9 #define GET_32BIT_LSB_FIRST(cp) \
10 (((unsigned long)(unsigned char)(cp)[0]) | \
11 ((unsigned long)(unsigned char)(cp)[1] << 8) | \
12 ((unsigned long)(unsigned char)(cp)[2] << 16) | \
13 ((unsigned long)(unsigned char)(cp)[3] << 24))
15 #define PUT_32BIT_LSB_FIRST(cp, value) ( \
17 (cp)[1] = (value) >> 8, \
18 (cp)[2] = (value) >> 16, \
19 (cp)[3] = (value) >> 24 )
21 #define GET_16BIT_LSB_FIRST(cp) \
22 (((unsigned long)(unsigned char)(cp)[0]) | \
23 ((unsigned long)(unsigned char)(cp)[1] << 8))
25 #define PUT_16BIT_LSB_FIRST(cp, value) ( \
27 (cp)[1] = (value) >> 8 )
29 #define GET_32BIT_MSB_FIRST(cp) \
30 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
31 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
32 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
33 ((unsigned long)(unsigned char)(cp)[3]))
35 #define PUT_32BIT_MSB_FIRST(cp, value) ( \
36 (cp)[0] = (value) >> 24, \
37 (cp)[1] = (value) >> 16, \
38 (cp)[2] = (value) >> 8, \
41 #define GET_16BIT_MSB_FIRST(cp) \
42 (((unsigned long)(unsigned char)(cp)[0] << 8) | \
43 ((unsigned long)(unsigned char)(cp)[1]))
45 #define PUT_16BIT_MSB_FIRST(cp, value) ( \
46 (cp)[0] = (value) >> 8, \
49 #define GET_16BIT(endian, cp) \
50 (endian=='B' ? GET_16BIT_MSB_FIRST(cp) : GET_16BIT_LSB_FIRST(cp))
52 #define PUT_16BIT(endian, cp, val) \
53 (endian=='B' ? PUT_16BIT_MSB_FIRST(cp, val) : PUT_16BIT_LSB_FIRST(cp, val))
55 const char *const x11_authnames
[] = {
56 "", "MIT-MAGIC-COOKIE-1", "XDM-AUTHORIZATION-1"
60 unsigned char fakedata
[64], realdata
[64];
61 int fakeproto
, realproto
;
66 const struct plug_function_table
*fn
;
67 /* the above variable absolutely *must* be the first in this structure */
68 unsigned char firstpkt
[12]; /* first X data packet */
71 unsigned char *auth_data
;
72 int data_read
, auth_plen
, auth_psize
, auth_dlen
, auth_dsize
;
74 int throttled
, throttle_override
;
75 void *c
; /* data used by ssh.c */
79 void *x11_invent_auth(char *proto
, int protomaxlen
,
80 char *data
, int datamaxlen
)
82 struct X11Auth
*auth
= smalloc(sizeof(struct X11Auth
));
86 auth
->fakeproto
= X11_MIT
;
88 /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
90 for (i
= 0; i
< 16; i
++)
91 auth
->fakedata
[i
] = random_byte();
93 /* Now format for the recipient. */
94 strncpy(proto
, x11_authnames
[auth
->fakeproto
], protomaxlen
);
96 for (i
= 0; i
< auth
->fakelen
; i
++)
97 sprintf(ourdata
+ strlen(ourdata
), "%02x", auth
->fakedata
[i
]);
98 strncpy(data
, ourdata
, datamaxlen
);
104 * Fetch the real auth data for a given display string, and store
105 * it in an X11Auth structure. Returns NULL on success, or an error
108 void x11_get_real_auth(void *authv
, char *display
)
110 struct X11Auth
*auth
= (struct X11Auth
*)authv
;
112 auth
->realproto
= X11_NO_AUTH
; /* in case next call does nothing */
114 auth
->reallen
= sizeof(auth
->realdata
);
115 platform_get_x11_auth(display
, &auth
->realproto
,
116 auth
->realdata
, &auth
->reallen
);
119 static int x11_verify(struct X11Auth
*auth
,
120 char *proto
, unsigned char *data
, int dlen
)
122 if (strcmp(proto
, x11_authnames
[auth
->fakeproto
]) != 0)
123 return 0; /* wrong protocol attempted */
124 if (auth
->fakeproto
== X11_MIT
) {
125 if (dlen
!= auth
->fakelen
)
126 return 0; /* cookie was wrong length */
127 if (memcmp(auth
->fakedata
, data
, dlen
) != 0)
128 return 0; /* cookie was wrong cookie! */
130 /* implement other protocols here if ever required */
134 static int x11_closing(Plug plug
, char *error_msg
, int error_code
,
137 struct X11Private
*pr
= (struct X11Private
*) plug
;
140 * We have no way to communicate down the forwarded connection,
141 * so if an error occurred on the socket, we just ignore it
142 * and treat it like a proper close.
149 static int x11_receive(Plug plug
, int urgent
, char *data
, int len
)
151 struct X11Private
*pr
= (struct X11Private
*) plug
;
153 if (sshfwd_write(pr
->c
, data
, len
) > 0) {
155 sk_set_frozen(pr
->s
, 1);
161 static void x11_sent(Plug plug
, int bufsize
)
163 struct X11Private
*pr
= (struct X11Private
*) plug
;
165 sshfwd_unthrottle(pr
->c
, bufsize
);
169 * When setting up X forwarding, we should send the screen number
170 * from the specified local display. This function extracts it from
171 * the display string.
173 int x11_get_screen_number(char *display
)
177 n
= strcspn(display
, ":");
180 n
= strcspn(display
, ".");
183 return atoi(display
+ n
+ 1);
187 * Called to set up the raw connection.
189 * Returns an error message, or NULL on success.
190 * also, fills the SocketsStructure
192 char *x11_init(Socket
* s
, char *display
, void *c
, void *auth
)
194 static const struct plug_function_table fn_table
= {
203 char *err
, *dummy_realhost
;
206 struct X11Private
*pr
;
209 * Split up display name into host and display-number parts.
211 n
= strcspn(display
, ":");
213 displaynum
= atoi(display
+ n
+ 1);
215 displaynum
= 0; /* sensible default */
216 if (n
> sizeof(host
) - 1)
217 n
= sizeof(host
) - 1;
219 strncpy(host
, display
, n
);
223 * Local display numbers, particularly on Unix, often omit
224 * the display part completely.
226 strcpy(host
, "localhost");
229 port
= 6000 + displaynum
;
234 addr
= name_lookup(host
, port
, &dummy_realhost
);
235 if ((err
= sk_addr_error(addr
)) != NULL
)
241 pr
= (struct X11Private
*) smalloc(sizeof(struct X11Private
));
243 pr
->auth_protocol
= NULL
;
244 pr
->auth
= (struct X11Auth
*)auth
;
247 pr
->throttled
= pr
->throttle_override
= 0;
250 pr
->s
= *s
= new_connection(addr
, dummy_realhost
, port
, 0, 1, 0, (Plug
) pr
);
251 if ((err
= sk_socket_error(*s
)) != NULL
) {
256 sk_set_private_ptr(*s
, pr
);
261 void x11_close(Socket s
)
263 struct X11Private
*pr
;
266 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
267 if (pr
->auth_protocol
) {
268 sfree(pr
->auth_protocol
);
269 sfree(pr
->auth_data
);
277 void x11_unthrottle(Socket s
)
279 struct X11Private
*pr
;
282 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
285 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
288 void x11_override_throttle(Socket s
, int enable
)
290 struct X11Private
*pr
;
293 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
295 pr
->throttle_override
= enable
;
296 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
300 * Called to send data down the raw connection.
302 int x11_send(Socket s
, char *data
, int len
)
304 struct X11Private
*pr
= (struct X11Private
*) sk_get_private_ptr(s
);
310 * Read the first packet.
312 while (len
> 0 && pr
->data_read
< 12)
313 pr
->firstpkt
[pr
->data_read
++] = (unsigned char) (len
--, *data
++);
314 if (pr
->data_read
< 12)
318 * If we have not allocated the auth_protocol and auth_data
319 * strings, do so now.
321 if (!pr
->auth_protocol
) {
322 pr
->auth_plen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6);
323 pr
->auth_dlen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8);
324 pr
->auth_psize
= (pr
->auth_plen
+ 3) & ~3;
325 pr
->auth_dsize
= (pr
->auth_dlen
+ 3) & ~3;
326 /* Leave room for a terminating zero, to make our lives easier. */
327 pr
->auth_protocol
= (char *) smalloc(pr
->auth_psize
+ 1);
328 pr
->auth_data
= (unsigned char *) smalloc(pr
->auth_dsize
);
332 * Read the auth_protocol and auth_data strings.
334 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
)
335 pr
->auth_protocol
[pr
->data_read
++ - 12] = (len
--, *data
++);
336 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
337 pr
->auth_data
[pr
->data_read
++ - 12 -
338 pr
->auth_psize
] = (unsigned char) (len
--, *data
++);
339 if (pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
343 * If we haven't verified the authentication, do so now.
348 pr
->auth_protocol
[pr
->auth_plen
] = '\0'; /* ASCIZ */
349 ret
= x11_verify(pr
->auth
, pr
->auth_protocol
,
350 pr
->auth_data
, pr
->auth_dlen
);
353 * If authentication failed, construct and send an error
354 * packet, then terminate the connection.
357 char message
[] = "Authentication failed at PuTTY X11 proxy";
358 unsigned char reply
[8 + sizeof(message
) + 4];
359 int msglen
= sizeof(message
) - 1; /* skip zero byte */
360 int msgsize
= (msglen
+ 3) & ~3;
361 reply
[0] = 0; /* failure */
362 reply
[1] = msglen
; /* length of reason string */
363 memcpy(reply
+ 2, pr
->firstpkt
+ 2, 4); /* major/minor proto vsn */
364 PUT_16BIT(pr
->firstpkt
[0], reply
+ 6, msgsize
>> 2);/* data len */
365 memset(reply
+ 8, 0, msgsize
);
366 memcpy(reply
+ 8, message
, msglen
);
367 sshfwd_write(pr
->c
, (char *)reply
, 8 + msgsize
);
374 * Now we know we're going to accept the connection. Strip
375 * the fake auth data, and optionally put real auth data in
379 char realauthdata
[64];
381 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
);
390 } else if (pr
->auth
->realproto
== X11_XDM
&&
391 pr
->auth
->reallen
== 16 &&
392 sk_getxdmdata(s
, &ip
, &port
)) {
395 memset(realauthdata
, 0, 24);
396 memcpy(realauthdata
, pr
->auth
->realdata
, 8);
397 PUT_32BIT_MSB_FIRST(realauthdata
+8, ip
);
398 PUT_16BIT_MSB_FIRST(realauthdata
+12, port
);
400 PUT_32BIT_MSB_FIRST(realauthdata
+14, t
);
401 des_encrypt_xdmauth(pr
->auth
->realdata
+9,
402 (unsigned char *)realauthdata
, 24);
404 /* implement other auth methods here if required */
406 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6, authstrlen
);
407 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8, realauthlen
);
409 sk_write(s
, (char *)pr
->firstpkt
, 12);
412 sk_write(s
, x11_authnames
[pr
->auth
->realproto
], authstrlen
);
413 sk_write(s
, zeroes
, 3 & (-authstrlen
));
416 sk_write(s
, realauthdata
, realauthlen
);
417 sk_write(s
, zeroes
, 3 & (-realauthlen
));
424 * After initialisation, just copy data simply.
427 return sk_write(s
, data
, len
);