package org.bouncycastle.crypto.tls; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.security.SecureRandom; import java.util.Enumeration; import java.util.Hashtable; import java.util.Vector; import org.bouncycastle.crypto.prng.ThreadedSeedGenerator; import org.bouncycastle.util.Arrays; public class TlsClientProtocol extends TlsProtocol { protected TlsClient tlsClient = null; protected TlsClientContextImpl tlsClientContext = null; protected byte[] selectedSessionID = null; protected TlsKeyExchange keyExchange = null; protected TlsAuthentication authentication = null; protected CertificateStatus certificateStatus = null; protected CertificateRequest certificateRequest = null; private static SecureRandom createSecureRandom() { /* * We use our threaded seed generator to generate a good random seed. If the user has a * better random seed, he should use the constructor with a SecureRandom. */ ThreadedSeedGenerator tsg = new ThreadedSeedGenerator(); SecureRandom random = new SecureRandom(); /* * Hopefully, 20 bytes in fast mode are good enough. */ random.setSeed(tsg.generateSeed(20, true)); return random; } public TlsClientProtocol(InputStream input, OutputStream output) { this(input, output, createSecureRandom()); } public TlsClientProtocol(InputStream input, OutputStream output, SecureRandom secureRandom) { super(input, output, secureRandom); } /** * Initiates a TLS handshake in the role of client * * @param tlsClient The {@link TlsClient} to use for the handshake. * @throws IOException If handshake was not successful. */ public void connect(TlsClient tlsClient) throws IOException { if (tlsClient == null) { throw new IllegalArgumentException("'tlsClient' cannot be null"); } if (this.tlsClient != null && !this.tlsClient.equals(tlsClient)) { throw new IllegalStateException("'connect' can only be called once"); } this.tlsClient = tlsClient; this.securityParameters = new SecurityParameters(); this.securityParameters.entity = ConnectionEnd.client; this.securityParameters.clientRandom = createRandomBlock(secureRandom); this.tlsClientContext = new TlsClientContextImpl(secureRandom, securityParameters); this.tlsClient.init(tlsClientContext); this.recordStream.init(tlsClientContext); TlsSession sessionToResume = tlsClient.getSessionToResume(); if (sessionToResume != null) { SessionParameters sessionParameters = sessionToResume.exportSessionParameters(); if (sessionParameters != null) { this.tlsSession = sessionToResume; this.sessionParameters = sessionParameters; } } sendClientHelloMessage(); this.connection_state = CS_CLIENT_HELLO; completeHandshake(); } protected void cleanupHandshake() { this.tlsClient.setSessionToResume(getContext().getResumableSession()); super.cleanupHandshake(); this.selectedSessionID = null; this.keyExchange = null; this.authentication = null; this.certificateStatus = null; this.certificateRequest = null; } protected AbstractTlsContext getContext() { return tlsClientContext; } protected TlsPeer getPeer() { return tlsClient; } protected void handleHandshakeMessage(short type, byte[] data) throws IOException { ByteArrayInputStream buf = new ByteArrayInputStream(data); if (this.resumedSession) { if (type != HandshakeType.finished || this.connection_state != CS_SERVER_HELLO) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } processFinishedMessage(buf); this.connection_state = CS_SERVER_FINISHED; sendFinishedMessage(); this.connection_state = CS_CLIENT_FINISHED; this.connection_state = CS_END; return; } switch (type) { case HandshakeType.certificate: { switch (this.connection_state) { case CS_SERVER_HELLO: { handleSupplementalData(null); // NB: Fall through to next case label } case CS_SERVER_SUPPLEMENTAL_DATA: { // Parse the Certificate message and send to cipher suite this.peerCertificate = Certificate.parse(buf); assertEmpty(buf); // TODO[RFC 3546] Check whether empty certificates is possible, allowed, or excludes CertificateStatus if (this.peerCertificate == null || this.peerCertificate.isEmpty()) { this.allowCertificateStatus = false; } this.keyExchange.processServerCertificate(this.peerCertificate); this.authentication = tlsClient.getAuthentication(); this.authentication.notifyServerCertificate(this.peerCertificate); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.connection_state = CS_SERVER_CERTIFICATE; break; } case HandshakeType.certificate_status: { switch (this.connection_state) { case CS_SERVER_CERTIFICATE: { if (!this.allowCertificateStatus) { /* * 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.certificateStatus = CertificateStatus.parse(buf); assertEmpty(buf); // TODO[RFC 3546] Figure out how to provide this to the client/authentication. this.connection_state = CS_CERTIFICATE_STATUS; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.finished: { switch (this.connection_state) { case CS_CLIENT_FINISHED: { processFinishedMessage(buf); this.connection_state = CS_SERVER_FINISHED; this.connection_state = CS_END; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.server_hello: { switch (this.connection_state) { case CS_CLIENT_HELLO: { receiveServerHelloMessage(buf); this.connection_state = CS_SERVER_HELLO; if (this.securityParameters.maxFragmentLength >= 0) { int plainTextLimit = 1 << (8 + this.securityParameters.maxFragmentLength); recordStream.setPlaintextLimit(plainTextLimit); } this.securityParameters.prfAlgorithm = getPRFAlgorithm(getContext(), this.securityParameters.getCipherSuite()); /* * RFC 5264 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. */ this.securityParameters.verifyDataLength = 12; this.recordStream.notifyHelloComplete(); if (this.resumedSession) { this.securityParameters.masterSecret = Arrays.clone(this.sessionParameters.getMasterSecret()); this.recordStream.setPendingConnectionState(getPeer().getCompression(), getPeer().getCipher()); sendChangeCipherSpecMessage(); } else { invalidateSession(); if (this.selectedSessionID.length > 0) { this.tlsSession = new TlsSessionImpl(this.selectedSessionID, null); } } break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.supplemental_data: { switch (this.connection_state) { case CS_SERVER_HELLO: { handleSupplementalData(readSupplementalDataMessage(buf)); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.server_hello_done: { switch (this.connection_state) { case CS_SERVER_HELLO: { handleSupplementalData(null); // NB: Fall through to next case label } case CS_SERVER_SUPPLEMENTAL_DATA: { // There was no server certificate message; check it's OK this.keyExchange.skipServerCredentials(); this.authentication = null; // NB: Fall through to next case label } case CS_SERVER_CERTIFICATE: case CS_CERTIFICATE_STATUS: { // There was no server key exchange message; check it's OK this.keyExchange.skipServerKeyExchange(); // NB: Fall through to next case label } case CS_SERVER_KEY_EXCHANGE: case CS_CERTIFICATE_REQUEST: { assertEmpty(buf); this.connection_state = CS_SERVER_HELLO_DONE; Vector clientSupplementalData = tlsClient.getClientSupplementalData(); if (clientSupplementalData != null) { sendSupplementalDataMessage(clientSupplementalData); } this.connection_state = CS_CLIENT_SUPPLEMENTAL_DATA; TlsCredentials clientCreds = null; if (certificateRequest == null) { this.keyExchange.skipClientCredentials(); } else { clientCreds = this.authentication.getClientCredentials(certificateRequest); if (clientCreds == null) { this.keyExchange.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.EMPTY_CHAIN); } else { this.keyExchange.processClientCredentials(clientCreds); sendCertificateMessage(clientCreds.getCertificate()); } } this.connection_state = CS_CLIENT_CERTIFICATE; /* * Send the client key exchange message, depending on the key exchange we are using * in our CipherSuite. */ sendClientKeyExchangeMessage(); this.connection_state = CS_CLIENT_KEY_EXCHANGE; establishMasterSecret(getContext(), keyExchange); recordStream.setPendingConnectionState(getPeer().getCompression(), getPeer().getCipher()); if (clientCreds != null && clientCreds instanceof TlsSignerCredentials) { TlsSignerCredentials signerCreds = (TlsSignerCredentials)clientCreds; /* * TODO RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm from TLS 1.2 */ SignatureAndHashAlgorithm algorithm = null; byte[] hash = recordStream.getCurrentHash(null); byte[] signature = signerCreds.generateCertificateSignature(hash); DigitallySigned certificateVerify = new DigitallySigned(algorithm, signature); sendCertificateVerifyMessage(certificateVerify); this.connection_state = CS_CERTIFICATE_VERIFY; } sendChangeCipherSpecMessage(); sendFinishedMessage(); this.connection_state = CS_CLIENT_FINISHED; break; } default: throw new TlsFatalAlert(AlertDescription.handshake_failure); } break; } case HandshakeType.server_key_exchange: { switch (this.connection_state) { case CS_SERVER_HELLO: { handleSupplementalData(null); // NB: Fall through to next case label } case CS_SERVER_SUPPLEMENTAL_DATA: { // There was no server certificate message; check it's OK this.keyExchange.skipServerCredentials(); this.authentication = null; // NB: Fall through to next case label } case CS_SERVER_CERTIFICATE: case CS_CERTIFICATE_STATUS: { this.keyExchange.processServerKeyExchange(buf); assertEmpty(buf); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.connection_state = CS_SERVER_KEY_EXCHANGE; break; } case HandshakeType.certificate_request: { switch (this.connection_state) { case CS_SERVER_CERTIFICATE: case CS_CERTIFICATE_STATUS: { // There was no server key exchange message; check it's OK this.keyExchange.skipServerKeyExchange(); // NB: Fall through to next case label } case CS_SERVER_KEY_EXCHANGE: { if (this.authentication == 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.certificateRequest = CertificateRequest.parse(getContext(), buf); assertEmpty(buf); this.keyExchange.validateCertificateRequest(this.certificateRequest); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.connection_state = CS_CERTIFICATE_REQUEST; break; } case HandshakeType.session_ticket: { switch (this.connection_state) { case CS_CLIENT_FINISHED: { if (!this.expectSessionTicket) { /* * 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); this.connection_state = CS_SERVER_SESSION_TICKET; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } } 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.connection_state == CS_END) { /* * RFC 5746 4.5 SSLv3 clients that refuse renegotiation SHOULD use a fatal * handshake_failure alert. */ if (TlsUtils.isSSL(getContext())) { throw new TlsFatalAlert(AlertDescription.handshake_failure); } secure_renegotiation = true; this.connect(this.tlsClient); } 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); } } protected void handleSupplementalData(Vector serverSupplementalData) throws IOException { this.tlsClient.processServerSupplementalData(serverSupplementalData); this.connection_state = CS_SERVER_SUPPLEMENTAL_DATA; this.keyExchange = tlsClient.getKeyExchange(); this.keyExchange.init(getContext()); } protected void receiveNewSessionTicketMessage(ByteArrayInputStream buf) throws IOException { NewSessionTicket newSessionTicket = NewSessionTicket.parse(buf); TlsProtocol.assertEmpty(buf); tlsClient.notifyNewSessionTicket(newSessionTicket); } protected void receiveServerHelloMessage(ByteArrayInputStream buf) throws IOException { ProtocolVersion server_version = TlsUtils.readVersion(buf); if (server_version.isDTLS()) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } // Check that this matches what the server is sending in the record layer if (!server_version.equals(this.recordStream.getReadVersion())) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } ProtocolVersion client_version = getContext().getClientVersion(); if (!server_version.isEqualOrEarlierVersionOf(client_version)) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } this.recordStream.setWriteVersion(server_version); getContext().setServerVersion(server_version); this.tlsClient.notifyServerVersion(server_version); /* * Read the server random */ this.securityParameters.serverRandom = TlsUtils.readFully(32, buf); this.selectedSessionID = TlsUtils.readOpaque8(buf); if (this.selectedSessionID.length > 32) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } this.tlsClient.notifySessionID(this.selectedSessionID); this.resumedSession = this.selectedSessionID.length > 0 && this.tlsSession != null && Arrays.areEqual(this.selectedSessionID, this.tlsSession.getSessionID()); /* * Find out which CipherSuite the server has chosen and check that it was one of the offered * ones. */ int selectedCipherSuite = TlsUtils.readUint16(buf); if (!arrayContains(this.offeredCipherSuites, selectedCipherSuite) || selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL || selectedCipherSuite == CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV) { throw new TlsFatalAlert(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. */ short selectedCompressionMethod = TlsUtils.readUint8(buf); if (!arrayContains(this.offeredCompressionMethods, selectedCompressionMethod)) { throw new TlsFatalAlert(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. */ this.serverExtensions = readExtensions(buf); /* * 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 (this.serverExtensions != null) { Enumeration e = this.serverExtensions.keys(); while (e.hasMoreElements()) { Integer extType = (Integer)e.nextElement(); /* * 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.equals(EXT_RenegotiationInfo)) { continue; } /* * 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 (this.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 // throw new TlsFatalAlert(AlertDescription.illegal_parameter); } /* * 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 == TlsUtils.getExtensionData(this.clientExtensions, extType)) { throw new TlsFatalAlert(AlertDescription.unsupported_extension); } } } /* * 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 = TlsUtils.getExtensionData(this.serverExtensions, EXT_RenegotiationInfo); 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). */ if (!secure_renegotiation) { // Initial Handshake if (!Arrays.constantTimeAreEqual(renegExtData, createRenegotiationInfo(TlsUtils.EMPTY_BYTES))) { throw new TlsFatalAlert(AlertDescription.handshake_failure); } } else { // renegotiated Handshake /* * RFC 5746 3.5. The client MUST then verify * that the first half of the * "renegotiated_connection" field is equal to * the saved client_verify_data value, and the * second half is equal to the saved * server_verify_data value. If they are not, * the client MUST abort the handshake. */ ByteArrayOutputStream bos = new ByteArrayOutputStream(); bos.write(client_verify_data); bos.write(server_verify_data); if (!Arrays.constantTimeAreEqual(renegExtData, createRenegotiationInfo(bos.toByteArray()))) { throw new TlsFatalAlert(AlertDescription.handshake_failure); } } } else { // extension not present if (secure_renegotiation) { /* * When a ServerHello is received, the client MUST verify that the * "renegotiation_info" extension is present; if it is not, the * client MUST abort the handshake. */ throw new TlsFatalAlert(AlertDescription.handshake_failure); } } } // TODO[compat-gnutls] GnuTLS test server fails to send renegotiation_info extension when resuming this.tlsClient.notifySecureRenegotiation(this.secure_renegotiation); Hashtable sessionClientExtensions = clientExtensions, sessionServerExtensions = serverExtensions; if (this.resumedSession) { if (selectedCipherSuite != this.sessionParameters.getCipherSuite() || selectedCompressionMethod != this.sessionParameters.getCompressionAlgorithm()) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } sessionClientExtensions = null; sessionServerExtensions = this.sessionParameters.readServerExtensions(); } this.securityParameters.cipherSuite = selectedCipherSuite; this.securityParameters.compressionAlgorithm = selectedCompressionMethod; if (sessionServerExtensions != null) { this.securityParameters.maxFragmentLength = processMaxFragmentLengthExtension(sessionClientExtensions, sessionServerExtensions, AlertDescription.illegal_parameter); this.securityParameters.truncatedHMac = TlsExtensionsUtils.hasTruncatedHMacExtension(sessionServerExtensions); /* * TODO It's surprising that there's no provision to allow a 'fresh' CertificateStatus to be sent in * a session resumption handshake. */ this.allowCertificateStatus = !this.resumedSession && TlsUtils.hasExpectedEmptyExtensionData(sessionServerExtensions, TlsExtensionsUtils.EXT_status_request, AlertDescription.illegal_parameter); this.expectSessionTicket = !this.resumedSession && TlsUtils.hasExpectedEmptyExtensionData(sessionServerExtensions, TlsProtocol.EXT_SessionTicket, AlertDescription.illegal_parameter); } if (sessionClientExtensions != null) { this.tlsClient.processServerExtensions(sessionServerExtensions); } } protected void sendCertificateVerifyMessage(DigitallySigned certificateVerify) throws IOException { HandshakeMessage message = new HandshakeMessage(HandshakeType.certificate_verify); certificateVerify.encode(message); message.writeToRecordStream(); } protected void sendClientHelloMessage() throws IOException { this.recordStream.setWriteVersion(this.tlsClient.getClientHelloRecordLayerVersion()); ProtocolVersion client_version = this.tlsClient.getClientVersion(); if (client_version.isDTLS()) { throw new TlsFatalAlert(AlertDescription.internal_error); } getContext().setClientVersion(client_version); /* * TODO RFC 5077 3.4. When presenting a ticket, the client MAY generate and include a * Session ID in the TLS ClientHello. */ byte[] session_id = TlsUtils.EMPTY_BYTES; if (this.tlsSession != null) { session_id = this.tlsSession.getSessionID(); if (session_id == null || session_id.length > 32) { session_id = TlsUtils.EMPTY_BYTES; } } this.offeredCipherSuites = this.tlsClient.getCipherSuites(); this.offeredCompressionMethods = this.tlsClient.getCompressionMethods(); if (session_id.length > 0 && this.sessionParameters != null) { if (!arrayContains(this.offeredCipherSuites, sessionParameters.getCipherSuite()) || !arrayContains(this.offeredCompressionMethods, sessionParameters.getCompressionAlgorithm())) { session_id = TlsUtils.EMPTY_BYTES; } } this.clientExtensions = this.tlsClient.getClientExtensions(); HandshakeMessage message = new HandshakeMessage(HandshakeType.client_hello); TlsUtils.writeVersion(client_version, message); message.write(this.securityParameters.getClientRandom()); TlsUtils.writeOpaque8(session_id, message); /* * RFC 5746 3.5. The client MUST include the "renegotiation_info" * extension in the ClientHello, containing the saved * client_verify_data. The SCSV MUST NOT be included. */ if (secure_renegotiation) { this.clientExtensions.put(EXT_RenegotiationInfo, createRenegotiationInfo(client_verify_data)); } // 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 = TlsUtils.getExtensionData(clientExtensions, EXT_RenegotiationInfo); boolean noRenegExt = (null == renegExtData); boolean noSCSV = !TlsProtocol.arrayContains(offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV); if (noRenegExt && noSCSV) { // TODO Consider whether to default to a client extension instead offeredCipherSuites = Arrays.append(offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV); } TlsUtils.writeUint16ArrayWithUint16Length(offeredCipherSuites, message); } TlsUtils.writeUint8ArrayWithUint8Length(offeredCompressionMethods, message); if (clientExtensions != null) { writeExtensions(message, clientExtensions); } message.writeToRecordStream(); } protected void sendClientKeyExchangeMessage() throws IOException { HandshakeMessage message = new HandshakeMessage(HandshakeType.client_key_exchange); this.keyExchange.generateClientKeyExchange(message); message.writeToRecordStream(); } }