ubase/passwd.c

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2.9 KiB
C
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/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "passwd.h"
#include "util.h"
static void
usage(void)
{
eprintf("usage: %s login\n", argv0);
}
int
main(int argc, char *argv[])
{
char *pass;
char *cryptpass1 = NULL, *cryptpass2 = NULL, *cryptpass3 = NULL;
char *p;
char template[] = "/tmp/pw.XXXXXX";
struct passwd *pw;
int ffd, tfd;
int r;
ARGBEGIN {
default:
usage();
} ARGEND;
if (argc != 1)
usage();
errno = 0;
pw = getpwnam(argv[0]);
if (errno)
eprintf("getpwnam: %s:", argv[0]);
else if (!pw)
eprintf("who are you?\n");
switch (pw->pw_passwd[0]) {
case '!':
case '*':
eprintf("denied\n");
}
if (pw->pw_passwd[0] == '\0') {
/* Default to SHA-512 for empty passwords */
pw->pw_passwd = "$6$";
goto newpass;
}
if (pw->pw_passwd[0] == 'x' && pw->pw_passwd[1] == '\0')
eprintf("no shadow support\n");
/* Flush pending input */
ioctl(STDIN_FILENO, TCFLSH, (void *)0);
pass = getpass("Current password: ");
putchar('\n');
if (!pass)
eprintf("getpass:");
if (pass[0] == '\0')
eprintf("no password supplied\n");
p = crypt(pass, pw->pw_passwd);
if (!p)
eprintf("crypt:");
cryptpass1 = estrdup(p);
if (strcmp(cryptpass1, pw->pw_passwd) != 0)
eprintf("incorrect password\n");
newpass:
/* Flush pending input */
ioctl(STDIN_FILENO, TCFLSH, (void *)0);
pass = getpass("Enter new password: ");
putchar('\n');
if (!pass)
eprintf("getpass:");
if (pass[0] == '\0')
eprintf("no password supplied\n");
p = crypt(pass, pw->pw_passwd);
if (!p)
eprintf("crypt:");
cryptpass2 = estrdup(p);
if (cryptpass1 && strcmp(cryptpass1, cryptpass2) == 0)
eprintf("password left unchanged\n");
/* Flush pending input */
ioctl(STDIN_FILENO, TCFLSH, (void *)0);
pass = getpass("Retype new password: ");
putchar('\n');
if (!pass)
eprintf("getpass:");
if (pass[0] == '\0')
eprintf("no password supplied\n");
p = crypt(pass, pw->pw_passwd);
if (!p)
eprintf("crypt:");
cryptpass3 = estrdup(p);
if (strcmp(cryptpass2, cryptpass3) != 0)
eprintf("passwords don't match\n");
pw->pw_passwd = cryptpass3;
ffd = open("/etc/passwd", O_RDWR);
if (ffd < 0)
eprintf("open %s:", "/etc/passwd");
tfd = mkostemp(template, O_RDWR);
if (tfd < 0)
eprintf("mkstemp:");
r = pw_copy(ffd, tfd, pw);
if (r < 0) {
unlink(template);
exit(EXIT_FAILURE);
}
r = lseek(ffd, 0, SEEK_SET);
if (r < 0) {
unlink(template);
exit(EXIT_FAILURE);
}
r = lseek(tfd, 0, SEEK_SET);
if (r < 0) {
unlink(template);
exit(EXIT_FAILURE);
}
r = pw_copy(tfd, ffd, NULL);
if (r < 0) {
unlink(template);
exit(EXIT_FAILURE);
}
close(tfd);
close(ffd);
unlink(template);
free(cryptpass3);
free(cryptpass2);
free(cryptpass1);
return EXIT_SUCCESS;
}