public TxTemplate SignTransaction(TxTemplate transaction, List <string> privateKeys)
{
var signedTx = (TxTemplate)transaction.Clone();
var serializedTransaction = JsonUtility.SerializeTransactionIntoCanonicalString(JsonConvert.SerializeObject(transaction));
var index = 0;
foreach (var privKey in privateKeys)
{
SignatureMetadata signatures = GetSignature(transaction, serializedTransaction, index, privKey);
bool verifyFullfill = signatures.Signature.VerifySignature(signatures.TransactionHash, signatures.PubKeyBuffer);
if (!verifyFullfill)
{
continue;
}
signedTx.Inputs[index].Fulfillment = GenerateFulfillmentUri(signatures.PubKeyBuffer, signatures.Signature);
index++;
}
var serializedSignedTransaction = JsonUtility.SerializeTransactionIntoCanonicalString(JsonConvert.SerializeObject(signedTx));
signedTx.Id = HashingUtils.ComputeSha3Hash(Encoding.UTF8.GetBytes(serializedSignedTransaction)).ToHex(false);
return(signedTx);
}
private static string GetUniqueFulfillment(TxTemplate transaction, string serializedTransaction, int index)
{
return(transaction.Inputs[index].Fulfills == null ?
serializedTransaction +
transaction.Inputs[index].Fulfills?.TransactionId +
transaction.Inputs[index].Fulfills?.OutputIndex : serializedTransaction);
}
public (byte[], byte[], byte[]) GetSignature(TxTemplate transaction, string serializedTransaction, int index, string privKey)
{
var pubKeyBuffer = Encoders.Base58.DecodeData(transaction.Outputs[index].PublicKeys[0]);
string transactionUniqueFulfillment = GetUniqueFulfillment(transaction, serializedTransaction, index);
var transactionHash = HashingUtils.ComputeSha3Hash(Encoding.UTF8.GetBytes(transactionUniqueFulfillment));
var signature = CryptographyUtility.Ed25519Sign(transactionHash, Encoders.Base58.DecodeData(privKey));
return(transactionHash, pubKeyBuffer, signature);
}
