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 = new_connection(addr, dummy_realhost, 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);