bool CKey::Verify(uint256 hash, const std::vector<unsigned char>& vchSig)
{
// decode the vchSig
Integer sigE, sigS;
if (vchSig.size() != (SCHNORR_SIG_SIZE * 2))
return false;
// extract bytes
std::vector<unsigned char> sigEVec(&vchSig[0], &vchSig[SCHNORR_SIG_SIZE]);
std::vector<unsigned char> sigSVec(&vchSig[SCHNORR_SIG_SIZE], &vchSig[1 + SCHNORR_SIG_SIZE * 2]);
// vectors -> Integers
sigE.Decode(&sigEVec[0], SCHNORR_SIG_SIZE);
sigS.Decode(&sigSVec[0], SCHNORR_SIG_SIZE);
// verify the hash
ECPPoint R;
R = ec.CascadeScalarMultiply(G, sigS, Q, sigE);
// encode hash as byte[]
std::vector<unsigned char> vchHash = hash.toVch();
Integer sigEd = HashPointMessage(R, &vchHash[0], sizeof(hash)) % q;
return (sigE == sigEd);
}
bool CKey::Sign(uint256 hash, std::vector<unsigned char>& vchSig)
{
// sign the hash
Integer k;
ECPPoint R;
Integer sigE, sigS;
k = Integer(rng, 256) % q;
R = ec.ScalarMultiply(G, k);
// encode hash as byte[]
std::vector<unsigned char> vchHash = hash.toVch();
sigE = HashPointMessage(R, &vchHash[0], sizeof(hash)) % q;
sigS = (k - secretKey*sigE) % q;
// encode the vch format
vchSig.resize(SCHNORR_SIG_SIZE * 2);
if (sigE.MinEncodedSize() > SCHNORR_SIG_SIZE || sigS.MinEncodedSize() > SCHNORR_SIG_SIZE)
return false;
sigE.Encode(&vchSig[0], SCHNORR_SIG_SIZE);
sigS.Encode(&vchSig[SCHNORR_SIG_SIZE], SCHNORR_SIG_SIZE);
return true;
}
