package org.bouncycastle.crypto.tls;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.SecureRandom;
import java.util.Hashtable;
import java.util.Vector;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.crypto.util.PublicKeyFactory;
import org.bouncycastle.util.Arrays;
public class TlsServerProtocol
extends TlsProtocol
{
protected TlsServer tlsServer = null;
protected TlsServerContextImpl tlsServerContext = null;
protected TlsKeyExchange keyExchange = null;
protected TlsCredentials serverCredentials = null;
protected CertificateRequest certificateRequest = null;
protected short clientCertificateType = -1;
protected byte[] certificateVerifyHash = null;
public TlsServerProtocol(InputStream input, OutputStream output, SecureRandom secureRandom)
{
super(input, output, secureRandom);
}
/**
* Receives a TLS handshake in the role of server
*
* @param tlsServer
* @throws IOException If handshake was not successful.
*/
public void accept(TlsServer tlsServer)
throws IOException
{
if (tlsServer == null)
{
throw new IllegalArgumentException("'tlsServer' cannot be null");
}
if (this.tlsServer != null)
{
throw new IllegalStateException("'accept' can only be called once");
}
this.tlsServer = tlsServer;
this.securityParameters = new SecurityParameters();
this.securityParameters.entity = ConnectionEnd.server;
this.securityParameters.serverRandom = createRandomBlock(secureRandom);
this.tlsServerContext = new TlsServerContextImpl(secureRandom, securityParameters);
this.tlsServer.init(tlsServerContext);
this.recordStream.init(tlsServerContext);
this.recordStream.setRestrictReadVersion(false);
completeHandshake();
}
protected void cleanupHandshake()
{
super.cleanupHandshake();
this.keyExchange = null;
this.serverCredentials = null;
this.certificateRequest = null;
this.certificateVerifyHash = null;
}
protected AbstractTlsContext getContext()
{
return tlsServerContext;
}
protected TlsPeer getPeer()
{
return tlsServer;
}
protected void handleHandshakeMessage(short type, byte[] data)
throws IOException
{
ByteArrayInputStream buf = new ByteArrayInputStream(data);
switch (type)
{
case HandshakeType.client_hello:
{
switch (this.connection_state)
{
case CS_START:
{
receiveClientHelloMessage(buf);
this.connection_state = CS_CLIENT_HELLO;
sendServerHelloMessage();
this.connection_state = CS_SERVER_HELLO;
Vector serverSupplementalData = tlsServer.getServerSupplementalData();
if (serverSupplementalData != null)
{
sendSupplementalDataMessage(serverSupplementalData);
}
this.connection_state = CS_SERVER_SUPPLEMENTAL_DATA;
this.keyExchange = tlsServer.getKeyExchange();
this.keyExchange.init(getContext());
this.serverCredentials = tlsServer.getCredentials();
Certificate serverCertificate = null;
if (this.serverCredentials == null)
{
this.keyExchange.skipServerCredentials();
}
else
{
this.keyExchange.processServerCredentials(this.serverCredentials);
serverCertificate = this.serverCredentials.getCertificate();
sendCertificateMessage(serverCertificate);
}
this.connection_state = CS_SERVER_CERTIFICATE;
// TODO[RFC 3546] Check whether empty certificates is possible, allowed, or excludes CertificateStatus
if (serverCertificate == null || serverCertificate.isEmpty())
{
this.allowCertificateStatus = false;
}
if (this.allowCertificateStatus)
{
CertificateStatus certificateStatus = tlsServer.getCertificateStatus();
if (certificateStatus != null)
{
sendCertificateStatusMessage(certificateStatus);
}
}
this.connection_state = CS_CERTIFICATE_STATUS;
byte[] serverKeyExchange = this.keyExchange.generateServerKeyExchange();
if (serverKeyExchange != null)
{
sendServerKeyExchangeMessage(serverKeyExchange);
}
this.connection_state = CS_SERVER_KEY_EXCHANGE;
if (this.serverCredentials != null)
{
this.certificateRequest = tlsServer.getCertificateRequest();
if (this.certificateRequest != null)
{
this.keyExchange.validateCertificateRequest(certificateRequest);
sendCertificateRequestMessage(certificateRequest);
}
}
this.connection_state = CS_CERTIFICATE_REQUEST;
sendServerHelloDoneMessage();
this.connection_state = CS_SERVER_HELLO_DONE;
break;
}
default:
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
break;
}
case HandshakeType.supplemental_data:
{
switch (this.connection_state)
{
case CS_SERVER_HELLO_DONE:
{
tlsServer.processClientSupplementalData(readSupplementalDataMessage(buf));
this.connection_state = CS_CLIENT_SUPPLEMENTAL_DATA;
break;
}
default:
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
break;
}
case HandshakeType.certificate:
{
switch (this.connection_state)
{
case CS_SERVER_HELLO_DONE:
{
tlsServer.processClientSupplementalData(null);
// NB: Fall through to next case label
}
case CS_CLIENT_SUPPLEMENTAL_DATA:
{
if (this.certificateRequest == null)
{
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
receiveCertificateMessage(buf);
this.connection_state = CS_CLIENT_CERTIFICATE;
break;
}
default:
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
break;
}
case HandshakeType.client_key_exchange:
{
switch (this.connection_state)
{
case CS_SERVER_HELLO_DONE:
{
tlsServer.processClientSupplementalData(null);
// NB: Fall through to next case label
}
case CS_CLIENT_SUPPLEMENTAL_DATA:
{
if (this.certificateRequest == null)
{
this.keyExchange.skipClientCredentials();
}
else
{
if (TlsUtils.isTLSv12(getContext()))
{
/*
* RFC 5246 If no suitable certificate is available, the client MUST send a
* certificate message containing no certificates.
*
* NOTE: In previous RFCs, this was SHOULD instead of MUST.
*/
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
else if (TlsUtils.isSSL(getContext()))
{
if (this.peerCertificate == null)
{
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
}
else
{
notifyClientCertificate(Certificate.EMPTY_CHAIN);
}
}
// NB: Fall through to next case label
}
case CS_CLIENT_CERTIFICATE:
{
receiveClientKeyExchangeMessage(buf);
this.connection_state = CS_CLIENT_KEY_EXCHANGE;
break;
}
default:
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
break;
}
case HandshakeType.certificate_verify:
{
switch (this.connection_state)
{
case CS_CLIENT_KEY_EXCHANGE:
{
/*
* RFC 5246 7.4.8 This message is only sent following a client certificate that has
* signing capability (i.e., all certificates except those containing fixed
* Diffie-Hellman parameters).
*/
if (this.certificateVerifyHash == null)
{
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
receiveCertificateVerifyMessage(buf);
this.connection_state = CS_CERTIFICATE_VERIFY;
break;
}
default:
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
break;
}
case HandshakeType.finished:
{
switch (this.connection_state)
{
case CS_CLIENT_KEY_EXCHANGE:
{
if (this.certificateVerifyHash != null)
{
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
// NB: Fall through to next case label
}
case CS_CERTIFICATE_VERIFY:
{
processFinishedMessage(buf);
this.connection_state = CS_CLIENT_FINISHED;
if (this.expectSessionTicket)
{
sendNewSessionTicketMessage(tlsServer.getNewSessionTicket());
sendChangeCipherSpecMessage();
}
this.connection_state = CS_SERVER_SESSION_TICKET;
sendFinishedMessage();
this.connection_state = CS_SERVER_FINISHED;
this.connection_state = CS_END;
break;
}
default:
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
break;
}
case HandshakeType.hello_request:
case HandshakeType.hello_verify_request:
case HandshakeType.server_hello:
case HandshakeType.server_key_exchange:
case HandshakeType.certificate_request:
case HandshakeType.server_hello_done:
case HandshakeType.session_ticket:
default:
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
}
protected void handleWarningMessage(short description)
throws IOException
{
switch (description)
{
case AlertDescription.no_certificate:
{
/*
* SSL 3.0 If the server has sent a certificate request Message, the client must send
* either the certificate message or a no_certificate alert.
*/
if (TlsUtils.isSSL(getContext()) && certificateRequest != null)
{
notifyClientCertificate(Certificate.EMPTY_CHAIN);
}
break;
}
default:
{
super.handleWarningMessage(description);
}
}
}
protected void notifyClientCertificate(Certificate clientCertificate)
throws IOException
{
if (certificateRequest == null)
{
throw new IllegalStateException();
}
if (this.peerCertificate != null)
{
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
this.peerCertificate = clientCertificate;
if (clientCertificate.isEmpty())
{
this.keyExchange.skipClientCredentials();
}
else
{
/*
* TODO RFC 5246 7.4.6. If the certificate_authorities list in the certificate request
* message was non-empty, one of the certificates in the certificate chain SHOULD be
* issued by one of the listed CAs.
*/
this.clientCertificateType = TlsUtils.getClientCertificateType(clientCertificate,
this.serverCredentials.getCertificate());
this.keyExchange.processClientCertificate(clientCertificate);
}
/*
* RFC 5246 7.4.6. If the client does not send any certificates, the server MAY at its
* discretion either continue the handshake without client authentication, or respond with a
* fatal handshake_failure alert. Also, if some aspect of the certificate chain was
* unacceptable (e.g., it was not signed by a known, trusted CA), the server MAY at its
* discretion either continue the handshake (considering the client unauthenticated) or send
* a fatal alert.
*/
this.tlsServer.notifyClientCertificate(clientCertificate);
}
protected void receiveCertificateMessage(ByteArrayInputStream buf)
throws IOException
{
Certificate clientCertificate = Certificate.parse(buf);
assertEmpty(buf);
notifyClientCertificate(clientCertificate);
}
protected void receiveCertificateVerifyMessage(ByteArrayInputStream buf)
throws IOException
{
DigitallySigned clientCertificateVerify = DigitallySigned.parse(getContext(), buf);
assertEmpty(buf);
// Verify the CertificateVerify message contains a correct signature.
try
{
org.bouncycastle.asn1.x509.Certificate x509Cert = this.peerCertificate.getCertificateAt(0);
SubjectPublicKeyInfo keyInfo = x509Cert.getSubjectPublicKeyInfo();
AsymmetricKeyParameter publicKey = PublicKeyFactory.createKey(keyInfo);
TlsSigner tlsSigner = TlsUtils.createTlsSigner(this.clientCertificateType);
tlsSigner.init(getContext());
tlsSigner.verifyRawSignature(clientCertificateVerify.getAlgorithm(),
clientCertificateVerify.getSignature(), publicKey, this.certificateVerifyHash);
}
catch (Exception e)
{
throw new TlsFatalAlert(AlertDescription.decrypt_error);
}
}
protected void receiveClientHelloMessage(ByteArrayInputStream buf)
throws IOException
{
ProtocolVersion client_version = TlsUtils.readVersion(buf);
if (client_version.isDTLS())
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
byte[] client_random = TlsUtils.readFully(32, buf);
/*
* TODO RFC 5077 3.4. If a ticket is presented by the client, the server MUST NOT attempt to
* use the Session ID in the ClientHello for stateful session resumption.
*/
byte[] sessionID = TlsUtils.readOpaque8(buf);
if (sessionID.length > 32)
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
/*
* TODO RFC 5246 7.4.1.2. If the session_id field is not empty (implying a session
* resumption request), this vector MUST include at least the cipher_suite from that
* session.
*/
int cipher_suites_length = TlsUtils.readUint16(buf);
if (cipher_suites_length < 2 || (cipher_suites_length & 1) != 0)
{
throw new TlsFatalAlert(AlertDescription.decode_error);
}
this.offeredCipherSuites = TlsUtils.readUint16Array(cipher_suites_length / 2, buf);
/*
* TODO RFC 5246 7.4.1.2. If the session_id field is not empty (implying a session
* resumption request), it MUST include the compression_method from that session.
*/
int compression_methods_length = TlsUtils.readUint8(buf);
if (compression_methods_length < 1)
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
this.offeredCompressionMethods = TlsUtils.readUint8Array(compression_methods_length, buf);
/*
* TODO RFC 3546 2.3 If [...] the older session is resumed, then the server MUST ignore
* extensions appearing in the client hello, and send a server hello containing no
* extensions.
*/
this.clientExtensions = readExtensions(buf);
getContext().setClientVersion(client_version);
tlsServer.notifyClientVersion(client_version);
securityParameters.clientRandom = client_random;
tlsServer.notifyOfferedCipherSuites(offeredCipherSuites);
tlsServer.notifyOfferedCompressionMethods(offeredCompressionMethods);
/*
* RFC 5746 3.6. Server Behavior: Initial Handshake
*/
{
/*
* RFC 5746 3.4. The client MUST include either an empty "renegotiation_info" extension,
* or the TLS_EMPTY_RENEGOTIATION_INFO_SCSV signaling cipher suite value in the
* ClientHello. Including both is NOT RECOMMENDED.
*/
/*
* When a ClientHello is received, the server MUST check if it includes the
* TLS_EMPTY_RENEGOTIATION_INFO_SCSV SCSV. If it does, set the secure_renegotiation flag
* to TRUE.
*/
if (arrayContains(offeredCipherSuites, CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV))
{
this.secure_renegotiation = true;
}
/*
* The server MUST check if the "renegotiation_info" extension is included in the
* ClientHello.
*/
byte[] renegExtData = TlsUtils.getExtensionData(clientExtensions, EXT_RenegotiationInfo);
if (renegExtData != null)
{
/*
* If the extension is present, set secure_renegotiation flag to TRUE. The
* server MUST then verify that the length of the "renegotiated_connection"
* field is zero, and if it is not, MUST abort the handshake.
*/
this.secure_renegotiation = true;
if (!Arrays.constantTimeAreEqual(renegExtData, createRenegotiationInfo(TlsUtils.EMPTY_BYTES)))
{
throw new TlsFatalAlert(AlertDescription.handshake_failure);
}
}
}
tlsServer.notifySecureRenegotiation(this.secure_renegotiation);
if (clientExtensions != null)
{
tlsServer.processClientExtensions(clientExtensions);
}
}
protected void receiveClientKeyExchangeMessage(ByteArrayInputStream buf)
throws IOException
{
this.keyExchange.processClientKeyExchange(buf);
assertEmpty(buf);
establishMasterSecret(getContext(), keyExchange);
recordStream.setPendingConnectionState(getPeer().getCompression(), getPeer().getCipher());
if (!expectSessionTicket)
{
sendChangeCipherSpecMessage();
}
if (expectCertificateVerifyMessage())
{
this.certificateVerifyHash = recordStream.getCurrentHash(null);
}
}
protected void sendCertificateRequestMessage(CertificateRequest certificateRequest)
throws IOException
{
HandshakeMessage message = new HandshakeMessage(HandshakeType.certificate_request);
certificateRequest.encode(message);
message.writeToRecordStream();
}
protected void sendCertificateStatusMessage(CertificateStatus certificateStatus)
throws IOException
{
HandshakeMessage message = new HandshakeMessage(HandshakeType.certificate_status);
certificateStatus.encode(message);
message.writeToRecordStream();
}
protected void sendNewSessionTicketMessage(NewSessionTicket newSessionTicket)
throws IOException
{
if (newSessionTicket == null)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
HandshakeMessage message = new HandshakeMessage(HandshakeType.session_ticket);
newSessionTicket.encode(message);
message.writeToRecordStream();
}
protected void sendServerHelloMessage()
throws IOException
{
HandshakeMessage message = new HandshakeMessage(HandshakeType.server_hello);
ProtocolVersion server_version = tlsServer.getServerVersion();
if (!server_version.isEqualOrEarlierVersionOf(getContext().getClientVersion()))
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
recordStream.setReadVersion(server_version);
recordStream.setWriteVersion(server_version);
recordStream.setRestrictReadVersion(true);
getContext().setServerVersion(server_version);
TlsUtils.writeVersion(server_version, message);
message.write(this.securityParameters.serverRandom);
/*
* The server may return an empty session_id to indicate that the session will not be cached
* and therefore cannot be resumed.
*/
TlsUtils.writeOpaque8(TlsUtils.EMPTY_BYTES, message);
int selectedCipherSuite = tlsServer.getSelectedCipherSuite();
if (!arrayContains(this.offeredCipherSuites, selectedCipherSuite)
|| selectedCipherSuite == CipherSuite.TLS_NULL_WITH_NULL_NULL
|| selectedCipherSuite == CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
securityParameters.cipherSuite = selectedCipherSuite;
short selectedCompressionMethod = tlsServer.getSelectedCompressionMethod();
if (!arrayContains(this.offeredCompressionMethods, selectedCompressionMethod))
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
securityParameters.compressionAlgorithm = selectedCompressionMethod;
TlsUtils.writeUint16(selectedCipherSuite, message);
TlsUtils.writeUint8(selectedCompressionMethod, message);
this.serverExtensions = tlsServer.getServerExtensions();
/*
* RFC 5746 3.6. Server Behavior: Initial Handshake
*/
if (this.secure_renegotiation)
{
byte[] renegExtData = TlsUtils.getExtensionData(this.serverExtensions, EXT_RenegotiationInfo);
boolean noRenegExt = (null == renegExtData);
if (noRenegExt)
{
/*
* Note that sending a "renegotiation_info" extension in response to a ClientHello
* containing only the SCSV is an explicit exception to the prohibition in RFC 5246,
* Section 7.4.1.4, on the server sending unsolicited extensions and is only allowed
* because the client is signaling its willingness to receive the extension via the
* TLS_EMPTY_RENEGOTIATION_INFO_SCSV SCSV.
*/
/*
* If the secure_renegotiation flag is set to TRUE, the server MUST include an empty
* "renegotiation_info" extension in the ServerHello message.
*/
this.serverExtensions = TlsExtensionsUtils.ensureExtensionsInitialised(this.serverExtensions);
this.serverExtensions.put(EXT_RenegotiationInfo, createRenegotiationInfo(TlsUtils.EMPTY_BYTES));
}
}
/*
* TODO RFC 3546 2.3 If [...] the older session is resumed, then the server MUST ignore
* extensions appearing in the client hello, and send a server hello containing no
* extensions.
*/
if (this.serverExtensions != null)
{
this.securityParameters.maxFragmentLength = processMaxFragmentLengthExtension(clientExtensions,
this.serverExtensions, AlertDescription.internal_error);
this.securityParameters.truncatedHMac = TlsExtensionsUtils.hasTruncatedHMacExtension(this.serverExtensions);
/*
* TODO It's surprising that there's no provision to allow a 'fresh' CertificateStatus to be sent in
* a session resumption handshake.
*/
this.allowCertificateStatus = !this.resumedSession
&& TlsUtils.hasExpectedEmptyExtensionData(this.serverExtensions, TlsExtensionsUtils.EXT_status_request,
AlertDescription.internal_error);
this.expectSessionTicket = !this.resumedSession
&& TlsUtils.hasExpectedEmptyExtensionData(this.serverExtensions, TlsProtocol.EXT_SessionTicket,
AlertDescription.internal_error);
writeExtensions(message, this.serverExtensions);
}
if (this.securityParameters.maxFragmentLength >= 0)
{
int plainTextLimit = 1 << (8 + this.securityParameters.maxFragmentLength);
recordStream.setPlaintextLimit(plainTextLimit);
}
securityParameters.prfAlgorithm = getPRFAlgorithm(getContext(), securityParameters.getCipherSuite());
/*
* RFC 5264 7.4.9. Any cipher suite which does not explicitly specify verify_data_length has
* a verify_data_length equal to 12. This includes all existing cipher suites.
*/
securityParameters.verifyDataLength = 12;
message.writeToRecordStream();
recordStream.notifyHelloComplete();
}
protected void sendServerHelloDoneMessage()
throws IOException
{
byte[] message = new byte[4];
TlsUtils.writeUint8(HandshakeType.server_hello_done, message, 0);
TlsUtils.writeUint24(0, message, 1);
writeHandshakeMessage(message, 0, message.length);
}
protected void sendServerKeyExchangeMessage(byte[] serverKeyExchange)
throws IOException
{
HandshakeMessage message = new HandshakeMessage(HandshakeType.server_key_exchange, serverKeyExchange.length);
message.write(serverKeyExchange);
message.writeToRecordStream();
}
protected boolean expectCertificateVerifyMessage()
{
return this.clientCertificateType >= 0 && TlsUtils.hasSigningCapability(this.clientCertificateType);
}
}