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))
55 struct plug_function_table
*fn
;
56 /* the above variable absolutely *must* be the first in this structure */
57 unsigned char firstpkt
[12]; /* first X data packet */
59 unsigned char *auth_data
;
60 int data_read
, auth_plen
, auth_psize
, auth_dlen
, auth_dsize
;
62 int throttled
, throttle_override
;
63 void *c
; /* data used by ssh.c */
67 void x11_close(Socket s
);
69 static unsigned char x11_authdata
[64];
70 static int x11_authdatalen
;
72 void x11_invent_auth(char *proto
, int protomaxlen
,
73 char *data
, int datamaxlen
)
78 /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
80 for (i
= 0; i
< 16; i
++)
81 x11_authdata
[i
] = random_byte();
83 /* Now format for the recipient. */
84 strncpy(proto
, "MIT-MAGIC-COOKIE-1", protomaxlen
);
86 for (i
= 0; i
< x11_authdatalen
; i
++)
87 sprintf(ourdata
+ strlen(ourdata
), "%02x", x11_authdata
[i
]);
88 strncpy(data
, ourdata
, datamaxlen
);
91 static int x11_verify(char *proto
, unsigned char *data
, int dlen
)
93 if (strcmp(proto
, "MIT-MAGIC-COOKIE-1") != 0)
94 return 0; /* wrong protocol attempted */
95 if (dlen
!= x11_authdatalen
)
96 return 0; /* cookie was wrong length */
97 if (memcmp(x11_authdata
, data
, dlen
) != 0)
98 return 0; /* cookie was wrong cookie! */
102 static int x11_closing(Plug plug
, char *error_msg
, int error_code
,
105 struct X11Private
*pr
= (struct X11Private
*) plug
;
108 * We have no way to communicate down the forwarded connection,
109 * so if an error occurred on the socket, we just ignore it
110 * and treat it like a proper close.
117 static int x11_receive(Plug plug
, int urgent
, char *data
, int len
)
119 struct X11Private
*pr
= (struct X11Private
*) plug
;
121 if (sshfwd_write(pr
->c
, data
, len
) > 0) {
123 sk_set_frozen(pr
->s
, 1);
129 static void x11_sent(Plug plug
, int bufsize
)
131 struct X11Private
*pr
= (struct X11Private
*) plug
;
133 sshfwd_unthrottle(pr
->c
, bufsize
);
137 * Called to set up the raw connection.
139 * Returns an error message, or NULL on success.
140 * also, fills the SocketsStructure
142 char *x11_init(Socket
* s
, char *display
, void *c
)
144 static struct plug_function_table fn_table
= {
153 char *err
, *dummy_realhost
;
156 struct X11Private
*pr
;
159 * Split up display name into host and display-number parts.
161 n
= strcspn(display
, ":");
163 displaynum
= atoi(display
+ n
+ 1);
165 displaynum
= 0; /* sensible default */
166 if (n
> sizeof(host
) - 1)
167 n
= sizeof(host
) - 1;
168 strncpy(host
, display
, n
);
174 addr
= sk_namelookup(host
, &dummy_realhost
);
175 if ((err
= sk_addr_error(addr
)))
178 port
= 6000 + displaynum
;
183 pr
= (struct X11Private
*) smalloc(sizeof(struct X11Private
));
185 pr
->auth_protocol
= NULL
;
188 pr
->throttled
= pr
->throttle_override
= 0;
191 pr
->s
= *s
= sk_new(addr
, port
, 0, 1, 0, (Plug
) pr
);
192 if ((err
= sk_socket_error(*s
))) {
197 sk_set_private_ptr(*s
, pr
);
202 void x11_close(Socket s
)
204 struct X11Private
*pr
;
207 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
208 if (pr
->auth_protocol
) {
209 sfree(pr
->auth_protocol
);
210 sfree(pr
->auth_data
);
218 void x11_unthrottle(Socket s
)
220 struct X11Private
*pr
;
223 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
226 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
229 void x11_override_throttle(Socket s
, int enable
)
231 struct X11Private
*pr
;
234 pr
= (struct X11Private
*) sk_get_private_ptr(s
);
236 pr
->throttle_override
= enable
;
237 sk_set_frozen(s
, pr
->throttled
|| pr
->throttle_override
);
241 * Called to send data down the raw connection.
243 int x11_send(Socket s
, char *data
, int len
)
245 struct X11Private
*pr
= (struct X11Private
*) sk_get_private_ptr(s
);
251 * Read the first packet.
253 while (len
> 0 && pr
->data_read
< 12)
254 pr
->firstpkt
[pr
->data_read
++] = (unsigned char) (len
--, *data
++);
255 if (pr
->data_read
< 12)
259 * If we have not allocated the auth_protocol and auth_data
260 * strings, do so now.
262 if (!pr
->auth_protocol
) {
263 pr
->auth_plen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6);
264 pr
->auth_dlen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8);
265 pr
->auth_psize
= (pr
->auth_plen
+ 3) & ~3;
266 pr
->auth_dsize
= (pr
->auth_dlen
+ 3) & ~3;
267 /* Leave room for a terminating zero, to make our lives easier. */
268 pr
->auth_protocol
= (char *) smalloc(pr
->auth_psize
+ 1);
269 pr
->auth_data
= (char *) smalloc(pr
->auth_dsize
);
273 * Read the auth_protocol and auth_data strings.
275 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
)
276 pr
->auth_protocol
[pr
->data_read
++ - 12] = (len
--, *data
++);
277 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
278 pr
->auth_data
[pr
->data_read
++ - 12 -
279 pr
->auth_psize
] = (unsigned char) (len
--, *data
++);
280 if (pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
284 * If we haven't verified the authentication, do so now.
289 pr
->auth_protocol
[pr
->auth_plen
] = '\0'; /* ASCIZ */
290 ret
= x11_verify(pr
->auth_protocol
, pr
->auth_data
, pr
->auth_dlen
);
293 * If authentication failed, construct and send an error
294 * packet, then terminate the connection.
297 char message
[] = "Authentication failed at PuTTY X11 proxy";
298 unsigned char reply
[8 + sizeof(message
) + 4];
299 int msglen
= sizeof(message
) - 1; /* skip zero byte */
300 int msgsize
= (msglen
+ 3) & ~3;
301 reply
[0] = 0; /* failure */
302 reply
[1] = msglen
; /* length of reason string */
303 memcpy(reply
+ 2, pr
->firstpkt
+ 2, 4); /* major/minor proto vsn */
304 PUT_16BIT(pr
->firstpkt
[0], reply
+ 6, msgsize
>> 2);/* data len */
305 memset(reply
+ 8, 0, msgsize
);
306 memcpy(reply
+ 8, message
, msglen
);
307 sshfwd_write(pr
->c
, reply
, 8 + msgsize
);
314 * Now we know we're going to accept the connection. Strip
315 * the auth data. (TODO: if we ever work out how, we should
316 * replace some real auth data in here.)
318 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6, 0); /* auth proto */
319 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8, 0); /* auth data */
320 sk_write(s
, pr
->firstpkt
, 12);
325 * After initialisation, just copy data simply.
328 return sk_write(s
, data
, len
);