mirror of git://git.suckless.org/ubase
95 lines
1.7 KiB
C
95 lines
1.7 KiB
C
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/* See LICENSE file for copyright and license details. */
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#include <sys/types.h>
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#include <unistd.h>
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#include <errno.h>
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#include <pwd.h>
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#include <grp.h>
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#include <shadow.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include "util.h"
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static void
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usage(void)
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{
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eprintf("usage: %s [username]\n", argv0);
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}
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int
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main(int argc, char **argv)
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{
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char *usr, *pass, *cryptpass;
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char **newargv;
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struct spwd *spw;
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struct passwd *pw;
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uid_t uid;
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int i;
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ARGBEGIN {
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default:
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usage();
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} ARGEND;
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if (argc < 1)
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usr = "root";
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else if (argc == 1)
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usr = argv[0];
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else
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usage();
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uid = getuid();
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spw = getspnam(usr);
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if (!spw)
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eprintf("getspnam: %s:", usr);
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switch (spw->sp_pwdp[0]) {
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case '!':
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case '*':
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enprintf(EXIT_FAILURE, "Denied\n");
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case '$':
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break;
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default:
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enprintf(EXIT_FAILURE, "Invalid shadow record\n");
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}
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if (uid) {
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pass = getpass("Password: ");
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if (!pass)
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eprintf("getpass:");
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}
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cryptpass = crypt(pass, spw->sp_pwdp);
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for (i = 0; pass[i]; i++)
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pass[i] = '\0';
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if (!cryptpass)
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eprintf("crypt:");
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if (strcmp(cryptpass, spw->sp_pwdp) != 0)
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enprintf(EXIT_FAILURE, "Denied\n");
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errno = 0;
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pw = getpwnam(usr);
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if (errno)
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eprintf("getpwnam: %s", usr);
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else if (!pw)
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enprintf(EXIT_FAILURE, "getpwnam: %s: no such user\n", usr);
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if (initgroups(usr, pw->pw_gid) < 0)
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eprintf("initgroups:");
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if (setgid(pw->pw_gid) < 0)
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eprintf("setgid:");
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if (setuid(pw->pw_uid) < 0)
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eprintf("setuid:");
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newargv = malloc(2 * sizeof(char *));
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if (!newargv)
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eprintf("malloc:");
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newargv[0] = pw->pw_shell;
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newargv[1] = NULL;
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setenv("HOME", pw->pw_dir, 1);
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execve(pw->pw_shell, newargv, environ);
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return (errno == ENOENT) ? 127 : 126;
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}
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