Esempio n. 1
0
        public byte[] DecryptApplicationData(TlsKeys tlsKeys, TlsPacket.TlsApplicationData applicationData, ulong sequenceNumber)
        {
            if (KeyBlock == null)
            {
                throw new InvalidOperationException($"KeyBlock not initialized. Please, call {nameof(InitializeKeyBlock)} first.");
            }

            var content = new Span <byte>(applicationData.Body);

            if (this.SecurityParameters.CipherType == TlsCipherType.Aead)
            {
                var macLength         = SecurityParameters.MacLength / 8;
                var recordNonceLength = SecurityParameters.RecordIVLength / 8;
                var nonce             = ComputeNonce(tlsKeys, content);
                var additionalData    = ByteString.Combine(
                    BitConverter.GetBytes(sequenceNumber).Reverse().ToArray(),
                    new byte[] { (byte)applicationData.M_Parent.ContentType,
                                 applicationData.M_Parent.Version.Major,
                                 applicationData.M_Parent.Version.Minor },
                    BitConverter.GetBytes((ushort)(applicationData.Body.Length - (recordNonceLength + macLength))).Reverse().ToArray()
                    );

                var aead = CreateAeadCipher(SecurityParameters.CipherMode, CreateBlockCipher(SecurityParameters.CipherAlgorithm.ToString().ToUpperInvariant()));
                return(DecryptAead(aead, tlsKeys.EncodingKey, nonce, content.Slice(recordNonceLength), additionalData));
            }
            if (this.SecurityParameters.CipherType == TlsCipherType.Block)
            {
                var cbc = CreateBlockCipher(SecurityParameters.CipherMode, CreateBlockCipher(SecurityParameters.CipherAlgorithm.ToString().ToUpperInvariant()));
                var mac = CreateHMacAlgorithm(SecurityParameters.MacAlgorithm);
                return(DecryptBlock(cbc, mac, tlsKeys.EncodingKey, tlsKeys.IV, tlsKeys.MacKey, content));
            }
            if (this.SecurityParameters.CipherType == TlsCipherType.Stream)
            {
                throw new NotImplementedException();
            }
            throw new NotSupportedException($"Decrypting {CipherSuite.ToString()} is not supported.");
        }
Esempio n. 2
0
 public override string ToString()
 {
     return(CipherSuite.ToString());
 }