N_AUTH_PROTOS
};
+#define AUTH_PROTO_XDM_AUTHORIZATION "XDM-AUTHORIZATION-1"
+#define AUTH_PROTO_MIT_MAGIC_COOKIE "MIT-MAGIC-COOKIE-1"
+
static char *authnames[N_AUTH_PROTOS] = {
#ifdef HASXDMAUTH
- "XDM-AUTHORIZATION-1",
+ AUTH_PROTO_XDM_AUTHORIZATION,
+#endif
+ AUTH_PROTO_MIT_MAGIC_COOKIE,
+};
+
+static int authnameslen[N_AUTH_PROTOS] = {
+#ifdef HASXDMAUTH
+ sizeof(AUTH_PROTO_XDM_AUTHORIZATION) - 1,
#endif
- "MIT-MAGIC-COOKIE-1",
+ sizeof(AUTH_PROTO_MIT_MAGIC_COOKIE) - 1,
};
static size_t memdup(char **dst, void *src, size_t len)
static int authname_match(enum auth_protos kind, char *name, size_t namelen)
{
- if(strlen(authnames[kind]) != namelen)
+ if(authnameslen[kind] != namelen)
return 0;
if(memcmp(authnames[kind], name, namelen))
return 0;
#define SIN6_ADDR(s) (&((struct sockaddr_in6 *)s)->sin6_addr)
-static Xauth *get_authptr(struct sockaddr *sockname, unsigned int socknamelen,
- int display)
+static Xauth *get_authptr(struct sockaddr *sockname, int display)
{
char *addr = 0;
int addrlen = 0;
unsigned short family;
char hostnamebuf[256]; /* big enough for max hostname */
char dispbuf[40]; /* big enough to hold more than 2^64 base 10 */
- int authnamelens[N_AUTH_PROTOS];
- int i;
+ int dispbuflen;
family = FamilyLocal; /* 256 */
switch(sockname->sa_family)
return 0; /* cannot authenticate this family */
}
- snprintf(dispbuf, sizeof(dispbuf), "%d", display);
+ dispbuflen = snprintf(dispbuf, sizeof(dispbuf), "%d", display);
+ if(dispbuflen < 0)
+ return 0;
+ /* snprintf may have truncate our text */
+ dispbuflen = MIN(dispbuflen, sizeof(dispbuf) - 1);
if (family == FamilyLocal) {
if (gethostname(hostnamebuf, sizeof(hostnamebuf)) == -1)
addrlen = strlen(addr);
}
- for (i = 0; i < N_AUTH_PROTOS; i++)
- authnamelens[i] = strlen(authnames[i]);
return XauGetBestAuthByAddr (family,
(unsigned short) addrlen, addr,
- (unsigned short) strlen(dispbuf), dispbuf,
- N_AUTH_PROTOS, authnames, authnamelens);
+ (unsigned short) dispbuflen, dispbuf,
+ N_AUTH_PROTOS, authnames, authnameslen);
}
#ifdef HASXDMAUTH
return 0; /* Unknown authorization type */
}
+/* `sockaddr_un.sun_path' typical size usually ranges between 92 and 108 */
+#define INITIAL_SOCKNAME_SLACK 108
+
+/* Return a dynamically allocated socket address structure according
+ to the value returned by either getpeername() or getsockname()
+ (according to POSIX, applications should not assume a particular
+ length for `sockaddr_un.sun_path') */
+static struct sockaddr *get_peer_sock_name(int (*socket_func)(int,
+ struct sockaddr *,
+ socklen_t *),
+ int fd)
+{
+ socklen_t socknamelen = sizeof(struct sockaddr) + INITIAL_SOCKNAME_SLACK;
+ socklen_t actual_socknamelen = socknamelen;
+ struct sockaddr *sockname = malloc(socknamelen), *new_sockname = NULL;
+
+ if (sockname == NULL)
+ return NULL;
+
+ /* Both getpeername() and getsockname() truncates sockname if
+ there is not enough space and set the required length in
+ actual_socknamelen */
+ if (socket_func(fd, sockname, &actual_socknamelen) == -1)
+ goto sock_or_realloc_error;
+
+ if (actual_socknamelen > socknamelen)
+ {
+ socknamelen = actual_socknamelen;
+
+ if ((new_sockname = realloc(sockname, actual_socknamelen)) == NULL ||
+ socket_func(fd, new_sockname, &actual_socknamelen) == -1 ||
+ actual_socknamelen > socknamelen)
+ goto sock_or_realloc_error;
+
+ sockname = new_sockname;
+ }
+
+ return sockname;
+
+ sock_or_realloc_error:
+ free(sockname);
+ return NULL;
+}
+
int _xcb_get_auth_info(int fd, xcb_auth_info_t *info, int display)
{
/* code adapted from Xlib/ConnDis.c, xtrans/Xtranssocket.c,
xtrans/Xtransutils.c */
- char sockbuf[sizeof(struct sockaddr) + MAXPATHLEN];
- unsigned int socknamelen = sizeof(sockbuf); /* need extra space */
- struct sockaddr *sockname = (struct sockaddr *) &sockbuf;
+ struct sockaddr *sockname = NULL;
+ int gotsockname = 0;
Xauth *authptr = 0;
int ret = 1;
- if (getpeername(fd, sockname, &socknamelen) == -1)
+ /* Some systems like hpux or Hurd do not expose peer names
+ * for UNIX Domain Sockets, but this is irrelevant,
+ * since compute_auth() ignores the peer name in this
+ * case anyway.*/
+ if ((sockname = get_peer_sock_name(getpeername, fd)) == NULL)
{
- if (getsockname(fd, sockname, &socknamelen) == -1)
- return 0; /* can only authenticate sockets */
+ if ((sockname = get_peer_sock_name(getsockname, fd)) == NULL)
+ return 0; /* can only authenticate sockets */
if (sockname->sa_family != AF_UNIX)
- return 0;
- /* Some systems like hpux or Hurd do not expose peer names
- * for UNIX Domain Sockets. We do not need it anyway. */
+ {
+ free(sockname);
+ return 0; /* except for AF_UNIX, sockets should have peernames */
+ }
+ gotsockname = 1;
}
- authptr = get_authptr(sockname, socknamelen, display);
+ authptr = get_authptr(sockname, display);
if (authptr == 0)
+ {
+ free(sockname);
return 0; /* cannot find good auth data */
+ }
info->namelen = memdup(&info->name, authptr->name, authptr->name_length);
- if(info->namelen)
- ret = compute_auth(info, authptr, sockname);
+ if (!info->namelen)
+ goto no_auth; /* out of memory */
+
+ if (!gotsockname && (sockname = get_peer_sock_name(getsockname, fd)) == NULL)
+ {
+ free(info->name);
+ goto no_auth; /* can only authenticate sockets */
+ }
+
+ ret = compute_auth(info, authptr, sockname);
if(!ret)
{
- free(info->name);
- info->name = 0;
- info->namelen = 0;
+ free(info->name);
+ goto no_auth; /* cannot build auth record */
}
+
+ free(sockname);
+ sockname = NULL;
+
XauDisposeAuth(authptr);
return ret;
+
+ no_auth:
+ free(sockname);
+
+ info->name = 0;
+ info->namelen = 0;
+ XauDisposeAuth(authptr);
+ return 0;
}