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/* 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"
#define SHADOW_BUFSIZE 256
/* Retrieve encrypted password string for pw.
* If pw == NULL, return a string which fails password check against any
* password.
*/
#if !ENABLE_FEATURE_SHADOWPASSWDS
#define get_passwd(pw, buffer) get_passwd(pw)
#endif
static const char *get_passwd(const struct passwd *pw, char buffer[SHADOW_BUFSIZE])
{
const char *pass;
if (!pw)
return "aa"; /* "aa" will never match */
pass = pw->pw_passwd;
#if ENABLE_FEATURE_SHADOWPASSWDS
/* Using _r function to avoid pulling in static buffers */
if ((pass[0] == 'x' || pass[0] == '*') && !pass[1]) {
struct spwd spw;
int r;
/* getspnam_r may return 0 yet set result to NULL.
* At least glibc 2.4 does this. Be extra paranoid here. */
struct spwd *result = NULL;
r = getspnam_r(pw->pw_name, &spw, buffer, SHADOW_BUFSIZE, &result);
pass = (r || !result) ? "aa" : result->sp_pwdp;
}
#endif
return pass;
}
/*
* Return CHECKPASS_PW_HAS_EMPTY_PASSWORD if PW has an empty password.
* Return 1 if the user gives the correct password for entry PW,
* 0 if not.
* NULL pw means "just fake it for login with bad username"
*/
int FAST_FUNC check_password(const struct passwd *pw, const char *plaintext)
{
IF_FEATURE_SHADOWPASSWDS(char buffer[SHADOW_BUFSIZE];)
char *encrypted;
const char *pw_pass;
int r;
pw_pass = get_passwd(pw, buffer);
if (!pw_pass[0]) { /* empty password field? */
return CHECKPASS_PW_HAS_EMPTY_PASSWORD;
}
encrypted = pw_encrypt(plaintext, /*salt:*/ pw_pass, 1);
r = (strcmp(encrypted, pw_pass) == 0);
free(encrypted);
return r;
}
/* Ask the user for a password.
* Return CHECKPASS_PW_HAS_EMPTY_PASSWORD without asking if PW has an empty password.
* Return -1 on EOF, error while reading input, or timeout.
* Return 1 if the user gives the correct password for entry PW,
* 0 if not.
*
* NULL pw means "just fake it for login with bad username"
*/
int FAST_FUNC ask_and_check_password_extended(const struct passwd *pw,
int timeout, const char *prompt)
{
IF_FEATURE_SHADOWPASSWDS(char buffer[SHADOW_BUFSIZE];)
char *plaintext;
const char *pw_pass;
int r;
pw_pass = get_passwd(pw, buffer);
if (!pw_pass[0]) /* empty password field? */
return CHECKPASS_PW_HAS_EMPTY_PASSWORD;
plaintext = bb_ask(STDIN_FILENO, timeout, prompt);
if (!plaintext) {
/* EOF (such as ^D) or error (such as ^C) or timeout */
return -1;
}
r = check_password(pw, plaintext);
nuke_str(plaintext);
return r;
}
int FAST_FUNC ask_and_check_password(const struct passwd *pw)
{
return ask_and_check_password_extended(pw, 0, "Password: ");
}
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