Updated on 2026-08-14

app/src/main/java/com/tangem/tap/domain/TopUpHelper.kt

@@ -1,8 +1,8 @@
 package com.tangem.tap.domain
 
 import android.net.Uri
+import android.util.Base64
 import com.tangem.tap.common.redux.global.CryptoCurrencyName
-import org.spongycastle.util.encoders.Base64
 import javax.crypto.Mac
 import javax.crypto.spec.SecretKeySpec
 
@@ -37,7 +37,8 @@ class TopUpHelper {
             val sha256Hmac = Mac.getInstance("HmacSHA256")
             val secretKey = SecretKeySpec(key.toByteArray(), "HmacSHA256")
             sha256Hmac.init(secretKey)
-            return Base64.toBase64String(sha256Hmac.doFinal(data.toByteArray()))
+            val sha256encoded = sha256Hmac.doFinal(data.toByteArray())
+            return Base64.encodeToString(sha256encoded, Base64.NO_WRAP)
         }
     }
 }

app/src/main/java/com/tangem/tap/domain/extensions/Blockchain.kt

@@ -3,16 +3,13 @@ package com.tangem.tap.domain.extensions
 import com.tangem.blockchain.common.Blockchain
 import com.tangem.blockchain.common.Token
 import com.tangem.commands.common.card.EllipticCurve
-import org.stellar.sdk.requests.ErrorResponse
 import java.math.BigDecimal
 
 
 fun Blockchain.isNoAccountError(exception: Throwable): Boolean {
     return when (this) {
-        Blockchain.Stellar -> {
-            (exception is ErrorResponse) && (exception.code == 404)
-        }
-        Blockchain.XRP -> exception.message?.contains("Account not found") == true
+        Blockchain.Stellar, Blockchain.XRP ->
+            exception.message?.contains("Account not found") == true
         else -> false
     }
 }

app/src/main/java/com/tangem/tap/domain/walletconnect/WalletConnectSdkHelper.kt

@@ -1,18 +1,15 @@
 package com.tangem.tap.domain.walletconnect
 
-import com.google.common.base.CharMatcher
 import com.tangem.Message
 import com.tangem.blockchain.blockchains.ethereum.EthereumGasLoader
-import com.tangem.blockchain.blockchains.ethereum.EthereumHelper
 import com.tangem.blockchain.blockchains.ethereum.EthereumTransactionExtras
+import com.tangem.blockchain.blockchains.ethereum.EthereumUtils
+import com.tangem.blockchain.blockchains.ethereum.EthereumUtils.Companion.toKeccak
 import com.tangem.blockchain.common.Amount
 import com.tangem.blockchain.common.AmountType
 import com.tangem.blockchain.common.TransactionData
 import com.tangem.blockchain.common.TransactionSender
-import com.tangem.blockchain.extensions.Result
-import com.tangem.blockchain.extensions.Signer
-import com.tangem.blockchain.extensions.SimpleResult
-import com.tangem.blockchain.extensions.hexToBigDecimal
+import com.tangem.blockchain.extensions.*
 import com.tangem.commands.SignCommand
 import com.tangem.commands.wallet.WalletIndex
 import com.tangem.common.CompletionResult
@@ -26,14 +23,8 @@ import com.tangem.tap.tangemSdk
 import com.tangem.tap.tangemSdkManager
 import com.trustwallet.walletconnect.models.ethereum.WCEthereumSignMessage
 import com.trustwallet.walletconnect.models.ethereum.WCEthereumTransaction
-import org.kethereum.crypto.api.ec.ECDSASignature
-import org.kethereum.crypto.determineRecId
-import org.kethereum.crypto.impl.ec.canonicalise
-import org.kethereum.keccakshortcut.keccak
-import org.kethereum.model.PublicKey
 import timber.log.Timber
 import java.math.BigDecimal
-import java.math.BigInteger
 
 class WalletConnectSdkHelper {
 
@@ -144,7 +135,7 @@ class WalletConnectSdkHelper {
     }
 
     private suspend fun signTransaction(data: WcTransactionData): String? {
-        val dataToSign = EthereumHelper.buildTransactionToSign(
+        val dataToSign = EthereumUtils.buildTransactionToSign(
             transactionData = data.transaction,
             nonce = null,
             blockchain = data.walletManager.wallet.blockchain,
@@ -176,7 +167,7 @@ class WalletConnectSdkHelper {
         val messageString = message.data.hexToAscii() ?: message.data
 
         val prefixData = (ETH_MESSAGE_PREFIX + messageData.size.toString()).toByteArray()
-        val hashToSign = (prefixData + messageData).keccak()
+        val hashToSign = (prefixData + messageData).toKeccak()
 
 
         val dialogData = PersonalSignDialogData(
@@ -203,8 +194,6 @@ class WalletConnectSdkHelper {
             .joinToString("")
     }
 
-    private fun Char.isAscii(): Boolean = CharMatcher.ascii().matches(this)
-
     suspend fun signPersonalMessage(hashToSign: ByteArray, wallet: WalletForSession): String? {
         val publicKey = wallet.walletPublicKey.hexToBytes()
         val command = SignCommand(
@@ -214,17 +203,9 @@ class WalletConnectSdkHelper {
             is CompletionResult.Success -> {
                 val hash = result.data.signatures.first()
 
-                val r = BigInteger(1, hash.copyOfRange(0, 32))
-                val s = BigInteger(1, hash.copyOfRange(32, 64))
-
-                val ecdsaSignature = ECDSASignature(r, s).canonicalise()
-
-                val recId = ecdsaSignature.determineRecId(hashToSign,
-                    PublicKey(publicKey.sliceArray(1..64)))
-                val v = (recId + 27).toBigInteger()
-
-                return HEX_PREFIX + ecdsaSignature.r.toString(16) + ecdsaSignature.s.toString(16) +
-                        v.toString(16)
+                return EthereumUtils.prepareSignedMessageData(
+                    hash, hashToSign, publicKey
+                )
             }
             is CompletionResult.Failure -> {
                 Timber.e(result.error.customMessage)