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WS_RESPONSE_KEY(3)	   libdill Library Functions	    WS_RESPONSE_KEY(3)

NAME
       ws_response_key	-  generates  a	WebSocket response key for a given re-
       quest key

SYNOPSIS
	      #include <libdill.h>

	      int ws_response_key(
		  const	char* request_key,
		  char*	response_key);

DESCRIPTION
       WARNING:	This is	experimental functionality and the API may  change  in
       the future.

       WebSocket  is  a	message-based protocol defined in RFC 6455.  It	can be
       used as a bidirectional communication channel for communication with  a
       web server.

       This  is	 a  helper  function that can be used when doing a custom HTTP
       handshake for the WebSocket protocol  (see  WS_NOHTTP  flag).   On  the
       server,	it  can	be used	to generates an	RFC-compliant response key, to
       be filled into Sec-WebSocket-Accept field, for a	request	 key  received
       from the	client.	 On the	client side, it	can be used to verify that the
       response	key received from the server is	correct.

       The generated key is null-terminated.

       request_key: The	request	key, as	passed in Sec-WebSocket-Key field.

       response_key: Buffer to hold the	generated response key.	 It must be at
       least WS_KEY_SIZE bytes long.

       This  function  is  not	available  if  libdill is compiled with	--dis-
       able-sockets option.

RETURN VALUE
       In case of success the function returns 0.  In case of error it returns
       -1 and sets errno to one	of the values below.

ERRORS
       • EINVAL: Invalid argument.

       • EPROTO: Supplied request key is not RFC 6455 compliant.

EXAMPLE
	      char name[256];
	      char value[256];
	      http_recvfield(s,	name, sizeof(name), value, sizeof(value), -1);
	      assert(strcasecmp(name, "Sec-WebSocket-Key") == 0);
	      ws_response_key(value, response_key);
	      http_sendfield(s,	"Sec-WebSocket-Accept",	response_key, -1);

SEE ALSO
       mrecv(3)	 mrecvl(3)  msend(3)  msendl(3)	  ws_attach_client(3)	ws_at-
       tach_client_mem(3)  ws_attach_server(3)	ws_attach_server_mem(3)	ws_de-
       tach(3) ws_done(3) ws_recv(3) ws_recvl(3) ws_request_key(3)  ws_send(3)
       ws_sendl(3) ws_status(3)

libdill							    WS_RESPONSE_KEY(3)

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