {
+                    changeProvider()
+                    return provider.sendTransaction(transaction)
+                } else {
+                    return result
+                }
+            }
+        }
+    }
+
+    suspend fun getFee(): Result<XrpFeeResponse> {
+        val result = provider.getFee()
+        when (result) {
+            is Result.Success -> return result
+            is Result.Failure -> {
+                if (result.error is IOException || result.error is HttpException) {
+                    changeProvider()
+                    return provider.getFee()
+                } else {
+                    return result
+                }
+            }
+        }
+    }
+}
+
+data class XrpInfoResponse(
+        val balance: BigDecimal = BigDecimal.ZERO,
+        val sequence: Long = 0,
+        val hasUnconfirmed: Boolean = false,
+        val reserveBase: BigDecimal,
+        val accountFound: Boolean = true
+)
+
+data class XrpFeeResponse(
+        val minimalFee: BigDecimal,
+        val normalFee: BigDecimal,
+        val priorityFee: BigDecimal
+)

blockchain/src/main/java/com/tangem/blockchain/xrp/network/rippled/RippledApi.kt

@@ -0,0 +1,38 @@
+package com.tangem.blockchain.xrp.network.rippled
+
+import retrofit2.http.Body
+import retrofit2.http.Headers
+import retrofit2.http.POST
+
+interface RippledApi {
+    @Headers("Content-Type: application/json")
+    @POST("./")
+    suspend fun getAccount(@Body rippledBody: RippledBody): RippledAccountResponse
+
+    @Headers("Content-Type: application/json")
+    @POST("./")
+    suspend fun getServerState(@Body rippledBody: RippledBody = serverStateBody): RippledStateResponse
+
+    @Headers("Content-Type: application/json")
+    @POST("./")
+    suspend fun getFee(@Body rippledBody: RippledBody = feeBody): RippledFeeResponse
+
+    @Headers("Content-Type: application/json")
+    @POST("./")
+    suspend fun submitTransaction(@Body rippledBody: RippledBody): RippledSubmitResponse
+}
+
+enum class RippledMethod(val value: String) {
+    ACCOUNT_INFO("account_info"),
+    SERVER_STATE("server_state"),
+    FEE("fee"),
+    SUBMIT("submit")
+}
+
+data class RippledBody(
+        val method: String,
+        val params: HashMap<String, String> = HashMap() //TODO =null?
+)
+
+val serverStateBody = RippledBody(RippledMethod.SERVER_STATE.value)
+val feeBody = RippledBody(RippledMethod.FEE.value)

blockchain/src/main/java/com/tangem/blockchain/xrp/network/rippled/RippledProvider.kt

@@ -0,0 +1,101 @@
+package com.tangem.blockchain.xrp.network.rippled
+
+import com.tangem.blockchain.common.Blockchain
+import com.tangem.blockchain.common.extensions.Result
+import com.tangem.blockchain.common.extensions.SimpleResult
+import com.tangem.blockchain.common.extensions.retryIO
+import com.tangem.blockchain.xrp.network.XrpFeeResponse
+import com.tangem.blockchain.xrp.network.XrpInfoResponse
+import kotlinx.coroutines.async
+import kotlinx.coroutines.coroutineScope
+import java.math.BigDecimal
+
+class RippledProvider(private val api: RippledApi) {
+    private val decimals = Blockchain.XRP.decimals.toInt()
+
+    suspend fun getInfo(address: String): Result<XrpInfoResponse> {
+        return try {
+            coroutineScope {
+                val accountBody = makeAccountBody(address, validated = true)
+                val accountDeferred = retryIO { async { api.getAccount(accountBody) } }
+
+                val unconfirmedBody = makeAccountBody(address, validated = false)
+                val unconfirmedDeferred = retryIO { async { api.getAccount(unconfirmedBody) } }
+
+                val stateDeferred = retryIO { async { api.getServerState() } }
+
+                val accountData = accountDeferred.await()
+                val unconfirmedData = unconfirmedDeferred.await()
+                val serverState = stateDeferred.await()
+
+                val reserveBase = serverState.result!!.state!!.validatedLedger!!.reserveBase!!
+                        .toBigDecimal().movePointLeft(decimals)
+
+                if (accountData.result!!.errorCode == 19) {
+                    Result.Success(XrpInfoResponse(
+                            reserveBase = reserveBase,
+                            accountFound = false
+                    ))
+                } else {
+                    val confirmedBalance =
+                            accountData.result!!.accountData!!.balance!!.toBigDecimal()
+                                    .movePointLeft(decimals)
+                    val unconfirmedBalance =
+                            unconfirmedData.result!!.accountData!!.balance!!.toBigDecimal()
+                                    .movePointLeft(decimals)
+
+                    Result.Success(XrpInfoResponse(
+                            balance = confirmedBalance,
+                            sequence = accountData.result!!.accountData!!.sequence!!,
+                            hasUnconfirmed = confirmedBalance != unconfirmedBalance,
+                            reserveBase = reserveBase
+                    ))
+                }
+
+            }
+        } catch (exception: Exception) {
+            Result.Failure(exception)
+        }
+    }
+
+    suspend fun getFee(): Result<XrpFeeResponse> {
+        return try {
+            val feeData = retryIO { api.getFee() }
+            Result.Success(XrpFeeResponse(
+                    feeData.result!!.feeData!!.minimalFee!!.toBigDecimal().movePointLeft(decimals),
+                    feeData.result!!.feeData!!.normalFee!!.toBigDecimal().movePointLeft(decimals),
+                    feeData.result!!.feeData!!.priorityFee!!.toBigDecimal().movePointLeft(decimals)
+            ))
+        } catch (exception: Exception) {
+            Result.Failure(exception)
+        }
+    }
+
+    suspend fun sendTransaction(transaction: String): SimpleResult {
+        return try {
+            val submitBody = makeSubmitBody(transaction)
+            val submitData = retryIO { api.submitTransaction(submitBody) }
+            if (submitData.result!!.resultCode == 0) {
+                SimpleResult.Success
+            } else {
+                SimpleResult.Failure(Exception(submitData.result!!.resultMessage
+                        ?: submitData.result!!.errorException))
+            }
+        } catch (exception: Exception) {
+            SimpleResult.Failure(exception)
+        }
+    }
+}
+
+private fun makeAccountBody(address: String, validated: Boolean): RippledBody {
+    val params = HashMap<String, String>()
+    params["account"] = address
+    params["ledger_index"] = if (validated) "validated" else "current"
+    return RippledBody(RippledMethod.ACCOUNT_INFO.value, params)
+}
+
+private fun makeSubmitBody(transaction: String): RippledBody {
+    val params = HashMap<String, String>()
+    params["tx_blob"] = transaction
+    return RippledBody(RippledMethod.SUBMIT.value, params)
+}

blockchain/src/main/java/com/tangem/blockchain/xrp/network/rippled/RippledResponse.kt

@@ -0,0 +1,103 @@
+package com.tangem.blockchain.xrp.network.rippled
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+// Rippled account
+@JsonClass(generateAdapter = true)
+data class RippledAccountResponse(
+        @Json(name = "result")
+        var result: RippledAccountResult? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class RippledAccountResult(
+        @Json(name = "account_data")
+        var accountData: RippledAccountData? = null,
+
+        @Json(name = "error_code")
+        var errorCode: Int? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class RippledAccountData(
+        @Json(name = "Balance")
+        var balance: String? = null,
+
+        @Json(name = "Sequence")
+        var sequence: Long? = null
+)
+
+// Rippled state
+@JsonClass(generateAdapter = true)
+data class RippledStateResponse(
+        @Json(name = "result")
+        var result: RippledStateResult? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class RippledStateResult(
+        @Json(name = "state")
+        var state: RippledState? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class RippledState(
+        @Json(name = "validated_ledger")
+        var validatedLedger: RippledLedger? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class RippledLedger(
+        @Json(name = "reserve_base")
+        var reserveBase: Long? = null
+)
+
+// Rippled fee
+@JsonClass(generateAdapter = true)
+data class RippledFeeResponse(
+        @Json(name = "result")
+        var result: RippledFeeResult? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class RippledFeeResult(
+        @Json(name = "drops")
+        var feeData: RippledFeeData? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class RippledFeeData(
+        //enough to put tx to queue
+        @Json(name = "minimum_fee")
+        var minimalFee: String? = null,
+
+        //enough to put tx to current ledger
+        @Json(name = "open_ledger_fee")
+        var normalFee: String? = null,
+
+        @Json(name = "median_fee")
+        var priorityFee: String? = null
+)
+
+// Rippled submit
+@JsonClass(generateAdapter = true)
+data class RippledSubmitResponse(
+        @Json(name = "result")
+        var result: RippledSubmitResult? = null
+)
+
+@JsonClass(generateAdapter = true)
+data class RippledSubmitResult(
+        @Json(name = "engine_result_code")
+        var resultCode: Int? = null,
+
+        @Json(name = "engine_result_message")
+        var resultMessage: String? = null,
+
+        @Json(name = "error")
+        var error: String? = null,
+
+        @Json(name = "error_exception")
+        var errorException: String? = null
+)

blockchain/src/main/java/com/tangem/blockchain/xrp/override/XrpBase58.java

@@ -0,0 +1,111 @@
+package com.tangem.blockchain.xrp.override;
+
+import java.math.BigInteger;
+
+public class XrpBase58 {
+    private static final char[] BASE58 = "rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ2bcdeCg65jkm8oFqi1tuvAxyz".toCharArray();
+
+    private static final int BASE58_CHUNK_DIGITS = 10;//how many base 58 digits fits in long
+    private static final BigInteger BASE58_CHUNK_MOD = BigInteger.valueOf(0x5fa8624c7fba400L); //58^BASE58_CHUNK_DIGITS
+    private static final byte[] BASE58_VALUES = new byte[]{-1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -2, -2, -2, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, -1, -1, -1, -1, -1, -1,
+            -1, 9, 10, 11, 12, 13, 14, 15, 16, -1, 17, 18, 19, 20, 21, -1,
+            22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, -1, -1, -1, -1, -1,
+            -1, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, -1, 44, 45, 46,
+            47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1};
+
+    public static byte[] decodeBase58(String input) {
+        if (input == null) {
+            return null;
+        }
+        input = input.trim();
+        if (input.length() == 0) {
+            return new byte[0];
+        }
+        BigInteger resultNum = BigInteger.ZERO;
+        int nLeadingZeros = 0;
+        while (nLeadingZeros < input.length() && input.charAt(nLeadingZeros) == BASE58[0]) {
+            nLeadingZeros++;
+        }
+        long acc = 0;
+        int nDigits = 0;
+        int p = nLeadingZeros;
+        while (p < input.length()) {
+            int v = BASE58_VALUES[input.charAt(p) & 0xff];
+            if (v >= 0) {
+                acc *= 58;
+                acc += v;
+                nDigits++;
+                if (nDigits == BASE58_CHUNK_DIGITS) {
+                    resultNum = resultNum.multiply(BASE58_CHUNK_MOD).add(BigInteger.valueOf(acc));
+                    acc = 0;
+                    nDigits = 0;
+                }
+                p++;
+            } else {
+                break;
+            }
+        }
+        if (nDigits > 0) {
+            long mul = 58;
+            while (--nDigits > 0) {
+                mul *= 58;
+            }
+            resultNum = resultNum.multiply(BigInteger.valueOf(mul)).add(BigInteger.valueOf(acc));
+        }
+        final int BASE58_SPACE = -2;
+        while (p < input.length() && BASE58_VALUES[input.charAt(p) & 0xff] == BASE58_SPACE) {
+            p++;
+        }
+        if (p < input.length()) {
+            return null;
+        }
+        byte[] plainNumber = resultNum.toByteArray();
+        int plainNumbersOffs = plainNumber[0] == 0 ? 1 : 0;
+        byte[] result = new byte[nLeadingZeros + plainNumber.length - plainNumbersOffs];
+        System.arraycopy(plainNumber, plainNumbersOffs, result, nLeadingZeros, plainNumber.length - plainNumbersOffs);
+        return result;
+    }
+
+    public static String encodeBase58(byte[] input) {
+        if (input == null) {
+            return null;
+        }
+        StringBuilder str = new StringBuilder((input.length * 350) / 256 + 1);
+        BigInteger bn = new BigInteger(1, input);
+        long rem;
+        while (true) {
+            BigInteger[] divideAndRemainder = bn.divideAndRemainder(BASE58_CHUNK_MOD);
+            bn = divideAndRemainder[0];
+            rem = divideAndRemainder[1].longValue();
+            if (bn.compareTo(BigInteger.ZERO) == 0) {
+                break;
+            }
+            for (int i = 0; i < BASE58_CHUNK_DIGITS; i++) {
+                str.append(BASE58[(int) (rem % 58)]);
+                rem /= 58;
+            }
+        }
+        while (rem != 0) {
+            str.append(BASE58[(int) (rem % 58)]);
+            rem /= 58;
+        }
+        str.reverse();
+        int nLeadingZeros = 0;
+        while (nLeadingZeros < input.length && input[nLeadingZeros] == 0) {
+            str.insert(0, BASE58[0]);
+            nLeadingZeros++;
+        }
+        return str.toString();
+    }
+}

blockchain/src/main/java/com/tangem/blockchain/xrp/override/XrpPayment.java

@@ -0,0 +1,18 @@
+package com.tangem.blockchain.xrp.override;
+
+
+import com.ripple.core.types.known.tx.txns.Payment;
+
+public class XrpPayment extends Payment {
+
+    public XrpPayment() {
+        super();
+    }
+
+    public XrpSignedTransaction prepare(byte[] pubKeyBytes) {
+        XrpSignedTransaction tx = XrpSignedTransaction.fromTx(this);
+        tx.prepare(pubKeyBytes);
+        return tx;
+    }
+
+}

blockchain/src/main/java/com/tangem/blockchain/xrp/override/XrpSignedTransaction.java

@@ -0,0 +1,81 @@
+package com.tangem.blockchain.xrp.override;
+
+import com.ripple.core.coretypes.Amount;
+import com.ripple.core.coretypes.Blob;
+import com.ripple.core.coretypes.STObject;
+import com.ripple.core.coretypes.hash.HalfSha512;
+import com.ripple.core.coretypes.hash.prefixes.HashPrefix;
+import com.ripple.core.coretypes.uint.UInt32;
+import com.ripple.core.serialized.BytesList;
+import com.ripple.core.serialized.MultiSink;
+import com.ripple.core.types.known.tx.Transaction;
+import com.ripple.core.types.known.tx.signed.SignedTransaction;
+
+import java.util.Arrays;
+
+public class XrpSignedTransaction extends SignedTransaction {
+    private XrpSignedTransaction(Transaction of) {
+        txn = (Transaction) STObject.fromBytes(of.toBytes());
+    }
+
+    protected XrpSignedTransaction() {
+    }
+
+    public static XrpSignedTransaction fromTx(Transaction tx) {
+        return new XrpSignedTransaction(tx);
+    }
+
+    public void prepare(byte[] pubKeyBytes) {
+        prepare(pubKeyBytes, null, null, null);
+    }
+
+    public void prepare(byte[] pubKeyBytes,
+                        Amount fee,
+                        UInt32 Sequence,
+                        UInt32 lastLedgerSequence) {
+
+        Blob pubKey = new Blob(pubKeyBytes);
+
+        // This won't always be specified
+        if (lastLedgerSequence != null) {
+            txn.put(UInt32.LastLedgerSequence, lastLedgerSequence);
+        }
+        if (Sequence != null) {
+            txn.put(UInt32.Sequence, Sequence);
+        }
+        if (fee != null) {
+            txn.put(Amount.Fee, fee);
+        }
+
+        txn.signingPubKey(pubKey);
+
+        if (Transaction.CANONICAL_FLAG_DEPLOYED) {
+            txn.setCanonicalSignatureFlag();
+        }
+
+        txn.checkFormat();
+        signingData = txn.signingData();
+        if (previousSigningData != null && Arrays.equals(signingData, previousSigningData)) {
+            return;
+        }
+    }
+
+    public void addSign(byte[] signature) {
+        try {
+            txn.txnSignature(new Blob(signature));
+
+            BytesList blob = new BytesList();
+            HalfSha512 id = HalfSha512.prefixed256(HashPrefix.transactionID);
+
+            txn.toBytesSink(new MultiSink(blob, id));
+            tx_blob = blob.bytesHex();
+            hash = id.finish();
+        } catch (Exception e) {
+            // electric paranoia
+            previousSigningData = null;
+            throw new RuntimeException(e);
+        } /*else {*/
+        previousSigningData = signingData;
+        // }
+    }
+}

blockchain/src/main/res/values/strings.xml

@@ -0,0 +1,3 @@
+<resources>
+    <string name="app_name">Blockchain</string>
+</resources>

blockchain/src/test/java/com/tangem/blockchain/bitcoin/BitcoinAddressTest.kt

@@ -0,0 +1,25 @@
+package com.tangem.blockchain.bitcoin
+
+import com.google.common.truth.Truth
+import com.tangem.common.extensions.hexToBytes
+import org.junit.Test
+import org.junit.jupiter.api.Assertions.*
+
+class BitcoinAddressTest {
+
+    @Test
+    fun makeAddressFromCorrectPublicKey() {
+        val walletPublicKey = "04752A727E14BBA5BD73B6714D72500F61FFD11026AD1196D2E1C54577CBEEAC3D11FC68A64700F8D533F4E311964EA8FB3AA26C588295F2133868D69C3E628693".hexToBytes()
+        val expected = "1D3vYSjCvzrsVVK5bNaPTjU3NxcN7NNXMN"
+
+        Truth.assertThat(BitcoinAddressFactory.makeAddress(walletPublicKey))
+                .isEqualTo(expected)
+    }
+
+    @Test
+    fun validateCorrectAddress() {
+        val address = "1D3vYSjCvzrsVVK5bNaPTjU3NxcN7NNXMN"
+        Truth.assertThat(BitcoinAddressValidator.validate(address))
+                .isTrue()
+    }
+}

blockchain/src/test/java/com/tangem/blockchain/common/WalletManagerFactoryTest.kt

@@ -0,0 +1,71 @@
+package com.tangem.blockchain.common
+
+import com.google.common.truth.Truth
+import com.tangem.common.CardEnvironment
+import com.tangem.blockchain.bitcoin.BitcoinWalletManager
+import com.tangem.blockchain.cardano.CardanoWalletManager
+import com.tangem.blockchain.ethereum.EthereumWalletManager
+import com.tangem.blockchain.stellar.StellarWalletManager
+import com.tangem.blockchain.xrp.XrpWalletManager
+import com.tangem.commands.ReadCommand
+import com.tangem.common.apdu.ResponseApdu
+import com.tangem.common.extensions.hexToBytes
+import org.junit.Test
+
+internal class WalletManagerFactoryTest {
+
+    @Test
+    fun createBitcoinWalletManager() {
+        val data = "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"
+        val responseApdu = ResponseApdu(data.hexToBytes())
+        val card = ReadCommand().deserialize(CardEnvironment(), responseApdu)
+        val walletManager = WalletManagerFactory.makeWalletManager(card!!)
+
+        Truth.assertThat(walletManager)
+                .isInstanceOf(BitcoinWalletManager::class.java)
+    }
+
+    @Test
+    fun createEthereumWalletManager() {
+        val data = "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"
+        val responseApdu = ResponseApdu(data.hexToBytes())
+        val card = ReadCommand().deserialize(CardEnvironment(), responseApdu)
+        val walletManager = WalletManagerFactory.makeWalletManager(card!!)
+
+        Truth.assertThat(walletManager)
+                .isInstanceOf(EthereumWalletManager::class.java)
+    }
+
+    @Test
+    fun createStellarWalletManager() {
+        val data = "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"
+        val responseApdu = ResponseApdu(data.hexToBytes())
+        val card = ReadCommand().deserialize(CardEnvironment(), responseApdu)
+        val walletManager = WalletManagerFactory.makeWalletManager(card!!)
+
+        Truth.assertThat(walletManager)
+                .isInstanceOf(StellarWalletManager::class.java)
+    }
+
+    @Test
+    fun createCardanoWalletManager() {
+        val data = "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"
+        val responseApdu = ResponseApdu(data.hexToBytes())
+        val card = ReadCommand().deserialize(CardEnvironment(), responseApdu)
+        val walletManager = WalletManagerFactory.makeWalletManager(card!!)
+
+        Truth.assertThat(walletManager)
+                .isInstanceOf(CardanoWalletManager::class.java)
+    }
+
+    @Test
+    fun createXrpWalletManager() {
+        val data = "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"
+        val responseApdu = ResponseApdu(data.hexToBytes())
+        val card = ReadCommand().deserialize(CardEnvironment(), responseApdu)
+        val walletManager = WalletManagerFactory.makeWalletManager(card!!)
+
+        Truth.assertThat(walletManager)
+                .isInstanceOf(XrpWalletManager::class.java)
+    }
+}

blockchain/src/test/java/com/tangem/blockchain/ethereum/EthereumAddressTest.kt

@@ -0,0 +1,24 @@
+package com.tangem.blockchain.ethereum
+
+import com.google.common.truth.Truth
+import com.tangem.common.extensions.hexToBytes
+import org.junit.Test
+
+internal class EthereumAddressTest {
+
+    @Test
+    fun makeAddressFromCorrectPublicKey() {
+        val walletPublicKey = "04BAEC8CD3BA50FDFE1E8CF2B04B58E17041245341CD1F1C6B3A496B48956DB4C896A6848BCF8FCFC33B88341507DD25E5F4609386C68086C74CF472B86E5C3820".hexToBytes()
+        val expected = "0xc63763572d45171e4c25ca0818b44e5dd7f5c15b"
+
+        Truth.assertThat(EthereumAddressFactory.makeAddress(walletPublicKey))
+                .isEqualTo(expected)
+    }
+
+    @Test
+    fun validateCorrectAddress() {
+        val address = "0xc63763572d45171e4c25ca0818b44e5dd7f5c15b"
+        Truth.assertThat(EthereumAddressValidator.validate(address))
+                .isTrue()
+    }
+}

blockchain/src/test/java/com/tangem/blockchain/stellar/StellarAddressTest.kt

@@ -0,0 +1,23 @@
+package com.tangem.blockchain.stellar
+
+import com.google.common.truth.Truth
+import com.tangem.common.extensions.hexToBytes
+import org.junit.Test
+
+internal class StellarAddressTest {
+    @Test
+    fun makeAddressFromCorrectPublicKey() {
+        val walletPublicKey = "EC5387D8B38BD9EF80BDBC78D0D7E1C53F08E269436C99D5B3C2DF4B2CE73012".hexToBytes()
+        val expected = "GDWFHB6YWOF5T34AXW6HRUGX4HCT6CHCNFBWZGOVWPBN6SZM44YBFUDZ"
+
+        Truth.assertThat(StellarAddressFactory.makeAddress(walletPublicKey))
+                .isEqualTo(expected)
+    }
+
+    @Test
+    fun validateCorrectAddress() {
+        val address = "GDWFHB6YWOF5T34AXW6HRUGX4HCT6CHCNFBWZGOVWPBN6SZM44YBFUDZ"
+        Truth.assertThat(StellarAddressValidator.validate(address))
+                .isTrue()
+    }
+}

blockchain/src/test/java/com/tangem/blockchain/xrp/XrpAddressTest.kt

@@ -0,0 +1,32 @@
+package com.tangem.blockchain.xrp
+
+import com.google.common.truth.Truth
+import com.tangem.common.extensions.hexToBytes
+import org.junit.Test
+
+internal class XrpAddressTest {
+    @Test
+    fun makeAddressFromCorrectSecpPublicKey() {
+        val walletPublicKey = "04D2B9FB288540D54E5B32ECAF0381CD571F97F6F1ECD036B66BB11AA52FFE9981110D883080E2E255C6B1640586F7765E6FAA325D1340F49B56B83D9DE56BC7ED".hexToBytes()
+        val expected = "rNxCXgKaCMAmowENKnYa5r8Ue78rjgrM6B"
+
+        Truth.assertThat(XrpAddressFactory.makeAddress(walletPublicKey))
+                .isEqualTo(expected)
+    }
+
+    @Test
+    fun makeAddressFromCorrectEdPublicKey() {
+        val walletPublicKey = "12CC4DE73BACF875D7423D152E46C1A665F1718CBE7CA0FEB2BA28C149E11909".hexToBytes()
+        val expected = "rwWMNBs2GtJwfX7YNVV1sUYaPy6DRmDHB4"
+
+        Truth.assertThat(XrpAddressFactory.makeAddress(walletPublicKey))
+                .isEqualTo(expected)
+    }
+
+    @Test
+    fun validateCorrectAddress() {
+        val address = "rwWMNBs2GtJwfX7YNVV1sUYaPy6DRmDHB4"
+        Truth.assertThat(XrpAddressValidator.validate(address))
+                .isTrue()
+    }
+}

build.gradle

@@ -1,15 +1,15 @@
 buildscript {
-    ext.kotlin_version = '1.3.61'
+    apply from: 'dependencies.gradle'
+
     repositories {
         google()
         jcenter()
         maven { url 'https://maven.fabric.io/public' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.3'
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-        classpath 'com.github.dcendents:android-maven-gradle-plugin:2.1'
-        classpath 'io.fabric.tools:gradle:1.31.0'
+        classpath "com.android.tools.build:gradle:$versions.build_gradle"
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$versions.kotlin"
+        classpath "io.fabric.tools:gradle:1.31.0"
     }
 }
 

dependencies.gradle

@@ -0,0 +1,4 @@
+ext.versions = [
+        kotlin      : '1.3.61',
+        build_gradle: '3.6.0',
+]

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Thu Aug 22 12:21:00 MSK 2019
+#Thu Feb 27 13:33:42 AST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip

jitpack.gradle

@@ -0,0 +1,4 @@
+ext.jitpackSdk = [
+        group: 'com.github.Tangem',
+        version  : '0.2.1',
+]

server-android/build.gradle

@@ -1,6 +1,5 @@
 apply plugin: 'com.android.library'
 apply plugin: 'kotlin-android'
-apply plugin: 'com.github.dcendents.android-maven'
 
 group='com.tangem'
 
@@ -41,7 +40,7 @@ dependencies {
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test:runner:1.2.0'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$versions.kotlin"
 }
 repositories {
     mavenCentral()

settings.gradle

@@ -1 +1 @@
-include ':app', ':tangem-sdk-old', ':server-android', ':tangem-card-old', ':tangem-core', ':tangem-sdk', ':tangem-demo'
+include ':app', ':tangem-sdk-old', ':server-android', ':tangem-card-old', ':tangem-core', ':tangem-sdk', ':tangem-demo', ':blockchain'

tangem-card-old/build.gradle

@@ -1,5 +1,4 @@
 apply plugin: 'java-library'
-apply plugin: 'com.github.dcendents.android-maven'
 
 group='com.tangem'
 

tangem-core/build.gradle

@@ -1,31 +1,33 @@
 apply plugin: "kotlin"
 apply plugin: 'org.jetbrains.dokka'
+apply from: '../dependencies.gradle'
+apply from: '../jitpack.gradle'
 
-group = 'com.github.TangemCash'
-version '0.1.0'
+group = "$jitpackSdk.group"
+version "$jitpackSdk.version"
 
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
-    implementation "com.madgag.spongycastle:core:1.56.0.0"
-    implementation "com.madgag.spongycastle:prov:1.56.0.0"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$versions.kotlin"
+    implementation "com.madgag.spongycastle:core:1.58.0.0"
+    implementation "com.madgag.spongycastle:prov:1.58.0.0"
     implementation 'net.i2p.crypto:eddsa:0.3.0'
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.5.2'
     testImplementation "com.google.truth:truth:1.0"
+    implementation "org.jetbrains.kotlin:kotlin-reflect:1.3.61"
 }
 
 sourceCompatibility = "8"
 targetCompatibility = "8"
 
 buildscript {
-    ext.kotlin_version = '1.3.50'
     ext.dokka_version = '0.10.0'
     repositories {
         mavenCentral()
         jcenter()
     }
     dependencies {
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$versions.kotlin"
         classpath "org.jetbrains.dokka:dokka-gradle-plugin:$dokka_version"
     }
 }

tangem-core/src/main/java/com/tangem/CardManager.kt

@@ -1,6 +1,8 @@
 package com.tangem
 
 import com.tangem.commands.*
+import com.tangem.common.CardEnvironment
+import com.tangem.common.TerminalKeysService
 import com.tangem.crypto.CryptoUtils
 import com.tangem.tasks.*
 import java.util.concurrent.Executors
@@ -16,10 +18,12 @@ import java.util.concurrent.Executors
  */
 class CardManager(
         private val reader: CardReader,
-        private val cardManagerDelegate: CardManagerDelegate? = null) {
+        private val cardManagerDelegate: CardManagerDelegate? = null,
+        private val config: Config = Config()
+) {
 
+    private var terminalKeysService: TerminalKeysService? = null
     private var isBusy = false
-    private val cardEnvironmentRepository = mutableMapOf<String, CardEnvironment>()
     private val cardManagerExecutor = Executors.newSingleThreadExecutor()
 
     init {
@@ -67,12 +71,13 @@ class CardManager(
              callback: (result: TaskEvent<SignResponse>) -> Unit) {
         val signCommand: SignCommand
         try {
-            signCommand = SignCommand(hashes, cardId)
+            signCommand = SignCommand(hashes)
         } catch (error: Exception) {
             if (error is TaskError) {
                 callback(TaskEvent.Completion(error))
             } else {
-                callback(TaskEvent.Completion(TaskError.GenericError(error.message)))
+                Log.e(this::class.simpleName!!, error.message ?: "")
+                callback(TaskEvent.Completion(TaskError.UnknownError()))
             }
             return
         }
@@ -91,8 +96,23 @@ class CardManager(
      */
     fun readIssuerData(cardId: String,
                        callback: (result: TaskEvent<ReadIssuerDataResponse>) -> Unit) {
-        val getIssuerDataCommand = ReadIssuerDataCommand(cardId)
-        val task = SingleCommandTask(getIssuerDataCommand)
+        val task = ReadIssuerDataTask(config.issuerPublicKey)
+        runTask(task, cardId, callback)
+    }
+
+    /**
+     * This task retrieves Issuer Extra Data field and its issuer’s signature.
+     * Issuer Extra Data is never changed or parsed from within the Tangem COS. The issuer defines purpose of use,
+     * format and payload of Issuer Data. . For example, this field may contain photo or
+     * biometric information for ID card product. Because of the large size of Issuer_Extra_Data,
+     * a series of these commands have to be executed to read the entire Issuer_Extra_Data.
+     * @param cardId CID, Unique Tangem card ID number.
+     * @param callback is triggered on the completion of the [ReadIssuerExtraDataTask],
+     * provides card response in the form of [ReadIssuerExtraDataResponse].
+     */
+    fun readIssuerExtraData(cardId: String,
+                            callback: (result: TaskEvent<ReadIssuerExtraDataResponse>) -> Unit) {
+        val task = ReadIssuerExtraDataTask(config.issuerPublicKey)
         runTask(task, cardId, callback)
     }
 
@@ -103,7 +123,7 @@ class CardManager(
      * wallet balance signed by the issuer or additional issuer’s attestation data.
      * @param cardId CID, Unique Tangem card ID number.
      * @param issuerData Data provided by issuer.
-     * @param issuerDataSignature Issuer’s signature of [issuerData] with Issuer Data Private Key (which is kept on card).
+     * @param issuerDataSignature Issuer’s signature of [issuerData] with Issuer Data Private Key.
      * @param issuerDataCounter An optional counter that protect issuer data against replay attack.
      * @param callback is triggered on the completion of the [WriteIssuerDataCommand],
      * provides card response in the form of [WriteIssuerDataResponse].
@@ -113,15 +133,89 @@ class CardManager(
                         issuerDataSignature: ByteArray,
                         issuerDataCounter: Int? = null,
                         callback: (result: TaskEvent<WriteIssuerDataResponse>) -> Unit) {
-        val writeIssuerDataCommand = WriteIssuerDataCommand(
-                    cardId,
-                    issuerData,
-                    issuerDataSignature,
-                    issuerDataCounter)
-        val task = SingleCommandTask(writeIssuerDataCommand)
+        val task = WriteIssuerDataTask(
+                issuerData,
+                issuerDataSignature,
+                issuerDataCounter,
+                config.issuerPublicKey
+        )
         runTask(task, cardId, callback)
     }
 
+    /**
+     * This task writes Issuer Extra Data field and its issuer’s signature.
+     * Issuer Extra Data is never changed or parsed from within the Tangem COS.
+     * The issuer defines purpose of use, format and payload of Issuer Data.
+     * For example, this field may contain a photo or biometric information for ID card products.
+     * Because of the large size of Issuer_Extra_Data, a series of these commands have to be executed
+     * to write entire Issuer_Extra_Data.
+     * @param cardId CID, Unique Tangem card ID number.
+     * @param issuerData Data provided by issuer.
+     * @param startingSignature Issuer’s signature with Issuer Data Private Key of [cardId],
+     * [issuerDataCounter] (if flags Protect_Issuer_Data_Against_Replay and
+     * Restrict_Overwrite_Issuer_Extra_Data are set in [SettingsMask]) and size of [issuerData].
+     * @param finalizingSignature Issuer’s signature with Issuer Data Private Key of [cardId],
+     * [issuerData] and [issuerDataCounter] (the latter one only if flags Protect_Issuer_Data_Against_Replay
+     * andRestrict_Overwrite_Issuer_Extra_Data are set in [SettingsMask]).
+     * @param issuerDataCounter An optional counter that protect issuer data against replay attack.
+     * @param callback is triggered on the completion of the [WriteIssuerDataCommand],
+     * provides card response in the form of [WriteIssuerDataResponse].
+     */
+    fun writeIssuerExtraData(cardId: String,
+                             issuerData: ByteArray,
+                             startingSignature: ByteArray,
+                             finalizingSignature: ByteArray,
+                             issuerDataCounter: Int? = null,
+                             callback: (result: TaskEvent<WriteIssuerDataResponse>) -> Unit) {
+        val task = WriteIssuerExtraDataTask(
+                issuerData,
+                startingSignature, finalizingSignature,
+                config.issuerPublicKey,
+                issuerDataCounter
+        )
+        runTask(task, cardId, callback)
+    }
+
+    /**
+     * This command write some of User_Data, User_ProtectedData, User_Counter and User_ProtectedCounter fields.
+     * User_Data and User_ProtectedData are never changed or parsed by the executable code the Tangem COS.
+     * The App defines purpose of use, format and it's payload. For example, this field may contain cashed information
+     * from blockchain to accelerate preparing new transaction.
+     * User_Counter and User_ProtectedCounter are counters, that initial values can be set by App and increased on every signing
+     * of new transaction (on SIGN command that calculate new signatures). The App defines purpose of use.
+     * For example, this fields may contain blockchain nonce value.
+     *
+     * Writing of User_Counter and User_Data protected only by PIN1.
+     * User_ProtectedCounter and User_ProtectedData additionaly need PIN2 to confirmation.
+     */
+    fun writeUserData(
+        cardId: String,
+        userData: ByteArray? = null,
+        userProtectedData: ByteArray? = null,
+        userCounter: Int? = null,
+        userProtectedCounter: Int? = null,
+        callback: (result: TaskEvent<WriteUserDataResponse>) -> Unit
+    ) {
+      val writeUserDataCommand = WriteUserDataCommand(userData, userProtectedData, userCounter, userProtectedCounter)
+      val task = SingleCommandTask(writeUserDataCommand)
+      runTask(task, cardId, callback)
+    }
+
+    /**
+     * This command returns two up to 512-byte User_Data, User_Protected_Data and two counters User_Counter and
+     * User_Protected_Counter fields.
+     * User_Data and User_ProtectedData are never changed or parsed by the executable code the Tangem COS.
+     * The App defines purpose of use, format and it's payload. For example, this field may contain cashed information
+     * from blockchain to accelerate preparing new transaction.
+     * User_Counter and User_ProtectedCounter are counters, that initial values can be set by App and increased on every signing
+     * of new transaction (on SIGN command that calculate new signatures). The App defines purpose of use.
+     * For example, this fields may contain blockchain nonce value.
+     */
+    fun readUserData(cardId: String, callback: (result: TaskEvent<ReadUserDataResponse>) -> Unit) {
+      val task = SingleCommandTask(ReadUserDataCommand())
+      runTask(task, cardId, callback)
+    }
+
     /**
      * This command will create a new wallet on the card having ‘Empty’ state.
      * A key pair WalletPublicKey / WalletPrivateKey is generated and securely stored in the card.
@@ -134,7 +228,7 @@ class CardManager(
      */
     fun createWallet(cardId: String,
                      callback: (result: TaskEvent<CreateWalletResponse>) -> Unit) {
-        val createWalletCommand = CreateWalletCommand(cardId)
+        val createWalletCommand = CreateWalletCommand()
         val task = SingleCommandTask(createWalletCommand)
         runTask(task, cardId, callback)
     }
@@ -148,7 +242,7 @@ class CardManager(
      */
     fun purgeWallet(cardId: String,
                     callback: (result: TaskEvent<PurgeWalletResponse>) -> Unit) {
-        val purgeWalletCommand = PurgeWalletCommand(cardId)
+        val purgeWalletCommand = PurgeWalletCommand()
         val task = SingleCommandTask(purgeWalletCommand)
         runTask(task, cardId, callback)
     }
@@ -156,14 +250,13 @@ class CardManager(
     /**
 
      */
-    fun <T> runTask(task: Task<T>, cardId: String? = null,
-                    callback: (result: TaskEvent<T>) -> Unit) {
+    fun <T> runTask(task: Task<T>, cardId: String? = null, callback: (result: TaskEvent<T>) -> Unit) {
         if (isBusy) {
             callback(TaskEvent.Completion(TaskError.Busy()))
             return
         }
 
-        val environment = fetchCardEnvironment(cardId)
+        val environment = prepareCardEnvironment(cardId)
         isBusy = true
 
         task.reader = reader
@@ -187,7 +280,21 @@ class CardManager(
         runTask(task, cardId, callback)
     }
 
-    private fun fetchCardEnvironment(cardId: String?): CardEnvironment {
-        return cardEnvironmentRepository[cardId] ?: CardEnvironment(cardId = cardId)
+    /**
+     * Allows to set a particular [TerminalKeysService] to retrieve terminal keys.
+     * Default implementation is provided in tangem-sdk module: [TerminalKeysStorage].
+     */
+    fun setTerminalKeysService(terminalKeysService: TerminalKeysService) {
+        this.terminalKeysService = terminalKeysService
     }
+
+    private fun prepareCardEnvironment(cardId: String?): CardEnvironment {
+        val terminalKeys = if (config.linkedTerminal) terminalKeysService?.getKeys() else null
+        return CardEnvironment(
+                cardId = cardId,
+                terminalKeys = terminalKeys
+        )
+    }
+
+    companion object
 }

tangem-core/src/main/java/com/tangem/CardManagerDelegate.kt

@@ -13,13 +13,19 @@ interface CardManagerDelegate {
     /**
      * It is called when user is expected to scan a Tangem Card with an Android device.
      */
-    fun onNfcSessionStarted()
+    fun onNfcSessionStarted(cardId: String?)
 
     /**
      * It is called when security delay is triggered by the card.
      * A user is expected to hold the card until the security delay is over.
      */
-    fun onSecurityDelay(ms: Int)
+    fun onSecurityDelay(ms: Int, totalDurationSeconds: Int)
+
+    /**
+     * It is called when long tasks are performed.
+     * A user is expected to hold the card until the task is complete.
+     */
+    fun onDelay(total: Int, current: Int, step: Int)
 
     /**
      * It is called when user takes the card away from the Android device during the scanning
@@ -35,7 +41,7 @@ interface CardManagerDelegate {
     /**
      * It is called when some error occur during NFC session.
      */
-    fun onError(error: TaskError? = null)
+    fun onError(error: TaskError)
 
     /**
      * It is called when a user is expected to enter pin code.

tangem-core/src/main/java/com/tangem/Config.kt

@@ -0,0 +1,6 @@
+package com.tangem
+
+class Config(
+        val linkedTerminal: Boolean = true,
+        val issuerPublicKey: ByteArray? = null
+)

tangem-core/src/main/java/com/tangem/commands/CheckWalletCommand.kt

@@ -1,14 +1,16 @@
 package com.tangem.commands
 
-import com.tangem.CardEnvironment
+import com.tangem.common.CardEnvironment
 import com.tangem.common.apdu.CommandApdu
 import com.tangem.common.apdu.Instruction
 import com.tangem.common.apdu.ResponseApdu
 import com.tangem.common.extensions.calculateSha256
 import com.tangem.common.extensions.hexToBytes
 import com.tangem.common.tlv.Tlv
+import com.tangem.common.tlv.TlvBuilder
 import com.tangem.common.tlv.TlvMapper
 import com.tangem.common.tlv.TlvTag
+import com.tangem.crypto.CryptoUtils
 import com.tangem.tasks.TaskError
 
 /**
@@ -22,7 +24,16 @@ class CheckWalletResponse(
         val cardId: String,
         val salt: ByteArray,
         val walletSignature: ByteArray
-) : CommandResponse
+) : CommandResponse {
+
+    fun verify(curve: EllipticCurve, publicKey: ByteArray, challenge: ByteArray): Boolean {
+        return CryptoUtils.verify(
+                publicKey,
+                challenge + salt,
+                walletSignature,
+                curve)
+    }
+}
 
 /**
  * This command proves that the wallet private key from the card corresponds to the wallet public key.
@@ -32,18 +43,16 @@ class CheckWalletResponse(
  * @property cardId Unique Tangem card ID number
  * @property challenge Random challenge generated by application
  */
-class CheckWalletCommand(
-        private val cardId: String,
-        private val challenge: ByteArray
-) : CommandSerializer<CheckWalletResponse>() {
+class CheckWalletCommand : CommandSerializer<CheckWalletResponse>() {
+
+    val challenge = CryptoUtils.generateRandomBytes(16)
 
     override fun serialize(cardEnvironment: CardEnvironment): CommandApdu {
-        val tlvData = listOf(
-                Tlv(TlvTag.Pin, cardEnvironment.pin1.calculateSha256()),
-                Tlv(TlvTag.CardId, cardId.hexToBytes()),
-                Tlv(TlvTag.Challenge, challenge)
-        )
-        return CommandApdu(Instruction.CheckWallet, tlvData)
+        val tlvBuilder = TlvBuilder()
+        tlvBuilder.append(TlvTag.Pin, cardEnvironment.pin1)
+        tlvBuilder.append(TlvTag.CardId, cardEnvironment.cardId)
+        tlvBuilder.append(TlvTag.Challenge, challenge)
+        return CommandApdu(Instruction.CheckWallet, tlvBuilder.serialize())
     }
 
     override fun deserialize(cardEnvironment: CardEnvironment, responseApdu: ResponseApdu): CheckWalletResponse? {

tangem-core/src/main/java/com/tangem/commands/CommandSerializer.kt

@@ -1,6 +1,6 @@
 package com.tangem.commands
 
-import com.tangem.CardEnvironment
+import com.tangem.common.CardEnvironment
 import com.tangem.common.apdu.CommandApdu
 import com.tangem.common.apdu.ResponseApdu
 import com.tangem.common.extensions.toInt