public static byte[] SignTransaction(byte[] privateKey,
Script script, Transaction transaction, int transactionInputIndex, SignatureHashType signatureType)
{
ContractsCommon.NotNull(privateKey, "privateKey");
ContractsCommon.NotNull(script, "script");
ContractsCommon.NotNull(transaction, "transaction");
ContractsCommon.ValidIndex(0, transaction.TransactionInputs.Count, transactionInputIndex, "transactionInputIndex");
ContractsCommon.ResultIsNonNull<byte[]>();
var hash = HashTransactionForSigning(script, transaction, transactionInputIndex, signatureType);
var ecdsa = new ECDsaBouncyCastle(privateKey, true);
return ecdsa.SignHash(hash.Bytes);
}
public static bool VerifySignature(byte[] publicKey, byte[] sigHash,
Script script, Transaction transaction, int transactionInputIndex, SignatureHashType signatureType)
{
ContractsCommon.NotNull(publicKey, "publicKey");
ContractsCommon.NotNull(sigHash, "sigHash");
ContractsCommon.NotNull(script, "script");
ContractsCommon.NotNull(transaction, "transaction");
ContractsCommon.ValidIndex(0, transaction.TransactionInputs.Count, transactionInputIndex, "transactionInputIndex");
// Cng ECC Public Key Blob format [72 bytes]:
//6fbfcf5da60c7e59dfe724f4fb1b4e73f12bc48f17fb90f1e74f0d058c65e77c76aa75787f18ddd8be32b08014046ff62fef598011583e6f2d77e2b2ab850e5f0000002031534345
//coordY[cBytes]BIG-ENDIAN coordX[cBytes]BIG-ENDIAN cBytes[4]LITTLE-ENDIAN magic[4]LITTLE-ENDIAN
// For ECDsaP256, that magic number is: 0x31534345U, and cBytes will be 0x00000020
// Bitcoin ECC Public Key Blob format [65 bytes]:
//04e77ae594d5932f11547eea049b526044cbf8ac938fabfa97d3ab37732822572bd7d71c77a8ac1f5ca46fd73260f5aecc7270efbbf283bacd64ef0a9bb41e3ab9
//type[1] coordX[cBytes] coordY[cBytes] (all LITTLE-ENDIAN)
// type = 04 means curve points are uncompressed. No other value is expected.
// For secp256k1, cBytes = 0x00000020
// Probable issue here: Cng supports the NIST P-256 curve (alias of secp256r1), but Bitcoin uses the secp256k1 curve.
if (signatureType == 0)
{
signatureType = (SignatureHashType)sigHash[sigHash.Length - 1];
}
else if (signatureType != (SignatureHashType)sigHash[sigHash.Length - 1])
{
return false;
}
var signature = new byte[72];
Array.Copy(sigHash, signature, signature.Length);
var hash = HashTransactionForSigning(script, transaction, transactionInputIndex, signatureType);
var ecdsa = new ECDsaBouncyCastle(publicKey, false);
return ecdsa.VerifyHash(hash.Bytes, signature);
}
