bool CryptoECDSA::VerifyData(SecureBinaryData const & binMessage,
SecureBinaryData const & binSignature,
BTC_PUBKEY const & cppPubKey)
{
CryptoPP::SHA256 sha256;
BTC_PRNG prng;
assert(cppPubKey.Validate(prng, 3));
// We execute the first SHA256 op, here. Next one is done by Verifier
SecureBinaryData hashVal(32);
sha256.CalculateDigest(hashVal.getPtr(),
binMessage.getPtr(),
binMessage.getSize());
// Verifying message
BTC_VERIFIER verifier(cppPubKey);
return verifier.VerifyMessage((const byte*)hashVal.getPtr(),
hashVal.getSize(),
(const byte*)binSignature.getPtr(),
binSignature.getSize());
}
bool CryptoECDSA::VerifyPublicKeyValid(SecureBinaryData const & pubKey65)
{
if(CRYPTO_DEBUG)
{
cout << "BinPub: " << pubKey65.toHexStr() << endl;
}
// Basically just copying the ParsePublicKey method, but without
// the assert that would throw an error from C++
SecureBinaryData pubXbin(pubKey65.getSliceRef( 1,32));
SecureBinaryData pubYbin(pubKey65.getSliceRef(33,32));
CryptoPP::Integer pubX;
CryptoPP::Integer pubY;
pubX.Decode(pubXbin.getPtr(), pubXbin.getSize(), UNSIGNED);
pubY.Decode(pubYbin.getPtr(), pubYbin.getSize(), UNSIGNED);
BTC_ECPOINT publicPoint(pubX, pubY);
// Initialize the public key with the ECP point just created
BTC_PUBKEY cppPubKey;
cppPubKey.Initialize(CryptoPP::ASN1::secp256k1(), publicPoint);
// Validate the public key -- not sure why this needs a PRNG
static BTC_PRNG prng;
return cppPubKey.Validate(prng, 3);
}
BTC_PUBKEY CryptoECDSA::ComputePublicKey(BTC_PRIVKEY const & cppPrivKey)
{
BTC_PUBKEY cppPubKey;
cppPrivKey.MakePublicKey(cppPubKey);
// Validate the public key -- not sure why this needs a prng...
BTC_PRNG prng;
assert(cppPubKey.Validate(prng, 3));
return cppPubKey;
}
bool CryptoECDSA::ECVerifyPoint(BinaryData const & x,
BinaryData const & y)
{
BTC_PUBKEY cppPubKey;
CryptoPP::Integer pubX;
CryptoPP::Integer pubY;
pubX.Decode(x.getPtr(), x.getSize(), UNSIGNED);
pubY.Decode(y.getPtr(), y.getSize(), UNSIGNED);
BTC_ECPOINT publicPoint(pubX, pubY);
// Initialize the public key with the ECP point just created
cppPubKey.Initialize(CryptoPP::ASN1::secp256k1(), publicPoint);
// Validate the public key -- not sure why this needs a PRNG
BTC_PRNG prng;
return cppPubKey.Validate(prng, 3);
}
BTC_PUBKEY CryptoECDSA::ParsePublicKey(SecureBinaryData const & pubKeyX32B,
SecureBinaryData const & pubKeyY32B)
{
BTC_PUBKEY cppPubKey;
CryptoPP::Integer pubX;
CryptoPP::Integer pubY;
pubX.Decode(pubKeyX32B.getPtr(), pubKeyX32B.getSize(), UNSIGNED);
pubY.Decode(pubKeyY32B.getPtr(), pubKeyY32B.getSize(), UNSIGNED);
BTC_ECPOINT publicPoint(pubX, pubY);
// Initialize the public key with the ECP point just created
cppPubKey.Initialize(CryptoPP::ASN1::secp256k1(), publicPoint);
// Validate the public key -- not sure why this needs a PRNG
BTC_PRNG prng;
assert(cppPubKey.Validate(prng, 3));
return cppPubKey;
}
bool CryptoECDSA::VerifyPublicKeyValid(SecureBinaryData const & pubKey)
{
if(CRYPTO_DEBUG)
{
cout << "BinPub: " << pubKey.toHexStr() << endl;
}
SecureBinaryData keyToCheck(65);
// To support compressed keys, we'll just check to see if a key is compressed
// and then decompress it.
if(pubKey.getSize() == 33) {
keyToCheck = UncompressPoint(pubKey);
}
else {
keyToCheck = pubKey;
}
// Basically just copying the ParsePublicKey method, but without
// the assert that would throw an error from C++
SecureBinaryData pubXbin(keyToCheck.getSliceRef( 1,32));
SecureBinaryData pubYbin(keyToCheck.getSliceRef(33,32));
CryptoPP::Integer pubX;
CryptoPP::Integer pubY;
pubX.Decode(pubXbin.getPtr(), pubXbin.getSize(), UNSIGNED);
pubY.Decode(pubYbin.getPtr(), pubYbin.getSize(), UNSIGNED);
BTC_ECPOINT publicPoint(pubX, pubY);
// Initialize the public key with the ECP point just created
BTC_PUBKEY cppPubKey;
cppPubKey.Initialize(CryptoPP::ASN1::secp256k1(), publicPoint);
// Validate the public key -- not sure why this needs a PRNG
BTC_PRNG prng;
return cppPubKey.Validate(prng, 3);
}
void StackInterpreter::op_checkmultisig()
{
//stack needs to have at least m, n, output script
if (stack_.size() < 3)
throw ScriptException("insufficient stack size for checkmultisig operation");
//pop n
auto&& n = pop_back();
auto nI = rawBinaryToInt(n);
if (nI < 0 || nI > 20)
throw ScriptException("invalid n");
//pop pubkeys
map<unsigned, pair<BTC_PUBKEY, BinaryData>> pubkeys;
for (unsigned i = 0; i < nI; i++)
{
auto&& pubkey = pop_back();
CryptoPP::ECP ecp = CryptoECDSA::Get_secp256k1_ECP();
BTC_ECPOINT ptPub;
ecp.DecodePoint(ptPub, (byte*)pubkey.getPtr(), pubkey.getSize());
BTC_PUBKEY cppPubKey;
cppPubKey.Initialize(CryptoPP::ASN1::secp256k1(), ptPub);
BTC_PRNG prng;
if (cppPubKey.Validate(prng, 3))
{
txInEvalState_.pubKeyState_.insert(make_pair(pubkey, false));
auto&& pubkeypair = make_pair(move(cppPubKey), pubkey);
pubkeys.insert(move(make_pair(i, move(pubkeypair))));
}
}
//pop m
auto&& m = pop_back();
auto mI = rawBinaryToInt(m);
if (mI < 0 || mI > nI)
throw ScriptException("invalid m");
txInEvalState_.n_ = nI;
txInEvalState_.m_ = mI;
//pop sigs
struct sigData
{
BinaryData sig_;
SIGHASH_TYPE hashType_;
};
vector<sigData> sigVec;
while (stack_.size() > 0)
{
auto&& sig = pop_back();
if (sig.getSize() == 0)
break;
sigData sdata;
sdata.sig_ = sig.getSliceCopy(0, sig.getSize() - 1);
//grab hash type
sdata.hashType_ =
getSigHashSingleByte(*(sig.getPtr() + sig.getSize() - 1));
//push to vector
sigVec.push_back(move(sdata));
}
//should have at least as many sigs as m
/*if (sigVec.size() < mI)
throw ScriptException("invalid sig count");*/
//check sigs
map<SIGHASH_TYPE, BinaryData> dataToHash;
//check sighashdata object
if (sigHashDataObject_ == nullptr)
sigHashDataObject_ = make_shared<SigHashDataLegacy>();
unsigned validSigCount = 0;
int index = nI - 1;
auto sigIter = sigVec.rbegin();
while(sigIter != sigVec.rend())
{
auto& sigD = *sigIter++;
//get data to hash
auto& hashdata = dataToHash[sigD.hashType_];
if (hashdata.getSize() == 0)
{
hashdata = sigHashDataObject_->getDataForSigHash(
sigD.hashType_, *txStubPtr_, outputScriptRef_, inputIndex_);
}
//prepare sig
auto&& rs = BtcUtils::extractRSFromDERSig(sigD.sig_);
BinaryWriter sigW;
//pop pubkeys from deque to verify against sig
while (pubkeys.size() > 0)
{
auto pubkey = pubkeys[index];
pubkeys.erase(index--);
#ifdef SIGNER_DEBUG
LOGWARN << "Verifying sig for: ";
LOGWARN << " pubkey: " << pubkey.second.toHexStr();
auto&& msg_hash = BtcUtils::getHash256(hashdata);
LOGWARN << " message: " << hashdata.toHexStr();
#endif
if (CryptoECDSA().VerifyData(hashdata, rs, pubkey.first))
{
txInEvalState_.pubKeyState_[pubkey.second] = true;
validSigCount++;
break;
}
}
}
if (validSigCount >= mI)
op_true();
else
op_0();
}