Add initial su(1)

This commit is contained in:
sin 2013-10-17 23:02:55 +01:00
parent 8c2bbb8fb3
commit ff2e11638f
3 changed files with 97 additions and 2 deletions

View File

@ -36,6 +36,7 @@ SRC = \
pivot_root.c \ pivot_root.c \
ps.c \ ps.c \
rmmod.c \ rmmod.c \
su.c \
swapoff.c \ swapoff.c \
swapon.c \ swapon.c \
truncate.c \ truncate.c \

View File

@ -10,10 +10,10 @@ MANPREFIX = $(PREFIX)/share/man
LD = $(CC) LD = $(CC)
CPPFLAGS = -D_BSD_SOURCE -D_GNU_SOURCE CPPFLAGS = -D_BSD_SOURCE -D_GNU_SOURCE
CFLAGS = -g -ansi -Wall -Wno-long-long $(CPPFLAGS) CFLAGS = -g -ansi -Wall -Wno-long-long $(CPPFLAGS)
LDFLAGS = -g LDFLAGS = -g -lcrypt
#CC = tcc #CC = tcc
#LD = $(CC) #LD = $(CC)
#CPPFLAGS = -D_BSD_SOURCE -D_GNU_SOURCE #CPPFLAGS = -D_BSD_SOURCE -D_GNU_SOURCE
#CFLAGS = -Os -Wall $(CPPFLAGS) #CFLAGS = -Os -Wall $(CPPFLAGS)
#LDFLAGS = #LDFLAGS = -lcrypt

94
su.c Normal file
View File

@ -0,0 +1,94 @@
/* 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 "util.h"
static void
usage(void)
{
eprintf("usage: %s [username]\n", argv0);
}
int
main(int argc, char **argv)
{
char *usr, *pass, *cryptpass;
char **newargv;
struct spwd *spw;
struct passwd *pw;
uid_t uid;
int i;
ARGBEGIN {
default:
usage();
} ARGEND;
if (argc < 1)
usr = "root";
else if (argc == 1)
usr = argv[0];
else
usage();
uid = getuid();
spw = getspnam(usr);
if (!spw)
eprintf("getspnam: %s:", usr);
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, "getpwnam: %s: no such user\n", usr);
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:");
newargv = malloc(2 * sizeof(char *));
if (!newargv)
eprintf("malloc:");
newargv[0] = pw->pw_shell;
newargv[1] = NULL;
setenv("HOME", pw->pw_dir, 1);
execve(pw->pw_shell, newargv, environ);
return (errno == ENOENT) ? 127 : 126;
}