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Diffstat (limited to 'driver/test-uid.c')
| -rw-r--r-- | driver/test-uid.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/driver/test-uid.c b/driver/test-uid.c new file mode 100644 index 0000000..6a1f9cc --- /dev/null +++ b/driver/test-uid.c @@ -0,0 +1,209 @@ +/* test-uid.c --- playing with setuid. + * xscreensaver, Copyright (c) 1998, 2005 Jamie Zawinski <jwz@jwz.org> + * + * Permission to use, copy, modify, distribute, and sell this software and its + * documentation for any purpose is hereby granted without fee, provided that + * the above copyright notice appear in all copies and that both that + * copyright notice and this permission notice appear in supporting + * documentation. No representations are made about the suitability of this + * software for any purpose. It is provided "as is" without express or + * implied warranty. + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <stdlib.h> +#ifdef HAVE_UNISTD_H +# include <unistd.h> +#endif + +#include <ctype.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <errno.h> +#include <pwd.h> +#include <grp.h> + +static void +print(void) +{ + int uid = getuid(); + int gid = getgid(); + int euid = geteuid(); + int egid = getegid(); + struct passwd *p = 0; + struct group *g = 0; + gid_t groups[1024]; + int n, size; + + p = getpwuid (uid); + g = getgrgid (gid); + fprintf(stderr, "real user/group: %ld/%ld (%s/%s)\n", (long) uid, (long) gid, + (p && p->pw_name ? p->pw_name : "???"), + (g && g->gr_name ? g->gr_name : "???")); + + p = getpwuid (euid); + g = getgrgid (egid); + fprintf(stderr, "eff. user/group: %ld/%ld (%s/%s)\n", (long)euid, (long)egid, + (p && p->pw_name ? p->pw_name : "???"), + (g && g->gr_name ? g->gr_name : "???")); + + size = sizeof(groups) / sizeof(gid_t); + n = getgroups(size - 1, groups); + if (n < 0) + perror("getgroups failed"); + else + { + int i; + fprintf (stderr, "eff. group list: ["); + for (i = 0; i < n; i++) + { + g = getgrgid (groups[i]); + fprintf(stderr, "%s%s=%ld", (i == 0 ? "" : ", "), + (g->gr_name ? g->gr_name : "???"), + (long) groups[i]); + } + fprintf (stderr, "]\n"); + } +} + +int +main (int argc, char **argv) +{ + int i; + struct passwd *p = 0; + struct group *g = 0; + + if (argc <= 1) + { + fprintf(stderr, + "usage: %s [ user/group ... ]\n" + "\tEach argument may be a user name, or user/group.\n" + "\tThis program will attempt to setuid/setgid to each\n" + "\tin turn, and report the results. The user and group\n" + "\tnames may be strings, or numeric.\n", + argv[0]); + exit(1); + } + + print(); + for (i = 1; i < argc; i++) + { + char *user = argv[i]; + char *group = strchr(user, '/'); + if (!group) + group = strchr(user, '.'); + if (group) + *group++ = 0; + + if (group && *group) + { + long gid = 0; + int was_numeric = 0; + + g = 0; + if (*group == '-' || (*group >= '0' && *group <= '9')) + if (1 == sscanf(group, "%ld", &gid)) + { + g = getgrgid (gid); + was_numeric = 1; + } + + if (!g) + g = getgrnam(group); + + if (g) + { + gid = g->gr_gid; + group = g->gr_name; + } + else + { + if (was_numeric) + { + fprintf(stderr, "no group numbered %s.\n", group); + group = ""; + } + else + { + fprintf(stderr, "no group named %s.\n", group); + goto NOGROUP; + } + } + + fprintf(stderr, "setgroups(1, [%ld]) \"%s\"", gid, group); + { + gid_t g2 = gid; + if (setgroups(1, &g2) == 0) + fprintf(stderr, " succeeded.\n"); + else + perror(" failed"); + } + + fprintf(stderr, "setgid(%ld) \"%s\"", gid, group); + if (setgid(gid) == 0) + fprintf(stderr, " succeeded.\n"); + else + perror(" failed"); + + NOGROUP: ; + } + + if (user && *user) + { + long uid = 0; + int was_numeric = 0; + + p = 0; + if (*user == '-' || (*user >= '0' && *user <= '9')) + if (1 == sscanf(user, "%ld", &uid)) + { + p = getpwuid (uid); + was_numeric = 1; + } + + if (!p) + p = getpwnam(user); + + if (p) + { + uid = p->pw_uid; + user = p->pw_name; + } + else + { + if (was_numeric) + { + fprintf(stderr, "no user numbered \"%s\".\n", user); + user = ""; + } + else + { + fprintf(stderr, "no user named %s.\n", user); + goto NOUSER; + } + } + + fprintf(stderr, "setuid(%ld) \"%s\"", uid, user); + if (setuid(uid) == 0) + fprintf(stderr, " succeeded.\n"); + else + perror(" failed"); + NOUSER: ; + } + print(); + } + + fprintf(stderr, + "running \"whoami\" and \"groups\" in a sub-process reports:\n"); + fflush(stdout); + fflush(stderr); + system ("/bin/sh -c 'echo \"`whoami` / `groups`\"'"); + + fflush(stdout); + fflush(stderr); + exit(0); +} |