164 lines
3.1 KiB
C
164 lines
3.1 KiB
C
/* See LICENSE file for copyright and license details. */
|
|
#include <sys/types.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <pwd.h>
|
|
#include <grp.h>
|
|
#include <shadow.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include "config.h"
|
|
#include "util.h"
|
|
|
|
extern char **environ;
|
|
|
|
static char *msetenv(const char *, const char *);
|
|
static void dologin(struct passwd *);
|
|
|
|
static void
|
|
usage(void)
|
|
{
|
|
eprintf("usage: %s [-lp] [username]\n", argv0);
|
|
}
|
|
|
|
static int lflag = 0;
|
|
static int pflag = 0;
|
|
|
|
int
|
|
main(int argc, char **argv)
|
|
{
|
|
char *usr, *pass, *cryptpass;
|
|
char * const *newargv;
|
|
struct spwd *spw;
|
|
struct passwd *pw;
|
|
uid_t uid;
|
|
int i;
|
|
|
|
ARGBEGIN {
|
|
case 'l':
|
|
lflag = 1;
|
|
break;
|
|
case 'p':
|
|
pflag = 1;
|
|
break;
|
|
default:
|
|
usage();
|
|
} ARGEND;
|
|
|
|
if (argc < 1)
|
|
usr = "root";
|
|
else if (argc == 1)
|
|
usr = argv[0];
|
|
else
|
|
usage();
|
|
|
|
uid = getuid();
|
|
|
|
errno = 0;
|
|
spw = getspnam(usr);
|
|
if (errno)
|
|
eprintf("getspnam: %s:", usr);
|
|
else if (!spw)
|
|
enprintf(EXIT_FAILURE, "who are you?\n");
|
|
|
|
switch (spw->sp_pwdp[0]) {
|
|
case '!':
|
|
case '*':
|
|
enprintf(EXIT_FAILURE, "Denied\n");
|
|
case '$':
|
|
break;
|
|
default:
|
|
enprintf(EXIT_FAILURE, "Invalid shadow record\n");
|
|
}
|
|
|
|
if (uid) {
|
|
pass = getpass("Password: ");
|
|
if (!pass)
|
|
eprintf("getpass:");
|
|
|
|
cryptpass = crypt(pass, spw->sp_pwdp);
|
|
for (i = 0; pass[i]; i++)
|
|
pass[i] = '\0';
|
|
if (!cryptpass)
|
|
eprintf("crypt:");
|
|
|
|
if (strcmp(cryptpass, spw->sp_pwdp) != 0)
|
|
enprintf(EXIT_FAILURE, "Denied\n");
|
|
}
|
|
|
|
errno = 0;
|
|
pw = getpwnam(usr);
|
|
if (errno)
|
|
eprintf("getpwnam: %s", usr);
|
|
else if (!pw)
|
|
enprintf(EXIT_FAILURE, "who are you?\n");
|
|
|
|
if (initgroups(usr, pw->pw_gid) < 0)
|
|
eprintf("initgroups:");
|
|
if (setgid(pw->pw_gid) < 0)
|
|
eprintf("setgid:");
|
|
if (setuid(pw->pw_uid) < 0)
|
|
eprintf("setuid:");
|
|
|
|
if (lflag) {
|
|
dologin(pw);
|
|
} else {
|
|
newargv = (char *const[]){pw->pw_shell, NULL};
|
|
if (!pflag) {
|
|
setenv("HOME", pw->pw_dir, 1);
|
|
setenv("SHELL", pw->pw_shell, 1);
|
|
if (strcmp(pw->pw_name, "root") != 0) {
|
|
setenv("USER", pw->pw_name, 1);
|
|
setenv("LOGNAME", pw->pw_name, 1);
|
|
}
|
|
}
|
|
if (strcmp(pw->pw_name, "root") == 0)
|
|
setenv("PATH", ENV_SUPATH, 1);
|
|
else
|
|
setenv("PATH", ENV_PATH, 1);
|
|
execve(pflag ? getenv("SHELL") : pw->pw_shell,
|
|
newargv, environ);
|
|
}
|
|
return (errno == ENOENT) ? 127 : 126;
|
|
}
|
|
|
|
static char *
|
|
msetenv(const char *name, const char *value)
|
|
{
|
|
char *buf;
|
|
size_t sz;
|
|
|
|
sz = strlen(name) + strlen(value) + 2;
|
|
buf = malloc(sz);
|
|
if (!buf)
|
|
eprintf("malloc:");
|
|
snprintf(buf, sz, "%s=%s", name, value);
|
|
return buf;
|
|
}
|
|
|
|
static void
|
|
dologin(struct passwd *pw)
|
|
{
|
|
char shbuf[strlen(pw->pw_shell) + 1];
|
|
char * const *newargv;
|
|
char * const *newenv;
|
|
|
|
strcpy(shbuf, pw->pw_shell);
|
|
newargv = (char *const[]){shbuf, NULL};
|
|
newenv = (char *const[]){
|
|
msetenv("HOME", pw->pw_dir),
|
|
msetenv("SHELL", pw->pw_shell),
|
|
msetenv("USER", pw->pw_name),
|
|
msetenv("LOGNAME", pw->pw_name),
|
|
msetenv("TERM", getenv("TERM")),
|
|
msetenv("PATH",
|
|
strcmp(pw->pw_name, "root") == 0 ?
|
|
ENV_SUPATH : ENV_PATH),
|
|
NULL
|
|
};
|
|
if (chdir(pw->pw_dir) < 0)
|
|
eprintf("chdir %s:", pw->pw_dir);
|
|
execve(pw->pw_shell, newargv, newenv);
|
|
}
|