Beispiel #1
0
        private static byte[] DecodeBytes(string token, object key = null, JwsAlgorithm?expectedJwsAlg = null, JweAlgorithm?expectedJweAlg = null, JweEncryption?expectedJweEnc = null, JwtSettings settings = null, byte[] payload = null, bool requireSignature = false)
        {
            Ensure.IsNotEmpty(token, "Incoming token expected to be in compact serialization form, not empty, whitespace or null.");

            Compact.Iterator parts = Compact.Iterate(token);

            if (parts.Count == 5) //encrypted JWT
            {
                return(DecryptBytes(parts, key, expectedJweAlg, expectedJweEnc, settings));
            }
            else
            {
                //signed or plain JWT
                JwtSettings jwtSettings = GetSettings(settings);

                byte[] header = parts.Next();

                Dictionary <string, object> headerData = jwtSettings.JsonMapper.Parse <Dictionary <string, object> >(Encoding.UTF8.GetString(header));

                bool b64 = true;

                if (headerData.TryGetValue("b64", out object value))
                {
                    b64 = (bool)value;
                }

                byte[] contentPayload   = parts.Next(b64);
                byte[] signature        = parts.Next();
                byte[] effectivePayload = payload ?? contentPayload;

                if (requireSignature && signature.Length == 0)
                {
                    throw new JoseException("Payload is missing required signature");
                }

                string       algorithm    = (string)headerData["alg"];
                JwsAlgorithm jwsAlgorithm = jwtSettings.JwsAlgorithmFromHeader(algorithm);

                if (expectedJwsAlg != null && expectedJwsAlg != jwsAlgorithm)
                {
                    throw new InvalidAlgorithmException("The algorithm type passed to the Decode method did not match the algorithm type in the header.");
                }

                IJwsAlgorithm jwsAlgorithmImpl = jwtSettings.Jws(jwsAlgorithm);

                if (jwsAlgorithmImpl == null)
                {
                    throw new JoseException(string.Format("Unsupported JWS algorithm requested: {0}", algorithm));
                }

                // If the key has not been specified, attempt to read it from the header.
                if (key == null && headerData.ContainsKey("kid") && jwsAlgorithm != JwsAlgorithm.none)
                {
                    if (jwsAlgorithm == JwsAlgorithm.ES256K)
                    {
                        key = (BitcoinPubKeyAddress)BitcoinPubKeyAddress.Create((string)headerData["kid"], jwtSettings.Network);
                    }
                    else
                    {
                        key = (string)headerData["kid"];
                    }
                }

                if (!jwsAlgorithmImpl.Verify(signature, securedInput(header, effectivePayload, b64), key))
                {
                    throw new IntegrityException("Invalid signature.");
                }

                return(effectivePayload);
            }
        }