bytes Secp256k1PP::eciesKDF(Secret const& _z, bytes _s1, unsigned kdByteLen)
{
auto reps = ((kdByteLen + 7) * 8) / (CryptoPP::SHA256::BLOCKSIZE * 8);
// SEC/ISO/Shoup specify counter size SHOULD be equivalent
// to size of hash output, however, it also notes that
// the 4 bytes is okay. NIST specifies 4 bytes.
bytes ctr({0, 0, 0, 1});
bytes k;
CryptoPP::SHA256 ctx;
for (unsigned i = 0; i <= reps; i++)
{
ctx.Update(ctr.data(), ctr.size());
ctx.Update(_z.data(), Secret::size);
ctx.Update(_s1.data(), _s1.size());
// append hash to k
bytes digest(32);
ctx.Final(digest.data());
ctx.Restart();
k.reserve(k.size() + h256::size);
move(digest.begin(), digest.end(), back_inserter(k));
if (++ctr[3] || ++ctr[2] || ++ctr[1] || ++ctr[0])
continue;
}
k.resize(kdByteLen);
return k;
}
void Secp256k1PP::encryptECIES(Public const& _k, bytesConstRef _sharedMacData, bytes& io_cipher)
{
// interop w/go ecies implementation
auto r = KeyPair::create();
Secret z;
ecdh::agree(r.sec(), _k, z);
auto key = eciesKDF(z, bytes(), 32);
bytesConstRef eKey = bytesConstRef(&key).cropped(0, 16);
bytesRef mKeyMaterial = bytesRef(&key).cropped(16, 16);
CryptoPP::SHA256 ctx;
ctx.Update(mKeyMaterial.data(), mKeyMaterial.size());
bytes mKey(32);
ctx.Final(mKey.data());
bytes cipherText = encryptSymNoAuth(SecureFixedHash<16>(eKey), h128(), bytesConstRef(&io_cipher));
if (cipherText.empty())
return;
bytes msg(1 + Public::size + h128::size + cipherText.size() + 32);
msg[0] = 0x04;
r.pub().ref().copyTo(bytesRef(&msg).cropped(1, Public::size));
bytesRef msgCipherRef = bytesRef(&msg).cropped(1 + Public::size + h128::size, cipherText.size());
bytesConstRef(&cipherText).copyTo(msgCipherRef);
// tag message
CryptoPP::HMAC<SHA256> hmacctx(mKey.data(), mKey.size());
bytesConstRef cipherWithIV = bytesRef(&msg).cropped(1 + Public::size, h128::size + cipherText.size());
hmacctx.Update(cipherWithIV.data(), cipherWithIV.size());
hmacctx.Update(_sharedMacData.data(), _sharedMacData.size());
hmacctx.Final(msg.data() + 1 + Public::size + cipherWithIV.size());
io_cipher.resize(msg.size());
io_cipher.swap(msg);
}
void CEncrypt::CreateUserKey()
{
CryptoPP::RandomPool prng;
CryptoPP::SecByteBlock salt(16);
CryptoPP::OS_GenerateRandomBlock(false, salt, salt.size());
prng.IncorporateEntropy(salt, salt.size());
memcpy(m_anUserKey + 32, salt.data(), salt.size());
CryptoPP::SHA256 hash;
hash.Update( (unsigned char*) impl->m_sUserPassword.c_str(), impl->m_sUserPassword.length());
hash.Update( m_anUserKey + 32, 8);
CryptoPP::SecByteBlock pHashData(hash.DigestSize());
hash.Final(pHashData);
if (MakeFileKey3(impl->m_sUserPassword, pHashData.data(), pHashData.size()))
{
memcpy(m_anUserKey, pHashData.data(), pHashData.size());
hash.Update( (unsigned char*) impl->m_sUserPassword.c_str(), impl->m_sUserPassword.length());
hash.Update( m_anUserKey + 40, 8);
CryptoPP::SecByteBlock pHashKeyData(hash.DigestSize());
hash.Final(pHashKeyData);
MakeFileKey3(impl->m_sUserPassword, pHashKeyData.data(), pHashKeyData.size());
unsigned char empty[16] = {};
CryptoPP::AES::Encryption aesEncryption(pHashKeyData.data(), pHashKeyData.size());
CryptoPP::CBC_Mode_ExternalCipher::Encryption cbcEncryption( aesEncryption, empty);
CryptoPP::StreamTransformationFilter stfEncryption(cbcEncryption, new CryptoPP::ArraySink( m_anUserEncryptKey, 32), CryptoPP::StreamTransformationFilter::NO_PADDING );
stfEncryption.Put2(impl->m_anEncryptionKey, 32, 1, true);
stfEncryption.MessageEnd();
}
}
bool Secp256k1PP::decryptECIES(Secret const& _k, bytesConstRef _sharedMacData, bytes& io_text)
{
// interop w/go ecies implementation
// io_cipher[0] must be 2, 3, or 4, else invalidpublickey
if (io_text.empty() || io_text[0] < 2 || io_text[0] > 4)
// invalid message: publickey
return false;
if (io_text.size() < (1 + Public::size + h128::size + 1 + h256::size))
// invalid message: length
return false;
Secret z;
if (!ecdh::agree(_k, *(Public*)(io_text.data() + 1), z))
return false; // Invalid pubkey or seckey.
auto key = ecies::kdf(z, bytes(), 64);
bytesConstRef eKey = bytesConstRef(&key).cropped(0, 16);
bytesRef mKeyMaterial = bytesRef(&key).cropped(16, 16);
bytes mKey(32);
CryptoPP::SHA256 ctx;
ctx.Update(mKeyMaterial.data(), mKeyMaterial.size());
ctx.Final(mKey.data());
bytes plain;
size_t cipherLen = io_text.size() - 1 - Public::size - h128::size - h256::size;
bytesConstRef cipherWithIV(io_text.data() + 1 + Public::size, h128::size + cipherLen);
bytesConstRef cipherIV = cipherWithIV.cropped(0, h128::size);
bytesConstRef cipherNoIV = cipherWithIV.cropped(h128::size, cipherLen);
bytesConstRef msgMac(cipherNoIV.data() + cipherLen, h256::size);
h128 iv(cipherIV.toBytes());
// verify tag
CryptoPP::HMAC<CryptoPP::SHA256> hmacctx(mKey.data(), mKey.size());
hmacctx.Update(cipherWithIV.data(), cipherWithIV.size());
hmacctx.Update(_sharedMacData.data(), _sharedMacData.size());
h256 mac;
hmacctx.Final(mac.data());
for (unsigned i = 0; i < h256::size; i++)
if (mac[i] != msgMac[i])
return false;
plain = decryptSymNoAuth(SecureFixedHash<16>(eKey), iv, cipherNoIV).makeInsecure();
io_text.resize(plain.size());
io_text.swap(plain);
return true;
}
bool CCryptoModulus::InitCrypto(BYTE *temp, DWORD length)
{
int hashid = 0;
BYTE digest[2048];
memset(digest, 0, sizeof(digest));
if (length >= 10)
{
hashid = temp[4] ^ (temp[3] | (temp[1] ^ temp[0]) < temp[2] % 3);
}
else
{
hashid = temp[0];
}
hashid = (hashid % 11) - 1;
switch (hashid)
{
case 0:
{
CryptoPP::SHA256 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[0] % 10;
this->InitCrypto(this->m_algorithm, digest, 32);
}
break;
case 2:
{
CryptoPP::SHA512 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[1] % 10;
this->InitCrypto(this->m_algorithm, digest, 64);
}
break;
case 3:
{
CryptoPP::SHA384 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[2] % 10;
this->InitCrypto(this->m_algorithm, digest, 48);
}
break;
case 4:
{
CryptoPP::Weak1::MD4 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[3] % 10;
this->InitCrypto(this->m_algorithm, digest, 16);
}
break;
case 5:
{
CryptoPP::Weak1::MD5 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[4] % 10;
this->InitCrypto(this->m_algorithm, digest, 16);
}
break;
case 6:
{
CryptoPP::RIPEMD160 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[5] % 10;
this->InitCrypto(this->m_algorithm, digest, 20);
}
break;
case 7:
{
CryptoPP::RIPEMD320 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[6] % 10;
this->InitCrypto(this->m_algorithm, digest, 40);
}
break;
case 8:
{
CryptoPP::RIPEMD128 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[7] % 10;
this->InitCrypto(this->m_algorithm, digest, 16);
}
break;
case 9:
{
CryptoPP::RIPEMD256 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[8] % 10;
this->InitCrypto(this->m_algorithm, digest, 32);
}
break;
default:
{
CryptoPP::Weak1::MD5 hash;
hash.Update(temp, length);
hash.Final(digest);
this->m_algorithm = digest[9] % 10;
this->InitCrypto(this->m_algorithm, digest, 16);
}
break;
}
return true;
}
