1 /* Copyright (C) 2001-2004 Bart Massey and Jamey Sharp.
3 * Permission is hereby granted, free of charge, to any person obtaining a
4 * copy of this software and associated documentation files (the "Software"),
5 * to deal in the Software without restriction, including without limitation
6 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
7 * and/or sell copies of the Software, and to permit persons to whom the
8 * Software is furnished to do so, subject to the following conditions:
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
17 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
18 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
20 * Except as contained in this notice, the names of the authors or their
21 * institutions shall not be used in advertising or otherwise to promote the
22 * sale, use or other dealings in this Software without prior written
23 * authorization from the authors.
26 /* Authorization systems for the X protocol. */
29 #include <X11/Xauth.h>
30 #include <sys/socket.h>
31 #include <netinet/in.h>
33 #include <sys/param.h>
41 #include <X11/Xdmcp.h>
52 static char *authnames[N_AUTH_PROTOS] = {
54 "XDM-AUTHORIZATION-1",
59 static size_t memdup(char **dst, void *src, size_t len)
67 memcpy(*dst, src, len);
71 static int authname_match(enum auth_protos kind, char *name, int namelen)
73 if(strlen(authnames[kind]) != namelen)
75 if(memcmp(authnames[kind], name, namelen))
80 static void *_xcb_memrchr(const void *s, int c, size_t n)
82 for(s = (char *) s + n - 1; n--; s = (char *) s - 1)
83 if(*(char *)s == (char)c)
88 static Xauth *get_authptr(struct sockaddr *sockname, unsigned int socknamelen)
92 unsigned short family, port = 0;
93 char hostnamebuf[256]; /* big enough for max hostname */
94 char dispbuf[40]; /* big enough to hold more than 2^64 base 10 */
96 int authnamelens[N_AUTH_PROTOS];
99 family = FamilyLocal; /* 256 */
100 switch(sockname->sa_family)
103 addr = (char *) &((struct sockaddr_in6 *)sockname)->sin6_addr;
104 addrlen = sizeof(((struct sockaddr_in6 *)sockname)->sin6_addr);
105 port = ((struct sockaddr_in6 *)sockname)->sin6_port;
106 if(!IN6_IS_ADDR_V4MAPPED(addr))
108 if(!IN6_IS_ADDR_LOOPBACK(addr))
109 family = XCB_FAMILY_INTERNET_6;
113 /* if v4-mapped, fall through. */
117 addr = (char *) &((struct sockaddr_in *)sockname)->sin_addr;
118 port = ((struct sockaddr_in *)sockname)->sin_port;
120 addrlen = sizeof(((struct sockaddr_in *)sockname)->sin_addr);
121 if(*(in_addr_t *) addr != htonl(INADDR_LOOPBACK))
122 family = XCB_FAMILY_INTERNET;
125 display = _xcb_memrchr(((struct sockaddr_un *) sockname)->sun_path, 'X',
128 return 0; /* sockname is mangled somehow */
132 return 0; /* cannot authenticate this family */
137 snprintf(dispbuf, sizeof(dispbuf), "%hu", ntohs(port) - X_TCP_PORT);
141 if (family == FamilyLocal) {
142 if (gethostname(hostnamebuf, sizeof(hostnamebuf)) == -1)
143 return 0; /* do not know own hostname */
145 addrlen = strlen(addr);
148 for (i = 0; i < N_AUTH_PROTOS; i++)
149 authnamelens[i] = strlen(authnames[i]);
150 return XauGetBestAuthByAddr (family,
151 (unsigned short) addrlen, addr,
152 (unsigned short) strlen(display), display,
153 N_AUTH_PROTOS, authnames, authnamelens);
157 static int next_nonce(void)
159 static int nonce = 0;
160 static pthread_mutex_t nonce_mutex = PTHREAD_MUTEX_INITIALIZER;
162 pthread_mutex_lock(&nonce_mutex);
164 pthread_mutex_unlock(&nonce_mutex);
168 static void do_append(char *buf, int *idxp, void *val, size_t valsize) {
169 memcpy(buf + *idxp, val, valsize);
174 static int compute_auth(xcb_auth_info_t *info, Xauth *authptr, struct sockaddr *sockname)
176 if (authname_match(AUTH_MC1, authptr->name, authptr->name_length)) {
177 info->datalen = memdup(&info->data, authptr->data, authptr->data_length);
183 #define APPEND(buf,idx,val) do_append((buf),&(idx),&(val),sizeof(val))
184 if (authname_match(AUTH_XA1, authptr->name, authptr->name_length)) {
187 info->data = malloc(192 / 8);
191 for (j = 0; j < 8; j++)
192 info->data[j] = authptr->data[j];
193 switch(sockname->sa_family) {
196 struct sockaddr_in *si = (struct sockaddr_in *) sockname;
197 APPEND(info->data, j, si->sin_addr.s_addr);
198 APPEND(info->data, j, si->sin_port);
203 long fakeaddr = htonl(0xffffffff - next_nonce());
204 short fakeport = htons(getpid());
205 APPEND(info->data, j, fakeaddr);
206 APPEND(info->data, j, fakeport);
211 return 0; /* do not know how to build this */
217 APPEND(info->data, j, now);
219 assert(j <= 192 / 8);
223 XdmcpWrap ((unsigned char *) info->data, (unsigned char *) authptr->data + 8, (unsigned char *) info->data, info->datalen);
229 return 0; /* Unknown authorization type */
232 int _xcb_get_auth_info(int fd, xcb_auth_info_t *info)
234 /* code adapted from Xlib/ConnDis.c, xtrans/Xtranssocket.c,
235 xtrans/Xtransutils.c */
236 char sockbuf[sizeof(struct sockaddr) + MAXPATHLEN];
237 unsigned int socknamelen = sizeof(sockbuf); /* need extra space */
238 struct sockaddr *sockname = (struct sockaddr *) &sockbuf;
242 /* ensure info has reasonable contents */
243 /* XXX This should be removed, but Jamey depends on it
244 somehow but can't remember how. Principle: don't touch
245 someone else's data if you're borken. */
246 info->namelen = info->datalen = 0;
247 info->name = info->data = 0;
249 if (getpeername(fd, sockname, &socknamelen) == -1)
250 return 0; /* can only authenticate sockets */
252 authptr = get_authptr(sockname, socknamelen);
254 return 0; /* cannot find good auth data */
256 info->namelen = memdup(&info->name, authptr->name, authptr->name_length);
258 ret = compute_auth(info, authptr, sockname);
265 XauDisposeAuth(authptr);