busybox/libbb/correct_password.c
Denis Vlasenko 5df955fce2 Do not fail password check if shadow password does not exist -
fall back to ordinary one

Reduced usage of functions returning datain static buffers.
(mostly passwd/group/shadow related):

function                                             old     new   delta
correct_password                                     143     193     +50
sulogin_main                                         490     533     +43
adduser_main                                         732     774     +42
passwd_main                                         1875    1915     +40
addgroup_main                                        330     365     +35
bb_internal_getspnam                                  38       -     -38
bb_internal_fgetpwent                                 38       -     -38
bb_internal_fgetgrent                                 38       -     -38
static.resultbuf                                     168      88     -80
static.buffer                                       1872    1104    -768
------------------------------------------------------------------------------
(add/remove: 0/3 grow/shrink: 5/2 up/down: 210/-962)         Total: -752 bytes
2007-03-13 13:01:14 +00:00

70 lines
2.6 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Copyright 1989 - 1991, Julianne Frances Haugh <jockgrrl@austin.rr.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Julianne F. Haugh nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "libbb.h"
/* Ask the user for a password.
Return 1 if the user gives the correct password for entry PW,
0 if not. Return 1 without asking for a password if run by UID 0
or if PW has an empty password. */
int correct_password(const struct passwd *pw)
{
char *unencrypted, *encrypted;
const char *correct;
#if ENABLE_FEATURE_SHADOWPASSWDS
/* Using _r function to avoid pulling in static buffers */
struct spwd spw;
struct spwd *result;
char buffer[256];
#endif
correct = pw->pw_passwd;
#if ENABLE_FEATURE_SHADOWPASSWDS
if (LONE_CHAR(pw->pw_passwd, 'x') || LONE_CHAR(pw->pw_passwd, '*')) {
if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result))
bb_error_msg("no valid shadow password, checking ordinary one");
else
correct = spw.sp_pwdp;
}
#endif
if (!correct || correct[0] == '\0')
return 1;
unencrypted = bb_askpass(0, "Password: ");
if (!unencrypted) {
return 0;
}
encrypted = crypt(unencrypted, correct);
memset(unencrypted, 0, strlen(unencrypted));
return strcmp(encrypted, correct) == 0;
}