7 #define GET_32BIT_LSB_FIRST(cp) \
8 (((unsigned long)(unsigned char)(cp)[0]) | \
9 ((unsigned long)(unsigned char)(cp)[1] << 8) | \
10 ((unsigned long)(unsigned char)(cp)[2] << 16) | \
11 ((unsigned long)(unsigned char)(cp)[3] << 24))
13 #define PUT_32BIT_LSB_FIRST(cp, value) ( \
15 (cp)[1] = (value) >> 8, \
16 (cp)[2] = (value) >> 16, \
17 (cp)[3] = (value) >> 24 )
19 #define GET_16BIT_LSB_FIRST(cp) \
20 (((unsigned long)(unsigned char)(cp)[0]) | \
21 ((unsigned long)(unsigned char)(cp)[1] << 8))
23 #define PUT_16BIT_LSB_FIRST(cp, value) ( \
25 (cp)[1] = (value) >> 8 )
27 #define GET_32BIT_MSB_FIRST(cp) \
28 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
29 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
30 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
31 ((unsigned long)(unsigned char)(cp)[3]))
33 #define PUT_32BIT_MSB_FIRST(cp, value) ( \
34 (cp)[0] = (value) >> 24, \
35 (cp)[1] = (value) >> 16, \
36 (cp)[2] = (value) >> 8, \
39 #define GET_16BIT_MSB_FIRST(cp) \
40 (((unsigned long)(unsigned char)(cp)[0] << 8) | \
41 ((unsigned long)(unsigned char)(cp)[1]))
43 #define PUT_16BIT_MSB_FIRST(cp, value) ( \
44 (cp)[0] = (value) >> 8, \
47 #define GET_16BIT(endian, cp) \
48 (endian=='B' ? GET_16BIT_MSB_FIRST(cp) : GET_16BIT_LSB_FIRST(cp))
50 #define PUT_16BIT(endian, cp, val) \
51 (endian=='B' ? PUT_16BIT_MSB_FIRST(cp, val) : PUT_16BIT_LSB_FIRST(cp, val))
54 unsigned char data[64];
59 const struct plug_function_table *fn;
60 /* the above variable absolutely *must* be the first in this structure */
61 unsigned char firstpkt[12]; /* first X data packet */
64 unsigned char *auth_data;
65 int data_read, auth_plen, auth_psize, auth_dlen, auth_dsize;
67 int throttled, throttle_override;
68 void *c; /* data used by ssh.c */
72 void *x11_invent_auth(char *proto, int protomaxlen,
73 char *data, int datamaxlen)
75 struct X11Auth *auth = smalloc(sizeof(struct X11Auth));
79 /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
81 for (i = 0; i < 16; i++)
82 auth->data[i] = random_byte();
84 /* Now format for the recipient. */
85 strncpy(proto, "MIT-MAGIC-COOKIE-1", protomaxlen);
87 for (i = 0; i < auth->len; i++)
88 sprintf(ourdata + strlen(ourdata), "%02x", auth->data[i]);
89 strncpy(data, ourdata, datamaxlen);
94 static int x11_verify(struct X11Auth *auth,
95 char *proto, unsigned char *data, int dlen)
97 if (strcmp(proto, "MIT-MAGIC-COOKIE-1") != 0)
98 return 0; /* wrong protocol attempted */
99 if (dlen != auth->len)
100 return 0; /* cookie was wrong length */
101 if (memcmp(auth->data, data, dlen) != 0)
102 return 0; /* cookie was wrong cookie! */
106 static int x11_closing(Plug plug, char *error_msg, int error_code,
109 struct X11Private *pr = (struct X11Private *) plug;
112 * We have no way to communicate down the forwarded connection,
113 * so if an error occurred on the socket, we just ignore it
114 * and treat it like a proper close.
121 static int x11_receive(Plug plug, int urgent, char *data, int len)
123 struct X11Private *pr = (struct X11Private *) plug;
125 if (sshfwd_write(pr->c, data, len) > 0) {
127 sk_set_frozen(pr->s, 1);
133 static void x11_sent(Plug plug, int bufsize)
135 struct X11Private *pr = (struct X11Private *) plug;
137 sshfwd_unthrottle(pr->c, bufsize);
141 * When setting up X forwarding, we should send the screen number
142 * from the specified local display. This function extracts it from
143 * the display string.
145 int x11_get_screen_number(char *display)
149 n = strcspn(display, ":");
152 n = strcspn(display, ".");
155 return atoi(display + n + 1);
159 * Called to set up the raw connection.
161 * Returns an error message, or NULL on success.
162 * also, fills the SocketsStructure
164 char *x11_init(Socket * s, char *display, void *c, void *auth)
166 static const struct plug_function_table fn_table = {
175 char *err, *dummy_realhost;
178 struct X11Private *pr;
181 * Split up display name into host and display-number parts.
183 n = strcspn(display, ":");
185 displaynum = atoi(display + n + 1);
187 displaynum = 0; /* sensible default */
188 if (n > sizeof(host) - 1)
189 n = sizeof(host) - 1;
191 strncpy(host, display, n);
195 * Local display numbers, particularly on Unix, often omit
196 * the display part completely.
198 strcpy(host, "localhost");
201 port = 6000 + displaynum;
206 addr = name_lookup(host, port, &dummy_realhost);
207 if ((err = sk_addr_error(addr)) != NULL)
213 pr = (struct X11Private *) smalloc(sizeof(struct X11Private));
215 pr->auth_protocol = NULL;
216 pr->auth = (struct X11Auth *)auth;
219 pr->throttled = pr->throttle_override = 0;
222 pr->s = *s = new_connection(addr, dummy_realhost, port, 0, 1, 0, (Plug) pr);
223 if ((err = sk_socket_error(*s)) != NULL) {
228 sk_set_private_ptr(*s, pr);
233 void x11_close(Socket s)
235 struct X11Private *pr;
238 pr = (struct X11Private *) sk_get_private_ptr(s);
239 if (pr->auth_protocol) {
240 sfree(pr->auth_protocol);
241 sfree(pr->auth_data);
249 void x11_unthrottle(Socket s)
251 struct X11Private *pr;
254 pr = (struct X11Private *) sk_get_private_ptr(s);
257 sk_set_frozen(s, pr->throttled || pr->throttle_override);
260 void x11_override_throttle(Socket s, int enable)
262 struct X11Private *pr;
265 pr = (struct X11Private *) sk_get_private_ptr(s);
267 pr->throttle_override = enable;
268 sk_set_frozen(s, pr->throttled || pr->throttle_override);
272 * Called to send data down the raw connection.
274 int x11_send(Socket s, char *data, int len)
276 struct X11Private *pr = (struct X11Private *) sk_get_private_ptr(s);
282 * Read the first packet.
284 while (len > 0 && pr->data_read < 12)
285 pr->firstpkt[pr->data_read++] = (unsigned char) (len--, *data++);
286 if (pr->data_read < 12)
290 * If we have not allocated the auth_protocol and auth_data
291 * strings, do so now.
293 if (!pr->auth_protocol) {
294 pr->auth_plen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 6);
295 pr->auth_dlen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 8);
296 pr->auth_psize = (pr->auth_plen + 3) & ~3;
297 pr->auth_dsize = (pr->auth_dlen + 3) & ~3;
298 /* Leave room for a terminating zero, to make our lives easier. */
299 pr->auth_protocol = (char *) smalloc(pr->auth_psize + 1);
300 pr->auth_data = (unsigned char *) smalloc(pr->auth_dsize);
304 * Read the auth_protocol and auth_data strings.
306 while (len > 0 && pr->data_read < 12 + pr->auth_psize)
307 pr->auth_protocol[pr->data_read++ - 12] = (len--, *data++);
308 while (len > 0 && pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
309 pr->auth_data[pr->data_read++ - 12 -
310 pr->auth_psize] = (unsigned char) (len--, *data++);
311 if (pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
315 * If we haven't verified the authentication, do so now.
320 pr->auth_protocol[pr->auth_plen] = '\0'; /* ASCIZ */
321 ret = x11_verify(pr->auth, pr->auth_protocol,
322 pr->auth_data, pr->auth_dlen);
325 * If authentication failed, construct and send an error
326 * packet, then terminate the connection.
329 char message[] = "Authentication failed at PuTTY X11 proxy";
330 unsigned char reply[8 + sizeof(message) + 4];
331 int msglen = sizeof(message) - 1; /* skip zero byte */
332 int msgsize = (msglen + 3) & ~3;
333 reply[0] = 0; /* failure */
334 reply[1] = msglen; /* length of reason string */
335 memcpy(reply + 2, pr->firstpkt + 2, 4); /* major/minor proto vsn */
336 PUT_16BIT(pr->firstpkt[0], reply + 6, msgsize >> 2);/* data len */
337 memset(reply + 8, 0, msgsize);
338 memcpy(reply + 8, message, msglen);
339 sshfwd_write(pr->c, (char *)reply, 8 + msgsize);
346 * Now we know we're going to accept the connection. Strip
347 * the auth data. (TODO: if we ever work out how, we should
348 * replace some real auth data in here.)
350 PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 6, 0); /* auth proto */
351 PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 8, 0); /* auth data */
352 sk_write(s, (char *)pr->firstpkt, 12);
357 * After initialisation, just copy data simply.
360 return sk_write(s, data, len);