public ECKeyInfo(
int length,
string p_str,
string a_str,
string b_str,
string gx_str,
string gy_str,
string n_str)
{
this.length = length;
p = new Org.BouncyCastle.Math.BigInteger(p_str, 16);
a = new Org.BouncyCastle.Math.BigInteger(a_str, 16);
b = new Org.BouncyCastle.Math.BigInteger(b_str, 16);
gx = new Org.BouncyCastle.Math.BigInteger(gx_str, 16);
gy = new Org.BouncyCastle.Math.BigInteger(gy_str, 16);
n = new Org.BouncyCastle.Math.BigInteger(n_str, 16);
Org.BouncyCastle.Math.BigInteger h = Org.BouncyCastle.Math.BigInteger.One;
this.curve = new Org.BouncyCastle.Math.EC.FpCurve(p, a, b, n, h);
//spec = new ECParameterSpec(curve, new ECPoint(gx, gy), n, 1);
this.spec = new Org.BouncyCastle.Crypto.Parameters.ECDomainParameters(
curve
, curve.CreatePoint(gx, gy) // G
, n
, h
);
}
public void SetUpSecp256k1()
{
//Set up OpenECC Curve
OpenECCSecp256k1 = OpenECC.CurveFactory.secp256k1;
OpenECCGenerator = OpenECCSecp256k1.Generator;
OpenECCPoint1 = OpenECCGenerator * 3;
OpenECCPoint2 = OpenECCGenerator * 5;
//Set up BouncyCastle curve
var bc_stuff = Org.BouncyCastle.Asn1.Sec.SecNamedCurves.GetByName("secp256k1");
BCSecp256k1 = bc_stuff.Curve;
BCGenerator = bc_stuff.G;
BCPoint1 = BCGenerator.Multiply(new Org.BouncyCastle.Math.BigInteger("3"));
BCPoint2 = BCGenerator.Multiply(new Org.BouncyCastle.Math.BigInteger("5"));
}
public static Key Deserialize(IEnumerable <byte> payload)
{
if (payload == null)
{
throw new ArgumentNullException(nameof(payload));
}
var c = SecNamedCurves.GetByName("secp256k1");
var domain = new ECDomainParameters(c.Curve, c.G, c.N, c.H);
Org.BouncyCastle.Math.EC.ECCurve curve = domain.Curve;
Org.BouncyCastle.Math.EC.ECPoint q = curve.DecodePoint(payload.ToArray());
var publicKey = new ECPublicKeyParameters(q, domain);
return(new Key(null, publicKey));
}
public static Key Deserialize(BigInteger publicKey, BigInteger privateKey)
{
if (publicKey == null)
{
throw new ArgumentNullException(nameof(publicKey));
}
if (privateKey == null)
{
throw new ArgumentNullException(nameof(privateKey));
}
var c = SecNamedCurves.GetByName("secp256k1");
var domain = new ECDomainParameters(c.Curve, c.G, c.N, c.H);
Org.BouncyCastle.Math.EC.ECCurve curve = domain.Curve;
Org.BouncyCastle.Math.EC.ECPoint q = curve.DecodePoint(publicKey.ToByteArray());
var pubK = new ECPublicKeyParameters(q, domain);
var prK = new ECPrivateKeyParameters(privateKey, domain);
return(new Key(prK, pubK));
}
public bool VerifySignature(byte[] message, byte[] signature, byte[] pubkey)
{
if (pubkey.Length == 33 && (pubkey[0] == 0x02 || pubkey[0] == 0x03))
{
try
{
pubkey = ECPoint.DecodePoint(pubkey, ECCurve.Secp256r1).EncodePoint(false).Skip(1).ToArray();
}
catch
{
return(false);
}
}
else if (pubkey.Length == 65 && pubkey[0] == 0x04)
{
pubkey = pubkey.Skip(1).ToArray();
}
else if (pubkey.Length != 64)
{
throw new ArgumentException();
}
BigInteger x = new BigInteger(1, pubkey.Take(32).ToArray());
BigInteger y = new BigInteger(1, pubkey.Skip(32).ToArray());
X9ECParameters ecParams = NistNamedCurves.GetByName("P-256");
ECDomainParameters domainParameters = new ECDomainParameters(ecParams.Curve, ecParams.G, ecParams.N,
ecParams.H, ecParams.GetSeed());
var G = ecParams.G;
Org.BouncyCastle.Math.EC.ECCurve curve = ecParams.Curve;
Org.BouncyCastle.Math.EC.ECPoint q = curve.CreatePoint(x, y);
ECPublicKeyParameters pubkeyParam = new ECPublicKeyParameters(q, domainParameters);
var verifier = SignerUtilities.GetSigner("SHA-256withECDSA");
verifier.Init(false, pubkeyParam);
verifier.BlockUpdate(message, 0, message.Length);
// expected format is SEQUENCE {INTEGER r, INTEGER s}
var derSignature = new DerSequence(
// first 32 bytes is "r" number
new DerInteger(new BigInteger(1, signature.Take(32).ToArray())),
// last 32 bytes is "s" number
new DerInteger(new BigInteger(1, signature.Skip(32).ToArray())))
.GetDerEncoded();
///old verify method
///
/*
* const int ECDSA_PUBLIC_P256_MAGIC = 0x31534345;
* pubkey = BitConverter.GetBytes(ECDSA_PUBLIC_P256_MAGIC).Concat(BitConverter.GetBytes(32)).Concat(pubkey).ToArray();
* using (CngKey key = CngKey.Import(pubkey, CngKeyBlobFormat.EccPublicBlob))
* using (ECDsaCng ecdsa = new ECDsaCng(key))
* {
* var result = ecdsa.VerifyData(message, signature, HashAlgorithmName.SHA256);
* }
*/
///////////////////
return(verifier.VerifySignature(derSignature));
}
