busybox/libbb/correct_password.c
2007-06-15 08:30:33 +00:00

79 lines
2.8 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 if PW has an empty password.
*
* NULL pw means "just fake it for login with bad username" */
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
/* fake salt. crypt() can choke otherwise.
* (bb_banner's first two chars are letters and thus are valid salt) */
correct = "aa";
if (!pw) {
/* "aa" will never match */
goto fake_it;
}
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;
fake_it:
unencrypted = bb_askpass(0, "Password: ");
if (!unencrypted) {
return 0;
}
encrypted = crypt(unencrypted, correct);
memset(unencrypted, 0, strlen(unencrypted));
return strcmp(encrypted, correct) == 0;
}