8 #define GET_32BIT_LSB_FIRST(cp) \
9 (((unsigned long)(unsigned char)(cp)[0]) | \
10 ((unsigned long)(unsigned char)(cp)[1] << 8) | \
11 ((unsigned long)(unsigned char)(cp)[2] << 16) | \
12 ((unsigned long)(unsigned char)(cp)[3] << 24))
14 #define PUT_32BIT_LSB_FIRST(cp, value) ( \
16 (cp)[1] = (value) >> 8, \
17 (cp)[2] = (value) >> 16, \
18 (cp)[3] = (value) >> 24 )
20 #define GET_16BIT_LSB_FIRST(cp) \
21 (((unsigned long)(unsigned char)(cp)[0]) | \
22 ((unsigned long)(unsigned char)(cp)[1] << 8))
24 #define PUT_16BIT_LSB_FIRST(cp, value) ( \
26 (cp)[1] = (value) >> 8 )
28 #define GET_32BIT_MSB_FIRST(cp) \
29 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
30 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
31 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
32 ((unsigned long)(unsigned char)(cp)[3]))
34 #define PUT_32BIT_MSB_FIRST(cp, value) ( \
35 (cp)[0] = (value) >> 24, \
36 (cp)[1] = (value) >> 16, \
37 (cp)[2] = (value) >> 8, \
40 #define GET_16BIT_MSB_FIRST(cp) \
41 (((unsigned long)(unsigned char)(cp)[0] << 8) | \
42 ((unsigned long)(unsigned char)(cp)[1]))
44 #define PUT_16BIT_MSB_FIRST(cp, value) ( \
45 (cp)[0] = (value) >> 8, \
48 #define GET_16BIT(endian, cp) \
49 (endian=='B' ? GET_16BIT_MSB_FIRST(cp) : GET_16BIT_LSB_FIRST(cp))
51 #define PUT_16BIT(endian, cp, val) \
52 (endian=='B' ? PUT_16BIT_MSB_FIRST(cp, val) : PUT_16BIT_LSB_FIRST(cp, val))
54 const char *const x11_authnames
[] = {
55 "", "MIT-MAGIC-COOKIE-1"
59 unsigned char fakedata
[64], realdata
[64];
60 int fakeproto
, realproto
;
64 extern void platform_get_x11_auth(char *display
, int *proto
,
65 unsigned char *data
, int *datalen
);
68 const struct plug_function_table
*fn
;
69 /* the above variable absolutely *must* be the first in this structure */
70 unsigned char firstpkt
[12]; /* first X data packet */
73 unsigned char *auth_data
;
74 int data_read
, auth_plen
, auth_psize
, auth_dlen
, auth_dsize
;
76 int throttled
, throttle_override
;
77 void *c
; /* data used by ssh.c */
81 void *x11_invent_auth(char *proto
, int protomaxlen
,
82 char *data
, int datamaxlen
)
84 struct X11Auth
*auth
= smalloc(sizeof(struct X11Auth
));
88 auth
->fakeproto
= X11_MIT
;
90 /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
92 for (i
= 0; i
< 16; i
++)
93 auth
->fakedata
[i
] = random_byte();
95 /* Now format for the recipient. */
96 strncpy(proto
, x11_authnames
[auth
->fakeproto
], protomaxlen
);
98 for (i
= 0; i
< auth
->fakelen
; i
++)
99 sprintf(ourdata
+ strlen(ourdata
), "%02x", auth
->fakedata
[i
]);
100 strncpy(data
, ourdata
, datamaxlen
);
106 * Fetch the real auth data for a given display string, and store
107 * it in an X11Auth structure. Returns NULL on success, or an error
110 void x11_get_real_auth(void *authv
, char *display
)
112 struct X11Auth
*auth
= (struct X11Auth
*)authv
;
114 auth
->realproto
= X11_NO_AUTH
; /* in case next call does nothing */
116 auth
->reallen
= sizeof(auth
->realdata
);
117 platform_get_x11_auth(display
, &auth
->realproto
,
118 auth
->realdata
, &auth
->reallen
);
121 static int x11_verify(struct X11Auth
*auth
,
122 char *proto
, unsigned char *data
, int dlen
)
124 if (strcmp(proto
, x11_authnames
[auth
->fakeproto
]) != 0)
125 return 0; /* wrong protocol attempted */
126 if (auth
->fakeproto
== X11_MIT
) {
127 if (dlen
!= auth
->fakelen
)
128 return 0; /* cookie was wrong length */
129 if (memcmp(auth
->fakedata
, data
, dlen
) != 0)
130 return 0; /* cookie was wrong cookie! */
132 /* implement other protocols here if ever required */
136 static int x11_closing(Plug plug
, char *error_msg
, int error_code
,
139 struct X11Private
*pr
= (struct X11Private
*) plug
;
142 * We have no way to communicate down the forwarded connection,
143 * so if an error occurred on the socket, we just ignore it
144 * and treat it like a proper close.
151 static int x11_receive(Plug plug
, int urgent
, char *data
, int len
)
153 struct X11Private
*pr
= (struct X11Private
*) plug
;
155 if (sshfwd_write(pr
->c
, data
, len
) > 0) {
157 sk_set_frozen(pr
->s
, 1);
163 static void x11_sent(Plug plug
, int bufsize
)
165 struct X11Private
*pr
= (struct X11Private
*) plug
;
167 sshfwd_unthrottle(pr
->c
, bufsize
);
171 * When setting up X forwarding, we should send the screen number
172 * from the specified local display. This function extracts it from
173 * the display string.
175 int x11_get_screen_number(char *display
)
179 n
= strcspn(display
, ":");
182 n
= strcspn(display
, ".");
185 return atoi(display
+ n
+ 1);
189 * Called to set up the raw connection.
191 * Returns an error message, or NULL on success.
192 * also, fills the SocketsStructure
194 char *x11_init(Socket
* s
, char *display
, void *c
, void *auth
)
196 static const struct plug_function_table fn_table
= {
205 char *err
, *dummy_realhost
;
208 struct X11Private
*pr
;
211 * Split up display name into host and display-number parts.
213 n
= strcspn(display
, ":");
215 displaynum
= atoi(display
+ n
+ 1);
217 displaynum
= 0; /* sensible default */
218 if (n
> sizeof(host
) - 1)
219 n
= sizeof(host
) - 1;
221 strncpy(host
, display
, n
);
225 * Local display numbers, particularly on Unix, often omit
226 * the display part completely.
228 strcpy(host
, "localhost");
231 port
= 6000 + displaynum
;
236 addr
= name_lookup(host
, port
, &dummy_realhost
);
237 if ((err
= sk_addr_error(addr
)) != NULL
)
243 pr
= (struct X11Private
*) smalloc(sizeof(struct X11Private
));
245 pr
->auth_protocol
= NULL
;
246 pr
->auth
= (struct X11Auth
*)auth
;
249 pr
->throttled
= pr
->throttle_override
= 0;
252 pr
->s
= *s
= new_connection(addr
, dummy_realhost
, port
, 0, 1, 0, (Plug
) pr
);
253 if ((err
= sk_socket_error(*s
)) != NULL
) {
258 sk_set_private_ptr(*s
, pr
);
263 void x11_close(Socket s
)
265 struct X11Private
*pr
;
268 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
269 if (pr
->auth_protocol
) {
270 sfree(pr
->auth_protocol
);
271 sfree(pr
->auth_data
);
279 void x11_unthrottle(Socket s
)
281 struct X11Private
*pr
;
284 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
287 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
290 void x11_override_throttle(Socket s
, int enable
)
292 struct X11Private
*pr
;
295 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
297 pr
->throttle_override
= enable
;
298 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
302 * Called to send data down the raw connection.
304 int x11_send(Socket s
, char *data
, int len
)
306 struct X11Private
*pr
= (struct X11Private
*) sk_get_private_ptr(s
);
312 * Read the first packet.
314 while (len
> 0 && pr
->data_read
< 12)
315 pr
->firstpkt
[pr
->data_read
++] = (unsigned char) (len
--, *data
++);
316 if (pr
->data_read
< 12)
320 * If we have not allocated the auth_protocol and auth_data
321 * strings, do so now.
323 if (!pr
->auth_protocol
) {
324 pr
->auth_plen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6);
325 pr
->auth_dlen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8);
326 pr
->auth_psize
= (pr
->auth_plen
+ 3) & ~3;
327 pr
->auth_dsize
= (pr
->auth_dlen
+ 3) & ~3;
328 /* Leave room for a terminating zero, to make our lives easier. */
329 pr
->auth_protocol
= (char *) smalloc(pr
->auth_psize
+ 1);
330 pr
->auth_data
= (unsigned char *) smalloc(pr
->auth_dsize
);
334 * Read the auth_protocol and auth_data strings.
336 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
)
337 pr
->auth_protocol
[pr
->data_read
++ - 12] = (len
--, *data
++);
338 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
339 pr
->auth_data
[pr
->data_read
++ - 12 -
340 pr
->auth_psize
] = (unsigned char) (len
--, *data
++);
341 if (pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
345 * If we haven't verified the authentication, do so now.
350 pr
->auth_protocol
[pr
->auth_plen
] = '\0'; /* ASCIZ */
351 ret
= x11_verify(pr
->auth
, pr
->auth_protocol
,
352 pr
->auth_data
, pr
->auth_dlen
);
355 * If authentication failed, construct and send an error
356 * packet, then terminate the connection.
359 char message
[] = "Authentication failed at PuTTY X11 proxy";
360 unsigned char reply
[8 + sizeof(message
) + 4];
361 int msglen
= sizeof(message
) - 1; /* skip zero byte */
362 int msgsize
= (msglen
+ 3) & ~3;
363 reply
[0] = 0; /* failure */
364 reply
[1] = msglen
; /* length of reason string */
365 memcpy(reply
+ 2, pr
->firstpkt
+ 2, 4); /* major/minor proto vsn */
366 PUT_16BIT(pr
->firstpkt
[0], reply
+ 6, msgsize
>> 2);/* data len */
367 memset(reply
+ 8, 0, msgsize
);
368 memcpy(reply
+ 8, message
, msglen
);
369 sshfwd_write(pr
->c
, (char *)reply
, 8 + msgsize
);
376 * Now we know we're going to accept the connection. Strip
377 * the fake auth data, and optionally put real auth data in
381 char realauthdata
[64];
383 int authstrlen
= strlen(x11_authnames
[pr
->auth
->realproto
]);
384 static const char zeroes
[4] = { 0,0,0,0 };
386 if (pr
->auth
->realproto
== X11_MIT
) {
387 assert(pr
->auth
->reallen
<= lenof(realauthdata
));
388 realauthlen
= pr
->auth
->reallen
;
389 memcpy(realauthdata
, pr
->auth
->realdata
, realauthlen
);
391 /* implement other auth methods here if required */
393 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6, authstrlen
);
394 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8, realauthlen
);
396 sk_write(s
, (char *)pr
->firstpkt
, 12);
399 sk_write(s
, x11_authnames
[pr
->auth
->realproto
], authstrlen
);
400 sk_write(s
, zeroes
, 3 & (-authstrlen
));
403 sk_write(s
, realauthdata
, realauthlen
);
404 sk_write(s
, zeroes
, 3 & (-realauthlen
));
411 * After initialisation, just copy data simply.
414 return sk_write(s
, data
, len
);