private bool CheckSig(byte[] vchSig, byte[] vchPubKey, Script scriptCode, Transaction txTo, int nIn)
{
//static CSignatureCache signatureCache;
if (!PubKey.IsValidSize(vchPubKey.Length))
{
return(false);
}
PubKey pubkey = null;
try
{
pubkey = new PubKey(vchPubKey);
}
catch (Exception)
{
return(false);
}
// Hash type is one byte tacked on to the end of the signature
if (vchSig.Length == 0)
{
return(false);
}
var scriptSig = new TransactionSignature(vchSig);
if (!IsAllowedSignature(scriptSig.SigHash))
{
return(false);
}
uint256 sighash = scriptCode.SignatureHash(txTo, nIn, scriptSig.SigHash);
//if (signatureCache.Get(sighash, vchSig, pubkey))
// return true;
if (!pubkey.Verify(sighash, scriptSig.Signature))
{
if ((ScriptVerify & ScriptVerify.StrictEnc) != 0)
{
return(false);
}
//Replicate OpenSSL bug on 23b397edccd3740a74adb603c9756370fafcde9bcc4483eb271ecad09a94dd63 (http://r6.ca/blog/20111119T211504Z.html)
var nLenR = vchSig[3];
var nLenS = vchSig[5 + nLenR];
var R = 4;
var S = 6 + nLenR;
var newS = new Org.BouncyCastle.Math.BigInteger(1, vchSig, S, nLenS);
var newR = new Org.BouncyCastle.Math.BigInteger(1, vchSig, R, nLenR);
var sig2 = new ECDSASignature(newR, newS);
if (sig2.R != scriptSig.Signature.R || sig2.S != scriptSig.Signature.S)
{
if (!pubkey.Verify(sighash, sig2))
{
return(false);
}
}
}
//if (!(flags & SCRIPT_VERIFY_NOCACHE))
// signatureCache.Set(sighash, vchSig, pubkey);
return(true);
}
