session.c

cryptlib安全工具包

			   the user can re-activate the session after confirming (or
			   denying) the resource */
			if( status == CRYPT_ENVELOPE_RESOURCE )
				sessionInfoPtr->flags |= SESSION_PARTIALOPEN;

			return( status );
			}

		/* Notify the kernel that the session key context is attached to the
		   session object.  Note that we increment its reference count even
		   though it's an internal object used only by the session, because
		   otherwise it'll be automatically destroyed by the kernel as a
		   zero-reference dependent object when the session object is
		   destroyed (but before the session object itself, since it's a
		   dependent object).  This automatic cleanup could cause problems 
		   for lower-level session management code that tries to work with 
		   the (apparently still-valid) handle, for example protocols that 
		   need to encrypt a close-channel message on shutdown */
		krnlSendMessage( sessionInfoPtr->objectHandle, IMESSAGE_SETDEPENDENT,
						 &sessionInfoPtr->iCryptInContext,
						 SETDEP_OPTION_INCREF );

		/* Set up the buffer management variables */
		sessionInfoPtr->receiveBufPos = sessionInfoPtr->receiveBufEnd = 0;
		sessionInfoPtr->sendBufPos = sessionInfoPtr->sendBufStartOfs;

		/* For data transport sessions, partial reads and writes (that is,
		   sending and receiving partial packets in the presence of 
		   timeouts) are permitted */
		sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_PARTIALREAD, NULL, 
				TRUE );
		sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_PARTIALWRITE, NULL, 
				TRUE );
		}

	/* The handshake has been completed, switch from the handshake timeout
	   to the data transfer timeout and remember that the session has been
	   successfully established */
	sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_HANDSHAKECOMPLETE, NULL, 0 );
	sessionInfoPtr->flags &= ~SESSION_PARTIALOPEN;
	sessionInfoPtr->flags |= SESSION_ISOPEN;

	return( CRYPT_OK );
	}

/* Activate a session */

static void cleanupReqResp( SESSION_INFO *sessionInfoPtr,
							const BOOLEAN isPostTransaction )
	{
	const BOOLEAN isServer = isServer( sessionInfoPtr );

	/* Clean up server requests left over from a previous transaction/
	   created by the just-completed transaction */
	if( isServer && sessionInfoPtr->iCertRequest != CRYPT_ERROR )
		{
		krnlSendNotifier( sessionInfoPtr->iCertRequest,
						  IMESSAGE_DECREFCOUNT );
		sessionInfoPtr->iCertRequest = CRYPT_ERROR;
		}

	/* Clean up client/server responses left over from a previous
	   transaction and server responses created by the just-completed
	   transaction */
	if( ( isServer || !isPostTransaction ) && \
		sessionInfoPtr->iCertResponse != CRYPT_ERROR )
		{
		krnlSendNotifier( sessionInfoPtr->iCertResponse,
						  IMESSAGE_DECREFCOUNT );
		sessionInfoPtr->iCertResponse = CRYPT_ERROR;
		}
	}

int activateSession( SESSION_INFO *sessionInfoPtr )
	{
	int streamState, status;

	/* Activate the connection if necessary */
	if( !( sessionInfoPtr->flags & SESSION_ISOPEN ) )
		{
		/* Try and activate the session */
		status = activateConnection( sessionInfoPtr );
		if( cryptStatusError( status ) )
			return( status );

		/* The session activation succeeded, make sure that we don't try
		   and replace the ephemeral attributes established during the 
		   session setup during any later operations */
		if( sessionInfoPtr->attributeList != NULL )
			lockEphemeralAttributes( sessionInfoPtr->attributeList );
		}

	/* If it's a secure data transport session, it's up to the caller to
	   move data over it, and we're done */
	if( !sessionInfoPtr->protocolInfo->isReqResp )
		return( CRYPT_OK );

	/* Carry out the transaction on the request-response connection.  We
	   perform a cleanup of request/response data around the activation,
	   beforehand to catch data such as responses left over from a previous
	   transaction, and afterwards to clean up ephemeral data such as
	   requests sent to a server */
	cleanupReqResp( sessionInfoPtr, FALSE );
	status = sessionInfoPtr->transactFunction( sessionInfoPtr );
	cleanupReqResp( sessionInfoPtr, TRUE );
	if( cryptStatusError( status ) )
		return( status );

	/* Check whether the other side has indicated that it's closing the 
	   stream and if it has, shut down our side as well and record the fact
	   that the session is now closed */
	sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_CONNSTATE,
			&streamState, 0 );
	if( !streamState )
		{
		sessionInfoPtr->flags &= ~SESSION_ISOPEN;
		sessionInfoPtr->shutdownFunction( sessionInfoPtr );
		}
	return( CRYPT_OK );
	}

/****************************************************************************
*																			*
*							Session Shutdown Functions						*
*																			*
****************************************************************************/

/* Send a close notification.  This requires special-case handling because
   it's not certain how long we should wait around for the close to happen.
   If we're in the middle of a cryptlib shutdown we don't want to wait 
   around forever since this would stall the overall shutdown, but if it's a 
   standard session shutdown we should wait for at least a small amount of
   time to ensure that all of the data is sent */

int sendCloseNotification( SESSION_INFO *sessionInfoPtr,
						   const void *data, const int length )
	{
	BOOLEAN isShutdown = FALSE;
	int dummy, status = CRYPT_OK;

	assert( ( data == NULL && length == 0 ) || \
			isReadPtr( data, length ) );

	/* Determine whether we're being shut down as a part of a general 
	   cryptlib shutdown or just a session shutdown.  We do this by trying 
	   to read a config option from the owning user object, if the kernel is 
	   in the middle of a shutdown it disallows all frivolous messages so 
	   if we get a permission error we're in the middle of the shutdown */
	if( krnlSendMessage( sessionInfoPtr->ownerHandle, IMESSAGE_GETATTRIBUTE, 
						 &dummy, CRYPT_OPTION_INFO_MAJORVERSION ) == CRYPT_ERROR_PERMISSION )
		isShutdown = TRUE;

	/* If necessary set a timeout sufficient to at least provide a chance of 
	   sending our close alert and receiving the other side's ack of the 
	   close, but without leading to excessive delays during the shutdown */
	if( isShutdown )
		{
		/* It's a cryptlib-wide shutdown, try and get out as quickly as
		   possible */
		sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_WRITETIMEOUT, 
				NULL, 2 );
		}
	else
		{
		int timeout;

		/* It's a standard session shutdown, wait around for at least five
		   seconds, but not more than fifteen */
		sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_WRITETIMEOUT, 
				&timeout, 0 );
		if( timeout < 5 )
			timeout = 5;
		if( timeout > 15 )
			timeout = 15;
		sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_WRITETIMEOUT, 
				NULL, timeout );
		}

	/* Send the close notification to the peer */
	if( data != NULL )
		status = swrite( &sessionInfoPtr->stream, data, length );

	/* Close the send side of the connection if it's a cryptlib-internal 
	   socket.  This is needed by some implementations that want to see a 
	   FIN before they react to a shutdown notification, as well as being
	   a hint to the network code to flush any remaining data enqueued for
	   sending before the arrival of the full close.  If it's a user-managed 
	   socket we can't perform the partial close since this would affect the 
	   state of the socket as seen by the user, since the need to see the 
	   FIN is fairly rare we choose this as the less problematic of the two 
	   options */
	if( sessionInfoPtr->networkSocket == CRYPT_ERROR )
		sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_CLOSESENDCHANNEL, 
				NULL, 0 );

	return( ( data == NULL || !cryptStatusError( status ) ) ? \
			CRYPT_OK : status );
	}

/****************************************************************************
*																			*
*							Default Action Handlers							*
*																			*
****************************************************************************/

/* Default init/shutdown functions used when no session-specific ones are
   provided */

static int defaultClientStartupFunction( SESSION_INFO *sessionInfoPtr )
	{
	const PROTOCOL_INFO *protocolInfoPtr = sessionInfoPtr->protocolInfo;
	NET_CONNECT_INFO connectInfo;
	int status;

	/* Connect to the server */
	initSessionNetConnectInfo( sessionInfoPtr, &connectInfo );
	if( sessionInfoPtr->flags & SESSION_ISHTTPTRANSPORT )
		status = sNetConnect( &sessionInfoPtr->stream, STREAM_PROTOCOL_HTTP,
							  &connectInfo, &sessionInfoPtr->errorInfo );
	else
		{
		if( sessionInfoPtr->flags & SESSION_USEALTTRANSPORT )
			{
			const ALTPROTOCOL_INFO *altProtocolInfoPtr = \
									protocolInfoPtr->altProtocolInfo;

			/* If we'd be using the HTTP port for a session-specific 
			   protocol, change it to the default port for the session-
			   specific protocol instead */
			if( connectInfo.port == 80 )
				connectInfo.port = altProtocolInfoPtr->port;
			status = sNetConnect( &sessionInfoPtr->stream,
								  altProtocolInfoPtr->type,
								  &connectInfo, &sessionInfoPtr->errorInfo );
			}
		else
			status = sNetConnect( &sessionInfoPtr->stream,
								  STREAM_PROTOCOL_TCPIP,
								  &connectInfo, &sessionInfoPtr->errorInfo );
		}
	return( status );
	}

static int defaultServerStartupFunction( SESSION_INFO *sessionInfoPtr )
	{
	const PROTOCOL_INFO *protocolInfoPtr = sessionInfoPtr->protocolInfo;
	NET_CONNECT_INFO connectInfo;
	int nameLen, port, status;

	/* Wait for a client connection */
	initSessionNetConnectInfo( sessionInfoPtr, &connectInfo );
	if( sessionInfoPtr->flags & SESSION_ISHTTPTRANSPORT )
		status = sNetListen( &sessionInfoPtr->stream, STREAM_PROTOCOL_HTTP,
							 &connectInfo, &sessionInfoPtr->errorInfo );
	else
		{
		if( sessionInfoPtr->flags & SESSION_USEALTTRANSPORT )
			{
			const ALTPROTOCOL_INFO *altProtocolInfoPtr = \
									protocolInfoPtr->altProtocolInfo;

			/* If we'd be using the HTTP port for a session-specific 
			   protocol, change it to the default port for the session-
			   specific protocol instead */
			if( connectInfo.port == 80 )
				connectInfo.port = altProtocolInfoPtr->port;
			status = sNetListen( &sessionInfoPtr->stream,
								 altProtocolInfoPtr->type,
								 &connectInfo, &sessionInfoPtr->errorInfo );
			}
		else
			status = sNetListen( &sessionInfoPtr->stream,
								 STREAM_PROTOCOL_TCPIP,
								 &connectInfo, &sessionInfoPtr->errorInfo );
		}
	if( cryptStatusError( status ) )
		return( status );

	/* Save the client details for the caller, using the (always-present)
	   receive buffer as the intermediate store */
	status = sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_GETCLIENTNAMELEN,
					 &nameLen, 0 );
	if( cryptStatusOK( status ) )
		status = sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_GETCLIENTNAME,
						 sessionInfoPtr->receiveBuffer, CRYPT_MAX_TEXTSIZE );
	if( cryptStatusError( status ) )
		{
		/* No client info available, exit */
		return( CRYPT_OK );
		}
	status = addSessionInfo( &sessionInfoPtr->attributeList, 
							 CRYPT_SESSINFO_CLIENT_NAME, 
							 sessionInfoPtr->receiveBuffer, nameLen );
	if( cryptStatusError( status ) )
		return( status );
	status = sioctl( &sessionInfoPtr->stream, STREAM_IOCTL_GETCLIENTPORT, 
					 &port, 0 );
	if( cryptStatusError( status ) )
		{
		/* No port info available, exit */
		return( CRYPT_OK );
		}
	return( addSessionInfo( &sessionInfoPtr->attributeList, 
							CRYPT_SESSINFO_CLIENT_PORT, NULL, port ) );
	}

static void defaultShutdownFunction( SESSION_INFO *sessionInfoPtr )
	{
	sNetDisconnect( &sessionInfoPtr->stream );
	}

/* Default get-attribute function used when no session-specific one is
   provided */

static int defaultGetAttributeFunction( SESSION_INFO *sessionInfoPtr,
										void *data,
										const CRYPT_ATTRIBUTE_TYPE type )
	{
	CRYPT_CERTIFICATE *responsePtr = ( CRYPT_CERTIFICATE * ) data;

	assert( type == CRYPT_SESSINFO_RESPONSE );

	/* If we didn't get a response there's nothing to return */
	if( sessionInfoPtr->iCertResponse == CRYPT_ERROR )
		return( CRYPT_ERROR_NOTFOUND );

/************************************************************************/
/* SCEP gets a bit complicated because a single object has to fill 
   multiple roles, so that for example the issued cert has to do double 
   duty for both encryption and authentication.  For now we work around 
   this by juggling the values around */
if( sessionInfoPtr->type == CRYPT_SESSION_SCEP && \
	sessionInfoPtr->iAuthInContext != CRYPT_ERROR )
	{
	*responsePtr = sessionInfoPtr->iCertResponse;
	sessionInfoPtr->iCertResponse = sessionInfoPtr->iAuthInContext;
	sessionInfoPtr->iAuthInContext = CRYPT_ERROR;

	return( CRYPT_OK );
	}
/************************************************************************/

	/* Return the info to the caller */
	krnlSendNotifier( sessionInfoPtr->iCertResponse, IMESSAGE_INCREFCOUNT );
	*responsePtr = sessionInfoPtr->iCertResponse;
	return( CRYPT_OK );
	}

/* Set up the function pointers to the session I/O methods */

int initSessionIO( SESSION_INFO *sessionInfoPtr )
	{
	const PROTOCOL_INFO *protocolInfoPtr = sessionInfoPtr->protocolInfo;

	/* Install default handler functions if required */
	if( sessionInfoPtr->shutdownFunction == NULL )
		sessionInfoPtr->shutdownFunction = defaultShutdownFunction;
	if( sessionInfoPtr->connectFunction == NULL )
		sessionInfoPtr->connectFunction = isServer( sessionInfoPtr ) ? 
			defaultServerStartupFunction : defaultClientStartupFunction;
	if( protocolInfoPtr->isReqResp && \
		sessionInfoPtr->getAttributeFunction == NULL )
		sessionInfoPtr->getAttributeFunction = defaultGetAttributeFunction;

	return( CRYPT_OK );
	}
#endif /* USE_SESSIONS */