/* 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_noecho(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: "); }