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))
61 extern void sshfwd_close(void *);
62 extern void sshfwd_write(void *, char *, int);
65 struct plug_function_table
*fn
;
66 /* the above variable absolutely *must* be the first in this structure */
67 unsigned char firstpkt
[12]; /* first X data packet */
69 unsigned char *auth_data
;
70 int data_read
, auth_plen
, auth_psize
, auth_dlen
, auth_dsize
;
72 void *c
; /* data used by ssh.c */
76 void x11_close(Socket s
);
78 static unsigned char x11_authdata
[64];
79 static int x11_authdatalen
;
81 void x11_invent_auth(char *proto
, int protomaxlen
,
82 char *data
, int datamaxlen
)
87 /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
89 for (i
= 0; i
< 16; i
++)
90 x11_authdata
[i
] = random_byte();
92 /* Now format for the recipient. */
93 strncpy(proto
, "MIT-MAGIC-COOKIE-1", protomaxlen
);
95 for (i
= 0; i
< x11_authdatalen
; i
++)
96 sprintf(ourdata
+ strlen(ourdata
), "%02x", x11_authdata
[i
]);
97 strncpy(data
, ourdata
, datamaxlen
);
100 static int x11_verify(char *proto
, unsigned char *data
, int dlen
)
102 if (strcmp(proto
, "MIT-MAGIC-COOKIE-1") != 0)
103 return 0; /* wrong protocol attempted */
104 if (dlen
!= x11_authdatalen
)
105 return 0; /* cookie was wrong length */
106 if (memcmp(x11_authdata
, data
, dlen
) != 0)
107 return 0; /* cookie was wrong cookie! */
111 static int x11_closing(Plug plug
, char *error_msg
, int error_code
,
114 struct X11Private
*pr
= (struct X11Private
*) plug
;
117 * We have no way to communicate down the forwarded connection,
118 * so if an error occurred on the socket, we just ignore it
119 * and treat it like a proper close.
126 static int x11_receive(Plug plug
, int urgent
, char *data
, int len
)
128 struct X11Private
*pr
= (struct X11Private
*) plug
;
130 sshfwd_write(pr
->c
, data
, len
);
135 * Called to set up the raw connection.
137 * Returns an error message, or NULL on success.
138 * also, fills the SocketsStructure
140 char *x11_init(Socket
* s
, char *display
, void *c
)
142 static struct plug_function_table fn_table
= {
149 char *err
, *dummy_realhost
;
152 struct X11Private
*pr
;
155 * Split up display name into host and display-number parts.
157 n
= strcspn(display
, ":");
159 displaynum
= atoi(display
+ n
+ 1);
161 displaynum
= 0; /* sensible default */
162 if (n
> sizeof(host
) - 1)
163 n
= sizeof(host
) - 1;
164 strncpy(host
, display
, n
);
170 addr
= sk_namelookup(host
, &dummy_realhost
);
171 if ((err
= sk_addr_error(addr
)))
174 port
= 6000 + displaynum
;
179 pr
= (struct X11Private
*) smalloc(sizeof(struct X11Private
));
181 pr
->auth_protocol
= NULL
;
186 pr
->s
= *s
= sk_new(addr
, port
, 0, 1, (Plug
) pr
);
187 if ((err
= sk_socket_error(*s
))) {
192 sk_set_private_ptr(*s
, pr
);
197 void x11_close(Socket s
)
199 struct X11Private
*pr
;
202
pr
= (struct X11Private
*) sk_get_private_ptr(s
);
204 if (pr
->auth_protocol
) {
205 sfree(pr
->auth_protocol
);
206 sfree(pr
->auth_data
);
215 * Called to send data down the raw connection.
217 void x11_send(Socket s
, char *data
, int len
)
219 struct X11Private
*pr
= (struct X11Private
*) sk_get_private_ptr(s
);
225 * Read the first packet.
227 while (len
> 0 && pr
->data_read
< 12)
228 pr
->firstpkt
[pr
->data_read
++] = (unsigned char) (len
--, *data
++);
229 if (pr
->data_read
< 12)
233 * If we have not allocated the auth_protocol and auth_data
234 * strings, do so now.
236 if (!pr
->auth_protocol
) {
237 pr
->auth_plen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6);
238 pr
->auth_dlen
= GET_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8);
239 pr
->auth_psize
= (pr
->auth_plen
+ 3) & ~3;
240 pr
->auth_dsize
= (pr
->auth_dlen
+ 3) & ~3;
241 /* Leave room for a terminating zero, to make our lives easier. */
242 pr
->auth_protocol
= (char *) smalloc(pr
->auth_psize
+ 1);
243 pr
->auth_data
= (char *) smalloc(pr
->auth_dsize
);
247 * Read the auth_protocol and auth_data strings.
249 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
)
250 pr
->auth_protocol
[pr
->data_read
++ - 12] = (len
--, *data
++);
251 while (len
> 0 && pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
252 pr
->auth_data
[pr
->data_read
++ - 12 -
253 pr
->auth_psize
] = (unsigned char) (len
--, *data
++);
254 if (pr
->data_read
< 12 + pr
->auth_psize
+ pr
->auth_dsize
)
258 * If we haven't verified the authentication, do so now.
263 pr
->auth_protocol
[pr
->auth_plen
] = '\0'; /* ASCIZ */
264 ret
= x11_verify(pr
->auth_protocol
, pr
->auth_data
, pr
->auth_dlen
);
267 * If authentication failed, construct and send an error
268 * packet, then terminate the connection.
271 char message
[] = "Authentication failed at PuTTY X11 proxy";
272 unsigned char reply
[8 + sizeof(message
) + 4];
273 int msglen
= sizeof(message
) - 1; /* skip zero byte */
274 int msgsize
= (msglen
+ 3) & ~3;
275 reply
[0] = 0; /* failure */
276 reply
[1] = msglen
; /* length of reason string */
277 memcpy(reply
+ 2, pr
->firstpkt
+ 2, 4); /* major/minor proto vsn */
278 PUT_16BIT(pr
->firstpkt
[0], reply
+ 6, msglen
>> 2); /* data len */
279 memset(reply
+ 8, 0, msgsize
);
280 memcpy(reply
+ 8, message
, msglen
);
281 sshfwd_write(pr
->c
, reply
, 8 + msgsize
);
288 * Now we know we're going to accept the connection. Strip
289 * the auth data. (TODO: if we ever work out how, we should
290 * replace some real auth data in here.)
292 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 6, 0); /* auth proto */
293 PUT_16BIT(pr
->firstpkt
[0], pr
->firstpkt
+ 8, 0); /* auth data */
294 sk_write(s
, pr
->firstpkt
, 12);
299 * After initialisation, just copy data simply.
302 sk_write(s
, data
, len
);