protected override void HandleHandshakeMessage(byte type, MemoryStream buf) { if (this.mResumedSession) { if (type != HandshakeType.finished || this.mConnectionState != CS_SERVER_HELLO) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } ProcessFinishedMessage(buf); this.mConnectionState = CS_SERVER_FINISHED; SendChangeCipherSpecMessage(); SendFinishedMessage(); this.mConnectionState = CS_CLIENT_FINISHED; CompleteHandshake(); return; } switch (type) { case HandshakeType.certificate: { switch (this.mConnectionState) { case CS_SERVER_HELLO: case CS_SERVER_SUPPLEMENTAL_DATA: { if (this.mConnectionState == CS_SERVER_HELLO) { HandleSupplementalData(null); } // Parse the Certificate message and Send to cipher suite this.mPeerCertificate = Certificate.Parse(buf); AssertEmpty(buf); // TODO[RFC 3546] Check whether empty certificates is possible, allowed, or excludes CertificateStatus if (this.mPeerCertificate == null || this.mPeerCertificate.IsEmpty) { this.mAllowCertificateStatus = false; } this.mKeyExchange.ProcessServerCertificate(this.mPeerCertificate); this.mAuthentication = mTlsClient.GetAuthentication(); this.mAuthentication.NotifyServerCertificate(this.mPeerCertificate); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mConnectionState = CS_SERVER_CERTIFICATE; break; } case HandshakeType.certificate_status: { switch (this.mConnectionState) { case CS_SERVER_CERTIFICATE: { if (!this.mAllowCertificateStatus) { /* * RFC 3546 3.6. If a server returns a "CertificateStatus" message, then the * server MUST have included an extension of type "status_request" with empty * "extension_data" in the extended server hello.. */ throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mCertificateStatus = CertificateStatus.Parse(buf); AssertEmpty(buf); // TODO[RFC 3546] Figure out how to provide this to the client/authentication. this.mConnectionState = CS_CERTIFICATE_STATUS; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.finished: { switch (this.mConnectionState) { case CS_CLIENT_FINISHED: case CS_SERVER_SESSION_TICKET: { if (this.mConnectionState == CS_CLIENT_FINISHED && this.mExpectSessionTicket) { /* * RFC 5077 3.3. This message MUST be sent if the server included a * SessionTicket extension in the ServerHello. */ throw new TlsFatalAlert(AlertDescription.unexpected_message); } ProcessFinishedMessage(buf); this.mConnectionState = CS_SERVER_FINISHED; CompleteHandshake(); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.server_hello: { switch (this.mConnectionState) { case CS_CLIENT_HELLO: { ReceiveServerHelloMessage(buf); this.mConnectionState = CS_SERVER_HELLO; this.mRecordStream.NotifyHelloComplete(); ApplyMaxFragmentLengthExtension(); if (this.mResumedSession) { this.mSecurityParameters.masterSecret = Arrays.Clone(this.mSessionParameters.MasterSecret); this.mRecordStream.SetPendingConnectionState(Peer.GetCompression(), Peer.GetCipher()); } else { InvalidateSession(); if (this.mSelectedSessionID.Length > 0) { this.mTlsSession = new TlsSessionImpl(this.mSelectedSessionID, null); } } break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.supplemental_data: { switch (this.mConnectionState) { case CS_SERVER_HELLO: { HandleSupplementalData(ReadSupplementalDataMessage(buf)); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.server_hello_done: { switch (this.mConnectionState) { case CS_SERVER_HELLO: case CS_SERVER_SUPPLEMENTAL_DATA: case CS_SERVER_CERTIFICATE: case CS_CERTIFICATE_STATUS: case CS_SERVER_KEY_EXCHANGE: case CS_CERTIFICATE_REQUEST: { if (mConnectionState < CS_SERVER_SUPPLEMENTAL_DATA) { HandleSupplementalData(null); } if (mConnectionState < CS_SERVER_CERTIFICATE) { // There was no server certificate message; check it's OK this.mKeyExchange.SkipServerCredentials(); this.mAuthentication = null; } if (mConnectionState < CS_SERVER_KEY_EXCHANGE) { // There was no server key exchange message; check it's OK this.mKeyExchange.SkipServerKeyExchange(); } AssertEmpty(buf); this.mConnectionState = CS_SERVER_HELLO_DONE; this.mRecordStream.HandshakeHash.SealHashAlgorithms(); IList clientSupplementalData = mTlsClient.GetClientSupplementalData(); if (clientSupplementalData != null) { SendSupplementalDataMessage(clientSupplementalData); } this.mConnectionState = CS_CLIENT_SUPPLEMENTAL_DATA; TlsCredentials clientCreds = null; if (mCertificateRequest == null) { this.mKeyExchange.SkipClientCredentials(); } else { clientCreds = this.mAuthentication.GetClientCredentials(mCertificateRequest); if (clientCreds == null) { this.mKeyExchange.SkipClientCredentials(); /* * 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. */ SendCertificateMessage(Certificate.EmptyChain); } else { this.mKeyExchange.ProcessClientCredentials(clientCreds); SendCertificateMessage(clientCreds.Certificate); } } this.mConnectionState = CS_CLIENT_CERTIFICATE; /* * Send the client key exchange message, depending on the key exchange we are using * in our CipherSuite. */ SendClientKeyExchangeMessage(); this.mConnectionState = CS_CLIENT_KEY_EXCHANGE; if (TlsUtilities.IsSsl(Context)) { EstablishMasterSecret(Context, mKeyExchange); } TlsHandshakeHash prepareFinishHash = mRecordStream.PrepareToFinish(); this.mSecurityParameters.sessionHash = GetCurrentPrfHash(Context, prepareFinishHash, null); if (!TlsUtilities.IsSsl(Context)) { EstablishMasterSecret(Context, mKeyExchange); } mRecordStream.SetPendingConnectionState(Peer.GetCompression(), Peer.GetCipher()); if (clientCreds != null && clientCreds is TlsSignerCredentials) { TlsSignerCredentials signerCredentials = (TlsSignerCredentials)clientCreds; /* * RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm from TLS 1.2 */ SignatureAndHashAlgorithm signatureAndHashAlgorithm = TlsUtilities.GetSignatureAndHashAlgorithm( Context, signerCredentials); byte[] hash; if (signatureAndHashAlgorithm == null) { hash = mSecurityParameters.SessionHash; } else { hash = prepareFinishHash.GetFinalHash(signatureAndHashAlgorithm.Hash); } byte[] signature = signerCredentials.GenerateCertificateSignature(hash); DigitallySigned certificateVerify = new DigitallySigned(signatureAndHashAlgorithm, signature); SendCertificateVerifyMessage(certificateVerify); this.mConnectionState = CS_CERTIFICATE_VERIFY; } SendChangeCipherSpecMessage(); SendFinishedMessage(); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mConnectionState = CS_CLIENT_FINISHED; break; } case HandshakeType.server_key_exchange: { switch (this.mConnectionState) { case CS_SERVER_HELLO: case CS_SERVER_SUPPLEMENTAL_DATA: case CS_SERVER_CERTIFICATE: case CS_CERTIFICATE_STATUS: { if (mConnectionState < CS_SERVER_SUPPLEMENTAL_DATA) { HandleSupplementalData(null); } if (mConnectionState < CS_SERVER_CERTIFICATE) { // There was no server certificate message; check it's OK this.mKeyExchange.SkipServerCredentials(); this.mAuthentication = null; } this.mKeyExchange.ProcessServerKeyExchange(buf); AssertEmpty(buf); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mConnectionState = CS_SERVER_KEY_EXCHANGE; break; } case HandshakeType.certificate_request: { switch (this.mConnectionState) { case CS_SERVER_CERTIFICATE: case CS_CERTIFICATE_STATUS: case CS_SERVER_KEY_EXCHANGE: { if (this.mConnectionState != CS_SERVER_KEY_EXCHANGE) { // There was no server key exchange message; check it's OK this.mKeyExchange.SkipServerKeyExchange(); } if (this.mAuthentication == null) { /* * RFC 2246 7.4.4. It is a fatal handshake_failure alert for an anonymous server * to request client identification. */ throw new TlsFatalAlert(AlertDescription.handshake_failure); } this.mCertificateRequest = CertificateRequest.Parse(Context, buf); AssertEmpty(buf); this.mKeyExchange.ValidateCertificateRequest(this.mCertificateRequest); /* * TODO Give the client a chance to immediately select the CertificateVerify hash * algorithm here to avoid tracking the other hash algorithms unnecessarily? */ TlsUtilities.TrackHashAlgorithms(this.mRecordStream.HandshakeHash, this.mCertificateRequest.SupportedSignatureAlgorithms); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mConnectionState = CS_CERTIFICATE_REQUEST; break; } case HandshakeType.session_ticket: { switch (this.mConnectionState) { case CS_CLIENT_FINISHED: { if (!this.mExpectSessionTicket) { /* * RFC 5077 3.3. This message MUST NOT be sent if the server did not include a * SessionTicket extension in the ServerHello. */ throw new TlsFatalAlert(AlertDescription.unexpected_message); } /* * RFC 5077 3.4. If the client receives a session ticket from the server, then it * discards any Session ID that was sent in the ServerHello. */ InvalidateSession(); ReceiveNewSessionTicketMessage(buf); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mConnectionState = CS_SERVER_SESSION_TICKET; break; } case HandshakeType.hello_request: { AssertEmpty(buf); /* * RFC 2246 7.4.1.1 Hello request This message will be ignored by the client if the * client is currently negotiating a session. This message may be ignored by the client * if it does not wish to renegotiate a session, or the client may, if it wishes, * respond with a no_renegotiation alert. */ if (this.mConnectionState == CS_END) { RefuseRenegotiation(); } break; } case HandshakeType.client_hello: case HandshakeType.client_key_exchange: case HandshakeType.certificate_verify: case HandshakeType.hello_verify_request: default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } }
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.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) .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 override void HandleHandshakeMessage(byte type, MemoryStream buf) { switch (type) { case HandshakeType.client_hello: { switch (this.mConnectionState) { case CS_START: { ReceiveClientHelloMessage(buf); this.mConnectionState = CS_CLIENT_HELLO; SendServerHelloMessage(); this.mConnectionState = CS_SERVER_HELLO; mRecordStream.NotifyHelloComplete(); IList serverSupplementalData = mTlsServer.GetServerSupplementalData(); if (serverSupplementalData != null) { SendSupplementalDataMessage(serverSupplementalData); } this.mConnectionState = CS_SERVER_SUPPLEMENTAL_DATA; this.mKeyExchange = mTlsServer.GetKeyExchange(); this.mKeyExchange.Init(Context); this.mServerCredentials = mTlsServer.GetCredentials(); Certificate serverCertificate = null; if (this.mServerCredentials == null) { this.mKeyExchange.SkipServerCredentials(); } else { this.mKeyExchange.ProcessServerCredentials(this.mServerCredentials); serverCertificate = this.mServerCredentials.Certificate; SendCertificateMessage(serverCertificate); } this.mConnectionState = CS_SERVER_CERTIFICATE; // TODO[RFC 3546] Check whether empty certificates is possible, allowed, or excludes CertificateStatus if (serverCertificate == null || serverCertificate.IsEmpty) { this.mAllowCertificateStatus = false; } if (this.mAllowCertificateStatus) { CertificateStatus certificateStatus = mTlsServer.GetCertificateStatus(); if (certificateStatus != null) { SendCertificateStatusMessage(certificateStatus); } } this.mConnectionState = CS_CERTIFICATE_STATUS; byte[] serverKeyExchange = this.mKeyExchange.GenerateServerKeyExchange(); if (serverKeyExchange != null) { SendServerKeyExchangeMessage(serverKeyExchange); } this.mConnectionState = CS_SERVER_KEY_EXCHANGE; if (this.mServerCredentials != null) { this.mCertificateRequest = mTlsServer.GetCertificateRequest(); if (this.mCertificateRequest != null) { if (TlsUtilities.IsTlsV12(Context) != (mCertificateRequest.SupportedSignatureAlgorithms != null)) { throw new TlsFatalAlert(AlertDescription.internal_error); } this.mKeyExchange.ValidateCertificateRequest(mCertificateRequest); SendCertificateRequestMessage(mCertificateRequest); TlsUtilities.TrackHashAlgorithms(this.mRecordStream.HandshakeHash, this.mCertificateRequest.SupportedSignatureAlgorithms); } } this.mConnectionState = CS_CERTIFICATE_REQUEST; SendServerHelloDoneMessage(); this.mConnectionState = CS_SERVER_HELLO_DONE; this.mRecordStream.HandshakeHash.SealHashAlgorithms(); break; } case CS_END: { RefuseRenegotiation(); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.supplemental_data: { switch (this.mConnectionState) { case CS_SERVER_HELLO_DONE: { mTlsServer.ProcessClientSupplementalData(ReadSupplementalDataMessage(buf)); this.mConnectionState = CS_CLIENT_SUPPLEMENTAL_DATA; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.certificate: { switch (this.mConnectionState) { case CS_SERVER_HELLO_DONE: case CS_CLIENT_SUPPLEMENTAL_DATA: { if (mConnectionState < CS_CLIENT_SUPPLEMENTAL_DATA) { mTlsServer.ProcessClientSupplementalData(null); } if (this.mCertificateRequest == null) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } ReceiveCertificateMessage(buf); this.mConnectionState = CS_CLIENT_CERTIFICATE; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.client_key_exchange: { switch (this.mConnectionState) { case CS_SERVER_HELLO_DONE: case CS_CLIENT_SUPPLEMENTAL_DATA: case CS_CLIENT_CERTIFICATE: { if (mConnectionState < CS_CLIENT_SUPPLEMENTAL_DATA) { mTlsServer.ProcessClientSupplementalData(null); } if (mConnectionState < CS_CLIENT_CERTIFICATE) { if (this.mCertificateRequest == null) { this.mKeyExchange.SkipClientCredentials(); } else { if (TlsUtilities.IsTlsV12(Context)) { /* * 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); } else if (TlsUtilities.IsSsl(Context)) { if (this.mPeerCertificate == null) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } } else { NotifyClientCertificate(Certificate.EmptyChain); } } } ReceiveClientKeyExchangeMessage(buf); this.mConnectionState = CS_CLIENT_KEY_EXCHANGE; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.certificate_verify: { switch (this.mConnectionState) { case CS_CLIENT_KEY_EXCHANGE: { /* * 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()) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } ReceiveCertificateVerifyMessage(buf); this.mConnectionState = CS_CERTIFICATE_VERIFY; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.finished: { switch (this.mConnectionState) { case CS_CLIENT_KEY_EXCHANGE: case CS_CERTIFICATE_VERIFY: { if (mConnectionState < CS_CERTIFICATE_VERIFY && ExpectCertificateVerifyMessage()) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } ProcessFinishedMessage(buf); this.mConnectionState = CS_CLIENT_FINISHED; if (this.mExpectSessionTicket) { SendNewSessionTicketMessage(mTlsServer.GetNewSessionTicket()); } this.mConnectionState = CS_SERVER_SESSION_TICKET; SendChangeCipherSpecMessage(); SendFinishedMessage(); this.mConnectionState = CS_SERVER_FINISHED; CompleteHandshake(); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.hello_request: case HandshakeType.hello_verify_request: case HandshakeType.server_hello: case HandshakeType.server_key_exchange: case HandshakeType.certificate_request: case HandshakeType.server_hello_done: case HandshakeType.session_ticket: default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } }