| public static GetExtensionData ( IDictionary extensions, int extensionType ) : byte[] | ||
| extensions | IDictionary | |
| extensionType | int | |
| Résultat | byte[] | |
public static int GetPaddingExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, 0x15);
return((extensionData != null) ? ReadPaddingExtension(extensionData) : -1);
}
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);
}
/*
* 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);
}
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);
}
this.mTlsClient.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.mServerExtensions = 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.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);
}
}
}
/*
* 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)
{
{
/*
* 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.extendedMasterSecret = TlsExtensionsUtilities.HasExtendedMasterSecretExtension(sessionServerExtensions);
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);
}
/*
* 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)
*/
if (sessionClientExtensions != null)
{
this.mTlsClient.ProcessServerExtensions(sessionServerExtensions);
}
this.mSecurityParameters.prfAlgorithm = GetPrfAlgorithm(Context, this.mSecurityParameters.CipherSuite);
/*
* 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.mSecurityParameters.verifyDataLength = 12;
}
public static byte[] GetNegotiatedDheGroupsClientExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.negotiated_ff_dhe_groups);
return(extensionData == null ? null : ReadNegotiatedDheGroupsClientExtension(extensionData));
}
protected virtual void ProcessClientHello(ServerHandshakeState state, byte[] body)
{
MemoryStream buf = new MemoryStream(body, false);
// TODO Read RFCs for guidance on the expected record layer version number
ProtocolVersion client_version = TlsUtilities.ReadVersion(buf);
if (!client_version.IsDtls)
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
/*
* Read the client random
*/
byte[] client_random = TlsUtilities.ReadFully(32, buf);
byte[] sessionID = TlsUtilities.ReadOpaque8(buf);
if (sessionID.Length > 32)
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
// TODO RFC 4347 has the cookie length restricted to 32, but not in RFC 6347
byte[] cookie = TlsUtilities.ReadOpaque8(buf);
int cipher_suites_length = TlsUtilities.ReadUint16(buf);
if (cipher_suites_length < 2 || (cipher_suites_length & 1) != 0)
{
throw new TlsFatalAlert(AlertDescription.decode_error);
}
/*
* NOTE: "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."
*/
state.offeredCipherSuites = TlsUtilities.ReadUint16Array(cipher_suites_length / 2, buf);
int compression_methods_length = TlsUtilities.ReadUint8(buf);
if (compression_methods_length < 1)
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
state.offeredCompressionMethods = TlsUtilities.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.
*/
state.clientExtensions = TlsProtocol.ReadExtensions(buf);
TlsServerContextImpl context = state.serverContext;
SecurityParameters securityParameters = context.SecurityParameters;
securityParameters.extendedMasterSecret = TlsExtensionsUtilities.HasExtendedMasterSecretExtension(state.clientExtensions);
context.SetClientVersion(client_version);
state.server.NotifyClientVersion(client_version);
state.server.NotifyFallback(Arrays.Contains(state.offeredCipherSuites, CipherSuite.TLS_FALLBACK_SCSV));
securityParameters.clientRandom = client_random;
state.server.NotifyOfferedCipherSuites(state.offeredCipherSuites);
state.server.NotifyOfferedCompressionMethods(state.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(state.offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV))
{
state.secure_renegotiation = true;
}
/*
* The server MUST check if the "renegotiation_info" extension is included in the
* ClientHello.
*/
byte[] renegExtData = TlsUtilities.GetExtensionData(state.clientExtensions, ExtensionType.renegotiation_info);
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.
*/
state.secure_renegotiation = true;
if (!Arrays.ConstantTimeAreEqual(renegExtData, TlsProtocol.CreateRenegotiationInfo(TlsUtilities.EmptyBytes)))
{
throw new TlsFatalAlert(AlertDescription.handshake_failure);
}
}
}
state.server.NotifySecureRenegotiation(state.secure_renegotiation);
if (state.clientExtensions != null)
{
state.server.ProcessClientExtensions(state.clientExtensions);
}
}
public static int[] GetSupportedEllipticCurvesExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.supported_groups);
return(extensionData == null ? null : ReadSupportedEllipticCurvesExtension(extensionData));
}
protected virtual byte[] GenerateClientHello(ClientHandshakeState state, TlsClient client)
{
ProtocolVersion client_version = client.ClientVersion;
if (!client_version.IsDtls)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
TlsClientContextImpl context = state.clientContext;
context.SetClientVersion(client_version);
SecurityParameters securityParameters = context.SecurityParameters;
// Session ID
byte[] session_id = TlsUtilities.EmptyBytes;
if (state.tlsSession != null)
{
session_id = state.tlsSession.SessionID;
if (session_id == null || session_id.Length > 32)
{
session_id = TlsUtilities.EmptyBytes;
}
}
bool fallback = client.IsFallback;
state.offeredCipherSuites = client.GetCipherSuites();
if (session_id.Length > 0 && state.sessionParameters != null)
{
if (!state.sessionParameters.IsExtendedMasterSecret ||
!Arrays.Contains(state.offeredCipherSuites, state.sessionParameters.CipherSuite) ||
CompressionMethod.cls_null != state.sessionParameters.CompressionAlgorithm)
{
session_id = TlsUtilities.EmptyBytes;
}
}
state.clientExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(client.GetClientExtensions());
TlsExtensionsUtilities.AddExtendedMasterSecretExtension(state.clientExtensions);
MemoryStream buf = new MemoryStream();
TlsUtilities.WriteVersion(client_version, buf);
buf.Write(securityParameters.ClientRandom, 0, securityParameters.ClientRandom.Length);
TlsUtilities.WriteOpaque8(session_id, buf);
// Cookie
TlsUtilities.WriteOpaque8(TlsUtilities.EmptyBytes, buf);
// 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 = TlsUtilities.GetExtensionData(state.clientExtensions, ExtensionType.renegotiation_info);
bool noRenegExt = (null == renegExtData);
bool noRenegSCSV = !Arrays.Contains(state.offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV);
if (noRenegExt && noRenegSCSV)
{
// TODO Consider whether to default to a client extension instead
state.offeredCipherSuites = Arrays.Append(state.offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV);
}
/*
* RFC 7507 4. If a client sends a ClientHello.client_version containing a lower value
* than the latest (highest-valued) version supported by the client, it SHOULD include
* the TLS_FALLBACK_SCSV cipher suite value in ClientHello.cipher_suites [..]. (The
* client SHOULD put TLS_FALLBACK_SCSV after all cipher suites that it actually intends
* to negotiate.)
*/
if (fallback && !Arrays.Contains(state.offeredCipherSuites, CipherSuite.TLS_FALLBACK_SCSV))
{
state.offeredCipherSuites = Arrays.Append(state.offeredCipherSuites, CipherSuite.TLS_FALLBACK_SCSV);
}
TlsUtilities.WriteUint16ArrayWithUint16Length(state.offeredCipherSuites, buf);
}
TlsUtilities.WriteUint8ArrayWithUint8Length(new byte[] { CompressionMethod.cls_null }, buf);
TlsProtocol.WriteExtensions(buf, state.clientExtensions);
return(buf.ToArray());
}
protected virtual void ProcessServerHello(ClientHandshakeState state, byte[] body)
{
SecurityParameters securityParameters = state.clientContext.SecurityParameters;
MemoryStream buf = new MemoryStream(body, false);
ProtocolVersion server_version = TlsUtilities.ReadVersion(buf);
ReportServerVersion(state, server_version);
securityParameters.serverRandom = TlsUtilities.ReadFully(32, buf);
state.selectedSessionID = TlsUtilities.ReadOpaque8(buf);
if (state.selectedSessionID.Length > 32)
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
state.client.NotifySessionID(state.selectedSessionID);
state.selectedCipherSuite = TlsUtilities.ReadUint16(buf);
if (!Arrays.Contains(state.offeredCipherSuites, state.selectedCipherSuite) ||
state.selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL ||
CipherSuite.IsScsv(state.selectedCipherSuite) ||
!TlsUtilities.IsValidCipherSuiteForVersion(state.selectedCipherSuite, server_version))
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
ValidateSelectedCipherSuite(state.selectedCipherSuite, AlertDescription.illegal_parameter);
state.client.NotifySelectedCipherSuite(state.selectedCipherSuite);
state.selectedCompressionMethod = TlsUtilities.ReadUint8(buf);
if (!Arrays.Contains(state.offeredCompressionMethods, (byte)state.selectedCompressionMethod))
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
state.client.NotifySelectedCompressionMethod((byte)state.selectedCompressionMethod);
/*
* RFC3546 2.2 The extended server hello message format MAY be sent in place of the server
* hello message when the client has requested extended functionality via the extended
* client hello message specified in Section 2.1. ... Note that the extended server hello
* message is only sent in response to an extended client hello message. This prevents the
* possibility that the extended server hello message could "break" existing TLS 1.0
* clients.
*/
/*
* TODO RFC 3546 2.3 If [...] the older session is resumed, then the server MUST ignore
* extensions appearing in the client hello, and send a server hello containing no
* extensions.
*/
// Integer -> byte[]
IDictionary serverExtensions = TlsProtocol.ReadExtensions(buf);
/*
* draft-ietf-tls-session-hash-01 5.2. If a server receives the "extended_master_secret"
* extension, it MUST include the "extended_master_secret" extension in its ServerHello
* message.
*/
bool serverSentExtendedMasterSecret = TlsExtensionsUtilities.HasExtendedMasterSecretExtension(serverExtensions);
if (serverSentExtendedMasterSecret != securityParameters.extendedMasterSecret)
{
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 (serverExtensions != null)
{
foreach (int extType in serverExtensions.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(state.clientExtensions, extType))
{
throw new TlsFatalAlert(AlertDescription.unsupported_extension);
}
/*
* draft-ietf-tls-session-hash-01 5.2. Implementation note: if the server decides to
* proceed with resumption, the extension does not have any effect. Requiring the
* extension to be included anyway makes the extension negotiation logic easier,
* because it does not depend on whether resumption is accepted or not.
*/
if (extType == ExtensionType.extended_master_secret)
{
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[.]
*/
// TODO[sessions]
// 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);
// }
}
/*
* 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 = (byte[])serverExtensions[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).
*/
state.secure_renegotiation = true;
if (!Arrays.ConstantTimeAreEqual(renegExtData, TlsProtocol.CreateRenegotiationInfo(TlsUtilities.EmptyBytes)))
{
throw new TlsFatalAlert(AlertDescription.handshake_failure);
}
}
}
/*
* 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(serverExtensions);
if (serverSentEncryptThenMAC && !TlsUtilities.IsBlockCipherSuite(state.selectedCipherSuite))
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
securityParameters.encryptThenMac = serverSentEncryptThenMAC;
state.maxFragmentLength = EvaluateMaxFragmentLengthExtension(state.clientExtensions, serverExtensions,
AlertDescription.illegal_parameter);
securityParameters.truncatedHMac = TlsExtensionsUtilities.HasTruncatedHMacExtension(serverExtensions);
state.allowCertificateStatus = TlsUtilities.HasExpectedEmptyExtensionData(serverExtensions,
ExtensionType.status_request, AlertDescription.illegal_parameter);
state.expectSessionTicket = TlsUtilities.HasExpectedEmptyExtensionData(serverExtensions,
ExtensionType.session_ticket, AlertDescription.illegal_parameter);
}
state.client.NotifySecureRenegotiation(state.secure_renegotiation);
if (state.clientExtensions != null)
{
state.client.ProcessServerExtensions(serverExtensions);
}
}
/// <exception cref="IOException"></exception>
public static HeartbeatExtension GetHeartbeatExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.heartbeat);
return(extensionData == null ? null : ReadHeartbeatExtension(extensionData));
}
/// <exception cref="IOException"></exception>
public static short GetMaxFragmentLengthExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.max_fragment_length);
return(extensionData == null ? (short)-1 : (short)ReadMaxFragmentLengthExtension(extensionData));
}
public static bool HasExtendedMasterSecretExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, 0x17);
return((extensionData != null) ? ReadExtendedMasterSecretExtension(extensionData) : false);
}
protected virtual byte[] GenerateServerHello(ServerHandshakeState state)
{
SecurityParameters securityParameters = state.serverContext.SecurityParameters;
MemoryStream buf = new MemoryStream();
{
ProtocolVersion server_version = state.server.GetServerVersion();
if (!server_version.IsEqualOrEarlierVersionOf(state.serverContext.ClientVersion))
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
// TODO Read RFCs for guidance on the expected record layer version number
// recordStream.setReadVersion(server_version);
// recordStream.setWriteVersion(server_version);
// recordStream.setRestrictReadVersion(true);
state.serverContext.SetServerVersion(server_version);
TlsUtilities.WriteVersion(state.serverContext.ServerVersion, buf);
}
buf.Write(securityParameters.ServerRandom, 0, securityParameters.ServerRandom.Length);
/*
* 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, buf);
int selectedCipherSuite = state.server.GetSelectedCipherSuite();
if (!Arrays.Contains(state.offeredCipherSuites, selectedCipherSuite) ||
selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL ||
CipherSuite.IsScsv(selectedCipherSuite) ||
!TlsUtilities.IsValidCipherSuiteForVersion(selectedCipherSuite, state.serverContext.ServerVersion))
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
ValidateSelectedCipherSuite(selectedCipherSuite, AlertDescription.internal_error);
securityParameters.cipherSuite = selectedCipherSuite;
byte selectedCompressionMethod = state.server.GetSelectedCompressionMethod();
if (!Arrays.Contains(state.offeredCompressionMethods, selectedCompressionMethod))
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
securityParameters.compressionAlgorithm = selectedCompressionMethod;
TlsUtilities.WriteUint16(selectedCipherSuite, buf);
TlsUtilities.WriteUint8(selectedCompressionMethod, buf);
state.serverExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(state.server.GetServerExtensions());
/*
* RFC 5746 3.6. Server Behavior: Initial Handshake
*/
if (state.secure_renegotiation)
{
byte[] renegExtData = TlsUtilities.GetExtensionData(state.serverExtensions, 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.
*/
state.serverExtensions[ExtensionType.renegotiation_info] = TlsProtocol.CreateRenegotiationInfo(TlsUtilities.EmptyBytes);
}
}
if (securityParameters.IsExtendedMasterSecret)
{
TlsExtensionsUtilities.AddExtendedMasterSecretExtension(state.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 (state.serverExtensions.Count > 0)
{
securityParameters.encryptThenMac = TlsExtensionsUtilities.HasEncryptThenMacExtension(state.serverExtensions);
securityParameters.maxFragmentLength = EvaluateMaxFragmentLengthExtension(state.resumedSession,
state.clientExtensions, state.serverExtensions, AlertDescription.internal_error);
securityParameters.truncatedHMac = TlsExtensionsUtilities.HasTruncatedHMacExtension(state.serverExtensions);
/*
* TODO It's surprising that there's no provision to allow a 'fresh' CertificateStatus to be sent in
* a session resumption handshake.
*/
state.allowCertificateStatus = !state.resumedSession &&
TlsUtilities.HasExpectedEmptyExtensionData(state.serverExtensions, ExtensionType.status_request,
AlertDescription.internal_error);
state.expectSessionTicket = !state.resumedSession &&
TlsUtilities.HasExpectedEmptyExtensionData(state.serverExtensions, ExtensionType.session_ticket,
AlertDescription.internal_error);
ProcessCertificateFormats(state, state.clientExtensions, state.serverExtensions);
TlsProtocol.WriteExtensions(buf, state.serverExtensions);
}
securityParameters.prfAlgorithm = TlsProtocol.GetPrfAlgorithm(state.serverContext,
securityParameters.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.
*/
securityParameters.verifyDataLength = 12;
return(buf.ToArray());
}
public static bool HasEncryptThenMacExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, 0x16);
return((extensionData != null) ? ReadEncryptThenMacExtension(extensionData) : false);
}
public static CertificateStatusRequest GetStatusRequestExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, 5);
return((extensionData != null) ? ReadStatusRequestExtension(extensionData) : null);
}
public static ServerNameList GetServerNameExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, 0);
return((extensionData != null) ? ReadServerNameExtension(extensionData) : null);
}
public static bool HasExtendedMasterSecretExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, 23);
return(extensionData != null && TlsExtensionsUtilities.ReadExtendedMasterSecretExtension(extensionData));
}
/// <exception cref="IOException"></exception>
public static ServerNameList GetServerNameExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.server_name);
return(extensionData == null ? null : ReadServerNameExtension(extensionData));
}
protected virtual void ReceiveServerHelloMessage(MemoryStream buf)
{
ProtocolVersion protocolVersion = TlsUtilities.ReadVersion(buf);
if (protocolVersion.IsDtls)
{
throw new TlsFatalAlert(47);
}
if (!protocolVersion.Equals(mRecordStream.ReadVersion))
{
throw new TlsFatalAlert(47);
}
ProtocolVersion clientVersion = Context.ClientVersion;
if (!protocolVersion.IsEqualOrEarlierVersionOf(clientVersion))
{
throw new TlsFatalAlert(47);
}
mRecordStream.SetWriteVersion(protocolVersion);
ContextAdmin.SetServerVersion(protocolVersion);
mTlsClient.NotifyServerVersion(protocolVersion);
mSecurityParameters.serverRandom = TlsUtilities.ReadFully(32, buf);
mSelectedSessionID = TlsUtilities.ReadOpaque8(buf);
if (mSelectedSessionID.Length > 32)
{
throw new TlsFatalAlert(47);
}
mTlsClient.NotifySessionID(mSelectedSessionID);
mResumedSession = (mSelectedSessionID.Length > 0 && mTlsSession != null && Arrays.AreEqual(mSelectedSessionID, mTlsSession.SessionID));
int num = TlsUtilities.ReadUint16(buf);
if (!Arrays.Contains(mOfferedCipherSuites, num) || num == 0 || CipherSuite.IsScsv(num) || !TlsUtilities.IsValidCipherSuiteForVersion(num, Context.ServerVersion))
{
throw new TlsFatalAlert(47);
}
mTlsClient.NotifySelectedCipherSuite(num);
byte b = TlsUtilities.ReadUint8(buf);
if (!Arrays.Contains(mOfferedCompressionMethods, b))
{
throw new TlsFatalAlert(47);
}
mTlsClient.NotifySelectedCompressionMethod(b);
mServerExtensions = TlsProtocol.ReadExtensions(buf);
if (mServerExtensions != null)
{
foreach (int key in mServerExtensions.Keys)
{
if (key != 65281)
{
if (TlsUtilities.GetExtensionData(mClientExtensions, key) == null)
{
throw new TlsFatalAlert(110);
}
if (!mResumedSession)
{
}
}
}
}
byte[] extensionData = TlsUtilities.GetExtensionData(mServerExtensions, 65281);
if (extensionData != null)
{
mSecureRenegotiation = true;
if (!Arrays.ConstantTimeAreEqual(extensionData, TlsProtocol.CreateRenegotiationInfo(TlsUtilities.EmptyBytes)))
{
throw new TlsFatalAlert(40);
}
}
mTlsClient.NotifySecureRenegotiation(mSecureRenegotiation);
IDictionary dictionary = mClientExtensions;
IDictionary dictionary2 = mServerExtensions;
if (mResumedSession)
{
if (num != mSessionParameters.CipherSuite || b != mSessionParameters.CompressionAlgorithm)
{
throw new TlsFatalAlert(47);
}
dictionary = null;
dictionary2 = mSessionParameters.ReadServerExtensions();
}
mSecurityParameters.cipherSuite = num;
mSecurityParameters.compressionAlgorithm = b;
if (dictionary2 != null)
{
bool flag = TlsExtensionsUtilities.HasEncryptThenMacExtension(dictionary2);
if (flag && !TlsUtilities.IsBlockCipherSuite(num))
{
throw new TlsFatalAlert(47);
}
mSecurityParameters.encryptThenMac = flag;
mSecurityParameters.extendedMasterSecret = TlsExtensionsUtilities.HasExtendedMasterSecretExtension(dictionary2);
mSecurityParameters.maxFragmentLength = ProcessMaxFragmentLengthExtension(dictionary, dictionary2, 47);
mSecurityParameters.truncatedHMac = TlsExtensionsUtilities.HasTruncatedHMacExtension(dictionary2);
mAllowCertificateStatus = (!mResumedSession && TlsUtilities.HasExpectedEmptyExtensionData(dictionary2, 5, 47));
mExpectSessionTicket = (!mResumedSession && TlsUtilities.HasExpectedEmptyExtensionData(dictionary2, 35, 47));
}
if (dictionary != null)
{
mTlsClient.ProcessServerExtensions(dictionary2);
}
mSecurityParameters.prfAlgorithm = TlsProtocol.GetPrfAlgorithm(Context, mSecurityParameters.CipherSuite);
mSecurityParameters.verifyDataLength = 12;
}
/// <exception cref="IOException"></exception>
public static CertificateStatusRequest GetStatusRequestExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.status_request);
return(extensionData == null ? null : ReadStatusRequestExtension(extensionData));
}
protected virtual byte[] GenerateClientHello(ClientHandshakeState state, TlsClient client)
{
MemoryStream buf = new MemoryStream();
ProtocolVersion client_version = client.ClientVersion;
if (!client_version.IsDtls)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
TlsClientContextImpl context = state.clientContext;
context.SetClientVersion(client_version);
TlsUtilities.WriteVersion(client_version, buf);
SecurityParameters securityParameters = context.SecurityParameters;
buf.Write(securityParameters.ClientRandom, 0, securityParameters.ClientRandom.Length);
// Session ID
byte[] session_id = TlsUtilities.EmptyBytes;
if (state.tlsSession != null)
{
session_id = state.tlsSession.SessionID;
if (session_id == null || session_id.Length > 32)
{
session_id = TlsUtilities.EmptyBytes;
}
}
TlsUtilities.WriteOpaque8(session_id, buf);
// Cookie
TlsUtilities.WriteOpaque8(TlsUtilities.EmptyBytes, buf);
bool fallback = client.IsFallback;
/*
* Cipher suites
*/
state.offeredCipherSuites = client.GetCipherSuites();
// Integer -> byte[]
state.clientExtensions = client.GetClientExtensions();
securityParameters.extendedMasterSecret = TlsExtensionsUtilities.HasExtendedMasterSecretExtension(state.clientExtensions);
// 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 = TlsUtilities.GetExtensionData(state.clientExtensions, ExtensionType.renegotiation_info);
bool noRenegExt = (null == renegExtData);
bool noRenegSCSV = !Arrays.Contains(state.offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV);
if (noRenegExt && noRenegSCSV)
{
// TODO Consider whether to default to a client extension instead
state.offeredCipherSuites = Arrays.Append(state.offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV);
}
/*
* draft-ietf-tls-downgrade-scsv-00 4. If a client sends a ClientHello.client_version
* containing a lower value than the latest (highest-valued) version supported by the
* client, it SHOULD include the TLS_FALLBACK_SCSV cipher suite value in
* ClientHello.cipher_suites.
*/
if (fallback && !Arrays.Contains(state.offeredCipherSuites, CipherSuite.TLS_FALLBACK_SCSV))
{
state.offeredCipherSuites = Arrays.Append(state.offeredCipherSuites, CipherSuite.TLS_FALLBACK_SCSV);
}
TlsUtilities.WriteUint16ArrayWithUint16Length(state.offeredCipherSuites, buf);
}
// TODO Add support for compression
// Compression methods
// state.offeredCompressionMethods = client.getCompressionMethods();
state.offeredCompressionMethods = new byte[] { CompressionMethod.cls_null };
TlsUtilities.WriteUint8ArrayWithUint8Length(state.offeredCompressionMethods, buf);
// Extensions
if (state.clientExtensions != null)
{
TlsProtocol.WriteExtensions(buf, state.clientExtensions);
}
return(buf.ToArray());
}
/// <exception cref="IOException"></exception>
public static bool HasEncryptThenMacExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.encrypt_then_mac);
return(extensionData == null ? false : ReadEncryptThenMacExtension(extensionData));
}
protected virtual byte[] GenerateServerHello(ServerHandshakeState state)
{
SecurityParameters securityParameters = state.serverContext.SecurityParameters;
MemoryStream buf = new MemoryStream();
ProtocolVersion server_version = state.server.GetServerVersion();
if (!server_version.IsEqualOrEarlierVersionOf(state.serverContext.ClientVersion))
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
// TODO Read RFCs for guidance on the expected record layer version number
// recordStream.setReadVersion(server_version);
// recordStream.setWriteVersion(server_version);
// recordStream.setRestrictReadVersion(true);
state.serverContext.SetServerVersion(server_version);
TlsUtilities.WriteVersion(state.serverContext.ServerVersion, buf);
buf.Write(securityParameters.ServerRandom, 0, securityParameters.ServerRandom.Length);
/*
* 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, buf);
state.selectedCipherSuite = state.server.GetSelectedCipherSuite();
if (!Arrays.Contains(state.offeredCipherSuites, state.selectedCipherSuite) ||
state.selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL ||
CipherSuite.IsScsv(state.selectedCipherSuite) ||
!TlsUtilities.IsValidCipherSuiteForVersion(state.selectedCipherSuite, server_version))
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
ValidateSelectedCipherSuite(state.selectedCipherSuite, AlertDescription.internal_error);
state.selectedCompressionMethod = state.server.GetSelectedCompressionMethod();
if (!Arrays.Contains(state.offeredCompressionMethods, (byte)state.selectedCompressionMethod))
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
TlsUtilities.WriteUint16(state.selectedCipherSuite, buf);
TlsUtilities.WriteUint8((byte)state.selectedCompressionMethod, buf);
state.serverExtensions = state.server.GetServerExtensions();
/*
* RFC 5746 3.6. Server Behavior: Initial Handshake
*/
if (state.secure_renegotiation)
{
byte[] renegExtData = TlsUtilities.GetExtensionData(state.serverExtensions, 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.
*/
state.serverExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(state.serverExtensions);
state.serverExtensions[ExtensionType.renegotiation_info] = TlsProtocol.CreateRenegotiationInfo(TlsUtilities.EmptyBytes);
}
}
if (securityParameters.extendedMasterSecret)
{
state.serverExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(state.serverExtensions);
TlsExtensionsUtilities.AddExtendedMasterSecretExtension(state.serverExtensions);
}
if (state.serverExtensions != null)
{
securityParameters.encryptThenMac = TlsExtensionsUtilities.HasEncryptThenMacExtension(state.serverExtensions);
state.maxFragmentLength = EvaluateMaxFragmentLengthExtension(state.clientExtensions, state.serverExtensions,
AlertDescription.internal_error);
securityParameters.truncatedHMac = TlsExtensionsUtilities.HasTruncatedHMacExtension(state.serverExtensions);
state.allowCertificateStatus = TlsUtilities.HasExpectedEmptyExtensionData(state.serverExtensions,
ExtensionType.status_request, AlertDescription.internal_error);
state.expectSessionTicket = TlsUtilities.HasExpectedEmptyExtensionData(state.serverExtensions,
ExtensionType.session_ticket, AlertDescription.internal_error);
TlsProtocol.WriteExtensions(buf, state.serverExtensions);
}
return(buf.ToArray());
}
/// <exception cref="IOException"></exception>
public static bool HasExtendedMasterSecretExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.extended_master_secret);
return(extensionData == null ? false : ReadExtendedMasterSecretExtension(extensionData));
}
public static UseSrtpData GetUseSrtpExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.use_srtp);
return(extensionData == null ? null : ReadUseSrtpExtension(extensionData));
}
/// <exception cref="IOException"></exception>
public static bool HasTruncatedHMacExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.truncated_hmac);
return(extensionData == null ? false : ReadTruncatedHMacExtension(extensionData));
}
public static byte[] GetSupportedPointFormatsExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.ec_point_formats);
return(extensionData == null ? null : ReadSupportedPointFormatsExtension(extensionData));
}
public static bool HasTruncatedHMacExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, 4);
return(extensionData != null && TlsExtensionsUtilities.ReadTruncatedHMacExtension(extensionData));
}
protected virtual void SendClientHelloMessage()
{
this.mRecordStream.SetWriteVersion(this.mTlsClient.ClientHelloRecordLayerVersion);
ProtocolVersion client_version = this.mTlsClient.ClientVersion;
if (client_version.IsDtls)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
ContextAdmin.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 = TlsUtilities.EmptyBytes;
if (this.mTlsSession != null)
{
session_id = this.mTlsSession.SessionID;
if (session_id == null || session_id.Length > 32)
{
session_id = TlsUtilities.EmptyBytes;
}
}
bool fallback = this.mTlsClient.IsFallback;
this.mOfferedCipherSuites = this.mTlsClient.GetCipherSuites();
this.mOfferedCompressionMethods = this.mTlsClient.GetCompressionMethods();
if (session_id.Length > 0 && this.mSessionParameters != null)
{
if (!Arrays.Contains(this.mOfferedCipherSuites, mSessionParameters.CipherSuite) ||
!Arrays.Contains(this.mOfferedCompressionMethods, mSessionParameters.CompressionAlgorithm))
{
session_id = TlsUtilities.EmptyBytes;
}
}
this.mClientExtensions = this.mTlsClient.GetClientExtensions();
HandshakeMessage message = new HandshakeMessage(HandshakeType.client_hello);
TlsUtilities.WriteVersion(client_version, message);
message.Write(this.mSecurityParameters.ClientRandom);
TlsUtilities.WriteOpaque8(session_id, message);
// 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 = TlsUtilities.GetExtensionData(mClientExtensions, ExtensionType.renegotiation_info);
bool noRenegExt = (null == renegExtData);
bool noRenegScsv = !Arrays.Contains(mOfferedCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV);
if (noRenegExt && noRenegScsv)
{
// TODO Consider whether to default to a client extension instead
// this.mClientExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(this.mClientExtensions);
// this.mClientExtensions[ExtensionType.renegotiation_info] = CreateRenegotiationInfo(TlsUtilities.EmptyBytes);
this.mOfferedCipherSuites = Arrays.Append(mOfferedCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV);
}
/*
* RFC 7507 4. If a client sends a ClientHello.client_version containing a lower value
* than the latest (highest-valued) version supported by the client, it SHOULD include
* the TLS_FALLBACK_SCSV cipher suite value in ClientHello.cipher_suites [..]. (The
* client SHOULD put TLS_FALLBACK_SCSV after all cipher suites that it actually intends
* to negotiate.)
*/
if (fallback && !Arrays.Contains(mOfferedCipherSuites, CipherSuite.TLS_FALLBACK_SCSV))
{
this.mOfferedCipherSuites = Arrays.Append(mOfferedCipherSuites, CipherSuite.TLS_FALLBACK_SCSV);
}
TlsUtilities.WriteUint16ArrayWithUint16Length(mOfferedCipherSuites, message);
}
TlsUtilities.WriteUint8ArrayWithUint8Length(mOfferedCompressionMethods, message);
if (mClientExtensions != null)
{
WriteExtensions(message, mClientExtensions);
}
message.WriteToRecordStream(this);
}
public static bool HasEncryptThenMacExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, 22);
return(extensionData != null && TlsExtensionsUtilities.ReadEncryptThenMacExtension(extensionData));
}
public static short GetNegotiatedDheGroupsServerExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.negotiated_ff_dhe_groups);
return(extensionData == null ? (short)-1 : (short)ReadNegotiatedDheGroupsServerExtension(extensionData));
}
public static short GetMaxFragmentLengthExtension(IDictionary extensions)
{
byte[] extensionData = TlsUtilities.GetExtensionData(extensions, 1);
return((extensionData != null) ? ReadMaxFragmentLengthExtension(extensionData) : ((short)(-1)));
}
