public void ReadData() { ContentType type = (ContentType)TlsUtilities.ReadUint8(inStr); TlsUtilities.CheckVersion(inStr, handler); int size = TlsUtilities.ReadUint16(inStr); byte[] buf = DecodeAndVerify(type, inStr, size); handler.ProcessData(type, buf, 0, buf.Length); }
private void processHandshake() { bool read; do { read = false; /* * We need the first 4 bytes, they contain type and length of * the message. */ if (handshakeQueue.Available >= 4) { byte[] beginning = new byte[4]; handshakeQueue.Read(beginning, 0, 4, 0); MemoryStream bis = new MemoryStream(beginning, false); short type = TlsUtilities.ReadUint8(bis); int len = TlsUtilities.ReadUint24(bis); /* * Check if we have enough bytes in the buffer to read * the full message. */ if (handshakeQueue.Available >= (len + 4)) { /* * Read the message. */ byte[] buf = new byte[len]; handshakeQueue.Read(buf, 0, len, 4); handshakeQueue.RemoveData(len + 4); /* * If it is not a finished message, update our hashes * we prepare for the finish message. */ if (type != HP_FINISHED) { rs.hash1.BlockUpdate(beginning, 0, 4); rs.hash2.BlockUpdate(beginning, 0, 4); rs.hash1.BlockUpdate(buf, 0, len); rs.hash2.BlockUpdate(buf, 0, len); } /* * Now, parse the message. */ MemoryStream inStr = new MemoryStream(buf, false); /* * Check the type. */ switch (type) { case HP_CERTIFICATE: { switch (connection_state) { case CS_SERVER_HELLO_RECEIVED: { /* * Parse the certificates. */ Certificate cert = Certificate.Parse(inStr); AssertEmpty(inStr); X509CertificateStructure x509Cert = cert.certs[0]; SubjectPublicKeyInfo keyInfo = x509Cert.SubjectPublicKeyInfo; try { this.serverPublicKey = PublicKeyFactory.CreateKey(keyInfo); } catch (Exception) { this.FailWithError(AL_fatal, AP_unsupported_certificate); } // Sanity check the PublicKeyFactory if (this.serverPublicKey.IsPrivate) { this.FailWithError(AL_fatal, AP_internal_error); } /* * Perform various checks per RFC2246 7.4.2 * TODO "Unless otherwise specified, the signing algorithm for the certificate * must be the same as the algorithm for the certificate key." */ switch (this.chosenCipherSuite.KeyExchangeAlgorithm) { case TlsCipherSuite.KE_RSA: if (!(this.serverPublicKey is RsaKeyParameters)) { this.FailWithError(AL_fatal, AP_certificate_unknown); } validateKeyUsage(x509Cert, KeyUsage.KeyEncipherment); break; case TlsCipherSuite.KE_DHE_RSA: if (!(this.serverPublicKey is RsaKeyParameters)) { this.FailWithError(AL_fatal, AP_certificate_unknown); } validateKeyUsage(x509Cert, KeyUsage.DigitalSignature); break; case TlsCipherSuite.KE_DHE_DSS: if (!(this.serverPublicKey is DsaPublicKeyParameters)) { this.FailWithError(AL_fatal, AP_certificate_unknown); } break; default: this.FailWithError(AL_fatal, AP_unsupported_certificate); break; } /* * Verify them. */ if (!this.verifyer.IsValid(cert.GetCerts())) { this.FailWithError(AL_fatal, AP_user_canceled); } break; } default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } connection_state = CS_SERVER_CERTIFICATE_RECEIVED; read = true; break; } case HP_FINISHED: switch (connection_state) { case CS_SERVER_CHANGE_CIPHER_SPEC_RECEIVED: /* * Read the checksum from the finished message, * it has always 12 bytes. */ byte[] receivedChecksum = new byte[12]; TlsUtilities.ReadFully(receivedChecksum, inStr); AssertEmpty(inStr); /* * Calculate our own checksum. */ byte[] checksum = new byte[12]; byte[] md5andsha1 = new byte[16 + 20]; rs.hash2.DoFinal(md5andsha1, 0); TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("server finished"), md5andsha1, checksum); /* * Compare both checksums. */ for (int i = 0; i < receivedChecksum.Length; i++) { if (receivedChecksum[i] != checksum[i]) { /* * Wrong checksum in the finished message. */ this.FailWithError(AL_fatal, AP_handshake_failure); } } connection_state = CS_DONE; /* * We are now ready to receive application data. */ this.appDataReady = true; read = true; break; default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } break; case HP_SERVER_HELLO: switch (connection_state) { case CS_CLIENT_HELLO_SEND: /* * Read the server hello message */ TlsUtilities.CheckVersion(inStr, this); /* * Read the server random */ this.serverRandom = new byte[32]; TlsUtilities.ReadFully(this.serverRandom, inStr); /* * Currently, we don't support session ids */ short sessionIdLength = TlsUtilities.ReadUint8(inStr); byte[] sessionId = new byte[sessionIdLength]; TlsUtilities.ReadFully(sessionId, inStr); /* * Find out which ciphersuite the server has * chosen. If we don't support this ciphersuite, * the TlsCipherSuiteManager will throw an * exception. */ this.chosenCipherSuite = TlsCipherSuiteManager.GetCipherSuite( TlsUtilities.ReadUint16(inStr), this); /* * We support only the null compression which * means no compression. */ short compressionMethod = TlsUtilities.ReadUint8(inStr); if (compressionMethod != 0) { this.FailWithError(TlsProtocolHandler.AL_fatal, TlsProtocolHandler.AP_illegal_parameter); } AssertEmpty(inStr); connection_state = CS_SERVER_HELLO_RECEIVED; read = true; break; default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } break; case HP_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 * that we are doing RSA key exchange. */ if (this.chosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_RSA) { this.FailWithError(AL_fatal, AP_unexpected_message); } } AssertEmpty(inStr); bool isCertReq = (connection_state == CS_CERTIFICATE_REQUEST_RECEIVED); connection_state = CS_SERVER_HELLO_DONE_RECEIVED; if (isCertReq) { sendClientCertificate(); } /* * Send the client key exchange message, depending * on the key exchange we are using in our * ciphersuite. */ switch (this.chosenCipherSuite.KeyExchangeAlgorithm) { case TlsCipherSuite.KE_RSA: { /* * We are doing RSA key exchange. We will * choose a pre master secret and send it * rsa encrypted to the server. * * Prepare pre master secret. */ pms = new byte[48]; pms[0] = 3; pms[1] = 1; random.NextBytes(pms, 2, 46); /* * Encode the pms and send it to the server. * * Prepare an Pkcs1Encoding with good random * padding. */ RsaBlindedEngine rsa = new RsaBlindedEngine(); Pkcs1Encoding encoding = new Pkcs1Encoding(rsa); encoding.Init(true, new ParametersWithRandom(this.serverPublicKey, this.random)); byte[] encrypted = null; try { encrypted = encoding.ProcessBlock(pms, 0, pms.Length); } catch (InvalidCipherTextException) { /* * This should never happen, only during decryption. */ this.FailWithError(AL_fatal, AP_internal_error); } /* * Send the encrypted pms. */ sendClientKeyExchange(encrypted); break; } case TlsCipherSuite.KE_DHE_DSS: case TlsCipherSuite.KE_DHE_RSA: { /* * Send the Client Key Exchange message for * DHE key exchange. */ byte[] YcByte = BigIntegers.AsUnsignedByteArray(this.Yc); sendClientKeyExchange(YcByte); break; } default: /* * Problem during handshake, we don't know * how to handle this key exchange method. */ this.FailWithError(AL_fatal, AP_unexpected_message); break; } connection_state = CS_CLIENT_KEY_EXCHANGE_SEND; /* * Now, we send change cipher state */ byte[] cmessage = new byte[1]; cmessage[0] = 1; rs.WriteMessage((short)RL_CHANGE_CIPHER_SPEC, cmessage, 0, cmessage.Length); connection_state = CS_CLIENT_CHANGE_CIPHER_SPEC_SEND; /* * Calculate the ms */ this.ms = new byte[48]; byte[] randBytes = new byte[clientRandom.Length + serverRandom.Length]; Array.Copy(clientRandom, 0, randBytes, 0, clientRandom.Length); Array.Copy(serverRandom, 0, randBytes, clientRandom.Length, serverRandom.Length); TlsUtilities.PRF(pms, TlsUtilities.ToByteArray("master secret"), randBytes, this.ms); /* * Initialize our cipher suite */ rs.writeSuite = this.chosenCipherSuite; rs.writeSuite.Init(this.ms, clientRandom, serverRandom); /* * Send our finished message. */ byte[] checksum = new byte[12]; byte[] md5andsha1 = new byte[16 + 20]; rs.hash1.DoFinal(md5andsha1, 0); TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("client finished"), md5andsha1, checksum); MemoryStream bos2 = new MemoryStream(); TlsUtilities.WriteUint8(HP_FINISHED, bos2); TlsUtilities.WriteUint24(12, bos2); bos2.Write(checksum, 0, checksum.Length); byte[] message2 = bos2.ToArray(); rs.WriteMessage((short)RL_HANDSHAKE, message2, 0, message2.Length); this.connection_state = CS_CLIENT_FINISHED_SEND; read = true; break; default: this.FailWithError(AL_fatal, AP_handshake_failure); break; } break; case HP_SERVER_KEY_EXCHANGE: { switch (connection_state) { case CS_SERVER_CERTIFICATE_RECEIVED: { /* * Check that we are doing DHE key exchange */ switch (this.chosenCipherSuite.KeyExchangeAlgorithm) { case TlsCipherSuite.KE_DHE_RSA: { processDHEKeyExchange(inStr, new TlsRsaSigner()); break; } case TlsCipherSuite.KE_DHE_DSS: { processDHEKeyExchange(inStr, new TlsDssSigner()); break; } default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } break; } default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } this.connection_state = CS_SERVER_KEY_EXCHANGE_RECEIVED; read = true; break; } case HP_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 * that we are doing RSA key exchange. */ if (this.chosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_RSA) { this.FailWithError(AL_fatal, AP_unexpected_message); } } int typesLength = TlsUtilities.ReadUint8(inStr); byte[] types = new byte[typesLength]; TlsUtilities.ReadFully(types, inStr); int authsLength = TlsUtilities.ReadUint16(inStr); byte[] auths = new byte[authsLength]; TlsUtilities.ReadFully(auths, inStr); AssertEmpty(inStr); break; } default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } this.connection_state = CS_CERTIFICATE_REQUEST_RECEIVED; read = true; break; case HP_HELLO_REQUEST: case HP_CLIENT_KEY_EXCHANGE: case HP_CERTIFICATE_VERIFY: case HP_CLIENT_HELLO: default: // We do not support this! this.FailWithError(AL_fatal, AP_unexpected_message); break; } } } }while (read); }
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; } }
private void ProcessHandshakeMessage(short type, byte[] buf) { MemoryStream inStr = new MemoryStream(buf, false); /* * Check the type. */ switch (type) { case HP_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); break; } default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } connection_state = CS_SERVER_CERTIFICATE_RECEIVED; break; } case HP_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(AL_fatal, AP_handshake_failure); } connection_state = CS_DONE; /* * We are now ready to receive application data. */ this.appDataReady = true; break; default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } break; case HP_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); /* * Currently, we don't support session ids */ byte[] sessionID = TlsUtilities.ReadOpaque8(inStr); if (sessionID.Length > 32) { this.FailWithError(TlsProtocolHandler.AL_fatal, TlsProtocolHandler.AP_illegal_parameter); } this.tlsClient.NotifySessionID(sessionID); /* * Find out which ciphersuite the server has chosen and check that * it was one of the offered ones. */ int selectedCipherSuite = TlsUtilities.ReadUint16(inStr); if (!WasCipherSuiteOffered(selectedCipherSuite)) { this.FailWithError(TlsProtocolHandler.AL_fatal, TlsProtocolHandler.AP_illegal_parameter); } this.tlsClient.NotifySelectedCipherSuite(selectedCipherSuite); /* * We support only the null compression which means no * compression. */ short compressionMethod = TlsUtilities.ReadUint8(inStr); if (compressionMethod != 0) { this.FailWithError(TlsProtocolHandler.AL_fatal, TlsProtocolHandler.AP_illegal_parameter); } /* * RFC4366 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. */ if (extendedClientHello) { // Integer -> byte[] Hashtable serverExtensions = new Hashtable(); 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) { int extType = TlsUtilities.ReadUint16(ext); byte[] extValue = TlsUtilities.ReadOpaque16(ext); serverExtensions.Add(extType, extValue); } } // TODO[RFC 5746] If renegotiation_info was sent in client hello, check here tlsClient.ProcessServerExtensions(serverExtensions); } AssertEmpty(inStr); this.keyExchange = tlsClient.CreateKeyExchange(); connection_state = CS_SERVER_HELLO_RECEIVED; break; default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } break; case HP_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); bool isClientCertificateRequested = (connection_state == CS_CERTIFICATE_REQUEST_RECEIVED); connection_state = CS_SERVER_HELLO_DONE_RECEIVED; if (isClientCertificateRequested) { SendClientCertificate(tlsClient.GetCertificate()); } /* * Send the client key exchange message, depending on the key * exchange we are using in our ciphersuite. */ SendClientKeyExchange(this.keyExchange.GenerateClientKeyExchange()); connection_state = CS_CLIENT_KEY_EXCHANGE_SEND; if (isClientCertificateRequested) { byte[] clientCertificateSignature = tlsClient.GenerateCertificateSignature(rs.GetCurrentHash()); if (clientCertificateSignature != null) { SendCertificateVerify(clientCertificateSignature); connection_state = CS_CERTIFICATE_VERIFY_SEND; } } /* * Now, we send change cipher state */ byte[] cmessage = new byte[1]; cmessage[0] = 1; rs.WriteMessage(RL_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.CreateCipher(securityParameters)); /* * Send our finished message. */ byte[] clientVerifyData = TlsUtilities.PRF(securityParameters.masterSecret, "client finished", rs.GetCurrentHash(), 12); MemoryStream bos = new MemoryStream(); TlsUtilities.WriteUint8(HP_FINISHED, bos); TlsUtilities.WriteOpaque24(clientVerifyData, bos); byte[] message = bos.ToArray(); rs.WriteMessage(RL_HANDSHAKE, message, 0, message.Length); this.connection_state = CS_CLIENT_FINISHED_SEND; break; default: this.FailWithError(AL_fatal, AP_handshake_failure); break; } break; case HP_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.keyExchange.ProcessServerKeyExchange(inStr, securityParameters); AssertEmpty(inStr); break; } default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } this.connection_state = CS_SERVER_KEY_EXCHANGE_RECEIVED; break; } case HP_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(); } byte[] types = TlsUtilities.ReadOpaque8(inStr); byte[] authorities = TlsUtilities.ReadOpaque16(inStr); AssertEmpty(inStr); ArrayList authorityDNs = new ArrayList(); MemoryStream bis = new MemoryStream(authorities, false); while (bis.Position < bis.Length) { byte[] dnBytes = TlsUtilities.ReadOpaque16(bis); authorityDNs.Add(X509Name.GetInstance(Asn1Object.FromByteArray(dnBytes))); } this.tlsClient.ProcessServerCertificateRequest(types, authorityDNs); break; } default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } this.connection_state = CS_CERTIFICATE_REQUEST_RECEIVED; break; case HP_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(AL_warning, AP_no_renegotiation); } break; case HP_CLIENT_KEY_EXCHANGE: case HP_CERTIFICATE_VERIFY: case HP_CLIENT_HELLO: default: // We do not support this! this.FailWithError(AL_fatal, AP_unexpected_message); break; } }
private void processHandshake() { bool read; do { read = false; /* * We need the first 4 bytes, they contain type and length of * the message. */ if (handshakeQueue.Available >= 4) { byte[] beginning = new byte[4]; handshakeQueue.Read(beginning, 0, 4, 0); MemoryStream bis = new MemoryStream(beginning, false); short type = TlsUtilities.ReadUint8(bis); int len = TlsUtilities.ReadUint24(bis); /* * Check if we have enough bytes in the buffer to read * the full message. */ if (handshakeQueue.Available >= (len + 4)) { /* * Read the message. */ byte[] buf = new byte[len]; handshakeQueue.Read(buf, 0, len, 4); handshakeQueue.RemoveData(len + 4); /* * If it is not a finished message, update our hashes * we prepare for the finish message. */ if (type != HP_FINISHED) { rs.hash1.BlockUpdate(beginning, 0, 4); rs.hash2.BlockUpdate(beginning, 0, 4); rs.hash1.BlockUpdate(buf, 0, len); rs.hash2.BlockUpdate(buf, 0, len); } /* * Now, parse the message. */ MemoryStream inStr = new MemoryStream(buf, false); /* * Check the type. */ switch (type) { case HP_CERTIFICATE: switch (connection_state) { case CS_SERVER_HELLO_RECEIVED: /* * Parse the certificates. */ Certificate cert = Certificate.Parse(inStr); AssertEmpty(inStr); /* * Verify them. */ if (!this.verifyer.IsValid(cert.GetCerts())) { this.FailWithError(AL_fatal, AP_user_canceled); } /* * We only support RSA certificates. Lets hope * this is one. */ RsaPublicKeyStructure rsaKey = null; try { rsaKey = RsaPublicKeyStructure.GetInstance( cert.certs[0].TbsCertificate.SubjectPublicKeyInfo.GetPublicKey()); } catch (Exception) { /* * Sorry, we have to fail ;-( */ this.FailWithError(AL_fatal, AP_unsupported_certificate); } /* * Parse the servers public RSA key. */ this.serverRsaKey = new RsaKeyParameters( false, rsaKey.Modulus, rsaKey.PublicExponent); connection_state = CS_SERVER_CERTIFICATE_RECEIVED; read = true; break; default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } break; case HP_FINISHED: switch (connection_state) { case CS_SERVER_CHANGE_CIPHER_SPEC_RECEIVED: /* * Read the checksum from the finished message, * it has always 12 bytes. */ byte[] receivedChecksum = new byte[12]; TlsUtilities.ReadFully(receivedChecksum, inStr); AssertEmpty(inStr); /* * Calculate our owne checksum. */ byte[] checksum = new byte[12]; byte[] md5andsha1 = new byte[16 + 20]; rs.hash2.DoFinal(md5andsha1, 0); TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("server finished"), md5andsha1, checksum); /* * Compare both checksums. */ for (int i = 0; i < receivedChecksum.Length; i++) { if (receivedChecksum[i] != checksum[i]) { /* * Wrong checksum in the finished message. */ this.FailWithError(AL_fatal, AP_handshake_failure); } } connection_state = CS_DONE; /* * We are now ready to receive application data. */ this.appDataReady = true; read = true; break; default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } break; case HP_SERVER_HELLO: switch (connection_state) { case CS_CLIENT_HELLO_SEND: /* * Read the server hello message */ TlsUtilities.CheckVersion(inStr, this); /* * Read the server random */ this.serverRandom = new byte[32]; TlsUtilities.ReadFully(this.serverRandom, inStr); /* * Currenty, we don't support session ids */ short sessionIdLength = TlsUtilities.ReadUint8(inStr); byte[] sessionId = new byte[sessionIdLength]; TlsUtilities.ReadFully(sessionId, inStr); /* * Find out which ciphersuite the server has * choosen. If we don't support this ciphersuite, * the TlsCipherSuiteManager will throw an * exception. */ this.choosenCipherSuite = TlsCipherSuiteManager.GetCipherSuite( TlsUtilities.ReadUint16(inStr), this); /* * We support only the null compression which * means no compression. */ short compressionMethod = TlsUtilities.ReadUint8(inStr); if (compressionMethod != 0) { this.FailWithError(TlsProtocolHandler.AL_fatal, TlsProtocolHandler.AP_illegal_parameter); } AssertEmpty(inStr); connection_state = CS_SERVER_HELLO_RECEIVED; read = true; break; default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } break; case HP_SERVER_HELLO_DONE: 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 * that we are doing RSA key exchange. */ if (this.choosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_RSA) { this.FailWithError(AL_fatal, AP_unexpected_message); } } AssertEmpty(inStr); connection_state = CS_SERVER_HELLO_DONE_RECEIVED; /* * Send the client key exchange message, depending * on the key exchange we are using in our * ciphersuite. */ short ke = this.choosenCipherSuite.KeyExchangeAlgorithm; switch (ke) { case TlsCipherSuite.KE_RSA: /* * We are doing RSA key exchange. We will * choose a pre master secret and send it * rsa encrypted to the server. * * Prepare pre master secret. */ pms = new byte[48]; pms[0] = 3; pms[1] = 1; random.NextBytes(pms, 2, 46); /* * Encode the pms and send it to the server. * * Prepare an Pkcs1Encoding with good random * padding. */ RsaBlindedEngine rsa = new RsaBlindedEngine(); Pkcs1Encoding encoding = new Pkcs1Encoding(rsa); encoding.Init(true, new ParametersWithRandom(this.serverRsaKey, this.random)); byte[] encrypted = null; try { encrypted = encoding.ProcessBlock(pms, 0, pms.Length); } catch (InvalidCipherTextException) { /* * This should never happen, only during decryption. */ this.FailWithError(AL_fatal, AP_internal_error); } /* * Send the encrypted pms. */ MemoryStream bos = new MemoryStream(); TlsUtilities.WriteUint8(HP_CLIENT_KEY_EXCHANGE, bos); TlsUtilities.WriteUint24(encrypted.Length + 2, bos); TlsUtilities.WriteUint16(encrypted.Length, bos); bos.Write(encrypted, 0, encrypted.Length); byte[] message = bos.ToArray(); rs.WriteMessage((short)RL_HANDSHAKE, message, 0, message.Length); break; case TlsCipherSuite.KE_DHE_RSA: /* * Send the Client Key Exchange message for * DHE key exchange. */ byte[] YcByte = this.Yc.ToByteArray(); MemoryStream DHbos = new MemoryStream(); TlsUtilities.WriteUint8(HP_CLIENT_KEY_EXCHANGE, DHbos); TlsUtilities.WriteUint24(YcByte.Length + 2, DHbos); TlsUtilities.WriteUint16(YcByte.Length, DHbos); DHbos.Write(YcByte, 0, YcByte.Length); byte[] DHmessage = DHbos.ToArray(); rs.WriteMessage((short)RL_HANDSHAKE, DHmessage, 0, DHmessage.Length); break; default: /* * Proble during handshake, we don't know * how to thandle this key exchange method. */ this.FailWithError(AL_fatal, AP_unexpected_message); break; } connection_state = CS_CLIENT_KEY_EXCHANGE_SEND; /* * Now, we send change cipher state */ byte[] cmessage = new byte[1]; cmessage[0] = 1; rs.WriteMessage((short)RL_CHANGE_CIPHER_SPEC, cmessage, 0, cmessage.Length); connection_state = CS_CLIENT_CHANGE_CIPHER_SPEC_SEND; /* * Calculate the ms */ this.ms = new byte[48]; byte[] randBytes = new byte[clientRandom.Length + serverRandom.Length]; Array.Copy(clientRandom, 0, randBytes, 0, clientRandom.Length); Array.Copy(serverRandom, 0, randBytes, clientRandom.Length, serverRandom.Length); TlsUtilities.PRF(pms, TlsUtilities.ToByteArray("master secret"), randBytes, this.ms); /* * Initialize our cipher suite */ rs.writeSuite = this.choosenCipherSuite; rs.writeSuite.Init(this.ms, clientRandom, serverRandom); /* * Send our finished message. */ byte[] checksum = new byte[12]; byte[] md5andsha1 = new byte[16 + 20]; rs.hash1.DoFinal(md5andsha1, 0); TlsUtilities.PRF(this.ms, TlsUtilities.ToByteArray("client finished"), md5andsha1, checksum); MemoryStream bos2 = new MemoryStream(); TlsUtilities.WriteUint8(HP_FINISHED, bos2); TlsUtilities.WriteUint24(12, bos2); bos2.Write(checksum, 0, checksum.Length); byte[] message2 = bos2.ToArray(); rs.WriteMessage((short)RL_HANDSHAKE, message2, 0, message2.Length); this.connection_state = CS_CLIENT_FINISHED_SEND; read = true; break; default: this.FailWithError(AL_fatal, AP_handshake_failure); break; } break; case HP_SERVER_KEY_EXCHANGE: switch (connection_state) { case CS_SERVER_CERTIFICATE_RECEIVED: /* * Check that we are doing DHE key exchange */ if (this.choosenCipherSuite.KeyExchangeAlgorithm != TlsCipherSuite.KE_DHE_RSA) { this.FailWithError(AL_fatal, AP_unexpected_message); } /* * Parse the Structure */ int pLength = TlsUtilities.ReadUint16(inStr); byte[] pByte = new byte[pLength]; TlsUtilities.ReadFully(pByte, inStr); int gLength = TlsUtilities.ReadUint16(inStr); byte[] gByte = new byte[gLength]; TlsUtilities.ReadFully(gByte, inStr); int YsLength = TlsUtilities.ReadUint16(inStr); byte[] YsByte = new byte[YsLength]; TlsUtilities.ReadFully(YsByte, inStr); int sigLength = TlsUtilities.ReadUint16(inStr); byte[] sigByte = new byte[sigLength]; TlsUtilities.ReadFully(sigByte, inStr); this.AssertEmpty(inStr); /* * Verify the Signature. * * First, calculate the hash. */ CombinedHash sigDigest = new CombinedHash(); MemoryStream signedData = new MemoryStream(); TlsUtilities.WriteUint16(pLength, signedData); signedData.Write(pByte, 0, pByte.Length); TlsUtilities.WriteUint16(gLength, signedData); signedData.Write(gByte, 0, gByte.Length); TlsUtilities.WriteUint16(YsLength, signedData); signedData.Write(YsByte, 0, YsByte.Length); byte[] signed = signedData.ToArray(); sigDigest.BlockUpdate(this.clientRandom, 0, this.clientRandom.Length); sigDigest.BlockUpdate(this.serverRandom, 0, this.serverRandom.Length); sigDigest.BlockUpdate(signed, 0, signed.Length); byte[] hash = new byte[sigDigest.GetDigestSize()]; sigDigest.DoFinal(hash, 0); /* * Now, do the RSA operation */ RsaBlindedEngine rsa = new RsaBlindedEngine(); Pkcs1Encoding encoding = new Pkcs1Encoding(rsa); encoding.Init(false, this.serverRsaKey); /* * The data which was signed */ byte[] sigHash = null; try { sigHash = encoding.ProcessBlock(sigByte, 0, sigByte.Length); } catch (InvalidCipherTextException) { this.FailWithError(AL_fatal, AP_bad_certificate); } /* * Check if the data which was signed is equal to * the hash we calculated. */ if (sigHash.Length != hash.Length) { this.FailWithError(AL_fatal, AP_bad_certificate); } for (int i = 0; i < sigHash.Length; i++) { if (sigHash[i] != hash[i]) { this.FailWithError(AL_fatal, AP_bad_certificate); } } /* * OK, Signature was correct. * * Do the DH calculation. */ BigInteger p = new BigInteger(1, pByte); BigInteger g = new BigInteger(1, gByte); BigInteger Ys = new BigInteger(1, YsByte); BigInteger x = new BigInteger(p.BitLength - 1, this.random); Yc = g.ModPow(x, p); this.pms = (Ys.ModPow(x, p)).ToByteArray(); /* * Remove leading zero byte, if present. */ if (this.pms[0] == 0) { byte[] tmp = new byte[this.pms.Length - 1]; Array.Copy(this.pms, 1, tmp, 0, tmp.Length); this.pms = tmp; } this.connection_state = CS_SERVER_KEY_EXCHANGE_RECEIVED; read = true; break; default: this.FailWithError(AL_fatal, AP_unexpected_message); break; } break; case HP_HELLO_REQUEST: case HP_CLIENT_KEY_EXCHANGE: case HP_CERTIFICATE_REQUEST: case HP_CERTIFICATE_VERIFY: case HP_CLIENT_HELLO: default: // We do not support this! this.FailWithError(AL_fatal, AP_unexpected_message); break; } } } }while (read); }