Inheritance: IComparable, IEquatable
コード例 #1
0
        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));
        }