package org.bouncycastle.crypto.tls; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.security.SecureRandom; import java.util.Vector; import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo; import org.bouncycastle.crypto.params.AsymmetricKeyParameter; import org.bouncycastle.crypto.util.PublicKeyFactory; import org.bouncycastle.util.Arrays; public class TlsServerProtocol extends TlsProtocol { protected TlsServer tlsServer = null; TlsServerContextImpl tlsServerContext = null; protected TlsKeyExchange keyExchange = null; protected TlsCredentials serverCredentials = null; protected CertificateRequest certificateRequest = null; protected short clientCertificateType = -1; protected TlsHandshakeHash prepareFinishHash = null; /** * Constructor for blocking mode. * @param input The stream of data from the client * @param output The stream of data to the client * @param secureRandom Random number generator for various cryptographic functions */ public TlsServerProtocol(InputStream input, OutputStream output, SecureRandom secureRandom) { super(input, output, secureRandom); } /** * Constructor for non-blocking mode.<br> * <br> * When data is received, use {@link #offerInput(java.nio.ByteBuffer)} to * provide the received ciphertext, then use * {@link #readInput(byte[], int, int)} to read the corresponding cleartext.<br> * <br> * Similarly, when data needs to be sent, use * {@link #offerOutput(byte[], int, int)} to provide the cleartext, then use * {@link #readOutput(byte[], int, int)} to get the corresponding * ciphertext. * * @param secureRandom * Random number generator for various cryptographic functions */ public TlsServerProtocol(SecureRandom secureRandom) { super(secureRandom); } /** * Receives a TLS handshake in the role of server.<br> * <br> * In blocking mode, this will not return until the handshake is complete. * In non-blocking mode, use {@link TlsPeer#notifyHandshakeComplete()} to * receive a callback when the handshake is complete. * * @param tlsServer * @throws IOException If in blocking mode and handshake was not successful. */ public void accept(TlsServer tlsServer) throws IOException { if (tlsServer == null) { throw new IllegalArgumentException("'tlsServer' cannot be null"); } if (this.tlsServer != null) { throw new IllegalStateException("'accept' can only be called once"); } this.tlsServer = tlsServer; this.securityParameters = new SecurityParameters(); this.securityParameters.entity = ConnectionEnd.server; this.tlsServerContext = new TlsServerContextImpl(secureRandom, securityParameters); this.securityParameters.serverRandom = createRandomBlock(tlsServer.shouldUseGMTUnixTime(), tlsServerContext.getNonceRandomGenerator()); this.tlsServer.init(tlsServerContext); this.recordStream.init(tlsServerContext); this.recordStream.setRestrictReadVersion(false); blockForHandshake(); } protected void cleanupHandshake() { super.cleanupHandshake(); this.keyExchange = null; this.serverCredentials = null; this.certificateRequest = null; this.prepareFinishHash = null; } protected TlsContext getContext() { return tlsServerContext; } AbstractTlsContext getContextAdmin() { return tlsServerContext; } protected TlsPeer getPeer() { return tlsServer; } protected void handleHandshakeMessage(short type, ByteArrayInputStream buf) throws IOException { switch (type) { case HandshakeType.client_hello: { switch (this.connection_state) { case CS_START: { receiveClientHelloMessage(buf); this.connection_state = CS_CLIENT_HELLO; sendServerHelloMessage(); this.connection_state = CS_SERVER_HELLO; recordStream.notifyHelloComplete(); Vector serverSupplementalData = tlsServer.getServerSupplementalData(); if (serverSupplementalData != null) { sendSupplementalDataMessage(serverSupplementalData); } this.connection_state = CS_SERVER_SUPPLEMENTAL_DATA; this.keyExchange = tlsServer.getKeyExchange(); this.keyExchange.init(getContext()); this.serverCredentials = tlsServer.getCredentials(); Certificate serverCertificate = null; if (this.serverCredentials == null) { this.keyExchange.skipServerCredentials(); } else { this.keyExchange.processServerCredentials(this.serverCredentials); serverCertificate = this.serverCredentials.getCertificate(); sendCertificateMessage(serverCertificate); } this.connection_state = CS_SERVER_CERTIFICATE; // TODO[RFC 3546] Check whether empty certificates is possible, allowed, or excludes CertificateStatus if (serverCertificate == null || serverCertificate.isEmpty()) { this.allowCertificateStatus = false; } if (this.allowCertificateStatus) { CertificateStatus certificateStatus = tlsServer.getCertificateStatus(); if (certificateStatus != null) { sendCertificateStatusMessage(certificateStatus); } } this.connection_state = CS_CERTIFICATE_STATUS; byte[] serverKeyExchange = this.keyExchange.generateServerKeyExchange(); if (serverKeyExchange != null) { sendServerKeyExchangeMessage(serverKeyExchange); } this.connection_state = CS_SERVER_KEY_EXCHANGE; if (this.serverCredentials != null) { this.certificateRequest = tlsServer.getCertificateRequest(); if (this.certificateRequest != null) { if (TlsUtils.isTLSv12(getContext()) != (certificateRequest.getSupportedSignatureAlgorithms() != null)) { throw new TlsFatalAlert(AlertDescription.internal_error); } this.keyExchange.validateCertificateRequest(certificateRequest); sendCertificateRequestMessage(certificateRequest); TlsUtils.trackHashAlgorithms(this.recordStream.getHandshakeHash(), this.certificateRequest.getSupportedSignatureAlgorithms()); } } this.connection_state = CS_CERTIFICATE_REQUEST; sendServerHelloDoneMessage(); this.connection_state = CS_SERVER_HELLO_DONE; this.recordStream.getHandshakeHash().sealHashAlgorithms(); break; } case CS_END: { refuseRenegotiation(); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.supplemental_data: { switch (this.connection_state) { case CS_SERVER_HELLO_DONE: { tlsServer.processClientSupplementalData(readSupplementalDataMessage(buf)); this.connection_state = CS_CLIENT_SUPPLEMENTAL_DATA; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.certificate: { switch (this.connection_state) { case CS_SERVER_HELLO_DONE: { tlsServer.processClientSupplementalData(null); // NB: Fall through to next case label } case CS_CLIENT_SUPPLEMENTAL_DATA: { if (this.certificateRequest == null) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } receiveCertificateMessage(buf); this.connection_state = CS_CLIENT_CERTIFICATE; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.client_key_exchange: { switch (this.connection_state) { case CS_SERVER_HELLO_DONE: { tlsServer.processClientSupplementalData(null); // NB: Fall through to next case label } case CS_CLIENT_SUPPLEMENTAL_DATA: { if (this.certificateRequest == null) { this.keyExchange.skipClientCredentials(); } else { if (TlsUtils.isTLSv12(getContext())) { /* * 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 (TlsUtils.isSSL(getContext())) { if (this.peerCertificate == null) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } } else { notifyClientCertificate(Certificate.EMPTY_CHAIN); } } // NB: Fall through to next case label } case CS_CLIENT_CERTIFICATE: { receiveClientKeyExchangeMessage(buf); this.connection_state = CS_CLIENT_KEY_EXCHANGE; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.certificate_verify: { switch (this.connection_state) { 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.connection_state = CS_CERTIFICATE_VERIFY; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.finished: { switch (this.connection_state) { case CS_CLIENT_KEY_EXCHANGE: { if (expectCertificateVerifyMessage()) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } // NB: Fall through to next case label } case CS_CERTIFICATE_VERIFY: { processFinishedMessage(buf); this.connection_state = CS_CLIENT_FINISHED; if (this.expectSessionTicket) { sendNewSessionTicketMessage(tlsServer.getNewSessionTicket()); sendChangeCipherSpecMessage(); } this.connection_state = CS_SERVER_SESSION_TICKET; sendFinishedMessage(); this.connection_state = 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); } } protected void handleWarningMessage(short description) throws IOException { switch (description) { case AlertDescription.no_certificate: { /* * SSL 3.0 If the server has sent a certificate request Message, the client must send * either the certificate message or a no_certificate alert. */ if (TlsUtils.isSSL(getContext()) && certificateRequest != null) { notifyClientCertificate(Certificate.EMPTY_CHAIN); } break; } default: { super.handleWarningMessage(description); break; } } } protected void notifyClientCertificate(Certificate clientCertificate) throws IOException { if (certificateRequest == null) { throw new IllegalStateException(); } if (peerCertificate != null) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.peerCertificate = clientCertificate; if (clientCertificate.isEmpty()) { this.keyExchange.skipClientCredentials(); } else { /* * TODO RFC 5246 7.4.6. If the certificate_authorities list in the certificate request * message was non-empty, one of the certificates in the certificate chain SHOULD be * issued by one of the listed CAs. */ this.clientCertificateType = TlsUtils.getClientCertificateType(clientCertificate, this.serverCredentials.getCertificate()); this.keyExchange.processClientCertificate(clientCertificate); } /* * RFC 5246 7.4.6. If the client does not send any certificates, the server MAY at its * discretion either continue the handshake without client authentication, or respond with a * fatal handshake_failure alert. Also, if some aspect of the certificate chain was * unacceptable (e.g., it was not signed by a known, trusted CA), the server MAY at its * discretion either continue the handshake (considering the client unauthenticated) or send * a fatal alert. */ this.tlsServer.notifyClientCertificate(clientCertificate); } protected void receiveCertificateMessage(ByteArrayInputStream buf) throws IOException { Certificate clientCertificate = Certificate.parse(buf); assertEmpty(buf); notifyClientCertificate(clientCertificate); } protected void receiveCertificateVerifyMessage(ByteArrayInputStream buf) throws IOException { if (certificateRequest == null) { throw new IllegalStateException(); } DigitallySigned clientCertificateVerify = DigitallySigned.parse(getContext(), buf); assertEmpty(buf); // Verify the CertificateVerify message contains a correct signature. try { SignatureAndHashAlgorithm signatureAlgorithm = clientCertificateVerify.getAlgorithm(); byte[] hash; if (TlsUtils.isTLSv12(getContext())) { TlsUtils.verifySupportedSignatureAlgorithm(certificateRequest.getSupportedSignatureAlgorithms(), signatureAlgorithm); hash = prepareFinishHash.getFinalHash(signatureAlgorithm.getHash()); } else { hash = securityParameters.getSessionHash(); } org.bouncycastle.asn1.x509.Certificate x509Cert = peerCertificate.getCertificateAt(0); SubjectPublicKeyInfo keyInfo = x509Cert.getSubjectPublicKeyInfo(); AsymmetricKeyParameter publicKey = PublicKeyFactory.createKey(keyInfo); TlsSigner tlsSigner = TlsUtils.createTlsSigner(clientCertificateType); tlsSigner.init(getContext()); if (!tlsSigner.verifyRawSignature(signatureAlgorithm, clientCertificateVerify.getSignature(), publicKey, hash)) { throw new TlsFatalAlert(AlertDescription.decrypt_error); } } catch (TlsFatalAlert e) { throw e; } catch (Exception e) { throw new TlsFatalAlert(AlertDescription.decrypt_error, e); } } protected void receiveClientHelloMessage(ByteArrayInputStream buf) throws IOException { ProtocolVersion client_version = TlsUtils.readVersion(buf); recordStream.setWriteVersion(client_version); if (client_version.isDTLS()) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } byte[] client_random = TlsUtils.readFully(32, buf); /* * TODO RFC 5077 3.4. If a ticket is presented by the client, the server MUST NOT attempt to * use the Session ID in the ClientHello for stateful session resumption. */ byte[] sessionID = TlsUtils.readOpaque8(buf); if (sessionID.length > 32) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } /* * TODO RFC 5246 7.4.1.2. If the session_id field is not empty (implying a session * resumption request), this vector MUST include at least the cipher_suite from that * session. */ int cipher_suites_length = TlsUtils.readUint16(buf); if (cipher_suites_length < 2 || (cipher_suites_length & 1) != 0) { throw new TlsFatalAlert(AlertDescription.decode_error); } this.offeredCipherSuites = TlsUtils.readUint16Array(cipher_suites_length / 2, buf); /* * TODO RFC 5246 7.4.1.2. If the session_id field is not empty (implying a session * resumption request), it MUST include the compression_method from that session. */ int compression_methods_length = TlsUtils.readUint8(buf); if (compression_methods_length < 1) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } this.offeredCompressionMethods = TlsUtils.readUint8Array(compression_methods_length, buf); /* * TODO RFC 3546 2.3 If [...] the older session is resumed, then the server MUST ignore * extensions appearing in the client hello, and send a server hello containing no * extensions. */ this.clientExtensions = readExtensions(buf); /* * TODO[session-hash] * * draft-ietf-tls-session-hash-04 4. Clients and servers SHOULD NOT accept handshakes * that do not use the extended master secret [..]. (and see 5.2, 5.3) */ this.securityParameters.extendedMasterSecret = TlsExtensionsUtils.hasExtendedMasterSecretExtension(clientExtensions); getContextAdmin().setClientVersion(client_version); tlsServer.notifyClientVersion(client_version); tlsServer.notifyFallback(Arrays.contains(offeredCipherSuites, CipherSuite.TLS_FALLBACK_SCSV)); securityParameters.clientRandom = client_random; tlsServer.notifyOfferedCipherSuites(offeredCipherSuites); tlsServer.notifyOfferedCompressionMethods(offeredCompressionMethods); /* * RFC 5746 3.6. Server Behavior: Initial Handshake */ { /* * RFC 5746 3.4. The client MUST include either an empty "renegotiation_info" extension, * or the TLS_EMPTY_RENEGOTIATION_INFO_SCSV signaling cipher suite value in the * ClientHello. Including both is NOT RECOMMENDED. */ /* * When a ClientHello is received, the server MUST check if it includes the * TLS_EMPTY_RENEGOTIATION_INFO_SCSV SCSV. If it does, set the secure_renegotiation flag * to TRUE. */ if (Arrays.contains(offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV)) { this.secure_renegotiation = true; } /* * The server MUST check if the "renegotiation_info" extension is included in the * ClientHello. */ byte[] renegExtData = TlsUtils.getExtensionData(clientExtensions, EXT_RenegotiationInfo); if (renegExtData != null) { /* * If the extension is present, set secure_renegotiation flag to TRUE. The * server MUST then verify that the length of the "renegotiated_connection" * field is zero, and if it is not, MUST abort the handshake. */ this.secure_renegotiation = true; if (!Arrays.constantTimeAreEqual(renegExtData, createRenegotiationInfo(TlsUtils.EMPTY_BYTES))) { throw new TlsFatalAlert(AlertDescription.handshake_failure); } } } tlsServer.notifySecureRenegotiation(this.secure_renegotiation); if (clientExtensions != null) { // NOTE: Validates the padding extension data, if present TlsExtensionsUtils.getPaddingExtension(clientExtensions); tlsServer.processClientExtensions(clientExtensions); } } protected void receiveClientKeyExchangeMessage(ByteArrayInputStream buf) throws IOException { keyExchange.processClientKeyExchange(buf); assertEmpty(buf); if (TlsUtils.isSSL(getContext())) { establishMasterSecret(getContext(), keyExchange); } this.prepareFinishHash = recordStream.prepareToFinish(); this.securityParameters.sessionHash = getCurrentPRFHash(getContext(), prepareFinishHash, null); if (!TlsUtils.isSSL(getContext())) { establishMasterSecret(getContext(), keyExchange); } recordStream.setPendingConnectionState(getPeer().getCompression(), getPeer().getCipher()); if (!expectSessionTicket) { sendChangeCipherSpecMessage(); } } protected void sendCertificateRequestMessage(CertificateRequest certificateRequest) throws IOException { HandshakeMessage message = new HandshakeMessage(HandshakeType.certificate_request); certificateRequest.encode(message); message.writeToRecordStream(); } protected void sendCertificateStatusMessage(CertificateStatus certificateStatus) throws IOException { HandshakeMessage message = new HandshakeMessage(HandshakeType.certificate_status); certificateStatus.encode(message); message.writeToRecordStream(); } protected void sendNewSessionTicketMessage(NewSessionTicket newSessionTicket) throws IOException { if (newSessionTicket == null) { throw new TlsFatalAlert(AlertDescription.internal_error); } HandshakeMessage message = new HandshakeMessage(HandshakeType.session_ticket); newSessionTicket.encode(message); message.writeToRecordStream(); } protected void sendServerHelloMessage() throws IOException { HandshakeMessage message = new HandshakeMessage(HandshakeType.server_hello); { ProtocolVersion server_version = tlsServer.getServerVersion(); if (!server_version.isEqualOrEarlierVersionOf(getContext().getClientVersion())) { throw new TlsFatalAlert(AlertDescription.internal_error); } recordStream.setReadVersion(server_version); recordStream.setWriteVersion(server_version); recordStream.setRestrictReadVersion(true); getContextAdmin().setServerVersion(server_version); TlsUtils.writeVersion(server_version, message); } message.write(this.securityParameters.serverRandom); /* * The server may return an empty session_id to indicate that the session will not be cached * and therefore cannot be resumed. */ TlsUtils.writeOpaque8(TlsUtils.EMPTY_BYTES, message); int selectedCipherSuite = tlsServer.getSelectedCipherSuite(); if (!Arrays.contains(offeredCipherSuites, selectedCipherSuite) || selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL || CipherSuite.isSCSV(selectedCipherSuite) || !TlsUtils.isValidCipherSuiteForVersion(selectedCipherSuite, getContext().getServerVersion())) { throw new TlsFatalAlert(AlertDescription.internal_error); } securityParameters.cipherSuite = selectedCipherSuite; short selectedCompressionMethod = tlsServer.getSelectedCompressionMethod(); if (!Arrays.contains(offeredCompressionMethods, selectedCompressionMethod)) { throw new TlsFatalAlert(AlertDescription.internal_error); } securityParameters.compressionAlgorithm = selectedCompressionMethod; TlsUtils.writeUint16(selectedCipherSuite, message); TlsUtils.writeUint8(selectedCompressionMethod, message); this.serverExtensions = tlsServer.getServerExtensions(); /* * RFC 5746 3.6. Server Behavior: Initial Handshake */ if (this.secure_renegotiation) { byte[] renegExtData = TlsUtils.getExtensionData(this.serverExtensions, EXT_RenegotiationInfo); boolean noRenegExt = (null == renegExtData); if (noRenegExt) { /* * Note that sending a "renegotiation_info" extension in response to a ClientHello * containing only the SCSV is an explicit exception to the prohibition in RFC 5246, * Section 7.4.1.4, on the server sending unsolicited extensions and is only allowed * because the client is signaling its willingness to receive the extension via the * TLS_EMPTY_RENEGOTIATION_INFO_SCSV SCSV. */ /* * If the secure_renegotiation flag is set to TRUE, the server MUST include an empty * "renegotiation_info" extension in the ServerHello message. */ this.serverExtensions = TlsExtensionsUtils.ensureExtensionsInitialised(serverExtensions); this.serverExtensions.put(EXT_RenegotiationInfo, createRenegotiationInfo(TlsUtils.EMPTY_BYTES)); } } if (securityParameters.extendedMasterSecret) { this.serverExtensions = TlsExtensionsUtils.ensureExtensionsInitialised(serverExtensions); TlsExtensionsUtils.addExtendedMasterSecretExtension(serverExtensions); } /* * TODO RFC 3546 2.3 If [...] the older session is resumed, then the server MUST ignore * extensions appearing in the client hello, and send a server hello containing no * extensions. */ if (this.serverExtensions != null) { this.securityParameters.encryptThenMAC = TlsExtensionsUtils.hasEncryptThenMACExtension(serverExtensions); this.securityParameters.maxFragmentLength = processMaxFragmentLengthExtension(clientExtensions, serverExtensions, AlertDescription.internal_error); this.securityParameters.truncatedHMac = TlsExtensionsUtils.hasTruncatedHMacExtension(serverExtensions); /* * TODO It's surprising that there's no provision to allow a 'fresh' CertificateStatus to be sent in * a session resumption handshake. */ this.allowCertificateStatus = !resumedSession && TlsUtils.hasExpectedEmptyExtensionData(serverExtensions, TlsExtensionsUtils.EXT_status_request, AlertDescription.internal_error); this.expectSessionTicket = !resumedSession && TlsUtils.hasExpectedEmptyExtensionData(serverExtensions, TlsProtocol.EXT_SessionTicket, AlertDescription.internal_error); writeExtensions(message, serverExtensions); } securityParameters.prfAlgorithm = getPRFAlgorithm(getContext(), securityParameters.getCipherSuite()); /* * RFC 5246 7.4.9. Any cipher suite which does not explicitly specify verify_data_length has * a verify_data_length equal to 12. This includes all existing cipher suites. */ securityParameters.verifyDataLength = 12; applyMaxFragmentLengthExtension(); message.writeToRecordStream(); } protected void sendServerHelloDoneMessage() throws IOException { byte[] message = new byte[4]; TlsUtils.writeUint8(HandshakeType.server_hello_done, message, 0); TlsUtils.writeUint24(0, message, 1); writeHandshakeMessage(message, 0, message.length); } protected void sendServerKeyExchangeMessage(byte[] serverKeyExchange) throws IOException { HandshakeMessage message = new HandshakeMessage(HandshakeType.server_key_exchange, serverKeyExchange.length); message.write(serverKeyExchange); message.writeToRecordStream(); } protected boolean expectCertificateVerifyMessage() { return clientCertificateType >= 0 && TlsUtils.hasSigningCapability(clientCertificateType); } }