public override void ProcessClientKeyExchange(Stream input) { byte[] array = TlsUtilities.ReadOpaque16(input); mPsk = mPskIdentityManager.GetPsk(array); if (mPsk == null) { throw new TlsFatalAlert(115); } mContext.SecurityParameters.pskIdentity = array; if (mKeyExchange == 14) { BigInteger y = TlsDHUtilities.ReadDHParameter(input); mDHAgreePublicKey = TlsDHUtilities.ValidateDHPublicKey(new DHPublicKeyParameters(y, mDHParameters)); } else if (mKeyExchange == 24) { byte[] encoding = TlsUtilities.ReadOpaque8(input); ECDomainParameters parameters = mECAgreePrivateKey.Parameters; mECAgreePublicKey = TlsEccUtilities.ValidateECPublicKey(TlsEccUtilities.DeserializeECPublicKey(mServerECPointFormats, parameters, encoding)); } else if (mKeyExchange == 15) { byte[] encryptedPreMasterSecret = (!TlsUtilities.IsSsl(mContext)) ? TlsUtilities.ReadOpaque16(input) : Streams.ReadAll(input); mPremasterSecret = mServerCredentials.DecryptPreMasterSecret(encryptedPreMasterSecret); } }
protected override void HandleAlertWarningMessage(byte alertDescription) { base.HandleAlertWarningMessage(alertDescription); switch (alertDescription) { 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 (TlsUtilities.IsSsl(Context) && this.mCertificateRequest != null) { switch (this.mConnectionState) { case CS_SERVER_HELLO_DONE: case CS_CLIENT_SUPPLEMENTAL_DATA: { if (mConnectionState < CS_CLIENT_SUPPLEMENTAL_DATA) { mTlsServer.ProcessClientSupplementalData(null); } NotifyClientCertificate(Certificate.EmptyChain); this.mConnectionState = CS_CLIENT_CERTIFICATE; return; } } } throw new TlsFatalAlert(AlertDescription.unexpected_message); } } }
public virtual byte[] CalculateMacConstantTime(long seqNo, byte type, byte[] message, int offset, int length, int fullLength, byte[] dummyData) { /* * Actual MAC only calculated on 'length' bytes... */ byte[] result = CalculateMac(seqNo, type, message, offset, length); /* * ...but ensure a constant number of complete digest blocks are processed (as many as would * be needed for 'fullLength' bytes of input). */ int headerLength = TlsUtilities.IsSsl(context) ? 11 : 13; // How many extra full blocks do we need to calculate? int extra = GetDigestBlockCount(headerLength + fullLength) - GetDigestBlockCount(headerLength + length); while (--extra >= 0) { mac.BlockUpdate(dummyData, 0, digestBlockSize); } // One more byte in case the implementation is "lazy" about processing blocks mac.Update(dummyData[0]); mac.Reset(); return(result); }
protected virtual int CheckPaddingConstantTime(byte[] buf, int off, int len, int blockSize, int macSize) { int num = off + len; byte b = buf[num - 1]; int num2 = b & 0xFF; int num3 = num2 + 1; int num4 = 0; byte b2 = 0; if ((TlsUtilities.IsSsl(context) && num3 > blockSize) || macSize + num3 > len) { num3 = 0; } else { int num5 = num - num3; do { b2 = (byte)(b2 | (byte)(buf[num5++] ^ b)); }while (num5 < num); num4 = num3; if (b2 != 0) { num3 = 0; } } byte[] array = randomData; while (num4 < 256) { b2 = (byte)(b2 | (byte)(array[num4++] ^ b)); } byte[] array2; (array2 = array)[0] = (byte)(array2[0] ^ b2); return(num3); }
public TlsMac(TlsContext context, IDigest digest, byte[] key, int keyOff, int keyLen) { this.context = context; KeyParameter keyParameter = new KeyParameter(key, keyOff, keyLen); secret = Arrays.Clone(keyParameter.GetKey()); if (digest is LongDigest) { digestBlockSize = 128; digestOverhead = 16; } else { digestBlockSize = 64; digestOverhead = 8; } if (TlsUtilities.IsSsl(context)) { mac = new Ssl3Mac(digest); if (digest.GetDigestSize() == 20) { digestOverhead = 4; } } else { mac = new HMac(digest); } mac.Init(keyParameter); macLength = mac.GetMacSize(); if (context.SecurityParameters.truncatedHMac) { macLength = Math.Min(macLength, 10); } }
protected virtual void RefuseRenegotiation() { if (TlsUtilities.IsSsl(Context)) { throw new TlsFatalAlert(40); } RaiseWarning(100, "Renegotiation not supported"); }
protected internal static byte[] GetCurrentPrfHash(TlsContext context, TlsHandshakeHash handshakeHash, byte[] sslSender) { IDigest digest = handshakeHash.ForkPrfHash(); if (sslSender != null && TlsUtilities.IsSsl(context)) { digest.BlockUpdate(sslSender, 0, sslSender.Length); } return(DigestUtilities.DoFinal(digest)); }
public virtual int DoFinal(byte[] output, int outOff) { if (mContext != null && TlsUtilities.IsSsl(mContext)) { Ssl3Complete(mMd5, Ssl3Mac.IPAD, Ssl3Mac.OPAD, 48); Ssl3Complete(mSha1, Ssl3Mac.IPAD, Ssl3Mac.OPAD, 40); } int num = mMd5.DoFinal(output, outOff); int num2 = mSha1.DoFinal(output, outOff + num); return(num + num2); }
public virtual byte[] CalculateMacConstantTime(long seqNo, byte type, byte[] message, int offset, int length, int fullLength, byte[] dummyData) { byte[] result = CalculateMac(seqNo, type, message, offset, length); int num = TlsUtilities.IsSsl(context) ? 11 : 13; int num2 = GetDigestBlockCount(num + fullLength) - GetDigestBlockCount(num + length); while (--num2 >= 0) { mac.BlockUpdate(dummyData, 0, digestBlockSize); } mac.Update(dummyData[0]); mac.Reset(); return(result); }
/** * Generate a new instance of an TlsMac. * * @param context the TLS client context * @param digest The digest to use. * @param key A byte-array where the key for this MAC is located. * @param keyOff The number of bytes to skip, before the key starts in the buffer. * @param keyLen The length of the key. */ public TlsMac(TlsContext context, IDigest digest, byte[] key, int keyOff, int keyLen) { this.context = context; KeyParameter keyParameter = new KeyParameter(key, keyOff, keyLen); this.secret = Arrays.Clone(keyParameter.GetKey()); // TODO This should check the actual algorithm, not rely on the engine type if (digest is LongDigest) { this.digestBlockSize = 128; this.digestOverhead = 16; } else { this.digestBlockSize = 64; this.digestOverhead = 8; } if (TlsUtilities.IsSsl(context)) { this.mac = new Ssl3Mac(digest); // TODO This should check the actual algorithm, not assume based on the digest size if (digest.GetDigestSize() == 20) { /* * NOTE: When SHA-1 is used with the SSL 3.0 MAC, the secret + input pad is not * digest block-aligned. */ this.digestOverhead = 4; } } else { this.mac = new HMac(digest); // NOTE: The input pad for HMAC is always a full digest block } this.mac.Init(keyParameter); this.macLength = mac.GetMacSize(); if (context.SecurityParameters.truncatedHMac) { this.macLength = System.Math.Min(this.macLength, 10); } }
public override void ProcessClientKeyExchange(Stream input) { byte[] encryptedPreMasterSecret; if (TlsUtilities.IsSsl(mContext)) { // TODO Do any SSLv3 clients actually include the length? encryptedPreMasterSecret = Streams.ReadAll(input); } else { encryptedPreMasterSecret = TlsUtilities.ReadOpaque16(input); } this.mPremasterSecret = mServerCredentials.DecryptPreMasterSecret(encryptedPreMasterSecret); }
protected override void HandleWarningMessage(byte description) { byte b = description; if (b == 41) { if (TlsUtilities.IsSsl(Context) && mCertificateRequest != null) { NotifyClientCertificate(Certificate.EmptyChain); } } else { base.HandleWarningMessage(description); } }
public override void ProcessClientKeyExchange(Stream input) { byte[] psk_identity = TlsUtilities.ReadOpaque16(input); this.mPsk = mPskIdentityManager.GetPsk(psk_identity); if (mPsk == null) { throw new TlsFatalAlert(AlertDescription.unknown_psk_identity); } mContext.SecurityParameters.pskIdentity = psk_identity; if (this.mKeyExchange == KeyExchangeAlgorithm.DHE_PSK) { BigInteger Yc = TlsDHUtilities.ReadDHParameter(input); this.mDHAgreePublicKey = TlsDHUtilities.ValidateDHPublicKey(new DHPublicKeyParameters(Yc, mDHParameters)); } else if (this.mKeyExchange == KeyExchangeAlgorithm.ECDHE_PSK) { byte[] point = TlsUtilities.ReadOpaque8(input); ECDomainParameters curve_params = this.mECAgreePrivateKey.Parameters; this.mECAgreePublicKey = TlsEccUtilities.ValidateECPublicKey(TlsEccUtilities.DeserializeECPublicKey( mServerECPointFormats, curve_params, point)); } else if (this.mKeyExchange == KeyExchangeAlgorithm.RSA_PSK) { byte[] encryptedPreMasterSecret; if (TlsUtilities.IsSsl(mContext)) { // TODO Do any SSLv3 clients actually include the length? encryptedPreMasterSecret = Streams.ReadAll(input); } else { encryptedPreMasterSecret = TlsUtilities.ReadOpaque16(input); } this.mPremasterSecret = mServerCredentials.DecryptPreMasterSecret(encryptedPreMasterSecret); } }
protected virtual int CheckPaddingConstantTime(byte[] buf, int off, int len, int blockSize, int macSize) { int end = off + len; byte lastByte = buf[end - 1]; int padlen = lastByte & 0xff; int totalPad = padlen + 1; int dummyIndex = 0; byte padDiff = 0; if ((TlsUtilities.IsSsl(context) && totalPad > blockSize) || (macSize + totalPad > len)) { totalPad = 0; } else { int padPos = end - totalPad; do { padDiff |= (byte)(buf[padPos++] ^ lastByte); }while (padPos < end); dummyIndex = totalPad; if (padDiff != 0) { totalPad = 0; } } // Run some extra dummy checks so the number of checks is always constant { byte[] dummyPad = randomData; while (dummyIndex < 256) { padDiff |= (byte)(dummyPad[dummyIndex++] ^ lastByte); } // Ensure the above loop is not eliminated dummyPad[0] ^= padDiff; } return(totalPad); }
protected virtual void ReceiveClientKeyExchangeMessage(MemoryStream buf) { mKeyExchange.ProcessClientKeyExchange(buf); AssertEmpty(buf); if (TlsUtilities.IsSsl(Context)) { EstablishMasterSecret(Context, mKeyExchange); } this.mPrepareFinishHash = mRecordStream.PrepareToFinish(); this.mSecurityParameters.sessionHash = GetCurrentPrfHash(Context, mPrepareFinishHash, null); if (!TlsUtilities.IsSsl(Context)) { EstablishMasterSecret(Context, mKeyExchange); } mRecordStream.SetPendingConnectionState(Peer.GetCompression(), Peer.GetCipher()); }
/// <exception cref="IOException"></exception> public static byte[] GenerateEncryptedPreMasterSecret(TlsContext context, RsaKeyParameters rsaServerPublicKey, Stream output) { /* * Choose a PremasterSecret and send it encrypted to the server */ byte[] premasterSecret = new byte[48]; context.SecureRandom.NextBytes(premasterSecret); TlsUtilities.WriteVersion(context.ClientVersion, premasterSecret, 0); Pkcs1Encoding encoding = new Pkcs1Encoding(new RsaBlindedEngine()); encoding.Init(true, new ParametersWithRandom(rsaServerPublicKey, context.SecureRandom)); try { byte[] encryptedPreMasterSecret = encoding.ProcessBlock(premasterSecret, 0, premasterSecret.Length); if (TlsUtilities.IsSsl(context)) { // TODO Do any SSLv3 servers actually expect the length? output.Write(encryptedPreMasterSecret, 0, encryptedPreMasterSecret.Length); } else { TlsUtilities.WriteOpaque16(encryptedPreMasterSecret, output); } } catch (InvalidCipherTextException e) { /* * This should never happen, only during decryption. */ throw new TlsFatalAlert(AlertDescription.internal_error, e); } return(premasterSecret); }
protected override void HandleWarningMessage(byte description) { 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 (TlsUtilities.IsSsl(Context) && mCertificateRequest != null) { NotifyClientCertificate(Certificate.EmptyChain); } break; } default: { base.HandleWarningMessage(description); break; } } }
protected override void HandleHandshakeMessage(byte type, MemoryStream buf) { switch (type) { case HandshakeType.client_hello: { switch (this.mConnectionState) { case CS_START: { ReceiveClientHelloMessage(buf); this.mConnectionState = CS_CLIENT_HELLO; SendServerHelloMessage(); this.mConnectionState = CS_SERVER_HELLO; mRecordStream.NotifyHelloComplete(); IList serverSupplementalData = mTlsServer.GetServerSupplementalData(); if (serverSupplementalData != null) { SendSupplementalDataMessage(serverSupplementalData); } this.mConnectionState = CS_SERVER_SUPPLEMENTAL_DATA; this.mKeyExchange = mTlsServer.GetKeyExchange(); this.mKeyExchange.Init(Context); this.mServerCredentials = mTlsServer.GetCredentials(); Certificate serverCertificate = null; if (this.mServerCredentials == null) { this.mKeyExchange.SkipServerCredentials(); } else { this.mKeyExchange.ProcessServerCredentials(this.mServerCredentials); serverCertificate = this.mServerCredentials.Certificate; SendCertificateMessage(serverCertificate); } this.mConnectionState = CS_SERVER_CERTIFICATE; // TODO[RFC 3546] Check whether empty certificates is possible, allowed, or excludes CertificateStatus if (serverCertificate == null || serverCertificate.IsEmpty) { this.mAllowCertificateStatus = false; } if (this.mAllowCertificateStatus) { CertificateStatus certificateStatus = mTlsServer.GetCertificateStatus(); if (certificateStatus != null) { SendCertificateStatusMessage(certificateStatus); } } this.mConnectionState = CS_CERTIFICATE_STATUS; byte[] serverKeyExchange = this.mKeyExchange.GenerateServerKeyExchange(); if (serverKeyExchange != null) { SendServerKeyExchangeMessage(serverKeyExchange); } this.mConnectionState = CS_SERVER_KEY_EXCHANGE; if (this.mServerCredentials != null) { this.mCertificateRequest = mTlsServer.GetCertificateRequest(); if (this.mCertificateRequest != null) { if (TlsUtilities.IsTlsV12(Context) != (mCertificateRequest.SupportedSignatureAlgorithms != null)) { throw new TlsFatalAlert(AlertDescription.internal_error); } this.mKeyExchange.ValidateCertificateRequest(mCertificateRequest); SendCertificateRequestMessage(mCertificateRequest); TlsUtilities.TrackHashAlgorithms(this.mRecordStream.HandshakeHash, this.mCertificateRequest.SupportedSignatureAlgorithms); } } this.mConnectionState = CS_CERTIFICATE_REQUEST; SendServerHelloDoneMessage(); this.mConnectionState = CS_SERVER_HELLO_DONE; this.mRecordStream.HandshakeHash.SealHashAlgorithms(); break; } case CS_END: { RefuseRenegotiation(); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.supplemental_data: { switch (this.mConnectionState) { case CS_SERVER_HELLO_DONE: { mTlsServer.ProcessClientSupplementalData(ReadSupplementalDataMessage(buf)); this.mConnectionState = CS_CLIENT_SUPPLEMENTAL_DATA; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.certificate: { switch (this.mConnectionState) { case CS_SERVER_HELLO_DONE: case CS_CLIENT_SUPPLEMENTAL_DATA: { if (mConnectionState < CS_CLIENT_SUPPLEMENTAL_DATA) { mTlsServer.ProcessClientSupplementalData(null); } if (this.mCertificateRequest == null) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } ReceiveCertificateMessage(buf); this.mConnectionState = CS_CLIENT_CERTIFICATE; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.client_key_exchange: { switch (this.mConnectionState) { case CS_SERVER_HELLO_DONE: case CS_CLIENT_SUPPLEMENTAL_DATA: case CS_CLIENT_CERTIFICATE: { if (mConnectionState < CS_CLIENT_SUPPLEMENTAL_DATA) { mTlsServer.ProcessClientSupplementalData(null); } if (mConnectionState < CS_CLIENT_CERTIFICATE) { if (this.mCertificateRequest == null) { this.mKeyExchange.SkipClientCredentials(); } else { if (TlsUtilities.IsTlsV12(Context)) { /* * RFC 5246 If no suitable certificate is available, the client MUST Send a * certificate message containing no certificates. * * NOTE: In previous RFCs, this was SHOULD instead of MUST. */ throw new TlsFatalAlert(AlertDescription.unexpected_message); } else if (TlsUtilities.IsSsl(Context)) { if (this.mPeerCertificate == null) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } } else { NotifyClientCertificate(Certificate.EmptyChain); } } } ReceiveClientKeyExchangeMessage(buf); this.mConnectionState = CS_CLIENT_KEY_EXCHANGE; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.certificate_verify: { switch (this.mConnectionState) { case CS_CLIENT_KEY_EXCHANGE: { /* * RFC 5246 7.4.8 This message is only sent following a client certificate that has * signing capability (i.e., all certificates except those containing fixed * Diffie-Hellman parameters). */ if (!ExpectCertificateVerifyMessage()) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } ReceiveCertificateVerifyMessage(buf); this.mConnectionState = CS_CERTIFICATE_VERIFY; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.finished: { switch (this.mConnectionState) { case CS_CLIENT_KEY_EXCHANGE: case CS_CERTIFICATE_VERIFY: { if (mConnectionState < CS_CERTIFICATE_VERIFY && ExpectCertificateVerifyMessage()) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } ProcessFinishedMessage(buf); this.mConnectionState = CS_CLIENT_FINISHED; if (this.mExpectSessionTicket) { SendNewSessionTicketMessage(mTlsServer.GetNewSessionTicket()); } this.mConnectionState = CS_SERVER_SESSION_TICKET; SendChangeCipherSpecMessage(); SendFinishedMessage(); this.mConnectionState = CS_SERVER_FINISHED; CompleteHandshake(); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.hello_request: case HandshakeType.hello_verify_request: case HandshakeType.server_hello: case HandshakeType.server_key_exchange: case HandshakeType.certificate_request: case HandshakeType.server_hello_done: case HandshakeType.session_ticket: default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } }
protected override void HandleHandshakeMessage(byte type, byte[] data) { MemoryStream memoryStream = new MemoryStream(data); switch (type) { case 1: switch (base.mConnectionState) { case 0: { ReceiveClientHelloMessage(memoryStream); base.mConnectionState = 1; SendServerHelloMessage(); base.mConnectionState = 2; mRecordStream.NotifyHelloComplete(); IList serverSupplementalData = mTlsServer.GetServerSupplementalData(); if (serverSupplementalData != null) { SendSupplementalDataMessage(serverSupplementalData); } base.mConnectionState = 3; mKeyExchange = mTlsServer.GetKeyExchange(); mKeyExchange.Init(Context); mServerCredentials = mTlsServer.GetCredentials(); Certificate certificate = null; if (mServerCredentials == null) { mKeyExchange.SkipServerCredentials(); } else { mKeyExchange.ProcessServerCredentials(mServerCredentials); certificate = mServerCredentials.Certificate; SendCertificateMessage(certificate); } base.mConnectionState = 4; if (certificate == null || certificate.IsEmpty) { mAllowCertificateStatus = false; } if (mAllowCertificateStatus) { CertificateStatus certificateStatus = mTlsServer.GetCertificateStatus(); if (certificateStatus != null) { SendCertificateStatusMessage(certificateStatus); } } base.mConnectionState = 5; byte[] array = mKeyExchange.GenerateServerKeyExchange(); if (array != null) { SendServerKeyExchangeMessage(array); } base.mConnectionState = 6; if (mServerCredentials != null) { mCertificateRequest = mTlsServer.GetCertificateRequest(); if (mCertificateRequest != null) { if (TlsUtilities.IsTlsV12(Context) != (mCertificateRequest.SupportedSignatureAlgorithms != null)) { throw new TlsFatalAlert(80); } mKeyExchange.ValidateCertificateRequest(mCertificateRequest); SendCertificateRequestMessage(mCertificateRequest); TlsUtilities.TrackHashAlgorithms(mRecordStream.HandshakeHash, mCertificateRequest.SupportedSignatureAlgorithms); } } base.mConnectionState = 7; SendServerHelloDoneMessage(); base.mConnectionState = 8; mRecordStream.HandshakeHash.SealHashAlgorithms(); break; } case 16: RefuseRenegotiation(); break; default: throw new TlsFatalAlert(10); } break; case 23: { short mConnectionState = base.mConnectionState; if (mConnectionState == 8) { mTlsServer.ProcessClientSupplementalData(TlsProtocol.ReadSupplementalDataMessage(memoryStream)); base.mConnectionState = 9; break; } throw new TlsFatalAlert(10); } case 11: switch (base.mConnectionState) { case 8: case 9: if (base.mConnectionState < 9) { mTlsServer.ProcessClientSupplementalData(null); } if (mCertificateRequest == null) { throw new TlsFatalAlert(10); } ReceiveCertificateMessage(memoryStream); base.mConnectionState = 10; break; default: throw new TlsFatalAlert(10); } break; case 16: switch (base.mConnectionState) { case 8: case 9: case 10: if (base.mConnectionState < 9) { mTlsServer.ProcessClientSupplementalData(null); } if (base.mConnectionState < 10) { if (mCertificateRequest == null) { mKeyExchange.SkipClientCredentials(); } else { if (TlsUtilities.IsTlsV12(Context)) { throw new TlsFatalAlert(10); } if (TlsUtilities.IsSsl(Context)) { if (mPeerCertificate == null) { throw new TlsFatalAlert(10); } } else { NotifyClientCertificate(Certificate.EmptyChain); } } } ReceiveClientKeyExchangeMessage(memoryStream); base.mConnectionState = 11; break; default: throw new TlsFatalAlert(10); } break; case 15: { short mConnectionState = base.mConnectionState; if (mConnectionState == 11) { if (!ExpectCertificateVerifyMessage()) { throw new TlsFatalAlert(10); } ReceiveCertificateVerifyMessage(memoryStream); base.mConnectionState = 12; break; } throw new TlsFatalAlert(10); } case 20: switch (base.mConnectionState) { case 11: case 12: if (base.mConnectionState < 12 && ExpectCertificateVerifyMessage()) { throw new TlsFatalAlert(10); } ProcessFinishedMessage(memoryStream); base.mConnectionState = 13; if (mExpectSessionTicket) { SendNewSessionTicketMessage(mTlsServer.GetNewSessionTicket()); SendChangeCipherSpecMessage(); } base.mConnectionState = 14; SendFinishedMessage(); base.mConnectionState = 15; base.mConnectionState = 16; CompleteHandshake(); break; default: throw new TlsFatalAlert(10); } break; default: throw new TlsFatalAlert(10); } }
protected override void HandleHandshakeMessage(byte type, MemoryStream buf) { if (HTTPManager.Logger.Level <= Loglevels.All) { HTTPManager.Logger.Verbose("TlsClientProtocol", "HandleHandshakeMessage " + type.ToString(), this.LoggingContext); } if (this.mResumedSession) { if (type != HandshakeType.finished || this.mConnectionState != CS_SERVER_HELLO) { throw new TlsFatalAlert(AlertDescription.unexpected_message); } ProcessFinishedMessage(buf); this.mConnectionState = CS_SERVER_FINISHED; SendChangeCipherSpecMessage(); SendFinishedMessage(); this.mConnectionState = CS_CLIENT_FINISHED; CompleteHandshake(); return; } switch (type) { case HandshakeType.certificate: { switch (this.mConnectionState) { case CS_SERVER_HELLO: case CS_SERVER_SUPPLEMENTAL_DATA: { if (this.mConnectionState == CS_SERVER_HELLO) { HandleSupplementalData(null); } // Parse the Certificate message and Send to cipher suite this.mPeerCertificate = Certificate.Parse(buf); AssertEmpty(buf); // TODO[RFC 3546] Check whether empty certificates is possible, allowed, or excludes CertificateStatus if (this.mPeerCertificate == null || this.mPeerCertificate.IsEmpty) { this.mAllowCertificateStatus = false; } this.mKeyExchange.ProcessServerCertificate(this.mPeerCertificate); this.mAuthentication = mTlsClient.GetAuthentication(); // We are expecting a Certificate_Status message, so going to delay the NotifyServerCertificate call // until the server_hello_done. (no until CS_SERVER_CERTIFICATE as the server might not send one) // This way, we can validate both the certificate status and the received certificates. if (!this.mTlsClient.ExpectEmptyCertificateStatusExtension) { 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.mTlsClient.CertificateStatus = CertificateStatus.Parse(buf); AssertEmpty(buf); // TODO[RFC 3546] Figure out how to provide this to the client/authentication. this.mConnectionState = CS_CERTIFICATE_STATUS; break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.finished: { switch (this.mConnectionState) { case CS_CLIENT_FINISHED: case CS_SERVER_SESSION_TICKET: { if (this.mConnectionState == CS_CLIENT_FINISHED && this.mExpectSessionTicket) { /* * RFC 5077 3.3. This message MUST be sent if the server included a * SessionTicket extension in the ServerHello. */ throw new TlsFatalAlert(AlertDescription.unexpected_message); } ProcessFinishedMessage(buf); this.mConnectionState = CS_SERVER_FINISHED; CompleteHandshake(); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.server_hello: { switch (this.mConnectionState) { case CS_CLIENT_HELLO: { ReceiveServerHelloMessage(buf); this.mConnectionState = CS_SERVER_HELLO; this.mRecordStream.NotifyHelloComplete(); ApplyMaxFragmentLengthExtension(); if (this.mResumedSession) { this.mSecurityParameters.masterSecret = Arrays.Clone(this.mSessionParameters.MasterSecret); this.mRecordStream.SetPendingConnectionState(Peer.GetCompression(), Peer.GetCipher()); } else { InvalidateSession(); if (this.mSelectedSessionID.Length > 0) { this.mTlsSession = new TlsSessionImpl(this.mSelectedSessionID, null); } } break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.supplemental_data: { switch (this.mConnectionState) { case CS_SERVER_HELLO: { HandleSupplementalData(ReadSupplementalDataMessage(buf)); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } break; } case HandshakeType.server_hello_done: { switch (this.mConnectionState) { case CS_SERVER_HELLO: case CS_SERVER_SUPPLEMENTAL_DATA: case CS_SERVER_CERTIFICATE: case CS_CERTIFICATE_STATUS: case CS_SERVER_KEY_EXCHANGE: case CS_CERTIFICATE_REQUEST: { if (this.mTlsClient.ExpectEmptyCertificateStatusExtension) { this.mAuthentication.NotifyServerCertificate(this.mPeerCertificate); } 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; if (TlsUtilities.IsSsl(Context)) { EstablishMasterSecret(Context, mKeyExchange); } TlsHandshakeHash prepareFinishHash = mRecordStream.PrepareToFinish(); this.mSecurityParameters.sessionHash = GetCurrentPrfHash(Context, prepareFinishHash, null); if (!TlsUtilities.IsSsl(Context)) { EstablishMasterSecret(Context, mKeyExchange); } mRecordStream.SetPendingConnectionState(Peer.GetCompression(), Peer.GetCipher()); if (clientCreds != null && clientCreds is TlsSignerCredentials) { TlsSignerCredentials signerCredentials = (TlsSignerCredentials)clientCreds; /* * RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm from TLS 1.2 */ SignatureAndHashAlgorithm signatureAndHashAlgorithm = TlsUtilities.GetSignatureAndHashAlgorithm( Context, signerCredentials); byte[] hash; if (signatureAndHashAlgorithm == null) { hash = mSecurityParameters.SessionHash; } else { hash = prepareFinishHash.GetFinalHash(signatureAndHashAlgorithm.Hash); } byte[] signature = signerCredentials.GenerateCertificateSignature(hash); DigitallySigned certificateVerify = new DigitallySigned(signatureAndHashAlgorithm, signature); SendCertificateVerifyMessage(certificateVerify); this.mConnectionState = CS_CERTIFICATE_VERIFY; } SendChangeCipherSpecMessage(); SendFinishedMessage(); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mConnectionState = CS_CLIENT_FINISHED; break; } case HandshakeType.server_key_exchange: { switch (this.mConnectionState) { case CS_SERVER_HELLO: case CS_SERVER_SUPPLEMENTAL_DATA: case CS_SERVER_CERTIFICATE: case CS_CERTIFICATE_STATUS: { if (mConnectionState < CS_SERVER_SUPPLEMENTAL_DATA) { HandleSupplementalData(null); } if (mConnectionState < CS_SERVER_CERTIFICATE) { // There was no server certificate message; check it's OK this.mKeyExchange.SkipServerCredentials(); this.mAuthentication = null; } this.mKeyExchange.ProcessServerKeyExchange(buf); AssertEmpty(buf); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mConnectionState = CS_SERVER_KEY_EXCHANGE; break; } case HandshakeType.certificate_request: { switch (this.mConnectionState) { case CS_SERVER_CERTIFICATE: case CS_CERTIFICATE_STATUS: case CS_SERVER_KEY_EXCHANGE: { if (this.mConnectionState != CS_SERVER_KEY_EXCHANGE) { // There was no server key exchange message; check it's OK this.mKeyExchange.SkipServerKeyExchange(); } if (this.mAuthentication == null) { /* * RFC 2246 7.4.4. It is a fatal handshake_failure alert for an anonymous server * to request client identification. */ throw new TlsFatalAlert(AlertDescription.handshake_failure); } this.mCertificateRequest = CertificateRequest.Parse(Context, buf); AssertEmpty(buf); this.mKeyExchange.ValidateCertificateRequest(this.mCertificateRequest); /* * TODO Give the client a chance to immediately select the CertificateVerify hash * algorithm here to avoid tracking the other hash algorithms unnecessarily? */ TlsUtilities.TrackHashAlgorithms(this.mRecordStream.HandshakeHash, this.mCertificateRequest.SupportedSignatureAlgorithms); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mConnectionState = CS_CERTIFICATE_REQUEST; break; } case HandshakeType.session_ticket: { switch (this.mConnectionState) { case CS_CLIENT_FINISHED: { if (!this.mExpectSessionTicket) { /* * RFC 5077 3.3. This message MUST NOT be sent if the server did not include a * SessionTicket extension in the ServerHello. */ throw new TlsFatalAlert(AlertDescription.unexpected_message); } /* * RFC 5077 3.4. If the client receives a session ticket from the server, then it * discards any Session ID that was sent in the ServerHello. */ InvalidateSession(); ReceiveNewSessionTicketMessage(buf); break; } default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } this.mConnectionState = CS_SERVER_SESSION_TICKET; break; } case HandshakeType.hello_request: { AssertEmpty(buf); /* * RFC 2246 7.4.1.1 Hello request This message will be ignored by the client if the * client is currently negotiating a session. This message may be ignored by the client * if it does not wish to renegotiate a session, or the client may, if it wishes, * respond with a no_renegotiation alert. */ if (this.mConnectionState == CS_END) { RefuseRenegotiation(); } break; } case HandshakeType.client_hello: case HandshakeType.client_key_exchange: case HandshakeType.certificate_verify: case HandshakeType.hello_verify_request: default: throw new TlsFatalAlert(AlertDescription.unexpected_message); } }
protected virtual void ReceiveServerHelloMessage(MemoryStream buf) { { ProtocolVersion server_version = TlsUtilities.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.mRecordStream.ReadVersion)) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } ProtocolVersion client_version = Context.ClientVersion; if (!server_version.IsEqualOrEarlierVersionOf(client_version)) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } this.mRecordStream.SetWriteVersion(server_version); ContextAdmin.SetServerVersion(server_version); this.mTlsClient.NotifyServerVersion(server_version); if (HTTPManager.Logger.Level <= Loglevels.All) { HTTPManager.Logger.Verbose("TlsClientProtocol", "ReceiveServerHelloMessage server_version: " + server_version.ToString(), this.LoggingContext); } } /* * Read the server random */ this.mSecurityParameters.serverRandom = TlsUtilities.ReadFully(32, buf); this.mSelectedSessionID = TlsUtilities.ReadOpaque8(buf); if (this.mSelectedSessionID.Length > 32) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } this.mTlsClient.NotifySessionID(this.mSelectedSessionID); this.mResumedSession = this.mSelectedSessionID.Length > 0 && this.mTlsSession != null && Arrays.AreEqual(this.mSelectedSessionID, this.mTlsSession.SessionID); /* * Find out which CipherSuite the server has chosen and check that it was one of the offered * ones, and is a valid selection for the negotiated version. */ int selectedCipherSuite = TlsUtilities.ReadUint16(buf); if (!Arrays.Contains(this.mOfferedCipherSuites, selectedCipherSuite) || selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL || CipherSuite.IsScsv(selectedCipherSuite) || !TlsUtilities.IsValidCipherSuiteForVersion(selectedCipherSuite, Context.ServerVersion)) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } if (HTTPManager.Logger.Level <= Loglevels.All) { HTTPManager.Logger.Verbose("TlsClientProtocol", "ReceiveServerHelloMessage selectedCipherSuite: " + selectedCipherSuite.ToString("X"), this.LoggingContext); } this.mTlsClient.NotifySelectedCipherSuite(selectedCipherSuite); /* * Find out which CompressionMethod the server has chosen and check that it was one of the * offered ones. */ byte selectedCompressionMethod = TlsUtilities.ReadUint8(buf); if (!Arrays.Contains(this.mOfferedCompressionMethods, selectedCompressionMethod)) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } if (HTTPManager.Logger.Level <= Loglevels.All) { HTTPManager.Logger.Verbose("TlsClientProtocol", "ReceiveServerHelloMessage selectedCompressionMethod: " + selectedCompressionMethod.ToString(), this.LoggingContext); } this.mTlsClient.NotifySelectedCompressionMethod(selectedCompressionMethod); /* * RFC 3546 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.mServerExtensions = ReadExtensions(buf); /* * RFC 7627 4. Clients and servers SHOULD NOT accept handshakes that do not use the extended * master secret [..]. (and see 5.2, 5.3) */ this.mSecurityParameters.extendedMasterSecret = !TlsUtilities.IsSsl(mTlsClientContext) && TlsExtensionsUtilities.HasExtendedMasterSecretExtension(mServerExtensions); if (!mSecurityParameters.IsExtendedMasterSecret && (mResumedSession || mTlsClient.RequiresExtendedMasterSecret())) { throw new TlsFatalAlert(AlertDescription.handshake_failure); } /* * 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.mServerExtensions != null) { foreach (int extType in this.mServerExtensions.Keys) { /* * 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 == ExtensionType.renegotiation_info) { continue; } /* * 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 == TlsUtilities.GetExtensionData(this.mClientExtensions, extType)) { throw new TlsFatalAlert(AlertDescription.unsupported_extension); } /* * 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.mResumedSession) { // 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 // TODO[compat-polarssl] PolarSSL test server Sends server extensions e.g. ec_point_formats // throw new TlsFatalAlert(AlertDescription.illegal_parameter); } if (HTTPManager.Logger.Level <= Loglevels.All) { HTTPManager.Logger.Verbose("TlsClientProtocol", "ReceiveServerHelloMessage mServerExtensions: " + extType.ToString(), this.LoggingContext); } } } /* * 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 = TlsUtilities.GetExtensionData(this.mServerExtensions, ExtensionType.renegotiation_info); 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). */ this.mSecureRenegotiation = true; if (!Arrays.ConstantTimeAreEqual(renegExtData, CreateRenegotiationInfo(TlsUtilities.EmptyBytes))) { throw new TlsFatalAlert(AlertDescription.handshake_failure); } } } // TODO[compat-gnutls] GnuTLS test server fails to Send renegotiation_info extension when resuming this.mTlsClient.NotifySecureRenegotiation(this.mSecureRenegotiation); IDictionary sessionClientExtensions = mClientExtensions, sessionServerExtensions = mServerExtensions; if (this.mResumedSession) { if (selectedCipherSuite != this.mSessionParameters.CipherSuite || selectedCompressionMethod != this.mSessionParameters.CompressionAlgorithm) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } sessionClientExtensions = null; sessionServerExtensions = this.mSessionParameters.ReadServerExtensions(); } this.mSecurityParameters.cipherSuite = selectedCipherSuite; this.mSecurityParameters.compressionAlgorithm = selectedCompressionMethod; if (sessionServerExtensions != null && sessionServerExtensions.Count > 0) { { /* * RFC 7366 3. If a server receives an encrypt-then-MAC request extension from a client * and then selects a stream or Authenticated Encryption with Associated Data (AEAD) * ciphersuite, it MUST NOT send an encrypt-then-MAC response extension back to the * client. */ bool serverSentEncryptThenMAC = TlsExtensionsUtilities.HasEncryptThenMacExtension(sessionServerExtensions); if (serverSentEncryptThenMAC && !TlsUtilities.IsBlockCipherSuite(selectedCipherSuite)) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } this.mSecurityParameters.encryptThenMac = serverSentEncryptThenMAC; } this.mSecurityParameters.maxFragmentLength = ProcessMaxFragmentLengthExtension(sessionClientExtensions, sessionServerExtensions, AlertDescription.illegal_parameter); this.mSecurityParameters.truncatedHMac = TlsExtensionsUtilities.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.mAllowCertificateStatus = !this.mResumedSession && TlsUtilities.HasExpectedEmptyExtensionData(sessionServerExtensions, ExtensionType.status_request, AlertDescription.illegal_parameter); this.mExpectSessionTicket = !this.mResumedSession && TlsUtilities.HasExpectedEmptyExtensionData(sessionServerExtensions, ExtensionType.session_ticket, AlertDescription.illegal_parameter); } if (sessionClientExtensions != null) { this.mTlsClient.ProcessServerExtensions(sessionServerExtensions); } this.mSecurityParameters.prfAlgorithm = GetPrfAlgorithm(Context, this.mSecurityParameters.CipherSuite); /* * 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. */ this.mSecurityParameters.verifyDataLength = 12; }
protected virtual void SendServerHelloMessage() { HandshakeMessage message = new HandshakeMessage(HandshakeType.server_hello); { ProtocolVersion server_version = mTlsServer.GetServerVersion(); if (!server_version.IsEqualOrEarlierVersionOf(Context.ClientVersion)) { throw new TlsFatalAlert(AlertDescription.internal_error); } mRecordStream.ReadVersion = server_version; mRecordStream.SetWriteVersion(server_version); mRecordStream.SetRestrictReadVersion(true); ContextAdmin.SetServerVersion(server_version); TlsUtilities.WriteVersion(server_version, message); } message.Write(this.mSecurityParameters.serverRandom); /* * The server may return an empty session_id to indicate that the session will not be cached * and therefore cannot be resumed. */ TlsUtilities.WriteOpaque8(TlsUtilities.EmptyBytes, message); int selectedCipherSuite = mTlsServer.GetSelectedCipherSuite(); if (!Arrays.Contains(mOfferedCipherSuites, selectedCipherSuite) || selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL || CipherSuite.IsScsv(selectedCipherSuite) || !TlsUtilities.IsValidCipherSuiteForVersion(selectedCipherSuite, Context.ServerVersion)) { throw new TlsFatalAlert(AlertDescription.internal_error); } mSecurityParameters.cipherSuite = selectedCipherSuite; byte selectedCompressionMethod = mTlsServer.GetSelectedCompressionMethod(); if (!Arrays.Contains(mOfferedCompressionMethods, selectedCompressionMethod)) { throw new TlsFatalAlert(AlertDescription.internal_error); } mSecurityParameters.compressionAlgorithm = selectedCompressionMethod; TlsUtilities.WriteUint16(selectedCipherSuite, message); TlsUtilities.WriteUint8(selectedCompressionMethod, message); this.mServerExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(mTlsServer.GetServerExtensions()); /* * RFC 5746 3.6. Server Behavior: Initial Handshake */ if (this.mSecureRenegotiation) { byte[] renegExtData = TlsUtilities.GetExtensionData(this.mServerExtensions, ExtensionType.renegotiation_info); bool 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.mServerExtensions[ExtensionType.renegotiation_info] = CreateRenegotiationInfo(TlsUtilities.EmptyBytes); } } if (TlsUtilities.IsSsl(mTlsServerContext)) { mSecurityParameters.extendedMasterSecret = false; } else if (mSecurityParameters.IsExtendedMasterSecret) { TlsExtensionsUtilities.AddExtendedMasterSecretExtension(mServerExtensions); } /* * 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.mServerExtensions.Count > 0) { this.mSecurityParameters.encryptThenMac = TlsExtensionsUtilities.HasEncryptThenMacExtension(mServerExtensions); this.mSecurityParameters.maxFragmentLength = ProcessMaxFragmentLengthExtension(mClientExtensions, mServerExtensions, AlertDescription.internal_error); this.mSecurityParameters.truncatedHMac = TlsExtensionsUtilities.HasTruncatedHMacExtension(mServerExtensions); /* * TODO It's surprising that there's no provision to allow a 'fresh' CertificateStatus to be sent in * a session resumption handshake. */ this.mAllowCertificateStatus = !mResumedSession && TlsUtilities.HasExpectedEmptyExtensionData(mServerExtensions, ExtensionType.status_request, AlertDescription.internal_error); this.mExpectSessionTicket = !mResumedSession && TlsUtilities.HasExpectedEmptyExtensionData(mServerExtensions, ExtensionType.session_ticket, AlertDescription.internal_error); WriteExtensions(message, this.mServerExtensions); } mSecurityParameters.prfAlgorithm = GetPrfAlgorithm(Context, mSecurityParameters.CipherSuite); /* * 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. */ mSecurityParameters.verifyDataLength = 12; ApplyMaxFragmentLengthExtension(); message.WriteToRecordStream(this); }