15 #define GET_32BIT_LSB_FIRST(cp) \
16 (((unsigned long)(unsigned char)(cp)[0]) | \
17 ((unsigned long)(unsigned char)(cp)[1] << 8) | \
18 ((unsigned long)(unsigned char)(cp)[2] << 16) | \
19 ((unsigned long)(unsigned char)(cp)[3] << 24))
21 #define PUT_32BIT_LSB_FIRST(cp, value) ( \
23 (cp)[1] = (value) >> 8, \
24 (cp)[2] = (value) >> 16, \
25 (cp)[3] = (value) >> 24 )
27 #define GET_16BIT_LSB_FIRST(cp) \
28 (((unsigned long)(unsigned char)(cp)[0]) | \
29 ((unsigned long)(unsigned char)(cp)[1] << 8))
31 #define PUT_16BIT_LSB_FIRST(cp, value) ( \
33 (cp)[1] = (value) >> 8 )
35 #define GET_32BIT_MSB_FIRST(cp) \
36 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
37 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
38 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
39 ((unsigned long)(unsigned char)(cp)[3]))
41 #define PUT_32BIT_MSB_FIRST(cp, value) ( \
42 (cp)[0] = (value) >> 24, \
43 (cp)[1] = (value) >> 16, \
44 (cp)[2] = (value) >> 8, \
47 #define GET_16BIT_MSB_FIRST(cp) \
48 (((unsigned long)(unsigned char)(cp)[0] << 8) | \
49 ((unsigned long)(unsigned char)(cp)[1]))
51 #define PUT_16BIT_MSB_FIRST(cp, value) ( \
52 (cp)[0] = (value) >> 8, \
55 #define GET_16BIT(endian, cp) \
56 (endian=='B' ? GET_16BIT_MSB_FIRST(cp) : GET_16BIT_LSB_FIRST(cp))
58 #define PUT_16BIT(endian, cp, val) \
59 (endian=='B' ? PUT_16BIT_MSB_FIRST(cp, val) : PUT_16BIT_LSB_FIRST(cp, val))
62 struct plug_function_table
*fn
;
63 /* the above variable absolutely *must* be the first in this structure */
64 unsigned char firstpkt
[12]; /* first X data packet */
66 unsigned char *auth_data
;
67 int data_read
, auth_plen
, auth_psize
, auth_dlen
, auth_dsize
;
69 int throttled
, throttle_override
;
70 void *c
; /* data used by ssh.c */
74 void x11_close(Socket s
);
76 static unsigned char x11_authdata
[64];
77 static int x11_authdatalen
;
79 void x11_invent_auth(char *proto
, int protomaxlen
,
80 char *data
, int datamaxlen
)
85 /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
87 for (i
= 0; i
< 16; i
++)
88 x11_authdata
[i
] = random_byte();
90 /* Now format for the recipient. */
91 strncpy(proto
, "MIT-MAGIC-COOKIE-1", protomaxlen
);
93 for (i
= 0; i
< x11_authdatalen
; i
++)
94 sprintf(ourdata
+ strlen(ourdata
), "%02x", x11_authdata
[i
]);
95 strncpy(data
, ourdata
, datamaxlen
);
98 static int x11_verify(char *proto
, unsigned char *data
, int dlen
)
100 if (strcmp(proto
, "MIT-MAGIC-COOKIE-1") != 0)
101 return 0; /* wrong protocol attempted */
102 if (dlen
!= x11_authdatalen
)
103 return 0; /* cookie was wrong length */
104 if (memcmp(x11_authdata
, data
, dlen
) != 0)
105 return 0; /* cookie was wrong cookie! */
109 static int x11_closing(Plug plug
, char *error_msg
, int error_code
,
112 struct X11Private
*pr
= (struct X11Private
*) plug
;
115 * We have no way to communicate down the forwarded connection,
116 * so if an error occurred on the socket, we just ignore it
117 * and treat it like a proper close.
124 static int x11_receive(Plug plug
, int urgent
, char *data
, int len
)
126 struct X11Private
*pr
= (struct X11Private
*) plug
;
128 if (sshfwd_write(pr
->c
, data
, len
) > 0) {
130 sk_set_frozen(pr
->s
, 1);
136 static void x11_sent(Plug plug
, int bufsize
)
138 struct X11Private
*pr
= (struct X11Private
*) plug
;
140 sshfwd_unthrottle(pr
->c
, bufsize
);
144 * Called to set up the raw connection.
146 * Returns an error message, or NULL on success.
147 * also, fills the SocketsStructure
149 char *x11_init(Socket
* s
, char *display
, void *c
)
151 static struct plug_function_table fn_table
= {
160 char *err
, *dummy_realhost
;
163 struct X11Private
*pr
;
166 * Split up display name into host and display-number parts.
168 n
= strcspn(display
, ":");
170 displaynum
= atoi(display
+ n
+ 1);
172 displaynum
= 0; /* sensible default */
173 if (n
> sizeof(host
) - 1)
174 n
= sizeof(host
) - 1;
175 strncpy(host
, display
, n
);
181 addr
= sk_namelookup(host
, &dummy_realhost
);
182 if ((err
= sk_addr_error(addr
)))
185 port
= 6000 + displaynum
;
190 pr
= (struct X11Private
*) smalloc(sizeof(struct X11Private
));
192 pr
->auth_protocol
= NULL
;
195 pr
->throttled
= pr
->throttle_override
= 0;
198 pr
->s
= *s
= sk_new(addr
, port
, 0, 1, 0, (Plug
) pr
);
199 if ((err
= sk_socket_error(*s
))) {
204 sk_set_private_ptr(*s
, pr
);
209 void x11_close(Socket s
)
211 struct X11Private
*pr
;
214 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
215 if (pr
->auth_protocol
) {
216 sfree(pr
->auth_protocol
);
217 sfree(pr
->auth_data
);
225 void x11_unthrottle(Socket s
)
227 struct X11Private
*pr
;
230 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
233 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
236 void x11_override_throttle(Socket s
, int enable
)
238 struct X11Private
*pr
;
241 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
243 pr
->throttle_override
= enable
;
244 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
248 * Called to send data down the raw connection.
250 int x11_send(Socket s
, char *data
, int len
)
252 struct X11Private
*pr
= (struct X11Private
*) sk_get_private_ptr(s
);
258 * Read the first packet.
260 while (len
> 0 && pr
->data_read
< 12)
261 pr
->firstpkt
[pr
->data_read
++] = (unsigned char) (len
--, *data
++);
262 if (pr
->data_read
< 12)
266 * If we have not allocated the auth_protocol and auth_data
267 * strings, do so now.
269 if (!pr
->auth_protocol
) {
270 pr
->auth_plen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6);
271 pr
->auth_dlen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8);
272 pr
->auth_psize
= (pr
->auth_plen
+ 3) & ~3;
273 pr
->auth_dsize
= (pr
->auth_dlen
+ 3) & ~3;
274 /* Leave room for a terminating zero, to make our lives easier. */
275 pr
->auth_protocol
= (char *) smalloc(pr
->auth_psize
+ 1);
276 pr
->auth_data
= (char *) smalloc(pr
->auth_dsize
);
280 * Read the auth_protocol and auth_data strings.
282 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
)
283 pr
->auth_protocol
[pr
->data_read
++ - 12] = (len
--, *data
++);
284 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
285 pr
->auth_data
[pr
->data_read
++ - 12 -
286 pr
->auth_psize
] = (unsigned char) (len
--, *data
++);
287 if (pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
291 * If we haven't verified the authentication, do so now.
296 pr
->auth_protocol
[pr
->auth_plen
] = '\0'; /* ASCIZ */
297 ret
= x11_verify(pr
->auth_protocol
, pr
->auth_data
, pr
->auth_dlen
);
300 * If authentication failed, construct and send an error
301 * packet, then terminate the connection.
304 char message
[] = "Authentication failed at PuTTY X11 proxy";
305 unsigned char reply
[8 + sizeof(message
) + 4];
306 int msglen
= sizeof(message
) - 1; /* skip zero byte */
307 int msgsize
= (msglen
+ 3) & ~3;
308 reply
[0] = 0; /* failure */
309 reply
[1] = msglen
; /* length of reason string */
310 memcpy(reply
+ 2, pr
->firstpkt
+ 2, 4); /* major/minor proto vsn */
311 PUT_16BIT(pr
->firstpkt
[0], reply
+ 6, msgsize
>> 2);/* data len */
312 memset(reply
+ 8, 0, msgsize
);
313 memcpy(reply
+ 8, message
, msglen
);
314 sshfwd_write(pr
->c
, reply
, 8 + msgsize
);
321 * Now we know we're going to accept the connection. Strip
322 * the auth data. (TODO: if we ever work out how, we should
323 * replace some real auth data in here.)
325 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6, 0); /* auth proto */
326 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8, 0); /* auth data */
327 sk_write(s
, pr
->firstpkt
, 12);
332 * After initialisation, just copy data simply.
335 return sk_write(s
, data
, len
);