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 unsigned char data[64];
60 const struct plug_function_table *fn;
61 /* the above variable absolutely *must* be the first in this structure */
62 unsigned char firstpkt[12]; /* first X data packet */
65 unsigned char *auth_data;
66 int data_read, auth_plen, auth_psize, auth_dlen, auth_dsize;
68 int throttled, throttle_override;
69 void *c; /* data used by ssh.c */
73 void x11_close(Socket s);
75 void *x11_invent_auth(char *proto, int protomaxlen,
76 char *data, int datamaxlen)
78 struct X11Auth *auth = smalloc(sizeof(struct X11Auth));
82 /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
84 for (i = 0; i < 16; i++)
85 auth->data[i] = random_byte();
87 /* Now format for the recipient. */
88 strncpy(proto, "MIT-MAGIC-COOKIE-1", protomaxlen);
90 for (i = 0; i < auth->len; i++)
91 sprintf(ourdata + strlen(ourdata), "%02x", auth->data[i]);
92 strncpy(data, ourdata, datamaxlen);
97 static int x11_verify(struct X11Auth *auth,
98 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 != auth->len)
103 return 0; /* cookie was wrong length */
104 if (memcmp(auth->data, 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, void *auth)
151 static const 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;
193 pr->auth = (struct X11Auth *)auth;
196 pr->throttled = pr->throttle_override = 0;
199 pr->s = *s = new_connection(addr, dummy_realhost, port, 0, 1, 0, (Plug) pr);
200 if ((err = sk_socket_error(*s))) {
205 sk_set_private_ptr(*s, pr);
210 void x11_close(Socket s)
212 struct X11Private *pr;
215 pr = (struct X11Private *) sk_get_private_ptr(s);
216 if (pr->auth_protocol) {
217 sfree(pr->auth_protocol);
218 sfree(pr->auth_data);
226 void x11_unthrottle(Socket s)
228 struct X11Private *pr;
231 pr = (struct X11Private *) sk_get_private_ptr(s);
234 sk_set_frozen(s, pr->throttled || pr->throttle_override);
237 void x11_override_throttle(Socket s, int enable)
239 struct X11Private *pr;
242 pr = (struct X11Private *) sk_get_private_ptr(s);
244 pr->throttle_override = enable;
245 sk_set_frozen(s, pr->throttled || pr->throttle_override);
249 * Called to send data down the raw connection.
251 int x11_send(Socket s, char *data, int len)
253 struct X11Private *pr = (struct X11Private *) sk_get_private_ptr(s);
259 * Read the first packet.
261 while (len > 0 && pr->data_read < 12)
262 pr->firstpkt[pr->data_read++] = (unsigned char) (len--, *data++);
263 if (pr->data_read < 12)
267 * If we have not allocated the auth_protocol and auth_data
268 * strings, do so now.
270 if (!pr->auth_protocol) {
271 pr->auth_plen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 6);
272 pr->auth_dlen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 8);
273 pr->auth_psize = (pr->auth_plen + 3) & ~3;
274 pr->auth_dsize = (pr->auth_dlen + 3) & ~3;
275 /* Leave room for a terminating zero, to make our lives easier. */
276 pr->auth_protocol = (char *) smalloc(pr->auth_psize + 1);
277 pr->auth_data = (char *) smalloc(pr->auth_dsize);
281 * Read the auth_protocol and auth_data strings.
283 while (len > 0 && pr->data_read < 12 + pr->auth_psize)
284 pr->auth_protocol[pr->data_read++ - 12] = (len--, *data++);
285 while (len > 0 && pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
286 pr->auth_data[pr->data_read++ - 12 -
287 pr->auth_psize] = (unsigned char) (len--, *data++);
288 if (pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
292 * If we haven't verified the authentication, do so now.
297 pr->auth_protocol[pr->auth_plen] = '\0'; /* ASCIZ */
298 ret = x11_verify(pr->auth, pr->auth_protocol,
299 pr->auth_data, pr->auth_dlen);
302 * If authentication failed, construct and send an error
303 * packet, then terminate the connection.
306 char message[] = "Authentication failed at PuTTY X11 proxy";
307 unsigned char reply[8 + sizeof(message) + 4];
308 int msglen = sizeof(message) - 1; /* skip zero byte */
309 int msgsize = (msglen + 3) & ~3;
310 reply[0] = 0; /* failure */
311 reply[1] = msglen; /* length of reason string */
312 memcpy(reply + 2, pr->firstpkt + 2, 4); /* major/minor proto vsn */
313 PUT_16BIT(pr->firstpkt[0], reply + 6, msgsize >> 2);/* data len */
314 memset(reply + 8, 0, msgsize);
315 memcpy(reply + 8, message, msglen);
316 sshfwd_write(pr->c, reply, 8 + msgsize);
323 * Now we know we're going to accept the connection. Strip
324 * the auth data. (TODO: if we ever work out how, we should
325 * replace some real auth data in here.)
327 PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 6, 0); /* auth proto */
328 PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 8, 0); /* auth data */
329 sk_write(s, pr->firstpkt, 12);
334 * After initialisation, just copy data simply.
337 return sk_write(s, data, len);