2 * ux_x11.c: fetch local auth data for X forwarding.
9 void platform_get_x11_auth(char *display, int *protocol,
10 unsigned char *data, int *datalen)
14 int maxsize = *datalen;
19 * Normally we should run `xauth list DISPLAYNAME'. However,
20 * there's an oddity when the display is local: the display
21 * `localhost:0' (or `:0') should become just `:0'.
23 if (!strncmp(display, "localhost:", 10))
24 command = dupprintf("xauth list %s 2>/dev/null", display+9);
26 command = dupprintf("xauth list %s 2>/dev/null", display);
27 fp = popen(command, "r");
31 return; /* assume no auth */
33 localbuf = snewn(maxsize, char);
37 * Read a line from stdin, and attempt to parse it into a
38 * display name (ignored), auth protocol, and auth string.
43 /* Skip the display name. */
44 while (c = getc(fp), c != EOF && c != '\n' && !isspace(c));
46 if (c == '\n') continue;
48 /* Skip white space. */
49 while (c != EOF && c != '\n' && isspace(c))
52 if (c == '\n') continue;
54 /* Read the auth protocol name, and see if it matches any we
57 while (c != EOF && c != '\n' && !isspace(c)) {
58 if (i < lenof(protoname)-1) protoname[i++] = c;
63 for (i = X11_NO_AUTH; ++i < X11_NAUTHS ;) {
64 if (!strcmp(protoname, x11_authnames[i]))
67 if (i >= X11_NAUTHS || i <= proto) {
68 /* Unrecognised protocol name, or a worse one than we already have.
70 while (c != EOF && c != '\n')
76 /* Skip white space. */
77 while (c != EOF && c != '\n' && isspace(c))
80 if (c == '\n') continue;
83 * Now grab pairs of hex digits and shove them into `data'.
87 while (c != EOF && c != '\n') {
89 if (c >= 'A' && c <= 'F')
90 hexval = c + 10 - 'A';
91 if (c >= 'a' && c <= 'f')
92 hexval = c + 10 - 'a';
93 if (c >= '0' && c <= '9')
97 hexdigit = (hexdigit << 4) + hexval;
99 localbuf[i++] = hexdigit;
109 memcpy(data, localbuf, i);
111 /* Nonetheless, continue looping round; we might find a better one. */