2 * Platform-independent bits of X11 forwarding.
14 #define GET_16BIT(endian, cp) \
15 (endian=='B' ? GET_16BIT_MSB_FIRST(cp) : GET_16BIT_LSB_FIRST(cp))
17 #define PUT_16BIT(endian, cp, val) \
18 (endian=='B' ? PUT_16BIT_MSB_FIRST(cp, val) : PUT_16BIT_LSB_FIRST(cp, val))
20 const char *const x11_authnames
[] = {
21 "", "MIT-MAGIC-COOKIE-1", "XDM-AUTHORIZATION-1"
26 unsigned char clientid
[6];
30 const struct plug_function_table
*fn
;
31 /* the above variable absolutely *must* be the first in this structure */
32 unsigned char firstpkt
[12]; /* first X data packet */
33 struct X11Display
*disp
;
35 unsigned char *auth_data
;
36 int data_read
, auth_plen
, auth_psize
, auth_dlen
, auth_dsize
;
38 int throttled
, throttle_override
;
39 unsigned long peer_ip
;
41 void *c
; /* data used by ssh.c */
45 static int xdmseen_cmp(void *a
, void *b
)
47 struct XDMSeen
*sa
= a
, *sb
= b
;
48 return sa
->time
> sb
->time ?
1 :
49 sa
->time
< sb
->time ?
-1 :
50 memcmp(sa
->clientid
, sb
->clientid
, sizeof(sa
->clientid
));
53 /* Do-nothing "plug" implementation, used by x11_setup_display() when it
54 * creates a trial connection (and then immediately closes it).
55 * XXX: bit out of place here, could in principle live in a platform-
56 * independent network.c or something */
57 static void dummy_plug_log(Plug p
, int type
, SockAddr addr
, int port
,
58 const char *error_msg
, int error_code
) { }
59 static int dummy_plug_closing
60 (Plug p
, const char *error_msg
, int error_code
, int calling_back
)
62 static int dummy_plug_receive(Plug p
, int urgent
, char *data
, int len
)
64 static void dummy_plug_sent(Plug p
, int bufsize
) { }
65 static int dummy_plug_accepting(Plug p
, OSSocket sock
) { return 1; }
66 static const struct plug_function_table dummy_plug
= {
67 dummy_plug_log
, dummy_plug_closing
, dummy_plug_receive
,
68 dummy_plug_sent
, dummy_plug_accepting
71 struct X11Display
*x11_setup_display(char *display
, int authtype
, Conf
*conf
)
73 struct X11Display
*disp
= snew(struct X11Display
);
77 if (!display
|| !*display
) {
78 localcopy
= platform_get_x_display();
79 if (!localcopy
|| !*localcopy
) {
81 localcopy
= dupstr(":0"); /* plausible default for any platform */
84 localcopy
= dupstr(display
);
87 * Parse the display name.
89 * We expect this to have one of the following forms:
91 * - the standard X format which looks like
92 * [ [ protocol '/' ] host ] ':' displaynumber [ '.' screennumber ]
93 * (X11 also permits a double colon to indicate DECnet, but
94 * that's not our problem, thankfully!)
96 * - only seen in the wild on MacOS (so far): a pathname to a
97 * Unix-domain socket, which will typically and confusingly
98 * end in ":0", and which I'm currently distinguishing from
99 * the standard scheme by noting that it starts with '/'.
101 if (localcopy
[0] == '/') {
102 disp
->unixsocketpath
= localcopy
;
103 disp
->unixdomain
= TRUE
;
104 disp
->hostname
= NULL
;
105 disp
->displaynum
= -1;
109 char *colon
, *dot
, *slash
;
110 char *protocol
, *hostname
;
112 colon
= strrchr(localcopy
, ':');
116 return NULL
; /* FIXME: report a specific error? */
120 dot
= strchr(colon
, '.');
124 disp
->displaynum
= atoi(colon
);
126 disp
->screennum
= atoi(dot
);
131 hostname
= localcopy
;
132 if (colon
> localcopy
) {
133 slash
= strchr(localcopy
, '/');
136 protocol
= localcopy
;
141 disp
->hostname
= *hostname ?
dupstr(hostname
) : NULL
;
144 disp
->unixdomain
= (!strcmp(protocol
, "local") ||
145 !strcmp(protocol
, "unix"));
146 else if (!*hostname
|| !strcmp(hostname
, "unix"))
147 disp
->unixdomain
= platform_uses_x11_unix_by_default
;
149 disp
->unixdomain
= FALSE
;
151 if (!disp
->hostname
&& !disp
->unixdomain
)
152 disp
->hostname
= dupstr("localhost");
154 disp
->unixsocketpath
= NULL
;
161 * Look up the display hostname, if we need to.
163 if (!disp
->unixdomain
) {
166 disp
->port
= 6000 + disp
->displaynum
;
167 disp
->addr
= name_lookup(disp
->hostname
, disp
->port
,
168 &disp
->realhost
, conf
, ADDRTYPE_UNSPEC
);
170 if ((err
= sk_addr_error(disp
->addr
)) != NULL
) {
171 sk_addr_free(disp
->addr
);
172 sfree(disp
->hostname
);
173 sfree(disp
->unixsocketpath
);
174 return NULL
; /* FIXME: report an error */
179 * Try upgrading an IP-style localhost display to a Unix-socket
180 * display (as the standard X connection libraries do).
182 if (!disp
->unixdomain
&& sk_address_is_local(disp
->addr
)) {
183 SockAddr ux
= platform_get_x11_unix_address(NULL
, disp
->displaynum
);
184 const char *err
= sk_addr_error(ux
);
186 /* Create trial connection to see if there is a useful Unix-domain
188 const struct plug_function_table
*dummy
= &dummy_plug
;
189 Socket s
= sk_new(sk_addr_dup(ux
), 0, 0, 0, 0, 0, (Plug
)&dummy
);
190 err
= sk_socket_error(s
);
196 sk_addr_free(disp
->addr
);
197 disp
->unixdomain
= TRUE
;
199 /* Fill in the rest in a moment */
203 if (disp
->unixdomain
) {
205 disp
->addr
= platform_get_x11_unix_address(disp
->unixsocketpath
,
207 if (disp
->unixsocketpath
)
208 disp
->realhost
= dupstr(disp
->unixsocketpath
);
210 disp
->realhost
= dupprintf("unix:%d", disp
->displaynum
);
215 * Invent the remote authorisation details.
217 if (authtype
== X11_MIT
) {
218 disp
->remoteauthproto
= X11_MIT
;
220 /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
221 disp
->remoteauthdata
= snewn(16, unsigned char);
222 for (i
= 0; i
< 16; i
++)
223 disp
->remoteauthdata
[i
] = random_byte();
224 disp
->remoteauthdatalen
= 16;
226 disp
->xdmseen
= NULL
;
228 assert(authtype
== X11_XDM
);
229 disp
->remoteauthproto
= X11_XDM
;
231 /* XDM-AUTHORIZATION-1. Cookie size is 16 bytes; byte 8 is zero. */
232 disp
->remoteauthdata
= snewn(16, unsigned char);
233 for (i
= 0; i
< 16; i
++)
234 disp
->remoteauthdata
[i
] = (i
== 8 ?
0 : random_byte());
235 disp
->remoteauthdatalen
= 16;
237 disp
->xdmseen
= newtree234(xdmseen_cmp
);
239 disp
->remoteauthprotoname
= dupstr(x11_authnames
[disp
->remoteauthproto
]);
240 disp
->remoteauthdatastring
= snewn(disp
->remoteauthdatalen
* 2 + 1, char);
241 for (i
= 0; i
< disp
->remoteauthdatalen
; i
++)
242 sprintf(disp
->remoteauthdatastring
+ i
*2, "%02x",
243 disp
->remoteauthdata
[i
]);
246 * Fetch the local authorisation details.
248 disp
->localauthproto
= X11_NO_AUTH
;
249 disp
->localauthdata
= NULL
;
250 disp
->localauthdatalen
= 0;
251 platform_get_x11_auth(disp
, conf
);
256 void x11_free_display(struct X11Display
*disp
)
258 if (disp
->xdmseen
!= NULL
) {
259 struct XDMSeen
*seen
;
260 while ((seen
= delpos234(disp
->xdmseen
, 0)) != NULL
)
262 freetree234(disp
->xdmseen
);
264 sfree(disp
->hostname
);
265 sfree(disp
->unixsocketpath
);
266 if (disp
->localauthdata
)
267 memset(disp
->localauthdata
, 0, disp
->localauthdatalen
);
268 sfree(disp
->localauthdata
);
269 if (disp
->remoteauthdata
)
270 memset(disp
->remoteauthdata
, 0, disp
->remoteauthdatalen
);
271 sfree(disp
->remoteauthdata
);
272 sfree(disp
->remoteauthprotoname
);
273 sfree(disp
->remoteauthdatastring
);
274 sk_addr_free(disp
->addr
);
278 #define XDM_MAXSKEW 20*60 /* 20 minute clock skew should be OK */
280 static char *x11_verify(unsigned long peer_ip
, int peer_port
,
281 struct X11Display
*disp
, char *proto
,
282 unsigned char *data
, int dlen
)
284 if (strcmp(proto
, x11_authnames
[disp
->remoteauthproto
]) != 0)
285 return "wrong authorisation protocol attempted";
286 if (disp
->remoteauthproto
== X11_MIT
) {
287 if (dlen
!= disp
->remoteauthdatalen
)
288 return "MIT-MAGIC-COOKIE-1 data was wrong length";
289 if (memcmp(disp
->remoteauthdata
, data
, dlen
) != 0)
290 return "MIT-MAGIC-COOKIE-1 data did not match";
292 if (disp
->remoteauthproto
== X11_XDM
) {
296 struct XDMSeen
*seen
, *ret
;
299 return "XDM-AUTHORIZATION-1 data was wrong length";
301 return "cannot do XDM-AUTHORIZATION-1 without remote address data";
302 des_decrypt_xdmauth(disp
->remoteauthdata
+9, data
, 24);
303 if (memcmp(disp
->remoteauthdata
, data
, 8) != 0)
304 return "XDM-AUTHORIZATION-1 data failed check"; /* cookie wrong */
305 if (GET_32BIT_MSB_FIRST(data
+8) != peer_ip
)
306 return "XDM-AUTHORIZATION-1 data failed check"; /* IP wrong */
307 if ((int)GET_16BIT_MSB_FIRST(data
+12) != peer_port
)
308 return "XDM-AUTHORIZATION-1 data failed check"; /* port wrong */
309 t
= GET_32BIT_MSB_FIRST(data
+14);
310 for (i
= 18; i
< 24; i
++)
311 if (data
[i
] != 0) /* zero padding wrong */
312 return "XDM-AUTHORIZATION-1 data failed check";
314 if (abs(t
- tim
) > XDM_MAXSKEW
)
315 return "XDM-AUTHORIZATION-1 time stamp was too far out";
316 seen
= snew(struct XDMSeen
);
318 memcpy(seen
->clientid
, data
+8, 6);
319 assert(disp
->xdmseen
!= NULL
);
320 ret
= add234(disp
->xdmseen
, seen
);
323 return "XDM-AUTHORIZATION-1 data replayed";
325 /* While we're here, purge entries too old to be replayed. */
327 seen
= index234(disp
->xdmseen
, 0);
328 assert(seen
!= NULL
);
329 if (t
- seen
->time
<= XDM_MAXSKEW
)
331 sfree(delpos234(disp
->xdmseen
, 0));
334 /* implement other protocols here if ever required */
338 void x11_get_auth_from_authfile(struct X11Display
*disp
,
339 const char *authfilename
)
342 char *buf
, *ptr
, *str
[4];
344 int family
, protocol
;
345 int ideal_match
= FALSE
;
346 char *ourhostname
= get_hostname();
349 * Normally we should look for precisely the details specified in
350 * `disp'. However, there's an oddity when the display is local:
351 * displays like "localhost:0" usually have their details stored
352 * in a Unix-domain-socket record (even if there isn't actually a
353 * real Unix-domain socket available, as with OpenSSH's proxy X11
356 * This is apparently a fudge to get round the meaninglessness of
357 * "localhost" in a shared-home-directory context -- xauth entries
358 * for Unix-domain sockets already disambiguate this by storing
359 * the *local* hostname in the conveniently-blank hostname field,
360 * but IP "localhost" records couldn't do this. So, typically, an
361 * IP "localhost" entry in the auth database isn't present and if
362 * it were it would be ignored.
364 * However, we don't entirely trust that (say) Windows X servers
365 * won't rely on a straight "localhost" entry, bad idea though
366 * that is; so if we can't find a Unix-domain-socket entry we'll
367 * fall back to an IP-based entry if we can find one.
369 int localhost
= !disp
->unixdomain
&& sk_address_is_local(disp
->addr
);
371 authfp
= fopen(authfilename
, "rb");
375 /* Records in .Xauthority contain four strings of up to 64K each */
376 buf
= snewn(65537 * 4, char);
378 while (!ideal_match
) {
379 int c
, i
, j
, match
= FALSE
;
381 #define GET do { c = fgetc(authfp); if (c == EOF) goto done; c = (unsigned char)c; } while (0)
382 /* Expect a big-endian 2-byte number giving address family */
384 GET
; family
= (family
<< 8) | c
;
385 /* Then expect four strings, each composed of a big-endian 2-byte
386 * length field followed by that many bytes of data */
388 for (i
= 0; i
< 4; i
++) {
390 GET
; len
[i
] = (len
[i
] << 8) | c
;
392 for (j
= 0; j
< len
[i
]; j
++) {
400 * Now we have a full X authority record in memory. See
401 * whether it matches the display we're trying to
404 * The details we've just read should be interpreted as
407 * - 'family' is the network address family used to
408 * connect to the display. 0 means IPv4; 6 means IPv6;
409 * 256 means Unix-domain sockets.
411 * - str[0] is the network address itself. For IPv4 and
412 * IPv6, this is a string of binary data of the
413 * appropriate length (respectively 4 and 16 bytes)
414 * representing the address in big-endian format, e.g.
415 * 7F 00 00 01 means IPv4 localhost. For Unix-domain
416 * sockets, this is the host name of the machine on
417 * which the Unix-domain display resides (so that an
418 * .Xauthority file on a shared file system can contain
419 * authority entries for Unix-domain displays on
420 * several machines without them clashing).
422 * - str[1] is the display number. I've no idea why
423 * .Xauthority stores this as a string when it has a
424 * perfectly good integer format, but there we go.
426 * - str[2] is the authorisation method, encoded as its
427 * canonical string name (i.e. "MIT-MAGIC-COOKIE-1",
428 * "XDM-AUTHORIZATION-1" or something we don't
431 * - str[3] is the actual authorisation data, stored in
435 if (disp
->displaynum
< 0 || disp
->displaynum
!= atoi(str
[1]))
436 continue; /* not the one */
438 for (protocol
= 1; protocol
< lenof(x11_authnames
); protocol
++)
439 if (!strcmp(str
[2], x11_authnames
[protocol
]))
441 if (protocol
== lenof(x11_authnames
))
442 continue; /* don't recognise this protocol, look for another */
446 if (!disp
->unixdomain
&&
447 sk_addrtype(disp
->addr
) == ADDRTYPE_IPV4
) {
449 sk_addrcopy(disp
->addr
, buf
);
450 if (len
[0] == 4 && !memcmp(str
[0], buf
, 4)) {
452 /* If this is a "localhost" entry, note it down
453 * but carry on looking for a Unix-domain entry. */
454 ideal_match
= !localhost
;
459 if (!disp
->unixdomain
&&
460 sk_addrtype(disp
->addr
) == ADDRTYPE_IPV6
) {
462 sk_addrcopy(disp
->addr
, buf
);
463 if (len
[0] == 16 && !memcmp(str
[0], buf
, 16)) {
465 ideal_match
= !localhost
;
469 case 256: /* Unix-domain / localhost */
470 if ((disp
->unixdomain
|| localhost
)
471 && ourhostname
&& !strcmp(ourhostname
, str
[0]))
472 /* A matching Unix-domain socket is always the best
474 match
= ideal_match
= TRUE
;
479 /* Current best guess -- may be overridden if !ideal_match */
480 disp
->localauthproto
= protocol
;
481 sfree(disp
->localauthdata
); /* free previous guess, if any */
482 disp
->localauthdata
= snewn(len
[3], unsigned char);
483 memcpy(disp
->localauthdata
, str
[3], len
[3]);
484 disp
->localauthdatalen
= len
[3];
490 memset(buf
, 0, 65537 * 4);
495 static void x11_log(Plug p
, int type
, SockAddr addr
, int port
,
496 const char *error_msg
, int error_code
)
498 /* We have no interface to the logging module here, so we drop these. */
501 static int x11_closing(Plug plug
, const char *error_msg
, int error_code
,
504 struct X11Private
*pr
= (struct X11Private
*) plug
;
507 * We have no way to communicate down the forwarded connection,
508 * so if an error occurred on the socket, we just ignore it
509 * and treat it like a proper close.
511 * FIXME: except we could initiate a full close here instead of
512 * just an outgoing EOF? ssh.c currently has no API for that, but
515 sshfwd_write_eof(pr
->c
);
519 static int x11_receive(Plug plug
, int urgent
, char *data
, int len
)
521 struct X11Private
*pr
= (struct X11Private
*) plug
;
523 if (sshfwd_write(pr
->c
, data
, len
) > 0) {
525 sk_set_frozen(pr
->s
, 1);
531 static void x11_sent(Plug plug
, int bufsize
)
533 struct X11Private
*pr
= (struct X11Private
*) plug
;
535 sshfwd_unthrottle(pr
->c
, bufsize
);
539 * When setting up X forwarding, we should send the screen number
540 * from the specified local display. This function extracts it from
541 * the display string.
543 int x11_get_screen_number(char *display
)
547 n
= strcspn(display
, ":");
550 n
= strcspn(display
, ".");
553 return atoi(display
+ n
+ 1);
557 * Called to set up the raw connection.
559 * Returns an error message, or NULL on success.
560 * also, fills the SocketsStructure
562 extern const char *x11_init(Socket
*s
, struct X11Display
*disp
, void *c
,
563 const char *peeraddr
, int peerport
, Conf
*conf
)
565 static const struct plug_function_table fn_table
= {
574 struct X11Private
*pr
;
579 pr
= snew(struct X11Private
);
581 pr
->auth_protocol
= NULL
;
585 pr
->throttled
= pr
->throttle_override
= 0;
588 pr
->s
= *s
= new_connection(sk_addr_dup(disp
->addr
),
589 disp
->realhost
, disp
->port
,
590 0, 1, 0, 0, (Plug
) pr
, conf
);
591 if ((err
= sk_socket_error(*s
)) != NULL
) {
597 * See if we can make sense of the peer address we were given.
602 4 == sscanf(peeraddr
, "%d.%d.%d.%d", i
+0, i
+1, i
+2, i
+3)) {
603 pr
->peer_ip
= (i
[0] << 24) | (i
[1] << 16) | (i
[2] << 8) | i
[3];
604 pr
->peer_port
= peerport
;
611 sk_set_private_ptr(*s
, pr
);
615 void x11_close(Socket s
)
617 struct X11Private
*pr
;
620 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
621 if (pr
->auth_protocol
) {
622 sfree(pr
->auth_protocol
);
623 sfree(pr
->auth_data
);
631 void x11_unthrottle(Socket s
)
633 struct X11Private
*pr
;
636 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
639 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
642 void x11_override_throttle(Socket s
, int enable
)
644 struct X11Private
*pr
;
647 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
649 pr
->throttle_override
= enable
;
650 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
654 * Called to send data down the raw connection.
656 int x11_send(Socket s
, char *data
, int len
)
658 struct X11Private
*pr
;
661 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
664 * Read the first packet.
666 while (len
> 0 && pr
->data_read
< 12)
667 pr
->firstpkt
[pr
->data_read
++] = (unsigned char) (len
--, *data
++);
668 if (pr
->data_read
< 12)
672 * If we have not allocated the auth_protocol and auth_data
673 * strings, do so now.
675 if (!pr
->auth_protocol
) {
676 pr
->auth_plen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6);
677 pr
->auth_dlen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8);
678 pr
->auth_psize
= (pr
->auth_plen
+ 3) & ~3;
679 pr
->auth_dsize
= (pr
->auth_dlen
+ 3) & ~3;
680 /* Leave room for a terminating zero, to make our lives easier. */
681 pr
->auth_protocol
= snewn(pr
->auth_psize
+ 1, char);
682 pr
->auth_data
= snewn(pr
->auth_dsize
, unsigned char);
686 * Read the auth_protocol and auth_data strings.
688 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
)
689 pr
->auth_protocol
[pr
->data_read
++ - 12] = (len
--, *data
++);
690 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
691 pr
->auth_data
[pr
->data_read
++ - 12 -
692 pr
->auth_psize
] = (unsigned char) (len
--, *data
++);
693 if (pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
697 * If we haven't verified the authorisation, do so now.
702 pr
->auth_protocol
[pr
->auth_plen
] = '\0'; /* ASCIZ */
703 err
= x11_verify(pr
->peer_ip
, pr
->peer_port
,
704 pr
->disp
, pr
->auth_protocol
,
705 pr
->auth_data
, pr
->auth_dlen
);
708 * If authorisation failed, construct and send an error
709 * packet, then terminate the connection.
714 unsigned char *reply
;
716 message
= dupprintf("%s X11 proxy: %s", appname
, err
);
717 msglen
= strlen(message
);
718 reply
= snewn(8 + msglen
+1 + 4, unsigned char); /* include zero */
719 msgsize
= (msglen
+ 3) & ~3;
720 reply
[0] = 0; /* failure */
721 reply
[1] = msglen
; /* length of reason string */
722 memcpy(reply
+ 2, pr
->firstpkt
+ 2, 4); /* major/minor proto vsn */
723 PUT_16BIT(pr
->firstpkt
[0], reply
+ 6, msgsize
>> 2);/* data len */
724 memset(reply
+ 8, 0, msgsize
);
725 memcpy(reply
+ 8, message
, msglen
);
726 sshfwd_write(pr
->c
, (char *)reply
, 8 + msgsize
);
727 sshfwd_write_eof(pr
->c
);
734 * Now we know we're going to accept the connection. Strip
735 * the fake auth data, and optionally put real auth data in
739 char realauthdata
[64];
741 int authstrlen
= strlen(x11_authnames
[pr
->disp
->localauthproto
]);
742 int buflen
= 0; /* initialise to placate optimiser */
743 static const char zeroes
[4] = { 0,0,0,0 };
746 if (pr
->disp
->localauthproto
== X11_MIT
) {
747 assert(pr
->disp
->localauthdatalen
<= lenof(realauthdata
));
748 realauthlen
= pr
->disp
->localauthdatalen
;
749 memcpy(realauthdata
, pr
->disp
->localauthdata
, realauthlen
);
750 } else if (pr
->disp
->localauthproto
== X11_XDM
&&
751 pr
->disp
->localauthdatalen
== 16 &&
752 ((buf
= sk_getxdmdata(s
, &buflen
))!=0)) {
754 realauthlen
= (buflen
+12+7) & ~7;
755 assert(realauthlen
<= lenof(realauthdata
));
756 memset(realauthdata
, 0, realauthlen
);
757 memcpy(realauthdata
, pr
->disp
->localauthdata
, 8);
758 memcpy(realauthdata
+8, buf
, buflen
);
760 PUT_32BIT_MSB_FIRST(realauthdata
+8+buflen
, t
);
761 des_encrypt_xdmauth(pr
->disp
->localauthdata
+9,
762 (unsigned char *)realauthdata
,
766 /* implement other auth methods here if required */
768 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6, authstrlen
);
769 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8, realauthlen
);
771 sk_write(s
, (char *)pr
->firstpkt
, 12);
774 sk_write(s
, x11_authnames
[pr
->disp
->localauthproto
],
776 sk_write(s
, zeroes
, 3 & (-authstrlen
));
779 sk_write(s
, realauthdata
, realauthlen
);
780 sk_write(s
, zeroes
, 3 & (-realauthlen
));
787 * After initialisation, just copy data simply.
790 return sk_write(s
, data
, len
);
793 void x11_send_eof(Socket s
)