tangem-app-android-audited/blockchain/src/main/java/com/tangem/blockchain/bitcoin/BitcoinAddress.kt
2020-02-03 18:21:16 +03:00

72 lines
No EOL
2.7 KiB
Kotlin

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 = sha256(decoded, 0, 21, 2)
return hash.sliceArray(0..3).contentEquals(decoded.sliceArray(21..24))
} else {
return validateSegwitAddress(address, testNet)
}
}
private fun sha256(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 sha256(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
}
}
}
}