protected override void HandleHandshakeMessage(byte type, byte[] data) { MemoryStream buf = new MemoryStream(data, false); 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; SendFinishedMessage(); this.mConnectionState = CS_CLIENT_FINISHED; this.mConnectionState = CS_END; 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; this.mConnectionState = CS_END; 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()); SendChangeCipherSpecMessage(); } 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(Context, 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; TlsHandshakeHash prepareFinishHash = mRecordStream.PrepareToFinish(); this.mSecurityParameters.sessionHash = GetCurrentPrfHash(Context, prepareFinishHash, null); 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.handshake_failure); } 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); } }
private void ProcessHandshakeMessage(HandshakeType type, byte[] buf) { MemoryStream inStr = new MemoryStream(buf, false); /* * Check the type. */ switch (type) { case HandshakeType.certificate: { switch (connection_state) { case CS_SERVER_HELLO_RECEIVED: { // Parse the Certificate message and send to cipher suite Certificate serverCertificate = Certificate.Parse(inStr); AssertEmpty(inStr); this.keyExchange.ProcessServerCertificate(serverCertificate); this.authentication = tlsClient.GetAuthentication(); this.authentication.NotifyServerCertificate(serverCertificate); break; } default: this.FailWithError(AlertLevel.fatal, AlertDescription.unexpected_message); break; } connection_state = CS_SERVER_CERTIFICATE_RECEIVED; break; } case HandshakeType.finished: switch (connection_state) { case CS_SERVER_CHANGE_CIPHER_SPEC_RECEIVED: /* * Read the checksum from the finished message, it has always 12 bytes. */ byte[] serverVerifyData = new byte[12]; TlsUtilities.ReadFully(serverVerifyData, inStr); AssertEmpty(inStr); /* * Calculate our own checksum. */ byte[] expectedServerVerifyData = TlsUtilities.PRF( securityParameters.masterSecret, "server finished", rs.GetCurrentHash(), 12); /* * Compare both checksums. */ if (!Arrays.ConstantTimeAreEqual(expectedServerVerifyData, serverVerifyData)) { /* * Wrong checksum in the finished message. */ this.FailWithError(AlertLevel.fatal, AlertDescription.handshake_failure); } connection_state = CS_DONE; /* * We are now ready to receive application data. */ this.appDataReady = true; break; default: this.FailWithError(AlertLevel.fatal, AlertDescription.unexpected_message); break; } break; case HandshakeType.server_hello: switch (connection_state) { case CS_CLIENT_HELLO_SEND: /* * Read the server hello message */ TlsUtilities.CheckVersion(inStr, this); /* * Read the server random */ securityParameters.serverRandom = new byte[32]; TlsUtilities.ReadFully(securityParameters.serverRandom, inStr); byte[] sessionID = TlsUtilities.ReadOpaque8(inStr); if (sessionID.Length > 32) { this.FailWithError(AlertLevel.fatal, AlertDescription.illegal_parameter); } this.tlsClient.NotifySessionID(sessionID); /* * Find out which CipherSuite the server has chosen and check that * it was one of the offered ones. */ CipherSuite selectedCipherSuite = (CipherSuite)TlsUtilities.ReadUint16(inStr); if (!ArrayContains(offeredCipherSuites, selectedCipherSuite) || selectedCipherSuite == CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV) { this.FailWithError(AlertLevel.fatal, AlertDescription.illegal_parameter); } this.tlsClient.NotifySelectedCipherSuite(selectedCipherSuite); /* * Find out which CompressionMethod the server has chosen and check that * it was one of the offered ones. */ CompressionMethod selectedCompressionMethod = (CompressionMethod)TlsUtilities.ReadUint8(inStr); if (!ArrayContains(offeredCompressionMethods, selectedCompressionMethod)) { this.FailWithError(AlertLevel.fatal, AlertDescription.illegal_parameter); } this.tlsClient.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. */ // ExtensionType -> byte[] IDictionary serverExtensions = Platform.CreateHashtable(); if (inStr.Position < inStr.Length) { // Process extensions from extended server hello byte[] extBytes = TlsUtilities.ReadOpaque16(inStr); MemoryStream ext = new MemoryStream(extBytes, false); while (ext.Position < ext.Length) { ExtensionType extType = (ExtensionType)TlsUtilities.ReadUint16(ext); byte[] extValue = TlsUtilities.ReadOpaque16(ext); // Note: RFC 5746 makes a special case for EXT_RenegotiationInfo if (extType != ExtensionType.renegotiation_info && !clientExtensions.Contains(extType)) { /* * RFC 3546 2.3 * Note that for all extension types (including those defined in * future), the extension type MUST NOT appear in the extended server * hello unless the same extension type appeared in the corresponding * client hello. Thus clients MUST abort the handshake if they receive * an extension type in the extended server hello that they did not * request in the associated (extended) client hello. */ this.FailWithError(AlertLevel.fatal, AlertDescription.unsupported_extension); } if (serverExtensions.Contains(extType)) { /* * RFC 3546 2.3 * Also note that when multiple extensions of different types are * present in the extended client hello or the extended server hello, * the extensions may appear in any order. There MUST NOT be more than * one extension of the same type. */ this.FailWithError(AlertLevel.fatal, AlertDescription.illegal_parameter); } serverExtensions.Add(extType, extValue); } } AssertEmpty(inStr); /* * RFC 5746 3.4. When a ServerHello is received, the client MUST check if it * includes the "renegotiation_info" extension: */ { bool secure_negotiation = serverExtensions.Contains(ExtensionType.renegotiation_info); /* * 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). */ if (secure_negotiation) { byte[] renegExtValue = (byte[])serverExtensions[ExtensionType.renegotiation_info]; if (!Arrays.ConstantTimeAreEqual(renegExtValue, CreateRenegotiationInfo(emptybuf))) { this.FailWithError(AlertLevel.fatal, AlertDescription.handshake_failure); } } tlsClient.NotifySecureRenegotiation(secure_negotiation); } if (clientExtensions != null) { tlsClient.ProcessServerExtensions(serverExtensions); } this.keyExchange = tlsClient.GetKeyExchange(); connection_state = CS_SERVER_HELLO_RECEIVED; break; default: this.FailWithError(AlertLevel.fatal, AlertDescription.unexpected_message); break; } break; case HandshakeType.server_hello_done: switch (connection_state) { case CS_SERVER_CERTIFICATE_RECEIVED: case CS_SERVER_KEY_EXCHANGE_RECEIVED: case CS_CERTIFICATE_REQUEST_RECEIVED: // NB: Original code used case label fall-through if (connection_state == CS_SERVER_CERTIFICATE_RECEIVED) { // There was no server key exchange message; check it's OK this.keyExchange.SkipServerKeyExchange(); } AssertEmpty(inStr); connection_state = CS_SERVER_HELLO_DONE_RECEIVED; TlsCredentials clientCreds = null; if (certificateRequest == null) { this.keyExchange.SkipClientCredentials(); } else { clientCreds = this.authentication.GetClientCredentials(certificateRequest); Certificate clientCert; if (clientCreds == null) { this.keyExchange.SkipClientCredentials(); clientCert = Certificate.EmptyChain; } else { this.keyExchange.ProcessClientCredentials(clientCreds); clientCert = clientCreds.Certificate; } SendClientCertificate(clientCert); } /* * Send the client key exchange message, depending on the key * exchange we are using in our CipherSuite. */ SendClientKeyExchange(); connection_state = CS_CLIENT_KEY_EXCHANGE_SEND; if (clientCreds != null && clientCreds is TlsSignerCredentials) { TlsSignerCredentials signerCreds = (TlsSignerCredentials)clientCreds; byte[] md5andsha1 = rs.GetCurrentHash(); byte[] clientCertificateSignature = signerCreds.GenerateCertificateSignature( md5andsha1); SendCertificateVerify(clientCertificateSignature); connection_state = CS_CERTIFICATE_VERIFY_SEND; } /* * Now, we send change cipher state */ byte[] cmessage = new byte[1]; cmessage[0] = 1; rs.WriteMessage(ContentType.change_cipher_spec, cmessage, 0, cmessage.Length); connection_state = CS_CLIENT_CHANGE_CIPHER_SPEC_SEND; /* * Calculate the master_secret */ byte[] pms = this.keyExchange.GeneratePremasterSecret(); securityParameters.masterSecret = TlsUtilities.PRF(pms, "master secret", TlsUtilities.Concat(securityParameters.clientRandom, securityParameters.serverRandom), 48); // TODO Is there a way to ensure the data is really overwritten? /* * RFC 2246 8.1. The pre_master_secret should be deleted from * memory once the master_secret has been computed. */ Array.Clear(pms, 0, pms.Length); /* * Initialize our cipher suite */ rs.ClientCipherSpecDecided(tlsClient.GetCompression(), tlsClient.GetCipher()); /* * Send our finished message. */ byte[] clientVerifyData = TlsUtilities.PRF(securityParameters.masterSecret, "client finished", rs.GetCurrentHash(), 12); MemoryStream bos = new MemoryStream(); TlsUtilities.WriteUint8((byte)HandshakeType.finished, bos); TlsUtilities.WriteOpaque24(clientVerifyData, bos); byte[] message = bos.ToArray(); rs.WriteMessage(ContentType.handshake, message, 0, message.Length); this.connection_state = CS_CLIENT_FINISHED_SEND; break; default: this.FailWithError(AlertLevel.fatal, AlertDescription.handshake_failure); break; } break; case HandshakeType.server_key_exchange: { switch (connection_state) { case CS_SERVER_HELLO_RECEIVED: case CS_SERVER_CERTIFICATE_RECEIVED: { // NB: Original code used case label fall-through if (connection_state == CS_SERVER_HELLO_RECEIVED) { // There was no server certificate message; check it's OK this.keyExchange.SkipServerCertificate(); this.authentication = null; } this.keyExchange.ProcessServerKeyExchange(inStr); AssertEmpty(inStr); break; } default: this.FailWithError(AlertLevel.fatal, AlertDescription.unexpected_message); break; } this.connection_state = CS_SERVER_KEY_EXCHANGE_RECEIVED; break; } case HandshakeType.certificate_request: switch (connection_state) { case CS_SERVER_CERTIFICATE_RECEIVED: case CS_SERVER_KEY_EXCHANGE_RECEIVED: { // NB: Original code used case label fall-through if (connection_state == CS_SERVER_CERTIFICATE_RECEIVED) { // There was no server key exchange message; check it's OK this.keyExchange.SkipServerKeyExchange(); } if (this.authentication == null) { /* * RFC 2246 7.4.4. It is a fatal handshake_failure alert * for an anonymous server to request client identification. */ this.FailWithError(AlertLevel.fatal, AlertDescription.handshake_failure); } int numTypes = TlsUtilities.ReadUint8(inStr); ClientCertificateType[] certificateTypes = new ClientCertificateType[numTypes]; for (int i = 0; i < numTypes; ++i) { certificateTypes[i] = (ClientCertificateType)TlsUtilities.ReadUint8(inStr); } byte[] authorities = TlsUtilities.ReadOpaque16(inStr); AssertEmpty(inStr); IList authorityDNs = Platform.CreateArrayList(); MemoryStream bis = new MemoryStream(authorities, false); while (bis.Position < bis.Length) { byte[] dnBytes = TlsUtilities.ReadOpaque16(bis); // TODO Switch to X500Name when available authorityDNs.Add(X509Name.GetInstance(Asn1Object.FromByteArray(dnBytes))); } this.certificateRequest = new CertificateRequest(certificateTypes, authorityDNs); this.keyExchange.ValidateCertificateRequest(this.certificateRequest); break; } default: this.FailWithError(AlertLevel.fatal, AlertDescription.unexpected_message); break; } this.connection_state = CS_CERTIFICATE_REQUEST_RECEIVED; break; case HandshakeType.hello_request: /* * 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 (connection_state == CS_DONE) { // Renegotiation not supported yet SendAlert(AlertLevel.warning, AlertDescription.no_renegotiation); } break; case HandshakeType.client_key_exchange: case HandshakeType.certificate_verify: case HandshakeType.client_hello: default: // We do not support this! this.FailWithError(AlertLevel.fatal, AlertDescription.unexpected_message); break; } }