AND-4561 Implement "approve" in blockchain sdk

Signed-off-by: Maqsudjon Ismoilov <[email protected]>
tangem · Sep 22, 2023 · 7ae20b2 · 7ae20b2
1 parent 65275fc
commit 7ae20b2
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Showing 6 changed files with 53 additions and 17 deletions.
diff --git a/blockchain/src/main/java/com/tangem/blockchain/blockchains/ethereum/EthereumUtils.kt b/blockchain/src/main/java/com/tangem/blockchain/blockchains/ethereum/EthereumUtils.kt
@@ -19,6 +19,7 @@ import org.kethereum.model.Address
 import org.kethereum.model.PublicKey
 import org.kethereum.model.SignatureData
 import org.kethereum.model.createTransactionWithDefaults
+import org.komputing.khex.extensions.toHexString
 import java.math.BigDecimal
 import java.math.BigInteger
 
@@ -32,6 +33,7 @@ class EthereumUtils {
         private val tokenTransferFromSignature = "transferFrom(address,address,uint256)".toByteArray().toKeccak().copyOf(4)
 
         private const val HEX_PREFIX = "0x"
+        private const val HEX_F = "f"
 
         // ERC-20 standard defines balanceOf function as returning uint256. Don't accept anything else.
         private const val UInt256Size = 32
@@ -295,7 +297,6 @@ class EthereumUtils {
             return CompiledEthereumTransaction(transaction, hash)
         }
 
-
         fun buildSetWalletToSign(
             processorContractAddress: String,
             cardAddress: String,
@@ -333,7 +334,6 @@ class EthereumUtils {
             return CompiledEthereumTransaction(transaction, hash)
         }
 
-
         fun buildProcessToSign(
             processorContractAddress: String,
             processorAddress: String,
@@ -428,6 +428,12 @@ class EthereumUtils {
             return CompiledEthereumTransaction(transaction, hash)
         }
 
+        fun createErc20ApproveDataHex(spender: String, amount: Amount?): String =
+            createErc20ApproveData(
+                spender = spender,
+                amount = amount?.value?.movePointRight(amount.decimals)?.toBigInteger()
+            ).toHexString()
+
         private fun createErc20TransferData(recipient: String, amount: BigInteger) =
             tokenTransferSignature.toByteArray() +
                 recipient.substring(2).hexToBytes().toFixedLengthByteArray(32) +
@@ -438,16 +444,10 @@ class EthereumUtils {
                 recepient, amount.value!!.movePointRight(amount.decimals).toBigInteger()
             )
 
-        private fun createErc20ApproveData(spender: String, amount: BigInteger) =
+        private fun createErc20ApproveData(spender: String, amount: BigInteger?): ByteArray =
             tokenApproveSignature +
                 spender.substring(2).hexToBytes().toFixedLengthByteArray(32) +
-                amount.toBytesPadded(32)
-
-        internal fun createErc20ApproveData(spender: String, amount: Amount) =
-            createErc20ApproveData(
-                spender = spender,
-                amount = amount.value!!.movePointRight(amount.decimals).toBigInteger()
-            )
+                (amount?.toBytesPadded(32) ?: HEX_F.repeat(64).hexToBytes())
 
         private fun createSetSpendLimitData(cardAddress: String, amount: BigInteger) =
             setSpendLimitSignature +

diff --git a/blockchain/src/main/java/com/tangem/blockchain/blockchains/ethereum/EthereumWalletManager.kt b/blockchain/src/main/java/com/tangem/blockchain/blockchains/ethereum/EthereumWalletManager.kt
@@ -16,6 +16,7 @@ import kotlinx.coroutines.async
 import kotlinx.coroutines.coroutineScope
 import org.kethereum.extensions.toHexString
 import org.kethereum.keccakshortcut.keccak
+import org.komputing.khex.extensions.toHexString
 import java.math.BigDecimal
 import java.math.BigInteger
 
@@ -28,7 +29,8 @@ open class EthereumWalletManager(
     TransactionSender,
     SignatureCountValidator,
     TokenFinder,
-    EthereumGasLoader {
+    EthereumGasLoader,
+    Approver {
 
     // move to constructor later
     protected val feesCalculator = EthereumFeesCalculator()
@@ -216,6 +218,18 @@ open class EthereumWalletManager(
         return getGasLimitInternal(amount, destination, data)
     }
 
+    override suspend fun getAllowance(
+        spenderAddress: String,
+        token: Token,
+    ): Result<BigDecimal> {
+        return networkProvider.getAllowance(wallet.address, token, spenderAddress)
+    }
+
+    override fun getApproveData(
+        spenderAddress: String,
+        value: Amount?,
+    ) = EthereumUtils.createErc20ApproveDataHex(spenderAddress, value)
+
     private suspend fun getGasLimitInternal(
         amount: Amount,
         destination: String,

diff --git a/...c/main/java/com/tangem/blockchain/blockchains/ethereum/network/EthereumJsonRpcProvider.kt b/...c/main/java/com/tangem/blockchain/blockchains/ethereum/network/EthereumJsonRpcProvider.kt
@@ -1,12 +1,13 @@
 package com.tangem.blockchain.blockchains.ethereum.network
 
 import com.tangem.blockchain.blockchains.ethereum.EthereumUtils
+import com.tangem.blockchain.blockchains.ethereum.EthereumUtils.Companion.toKeccak
 import com.tangem.blockchain.common.NetworkProvider
 import com.tangem.blockchain.common.toBlockchainSdkError
 import com.tangem.blockchain.extensions.Result
 import com.tangem.blockchain.extensions.retryIO
 import com.tangem.blockchain.network.createRetrofitInstance
-import com.tangem.common.extensions.toHexString
+import org.komputing.khex.extensions.toHexString
 import java.math.BigDecimal
 
 class EthereumJsonRpcProvider(
@@ -97,7 +98,12 @@ class EthereumJsonRpcProvider(
     ) = EthCallObject(
         to = contractAddress,
         //5c9b5c6313a3746a1246d07bbedc0292da99f8e2000000000000000000000000e4c4693526e4e3a26f36311d3f80a193b2bae906
-        data = "0xdd62ed3e000000000000000000000000" + ownerAddress.substring(2) + "000000000000000000000000" + spenderAddress.substring(2)
+        data = buildString {
+            append(tokenAllowanceSignature)
+            append(ownerAddress.substring(2))
+            append(CALL_DATA_SEPARATOR)
+            append(spenderAddress.substring(2))
+        }
     )
 
     private fun createProcessCallObject(
@@ -133,6 +139,11 @@ class EthereumJsonRpcProvider(
             Result.Failure(exception.toBlockchainSdkError())
         }
     }
+
+    companion object {
+        private val tokenAllowanceSignature = "allowance(address,address)".toByteArray().toKeccak().copyOf(4)
+        private const val CALL_DATA_SEPARATOR = "000000000000000000000000"
+    }
 }
 
 data class EthereumTokenBalanceRequestData(

diff --git a/...c/main/java/com/tangem/blockchain/blockchains/ethereum/network/EthereumNetworkProvider.kt b/...c/main/java/com/tangem/blockchain/blockchains/ethereum/network/EthereumNetworkProvider.kt
@@ -1,6 +1,5 @@
 package com.tangem.blockchain.blockchains.ethereum.network
 
-import com.tangem.blockchain.common.Amount
 import com.tangem.blockchain.common.NetworkProvider
 import com.tangem.blockchain.common.Token
 import com.tangem.blockchain.common.TransactionData
@@ -12,7 +11,7 @@ import java.math.BigInteger
 
 interface EthereumNetworkProvider: NetworkProvider {
     suspend fun getInfo(address: String, tokens: Set<Token>): Result<EthereumInfoResponse>
-    suspend fun getAllowance(ownerAddress: String, token: Token, spenderAddress: String): Result<Amount>
+    suspend fun getAllowance(ownerAddress: String, token: Token, spenderAddress: String): Result<BigDecimal>
     suspend fun sendTransaction(transaction: String): SimpleResult
     suspend fun getSignatureCount(address: String): Result<Int>
     suspend fun findErc20Tokens(address: String): Result<List<BlockchairToken>>

diff --git a/...rc/main/java/com/tangem/blockchain/blockchains/ethereum/network/EthereumNetworkService.kt b/...rc/main/java/com/tangem/blockchain/blockchains/ethereum/network/EthereumNetworkService.kt
@@ -76,15 +76,15 @@ class EthereumNetworkService(
         }
     }
 
-    override suspend fun getAllowance(ownerAddress: String, token: Token, spenderAddress: String): Result<Amount> {
+    override suspend fun getAllowance(ownerAddress: String, token: Token, spenderAddress: String): Result<BigDecimal> {
         return try {
             val requestData = EthereumTokenAllowanceRequestData(ownerAddress, token.contractAddress, spenderAddress)
             val amountValue = multiJsonRpcProvider.performRequest(
                 request = EthereumJsonRpcProvider::getTokenAllowance,
                 data = requestData
             ).extractResult().parseAmount(token.decimals)
 
-            Result.Success(Amount(token, amountValue))
+            Result.Success(amountValue)
         } catch (exception: Exception) {
             Result.Failure(exception.toBlockchainSdkError())
         }

diff --git a/blockchain/src/main/java/com/tangem/blockchain/common/WalletManager.kt b/blockchain/src/main/java/com/tangem/blockchain/common/WalletManager.kt
@@ -184,3 +184,15 @@ interface SignatureCountValidator {
 interface TokenFinder {
     suspend fun findTokens(): Result<List<Token>>
 }
+
+interface Approver {
+    suspend fun getAllowance(
+        spenderAddress: String,
+        token: Token,
+    ): Result<BigDecimal>
+
+    fun getApproveData(
+        spenderAddress: String,
+        value: Amount? = null,
+    ): String
+}