Esempio n. 1
0
        public override byte[] GenerateServerKeyExchange()
        {
            mSrpServer.Init(mSrpGroup, mSrpVerifier, TlsUtilities.CreateHash(HashAlgorithm.sha1), mContext.SecureRandom);
            BigInteger B = mSrpServer.GenerateServerCredentials();

            ServerSrpParams srpParams = new ServerSrpParams(mSrpGroup.N, mSrpGroup.G, mSrpSalt, B);

            DigestInputBuffer buf = new DigestInputBuffer();

            srpParams.Encode(buf);

            if (mServerCredentials != null)
            {
                /*
                 * RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm from TLS 1.2
                 */
                SignatureAndHashAlgorithm signatureAndHashAlgorithm = TlsUtilities.GetSignatureAndHashAlgorithm(
                    mContext, mServerCredentials);

                IDigest d = TlsUtilities.CreateHash(signatureAndHashAlgorithm);

                SecurityParameters securityParameters = mContext.SecurityParameters;
                d.BlockUpdate(securityParameters.clientRandom, 0, securityParameters.clientRandom.Length);
                d.BlockUpdate(securityParameters.serverRandom, 0, securityParameters.serverRandom.Length);
                buf.UpdateDigest(d);

                byte[] hash = new byte[d.GetDigestSize()];
                d.DoFinal(hash, 0);

                byte[] signature = mServerCredentials.GenerateCertificateSignature(hash);

                DigitallySigned signed_params = new DigitallySigned(signatureAndHashAlgorithm, signature);
                signed_params.Encode(buf);
            }

            return(buf.ToArray());
        }
Esempio n. 2
0
        public override byte[] GenerateServerKeyExchange()
        {
            if (this.mDHParameters == null)
            {
                throw new TlsFatalAlert(AlertDescription.internal_error);
            }

            DigestInputBuffer buf = new DigestInputBuffer();

            this.mDHAgreePrivateKey = TlsDHUtilities.GenerateEphemeralServerKeyExchange(mContext.SecureRandom,
                                                                                        this.mDHParameters, buf);

            /*
             * RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm from TLS 1.2
             */
            SignatureAndHashAlgorithm signatureAndHashAlgorithm = TlsUtilities.GetSignatureAndHashAlgorithm(
                mContext, mServerCredentials);

            IDigest d = TlsUtilities.CreateHash(signatureAndHashAlgorithm);

            SecurityParameters securityParameters = mContext.SecurityParameters;

            d.BlockUpdate(securityParameters.clientRandom, 0, securityParameters.clientRandom.Length);
            d.BlockUpdate(securityParameters.serverRandom, 0, securityParameters.serverRandom.Length);
            buf.UpdateDigest(d);

            byte[] hash = DigestUtilities.DoFinal(d);

            byte[] signature = mServerCredentials.GenerateCertificateSignature(hash);

            DigitallySigned signed_params = new DigitallySigned(signatureAndHashAlgorithm, signature);

            signed_params.Encode(buf);

            return(buf.ToArray());
        }
        public override void ProcessServerKeyExchange(Stream input)
        {
            SecurityParameters securityParameters = mContext.SecurityParameters;

            SignerInputBuffer buf   = new SignerInputBuffer();
            Stream            teeIn = new TeeInputStream(input, buf);

            ECDomainParameters curve_params = TlsEccUtilities.ReadECParameters(mNamedCurves, mClientECPointFormats, teeIn);

            byte[] point = TlsUtilities.ReadOpaque8(teeIn);

            DigitallySigned signed_params = ParseSignature(input);

            ISigner signer = InitVerifyer(mTlsSigner, signed_params.Algorithm, securityParameters);

            buf.UpdateSigner(signer);
            if (!signer.VerifySignature(signed_params.Signature))
            {
                throw new TlsFatalAlert(AlertDescription.decrypt_error);
            }

            this.mECAgreePublicKey = TlsEccUtilities.ValidateECPublicKey(TlsEccUtilities.DeserializeECPublicKey(
                                                                             mClientECPointFormats, curve_params, point));
        }
        internal virtual DtlsTransport ClientHandshake(ClientHandshakeState state, DtlsRecordLayer recordLayer)
        {
            SecurityParameters    securityParameters = state.clientContext.SecurityParameters;
            DtlsReliableHandshake handshake          = new DtlsReliableHandshake(state.clientContext, recordLayer);

            byte[] clientHelloBody = GenerateClientHello(state, state.client);

            recordLayer.SetWriteVersion(ProtocolVersion.DTLSv10);

            handshake.SendMessage(HandshakeType.client_hello, clientHelloBody);

            DtlsReliableHandshake.Message serverMessage = handshake.ReceiveMessage();

            while (serverMessage.Type == HandshakeType.hello_verify_request)
            {
                ProtocolVersion recordLayerVersion = recordLayer.ReadVersion;
                ProtocolVersion client_version     = state.clientContext.ClientVersion;

                /*
                 * RFC 6347 4.2.1 DTLS 1.2 server implementations SHOULD use DTLS version 1.0 regardless of
                 * the version of TLS that is expected to be negotiated. DTLS 1.2 and 1.0 clients MUST use
                 * the version solely to indicate packet formatting (which is the same in both DTLS 1.2 and
                 * 1.0) and not as part of version negotiation.
                 */
                if (!recordLayerVersion.IsEqualOrEarlierVersionOf(client_version))
                {
                    throw new TlsFatalAlert(AlertDescription.illegal_parameter);
                }

                recordLayer.ReadVersion = null;

                byte[] cookie  = ProcessHelloVerifyRequest(state, serverMessage.Body);
                byte[] patched = PatchClientHelloWithCookie(clientHelloBody, cookie);

                handshake.ResetHandshakeMessagesDigest();
                handshake.SendMessage(HandshakeType.client_hello, patched);

                serverMessage = handshake.ReceiveMessage();
            }

            if (serverMessage.Type == HandshakeType.server_hello)
            {
                ProtocolVersion recordLayerVersion = recordLayer.ReadVersion;
                ReportServerVersion(state, recordLayerVersion);
                recordLayer.SetWriteVersion(recordLayerVersion);

                ProcessServerHello(state, serverMessage.Body);
            }
            else
            {
                throw new TlsFatalAlert(AlertDescription.unexpected_message);
            }

            handshake.NotifyHelloComplete();

            ApplyMaxFragmentLengthExtension(recordLayer, securityParameters.maxFragmentLength);

            if (state.resumedSession)
            {
                securityParameters.masterSecret = Arrays.Clone(state.sessionParameters.MasterSecret);
                recordLayer.InitPendingEpoch(state.client.GetCipher());

                // NOTE: Calculated exclusive of the actual Finished message from the server
                byte[] resExpectedServerVerifyData = TlsUtilities.CalculateVerifyData(state.clientContext, ExporterLabel.server_finished,
                                                                                      TlsProtocol.GetCurrentPrfHash(state.clientContext, handshake.HandshakeHash, null));
                ProcessFinished(handshake.ReceiveMessageBody(HandshakeType.finished), resExpectedServerVerifyData);

                // NOTE: Calculated exclusive of the Finished message itself
                byte[] resClientVerifyData = TlsUtilities.CalculateVerifyData(state.clientContext, ExporterLabel.client_finished,
                                                                              TlsProtocol.GetCurrentPrfHash(state.clientContext, handshake.HandshakeHash, null));
                handshake.SendMessage(HandshakeType.finished, resClientVerifyData);

                handshake.Finish();

                state.clientContext.SetResumableSession(state.tlsSession);

                state.client.NotifyHandshakeComplete();

                return(new DtlsTransport(recordLayer));
            }

            InvalidateSession(state);

            if (state.selectedSessionID.Length > 0)
            {
                state.tlsSession = new TlsSessionImpl(state.selectedSessionID, null);
            }

            serverMessage = handshake.ReceiveMessage();

            if (serverMessage.Type == HandshakeType.supplemental_data)
            {
                ProcessServerSupplementalData(state, serverMessage.Body);
                serverMessage = handshake.ReceiveMessage();
            }
            else
            {
                state.client.ProcessServerSupplementalData(null);
            }

            state.keyExchange = state.client.GetKeyExchange();
            state.keyExchange.Init(state.clientContext);

            Certificate serverCertificate = null;

            if (serverMessage.Type == HandshakeType.certificate)
            {
                serverCertificate = ProcessServerCertificate(state, serverMessage.Body);
                serverMessage     = handshake.ReceiveMessage();
            }
            else
            {
                // Okay, Certificate is optional
                state.keyExchange.SkipServerCredentials();
            }

            // TODO[RFC 3546] Check whether empty certificates is possible, allowed, or excludes CertificateStatus
            if (serverCertificate == null || serverCertificate.IsEmpty)
            {
                state.allowCertificateStatus = false;
            }

            if (serverMessage.Type == HandshakeType.certificate_status)
            {
                ProcessCertificateStatus(state, serverMessage.Body);
                serverMessage = handshake.ReceiveMessage();
            }
            else
            {
                // Okay, CertificateStatus is optional
            }

            if (serverMessage.Type == HandshakeType.server_key_exchange)
            {
                ProcessServerKeyExchange(state, serverMessage.Body);
                serverMessage = handshake.ReceiveMessage();
            }
            else
            {
                // Okay, ServerKeyExchange is optional
                state.keyExchange.SkipServerKeyExchange();
            }

            if (serverMessage.Type == HandshakeType.certificate_request)
            {
                ProcessCertificateRequest(state, serverMessage.Body);

                /*
                 * TODO Give the client a chance to immediately select the CertificateVerify hash
                 * algorithm here to avoid tracking the other hash algorithms unnecessarily?
                 */
                TlsUtilities.TrackHashAlgorithms(handshake.HandshakeHash,
                                                 state.certificateRequest.SupportedSignatureAlgorithms);

                serverMessage = handshake.ReceiveMessage();
            }
            else
            {
                // Okay, CertificateRequest is optional
            }

            if (serverMessage.Type == HandshakeType.server_hello_done)
            {
                if (serverMessage.Body.Length != 0)
                {
                    throw new TlsFatalAlert(AlertDescription.decode_error);
                }
            }
            else
            {
                throw new TlsFatalAlert(AlertDescription.unexpected_message);
            }

            handshake.HandshakeHash.SealHashAlgorithms();

            IList clientSupplementalData = state.client.GetClientSupplementalData();

            if (clientSupplementalData != null)
            {
                byte[] supplementalDataBody = GenerateSupplementalData(clientSupplementalData);
                handshake.SendMessage(HandshakeType.supplemental_data, supplementalDataBody);
            }

            if (state.certificateRequest != null)
            {
                state.clientCredentials = state.authentication.GetClientCredentials(state.clientContext, state.certificateRequest);

                /*
                 * RFC 5246 If no suitable certificate is available, the client MUST send a certificate
                 * message containing no certificates.
                 *
                 * NOTE: In previous RFCs, this was SHOULD instead of MUST.
                 */
                Certificate clientCertificate = null;
                if (state.clientCredentials != null)
                {
                    clientCertificate = state.clientCredentials.Certificate;
                }
                if (clientCertificate == null)
                {
                    clientCertificate = Certificate.EmptyChain;
                }

                byte[] certificateBody = GenerateCertificate(clientCertificate);
                handshake.SendMessage(HandshakeType.certificate, certificateBody);
            }

            if (state.clientCredentials != null)
            {
                state.keyExchange.ProcessClientCredentials(state.clientCredentials);
            }
            else
            {
                state.keyExchange.SkipClientCredentials();
            }

            byte[] clientKeyExchangeBody = GenerateClientKeyExchange(state);
            handshake.SendMessage(HandshakeType.client_key_exchange, clientKeyExchangeBody);

            TlsHandshakeHash prepareFinishHash = handshake.PrepareToFinish();

            securityParameters.sessionHash = TlsProtocol.GetCurrentPrfHash(state.clientContext, prepareFinishHash, null);

            TlsProtocol.EstablishMasterSecret(state.clientContext, state.keyExchange);
            recordLayer.InitPendingEpoch(state.client.GetCipher());

            if (state.clientCredentials != null && state.clientCredentials is TlsSignerCredentials)
            {
                TlsSignerCredentials signerCredentials = (TlsSignerCredentials)state.clientCredentials;

                /*
                 * RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm from TLS 1.2
                 */
                SignatureAndHashAlgorithm signatureAndHashAlgorithm = TlsUtilities.GetSignatureAndHashAlgorithm(
                    state.clientContext, signerCredentials);

                byte[] hash;
                if (signatureAndHashAlgorithm == null)
                {
                    hash = securityParameters.SessionHash;
                }
                else
                {
                    hash = prepareFinishHash.GetFinalHash(signatureAndHashAlgorithm.Hash);
                }

                byte[]          signature             = signerCredentials.GenerateCertificateSignature(hash);
                DigitallySigned certificateVerify     = new DigitallySigned(signatureAndHashAlgorithm, signature);
                byte[]          certificateVerifyBody = GenerateCertificateVerify(state, certificateVerify);
                handshake.SendMessage(HandshakeType.certificate_verify, certificateVerifyBody);
            }

            // NOTE: Calculated exclusive of the Finished message itself
            byte[] clientVerifyData = TlsUtilities.CalculateVerifyData(state.clientContext, ExporterLabel.client_finished,
                                                                       TlsProtocol.GetCurrentPrfHash(state.clientContext, handshake.HandshakeHash, null));
            handshake.SendMessage(HandshakeType.finished, clientVerifyData);

            if (state.expectSessionTicket)
            {
                serverMessage = handshake.ReceiveMessage();
                if (serverMessage.Type == HandshakeType.session_ticket)
                {
                    ProcessNewSessionTicket(state, serverMessage.Body);
                }
                else
                {
                    throw new TlsFatalAlert(AlertDescription.unexpected_message);
                }
            }

            // NOTE: Calculated exclusive of the actual Finished message from the server
            byte[] expectedServerVerifyData = TlsUtilities.CalculateVerifyData(state.clientContext, ExporterLabel.server_finished,
                                                                               TlsProtocol.GetCurrentPrfHash(state.clientContext, handshake.HandshakeHash, null));
            ProcessFinished(handshake.ReceiveMessageBody(HandshakeType.finished), expectedServerVerifyData);

            handshake.Finish();

            if (state.tlsSession != null)
            {
                state.sessionParameters = new SessionParameters.Builder()
                                          .SetCipherSuite(securityParameters.CipherSuite)
                                          .SetCompressionAlgorithm(securityParameters.CompressionAlgorithm)
                                          .SetExtendedMasterSecret(securityParameters.IsExtendedMasterSecret)
                                          .SetMasterSecret(securityParameters.MasterSecret)
                                          .SetPeerCertificate(serverCertificate)
                                          .SetPskIdentity(securityParameters.PskIdentity)
                                          .SetSrpIdentity(securityParameters.SrpIdentity)
                                          // TODO Consider filtering extensions that aren't relevant to resumed sessions
                                          .SetServerExtensions(state.serverExtensions)
                                          .Build();

                state.tlsSession = TlsUtilities.ImportSession(state.tlsSession.SessionID, state.sessionParameters);

                state.clientContext.SetResumableSession(state.tlsSession);
            }

            state.client.NotifyHandshakeComplete();

            return(new DtlsTransport(recordLayer));
        }
        protected virtual void ProcessServerHello(ClientHandshakeState state, byte[] body)
        {
            SecurityParameters securityParameters = state.clientContext.SecurityParameters;

            MemoryStream buf = new MemoryStream(body, false);

            {
                ProtocolVersion server_version = TlsUtilities.ReadVersion(buf);
                ReportServerVersion(state, server_version);
            }

            securityParameters.serverRandom = TlsUtilities.ReadFully(32, buf);

            state.selectedSessionID = TlsUtilities.ReadOpaque8(buf);
            if (state.selectedSessionID.Length > 32)
            {
                throw new TlsFatalAlert(AlertDescription.illegal_parameter);
            }
            state.client.NotifySessionID(state.selectedSessionID);
            state.resumedSession = state.selectedSessionID.Length > 0 && state.tlsSession != null &&
                                   Arrays.AreEqual(state.selectedSessionID, state.tlsSession.SessionID);

            int selectedCipherSuite = TlsUtilities.ReadUint16(buf);

            if (!Arrays.Contains(state.offeredCipherSuites, selectedCipherSuite) ||
                selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL ||
                CipherSuite.IsScsv(selectedCipherSuite) ||
                !TlsUtilities.IsValidCipherSuiteForVersion(selectedCipherSuite, state.clientContext.ServerVersion))
            {
                throw new TlsFatalAlert(AlertDescription.illegal_parameter);
            }
            ValidateSelectedCipherSuite(selectedCipherSuite, AlertDescription.illegal_parameter);
            state.client.NotifySelectedCipherSuite(selectedCipherSuite);

            byte selectedCompressionMethod = TlsUtilities.ReadUint8(buf);

            if (CompressionMethod.cls_null != selectedCompressionMethod)
            {
                throw new TlsFatalAlert(AlertDescription.illegal_parameter);
            }
            state.client.NotifySelectedCompressionMethod(selectedCompressionMethod);

            /*
             * RFC3546 2.2 The extended server hello message format MAY be sent in place of the server
             * hello message when the client has requested extended functionality via the extended
             * client hello message specified in Section 2.1. ... Note that the extended server hello
             * message is only sent in response to an extended client hello message. This prevents the
             * possibility that the extended server hello message could "break" existing TLS 1.0
             * clients.
             */

            /*
             * TODO RFC 3546 2.3 If [...] the older session is resumed, then the server MUST ignore
             * extensions appearing in the client hello, and send a server hello containing no
             * extensions.
             */

            // Integer -> byte[]
            state.serverExtensions = TlsProtocol.ReadExtensions(buf);

            /*
             * RFC 7627 4. Clients and servers SHOULD NOT accept handshakes that do not use the extended
             * master secret [..]. (and see 5.2, 5.3)
             */
            securityParameters.extendedMasterSecret = TlsExtensionsUtilities.HasExtendedMasterSecretExtension(state.serverExtensions);

            if (!securityParameters.IsExtendedMasterSecret &&
                (state.resumedSession || state.client.RequiresExtendedMasterSecret()))
            {
                throw new TlsFatalAlert(AlertDescription.handshake_failure);
            }

            /*
             * RFC 3546 2.2 Note that the extended server hello message is only sent in response to an
             * extended client hello message. However, see RFC 5746 exception below. We always include
             * the SCSV, so an Extended Server Hello is always allowed.
             */
            if (state.serverExtensions != null)
            {
                foreach (int extType in state.serverExtensions.Keys)
                {
                    /*
                     * RFC 5746 3.6. Note that sending a "renegotiation_info" extension in response to a
                     * ClientHello containing only the SCSV is an explicit exception to the prohibition
                     * in RFC 5246, Section 7.4.1.4, on the server sending unsolicited extensions and is
                     * only allowed because the client is signaling its willingness to receive the
                     * extension via the TLS_EMPTY_RENEGOTIATION_INFO_SCSV SCSV.
                     */
                    if (extType == ExtensionType.renegotiation_info)
                    {
                        continue;
                    }

                    /*
                     * RFC 5246 7.4.1.4 An extension type MUST NOT appear in the ServerHello unless the
                     * same extension type appeared in the corresponding ClientHello. If a client
                     * receives an extension type in ServerHello that it did not request in the
                     * associated ClientHello, it MUST abort the handshake with an unsupported_extension
                     * fatal alert.
                     */
                    if (null == TlsUtilities.GetExtensionData(state.clientExtensions, extType))
                    {
                        throw new TlsFatalAlert(AlertDescription.unsupported_extension);
                    }

                    /*
                     * RFC 3546 2.3. If [...] the older session is resumed, then the server MUST ignore
                     * extensions appearing in the client hello, and send a server hello containing no
                     * extensions[.]
                     */
                    if (state.resumedSession)
                    {
                        // TODO[compat-gnutls] GnuTLS test server sends server extensions e.g. ec_point_formats
                        // TODO[compat-openssl] OpenSSL test server sends server extensions e.g. ec_point_formats
                        // TODO[compat-polarssl] PolarSSL test server sends server extensions e.g. ec_point_formats
                        //throw new TlsFatalAlert(AlertDescription.illegal_parameter);
                    }
                }
            }

            /*
             * RFC 5746 3.4. Client Behavior: Initial Handshake
             */
            {
                /*
                 * When a ServerHello is received, the client MUST check if it includes the
                 * "renegotiation_info" extension:
                 */
                byte[] renegExtData = TlsUtilities.GetExtensionData(state.serverExtensions, ExtensionType.renegotiation_info);
                if (renegExtData != null)
                {
                    /*
                     * If the extension is present, set the secure_renegotiation flag to TRUE. The
                     * client MUST then verify that the length of the "renegotiated_connection"
                     * field is zero, and if it is not, MUST abort the handshake (by sending a fatal
                     * handshake_failure alert).
                     */
                    state.secure_renegotiation = true;

                    if (!Arrays.ConstantTimeAreEqual(renegExtData, TlsProtocol.CreateRenegotiationInfo(TlsUtilities.EmptyBytes)))
                    {
                        throw new TlsFatalAlert(AlertDescription.handshake_failure);
                    }
                }
            }

            // TODO[compat-gnutls] GnuTLS test server fails to send renegotiation_info extension when resuming
            state.client.NotifySecureRenegotiation(state.secure_renegotiation);

            IDictionary sessionClientExtensions = state.clientExtensions, sessionServerExtensions = state.serverExtensions;

            if (state.resumedSession)
            {
                if (selectedCipherSuite != state.sessionParameters.CipherSuite ||
                    selectedCompressionMethod != state.sessionParameters.CompressionAlgorithm)
                {
                    throw new TlsFatalAlert(AlertDescription.illegal_parameter);
                }

                sessionClientExtensions = null;
                sessionServerExtensions = state.sessionParameters.ReadServerExtensions();
            }

            securityParameters.cipherSuite          = selectedCipherSuite;
            securityParameters.compressionAlgorithm = selectedCompressionMethod;

            if (sessionServerExtensions != null && sessionServerExtensions.Count > 0)
            {
                {
                    /*
                     * RFC 7366 3. If a server receives an encrypt-then-MAC request extension from a client
                     * and then selects a stream or Authenticated Encryption with Associated Data (AEAD)
                     * ciphersuite, it MUST NOT send an encrypt-then-MAC response extension back to the
                     * client.
                     */
                    bool serverSentEncryptThenMAC = TlsExtensionsUtilities.HasEncryptThenMacExtension(sessionServerExtensions);
                    if (serverSentEncryptThenMAC && !TlsUtilities.IsBlockCipherSuite(securityParameters.CipherSuite))
                    {
                        throw new TlsFatalAlert(AlertDescription.illegal_parameter);
                    }
                    securityParameters.encryptThenMac = serverSentEncryptThenMAC;
                }

                securityParameters.maxFragmentLength = EvaluateMaxFragmentLengthExtension(state.resumedSession,
                                                                                          sessionClientExtensions, sessionServerExtensions, AlertDescription.illegal_parameter);

                securityParameters.truncatedHMac = TlsExtensionsUtilities.HasTruncatedHMacExtension(sessionServerExtensions);

                /*
                 * TODO It's surprising that there's no provision to allow a 'fresh' CertificateStatus to be
                 * sent in a session resumption handshake.
                 */
                state.allowCertificateStatus = !state.resumedSession &&
                                               TlsUtilities.HasExpectedEmptyExtensionData(sessionServerExtensions, ExtensionType.status_request,
                                                                                          AlertDescription.illegal_parameter);

                state.expectSessionTicket = !state.resumedSession &&
                                            TlsUtilities.HasExpectedEmptyExtensionData(sessionServerExtensions, ExtensionType.session_ticket,
                                                                                       AlertDescription.illegal_parameter);
            }

            if (sessionClientExtensions != null)
            {
                state.client.ProcessServerExtensions(sessionServerExtensions);
            }

            securityParameters.prfAlgorithm = TlsProtocol.GetPrfAlgorithm(state.clientContext,
                                                                          securityParameters.CipherSuite);

            /*
             * RFC 5246 7.4.9. Any cipher suite which does not explicitly specify verify_data_length has
             * a verify_data_length equal to 12. This includes all existing cipher suites.
             */
            securityParameters.verifyDataLength = 12;
        }
        protected virtual byte[] GenerateClientHello(ClientHandshakeState state, TlsClient client)
        {
            ProtocolVersion client_version = client.ClientVersion;

            if (!client_version.IsDtls)
            {
                throw new TlsFatalAlert(AlertDescription.internal_error);
            }

            TlsClientContextImpl context = state.clientContext;

            context.SetClientVersion(client_version);

            SecurityParameters securityParameters = context.SecurityParameters;

            // Session ID
            byte[] session_id = TlsUtilities.EmptyBytes;
            if (state.tlsSession != null)
            {
                session_id = state.tlsSession.SessionID;
                if (session_id == null || session_id.Length > 32)
                {
                    session_id = TlsUtilities.EmptyBytes;
                }
            }

            bool fallback = client.IsFallback;

            state.offeredCipherSuites = client.GetCipherSuites();

            if (session_id.Length > 0 && state.sessionParameters != null)
            {
                if (!state.sessionParameters.IsExtendedMasterSecret ||
                    !Arrays.Contains(state.offeredCipherSuites, state.sessionParameters.CipherSuite) ||
                    CompressionMethod.cls_null != state.sessionParameters.CompressionAlgorithm)
                {
                    session_id = TlsUtilities.EmptyBytes;
                }
            }

            state.clientExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(client.GetClientExtensions());

            TlsExtensionsUtilities.AddExtendedMasterSecretExtension(state.clientExtensions);

            MemoryStream buf = new MemoryStream();

            TlsUtilities.WriteVersion(client_version, buf);

            buf.Write(securityParameters.ClientRandom, 0, securityParameters.ClientRandom.Length);

            TlsUtilities.WriteOpaque8(session_id, buf);

            // Cookie
            TlsUtilities.WriteOpaque8(TlsUtilities.EmptyBytes, buf);

            // Cipher Suites (and SCSV)
            {
                /*
                 * RFC 5746 3.4. The client MUST include either an empty "renegotiation_info" extension,
                 * or the TLS_EMPTY_RENEGOTIATION_INFO_SCSV signaling cipher suite value in the
                 * ClientHello. Including both is NOT RECOMMENDED.
                 */
                byte[] renegExtData = TlsUtilities.GetExtensionData(state.clientExtensions, ExtensionType.renegotiation_info);
                bool   noRenegExt   = (null == renegExtData);

                bool noRenegSCSV = !Arrays.Contains(state.offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV);

                if (noRenegExt && noRenegSCSV)
                {
                    // TODO Consider whether to default to a client extension instead
                    state.offeredCipherSuites = Arrays.Append(state.offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV);
                }

                /*
                 * RFC 7507 4. If a client sends a ClientHello.client_version containing a lower value
                 * than the latest (highest-valued) version supported by the client, it SHOULD include
                 * the TLS_FALLBACK_SCSV cipher suite value in ClientHello.cipher_suites [..]. (The
                 * client SHOULD put TLS_FALLBACK_SCSV after all cipher suites that it actually intends
                 * to negotiate.)
                 */
                if (fallback && !Arrays.Contains(state.offeredCipherSuites, CipherSuite.TLS_FALLBACK_SCSV))
                {
                    state.offeredCipherSuites = Arrays.Append(state.offeredCipherSuites, CipherSuite.TLS_FALLBACK_SCSV);
                }

                TlsUtilities.WriteUint16ArrayWithUint16Length(state.offeredCipherSuites, buf);
            }

            TlsUtilities.WriteUint8ArrayWithUint8Length(new byte[] { CompressionMethod.cls_null }, buf);

            TlsProtocol.WriteExtensions(buf, state.clientExtensions);

            return(buf.ToArray());
        }
        public virtual DtlsTransport Connect(TlsClient client, DatagramTransport transport)
        {
            if (client == null)
            {
                throw new ArgumentNullException("client");
            }
            if (transport == null)
            {
                throw new ArgumentNullException("transport");
            }

            SecurityParameters securityParameters = new SecurityParameters();

            securityParameters.entity = ConnectionEnd.client;

            ClientHandshakeState state = new ClientHandshakeState();

            state.client        = client;
            state.clientContext = new TlsClientContextImpl(mSecureRandom, securityParameters);

            securityParameters.clientRandom = TlsProtocol.CreateRandomBlock(client.ShouldUseGmtUnixTime(),
                                                                            state.clientContext.NonceRandomGenerator);

            client.Init(state.clientContext);

            DtlsRecordLayer recordLayer = new DtlsRecordLayer(transport, state.clientContext, client, ContentType.handshake);

            TlsSession sessionToResume = state.client.GetSessionToResume();

            if (sessionToResume != null && sessionToResume.IsResumable)
            {
                SessionParameters sessionParameters = sessionToResume.ExportSessionParameters();
                if (sessionParameters != null && sessionParameters.IsExtendedMasterSecret)
                {
                    state.tlsSession        = sessionToResume;
                    state.sessionParameters = sessionParameters;
                }
            }

            try
            {
                return(ClientHandshake(state, recordLayer));
            }
            catch (TlsFatalAlert fatalAlert)
            {
                AbortClientHandshake(state, recordLayer, fatalAlert.AlertDescription);
                throw fatalAlert;
            }
            catch (IOException e)
            {
                AbortClientHandshake(state, recordLayer, AlertDescription.internal_error);
                throw e;
            }
            catch (Exception e)
            {
                AbortClientHandshake(state, recordLayer, AlertDescription.internal_error);
                throw new TlsFatalAlert(AlertDescription.internal_error, e);
            }
            finally
            {
                securityParameters.Clear();
            }
        }
Esempio n. 8
0
 internal TlsClientContextImpl(SecureRandom secureRandom, SecurityParameters securityParameters)
     :   base(secureRandom, securityParameters)
 {
 }
Esempio n. 9
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        internal virtual DtlsTransport ServerHandshake(ServerHandshakeState state, DtlsRecordLayer recordLayer)
        {
            SecurityParameters    securityParameters = state.serverContext.SecurityParameters;
            DtlsReliableHandshake handshake          = new DtlsReliableHandshake(state.serverContext, recordLayer);

            DtlsReliableHandshake.Message clientMessage = handshake.ReceiveMessage();

            // NOTE: DTLSRecordLayer requires any DTLS version, we don't otherwise constrain this
            //ProtocolVersion recordLayerVersion = recordLayer.ReadVersion;

            if (clientMessage.Type == HandshakeType.client_hello)
            {
                ProcessClientHello(state, clientMessage.Body);
            }
            else
            {
                throw new TlsFatalAlert(AlertDescription.unexpected_message);
            }

            {
                byte[] serverHelloBody = GenerateServerHello(state);

                ApplyMaxFragmentLengthExtension(recordLayer, securityParameters.maxFragmentLength);

                ProtocolVersion recordLayerVersion = state.serverContext.ServerVersion;
                recordLayer.ReadVersion = recordLayerVersion;
                recordLayer.SetWriteVersion(recordLayerVersion);

                handshake.SendMessage(HandshakeType.server_hello, serverHelloBody);
            }

            handshake.NotifyHelloComplete();

            IList serverSupplementalData = state.server.GetServerSupplementalData();

            if (serverSupplementalData != null)
            {
                byte[] supplementalDataBody = GenerateSupplementalData(serverSupplementalData);
                handshake.SendMessage(HandshakeType.supplemental_data, supplementalDataBody);
            }

            state.keyExchange = state.server.GetKeyExchange();
            state.keyExchange.Init(state.serverContext);

            state.serverCredentials = state.server.GetCredentials();

            Certificate serverCertificate = null;

            if (state.serverCredentials == null)
            {
                state.keyExchange.SkipServerCredentials();
            }
            else
            {
                state.keyExchange.ProcessServerCredentials(state.serverCredentials);

                serverCertificate = state.serverCredentials.Certificate;
                byte[] certificateBody = GenerateCertificate(serverCertificate);
                handshake.SendMessage(HandshakeType.certificate, certificateBody);
            }

            // TODO[RFC 3546] Check whether empty certificates is possible, allowed, or excludes CertificateStatus
            if (serverCertificate == null || serverCertificate.IsEmpty)
            {
                state.allowCertificateStatus = false;
            }

            if (state.allowCertificateStatus)
            {
                CertificateStatus certificateStatus = state.server.GetCertificateStatus();
                if (certificateStatus != null)
                {
                    byte[] certificateStatusBody = GenerateCertificateStatus(state, certificateStatus);
                    handshake.SendMessage(HandshakeType.certificate_status, certificateStatusBody);
                }
            }

            byte[] serverKeyExchange = state.keyExchange.GenerateServerKeyExchange();
            if (serverKeyExchange != null)
            {
                handshake.SendMessage(HandshakeType.server_key_exchange, serverKeyExchange);
            }

            if (state.serverCredentials != null)
            {
                state.certificateRequest = state.server.GetCertificateRequest();
                if (state.certificateRequest != null)
                {
                    if (TlsUtilities.IsTlsV12(state.serverContext) != (state.certificateRequest.SupportedSignatureAlgorithms != null))
                    {
                        throw new TlsFatalAlert(AlertDescription.internal_error);
                    }

                    state.keyExchange.ValidateCertificateRequest(state.certificateRequest);

                    byte[] certificateRequestBody = GenerateCertificateRequest(state, state.certificateRequest);
                    handshake.SendMessage(HandshakeType.certificate_request, certificateRequestBody);

                    TlsUtilities.TrackHashAlgorithms(handshake.HandshakeHash,
                                                     state.certificateRequest.SupportedSignatureAlgorithms);
                }
            }

            handshake.SendMessage(HandshakeType.server_hello_done, TlsUtilities.EmptyBytes);

            handshake.HandshakeHash.SealHashAlgorithms();

            clientMessage = handshake.ReceiveMessage();

            if (clientMessage.Type == HandshakeType.supplemental_data)
            {
                ProcessClientSupplementalData(state, clientMessage.Body);
                clientMessage = handshake.ReceiveMessage();
            }
            else
            {
                state.server.ProcessClientSupplementalData(null);
            }

            if (state.certificateRequest == null)
            {
                state.keyExchange.SkipClientCredentials();
            }
            else
            {
                if (clientMessage.Type == HandshakeType.certificate)
                {
                    ProcessClientCertificate(state, clientMessage.Body);
                    clientMessage = handshake.ReceiveMessage();
                }
                else
                {
                    if (TlsUtilities.IsTlsV12(state.serverContext))
                    {
                        /*
                         * RFC 5246 If no suitable certificate is available, the client MUST send a
                         * certificate message containing no certificates.
                         *
                         * NOTE: In previous RFCs, this was SHOULD instead of MUST.
                         */
                        throw new TlsFatalAlert(AlertDescription.unexpected_message);
                    }

                    NotifyClientCertificate(state, Certificate.EmptyChain);
                }
            }

            if (clientMessage.Type == HandshakeType.client_key_exchange)
            {
                ProcessClientKeyExchange(state, clientMessage.Body);
            }
            else
            {
                throw new TlsFatalAlert(AlertDescription.unexpected_message);
            }

            TlsHandshakeHash prepareFinishHash = handshake.PrepareToFinish();

            securityParameters.sessionHash = TlsProtocol.GetCurrentPrfHash(state.serverContext, prepareFinishHash, null);

            TlsProtocol.EstablishMasterSecret(state.serverContext, state.keyExchange);
            recordLayer.InitPendingEpoch(state.server.GetCipher());

            /*
             * RFC 5246 7.4.8 This message is only sent following a client certificate that has signing
             * capability (i.e., all certificates except those containing fixed Diffie-Hellman
             * parameters).
             */
            if (ExpectCertificateVerifyMessage(state))
            {
                byte[] certificateVerifyBody = handshake.ReceiveMessageBody(HandshakeType.certificate_verify);
                ProcessCertificateVerify(state, certificateVerifyBody, prepareFinishHash);
            }

            // NOTE: Calculated exclusive of the actual Finished message from the client
            byte[] expectedClientVerifyData = TlsUtilities.CalculateVerifyData(state.serverContext, ExporterLabel.client_finished,
                                                                               TlsProtocol.GetCurrentPrfHash(state.serverContext, handshake.HandshakeHash, null));
            ProcessFinished(handshake.ReceiveMessageBody(HandshakeType.finished), expectedClientVerifyData);

            if (state.expectSessionTicket)
            {
                NewSessionTicket newSessionTicket     = state.server.GetNewSessionTicket();
                byte[]           newSessionTicketBody = GenerateNewSessionTicket(state, newSessionTicket);
                handshake.SendMessage(HandshakeType.session_ticket, newSessionTicketBody);
            }

            // NOTE: Calculated exclusive of the Finished message itself
            byte[] serverVerifyData = TlsUtilities.CalculateVerifyData(state.serverContext, ExporterLabel.server_finished,
                                                                       TlsProtocol.GetCurrentPrfHash(state.serverContext, handshake.HandshakeHash, null));
            handshake.SendMessage(HandshakeType.finished, serverVerifyData);

            handshake.Finish();

            //{
            //    state.sessionParameters = new SessionParameters.Builder()
            //        .SetCipherSuite(securityParameters.CipherSuite)
            //        .SetCompressionAlgorithm(securityParameters.CompressionAlgorithm)
            //        .SetExtendedMasterSecret(securityParameters.IsExtendedMasterSecret)
            //        .SetMasterSecret(securityParameters.MasterSecret)
            //        .SetPeerCertificate(state.clientCertificate)
            //        .SetPskIdentity(securityParameters.PskIdentity)
            //        .SetSrpIdentity(securityParameters.SrpIdentity)
            //        // TODO Consider filtering extensions that aren't relevant to resumed sessions
            //        .SetServerExtensions(state.serverExtensions)
            //        .Build();

            //    state.tlsSession = TlsUtilities.ImportSession(state.tlsSession.SessionID, state.sessionParameters);

            //    state.serverContext.SetResumableSession(state.tlsSession);
            //}

            state.server.NotifyHandshakeComplete();

            return(new DtlsTransport(recordLayer));
        }
Esempio n. 10
0
        protected virtual void ProcessClientHello(ServerHandshakeState state, byte[] body)
        {
            MemoryStream buf = new MemoryStream(body, false);

            // TODO Read RFCs for guidance on the expected record layer version number
            ProtocolVersion client_version = TlsUtilities.ReadVersion(buf);

            if (!client_version.IsDtls)
            {
                throw new TlsFatalAlert(AlertDescription.illegal_parameter);
            }

            /*
             * Read the client random
             */
            byte[] client_random = TlsUtilities.ReadFully(32, buf);

            byte[] sessionID = TlsUtilities.ReadOpaque8(buf);
            if (sessionID.Length > 32)
            {
                throw new TlsFatalAlert(AlertDescription.illegal_parameter);
            }

            // TODO RFC 4347 has the cookie length restricted to 32, but not in RFC 6347
            byte[] cookie = TlsUtilities.ReadOpaque8(buf);

            int cipher_suites_length = TlsUtilities.ReadUint16(buf);

            if (cipher_suites_length < 2 || (cipher_suites_length & 1) != 0)
            {
                throw new TlsFatalAlert(AlertDescription.decode_error);
            }

            /*
             * NOTE: "If the session_id field is not empty (implying a session resumption request) this
             * vector must include at least the cipher_suite from that session."
             */
            state.offeredCipherSuites = TlsUtilities.ReadUint16Array(cipher_suites_length / 2, buf);

            int compression_methods_length = TlsUtilities.ReadUint8(buf);

            if (compression_methods_length < 1)
            {
                throw new TlsFatalAlert(AlertDescription.illegal_parameter);
            }

            state.offeredCompressionMethods = TlsUtilities.ReadUint8Array(compression_methods_length, buf);

            /*
             * TODO RFC 3546 2.3 If [...] the older session is resumed, then the server MUST ignore
             * extensions appearing in the client hello, and send a server hello containing no
             * extensions.
             */
            state.clientExtensions = TlsProtocol.ReadExtensions(buf);

            TlsServerContextImpl context            = state.serverContext;
            SecurityParameters   securityParameters = context.SecurityParameters;

            /*
             * TODO[resumption] Check RFC 7627 5.4. for required behaviour
             */

            /*
             * RFC 7627 4. Clients and servers SHOULD NOT accept handshakes that do not use the extended
             * master secret [..]. (and see 5.2, 5.3)
             */
            securityParameters.extendedMasterSecret = TlsExtensionsUtilities.HasExtendedMasterSecretExtension(state.clientExtensions);
            if (!securityParameters.IsExtendedMasterSecret && state.server.RequiresExtendedMasterSecret())
            {
                throw new TlsFatalAlert(AlertDescription.handshake_failure);
            }

            context.SetClientVersion(client_version);

            state.server.NotifyClientVersion(client_version);
            state.server.NotifyFallback(Arrays.Contains(state.offeredCipherSuites, CipherSuite.TLS_FALLBACK_SCSV));

            securityParameters.clientRandom = client_random;

            state.server.NotifyOfferedCipherSuites(state.offeredCipherSuites);
            state.server.NotifyOfferedCompressionMethods(state.offeredCompressionMethods);

            /*
             * RFC 5746 3.6. Server Behavior: Initial Handshake
             */
            {
                /*
                 * RFC 5746 3.4. The client MUST include either an empty "renegotiation_info" extension,
                 * or the TLS_EMPTY_RENEGOTIATION_INFO_SCSV signaling cipher suite value in the
                 * ClientHello. Including both is NOT RECOMMENDED.
                 */

                /*
                 * When a ClientHello is received, the server MUST check if it includes the
                 * TLS_EMPTY_RENEGOTIATION_INFO_SCSV SCSV. If it does, set the secure_renegotiation flag
                 * to TRUE.
                 */
                if (Arrays.Contains(state.offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV))
                {
                    state.secure_renegotiation = true;
                }

                /*
                 * The server MUST check if the "renegotiation_info" extension is included in the
                 * ClientHello.
                 */
                byte[] renegExtData = TlsUtilities.GetExtensionData(state.clientExtensions, ExtensionType.renegotiation_info);
                if (renegExtData != null)
                {
                    /*
                     * If the extension is present, set secure_renegotiation flag to TRUE. The
                     * server MUST then verify that the length of the "renegotiated_connection"
                     * field is zero, and if it is not, MUST abort the handshake.
                     */
                    state.secure_renegotiation = true;

                    if (!Arrays.ConstantTimeAreEqual(renegExtData, TlsProtocol.CreateRenegotiationInfo(TlsUtilities.EmptyBytes)))
                    {
                        throw new TlsFatalAlert(AlertDescription.handshake_failure);
                    }
                }
            }

            state.server.NotifySecureRenegotiation(state.secure_renegotiation);

            if (state.clientExtensions != null)
            {
                // NOTE: Validates the padding extension data, if present
                TlsExtensionsUtilities.GetPaddingExtension(state.clientExtensions);

                state.server.ProcessClientExtensions(state.clientExtensions);
            }
        }
Esempio n. 11
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        protected virtual byte[] GenerateServerHello(ServerHandshakeState state)
        {
            SecurityParameters securityParameters = state.serverContext.SecurityParameters;

            MemoryStream buf = new MemoryStream();

            {
                ProtocolVersion server_version = state.server.GetServerVersion();
                if (!server_version.IsEqualOrEarlierVersionOf(state.serverContext.ClientVersion))
                {
                    throw new TlsFatalAlert(AlertDescription.internal_error);
                }

                // TODO Read RFCs for guidance on the expected record layer version number
                // recordStream.setReadVersion(server_version);
                // recordStream.setWriteVersion(server_version);
                // recordStream.setRestrictReadVersion(true);
                state.serverContext.SetServerVersion(server_version);

                TlsUtilities.WriteVersion(state.serverContext.ServerVersion, buf);
            }

            buf.Write(securityParameters.ServerRandom, 0, securityParameters.ServerRandom.Length);

            /*
             * The server may return an empty session_id to indicate that the session will not be cached
             * and therefore cannot be resumed.
             */
            TlsUtilities.WriteOpaque8(TlsUtilities.EmptyBytes, buf);

            int selectedCipherSuite = state.server.GetSelectedCipherSuite();

            if (!Arrays.Contains(state.offeredCipherSuites, selectedCipherSuite) ||
                selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL ||
                CipherSuite.IsScsv(selectedCipherSuite) ||
                !TlsUtilities.IsValidCipherSuiteForVersion(selectedCipherSuite, state.serverContext.ServerVersion))
            {
                throw new TlsFatalAlert(AlertDescription.internal_error);
            }
            ValidateSelectedCipherSuite(selectedCipherSuite, AlertDescription.internal_error);
            securityParameters.cipherSuite = selectedCipherSuite;

            byte selectedCompressionMethod = state.server.GetSelectedCompressionMethod();

            if (!Arrays.Contains(state.offeredCompressionMethods, selectedCompressionMethod))
            {
                throw new TlsFatalAlert(AlertDescription.internal_error);
            }
            securityParameters.compressionAlgorithm = selectedCompressionMethod;

            TlsUtilities.WriteUint16(selectedCipherSuite, buf);
            TlsUtilities.WriteUint8(selectedCompressionMethod, buf);

            state.serverExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(state.server.GetServerExtensions());

            /*
             * RFC 5746 3.6. Server Behavior: Initial Handshake
             */
            if (state.secure_renegotiation)
            {
                byte[] renegExtData = TlsUtilities.GetExtensionData(state.serverExtensions, ExtensionType.renegotiation_info);
                bool   noRenegExt   = (null == renegExtData);

                if (noRenegExt)
                {
                    /*
                     * Note that sending a "renegotiation_info" extension in response to a ClientHello
                     * containing only the SCSV is an explicit exception to the prohibition in RFC 5246,
                     * Section 7.4.1.4, on the server sending unsolicited extensions and is only allowed
                     * because the client is signaling its willingness to receive the extension via the
                     * TLS_EMPTY_RENEGOTIATION_INFO_SCSV SCSV.
                     */

                    /*
                     * If the secure_renegotiation flag is set to TRUE, the server MUST include an empty
                     * "renegotiation_info" extension in the ServerHello message.
                     */
                    state.serverExtensions[ExtensionType.renegotiation_info] = TlsProtocol.CreateRenegotiationInfo(TlsUtilities.EmptyBytes);
                }
            }

            if (securityParameters.IsExtendedMasterSecret)
            {
                TlsExtensionsUtilities.AddExtendedMasterSecretExtension(state.serverExtensions);
            }

            /*
             * TODO RFC 3546 2.3 If [...] the older session is resumed, then the server MUST ignore
             * extensions appearing in the client hello, and send a server hello containing no
             * extensions.
             */

            if (state.serverExtensions.Count > 0)
            {
                securityParameters.encryptThenMac = TlsExtensionsUtilities.HasEncryptThenMacExtension(state.serverExtensions);

                securityParameters.maxFragmentLength = EvaluateMaxFragmentLengthExtension(state.resumedSession,
                                                                                          state.clientExtensions, state.serverExtensions, AlertDescription.internal_error);

                securityParameters.truncatedHMac = TlsExtensionsUtilities.HasTruncatedHMacExtension(state.serverExtensions);

                /*
                 * TODO It's surprising that there's no provision to allow a 'fresh' CertificateStatus to be sent in
                 * a session resumption handshake.
                 */
                state.allowCertificateStatus = !state.resumedSession &&
                                               TlsUtilities.HasExpectedEmptyExtensionData(state.serverExtensions, ExtensionType.status_request,
                                                                                          AlertDescription.internal_error);

                state.expectSessionTicket = !state.resumedSession &&
                                            TlsUtilities.HasExpectedEmptyExtensionData(state.serverExtensions, ExtensionType.session_ticket,
                                                                                       AlertDescription.internal_error);

                TlsProtocol.WriteExtensions(buf, state.serverExtensions);
            }

            securityParameters.prfAlgorithm = TlsProtocol.GetPrfAlgorithm(state.serverContext,
                                                                          securityParameters.CipherSuite);

            /*
             * RFC 5246 7.4.9. Any cipher suite which does not explicitly specify verify_data_length
             * has a verify_data_length equal to 12. This includes all existing cipher suites.
             */
            securityParameters.verifyDataLength = 12;

            return(buf.ToArray());
        }
Esempio n. 12
0
 internal TlsServerContextImpl(SecureRandom secureRandom, SecurityParameters securityParameters)
     : base(secureRandom, securityParameters)
 {
 }