auth-passwd.c revision 137019
157429Smarkm/* 257429Smarkm * Author: Tatu Ylonen <ylo@cs.hut.fi> 357429Smarkm * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 457429Smarkm * All rights reserved 557429Smarkm * Password authentication. This file contains the functions to check whether 657429Smarkm * the password is valid for the user. 765674Skris * 865674Skris * As far as I am concerned, the code I have written for this software 965674Skris * can be used freely for any purpose. Any derived versions of this 1065674Skris * software must be clearly marked as such, and if the derived work is 1165674Skris * incompatible with the protocol description in the RFC file, it must be 1265674Skris * called by a name other than "ssh" or "Secure Shell". 1365674Skris * 1465674Skris * Copyright (c) 1999 Dug Song. All rights reserved. 1565674Skris * Copyright (c) 2000 Markus Friedl. All rights reserved. 1665674Skris * 1765674Skris * Redistribution and use in source and binary forms, with or without 1865674Skris * modification, are permitted provided that the following conditions 1965674Skris * are met: 2065674Skris * 1. Redistributions of source code must retain the above copyright 2165674Skris * notice, this list of conditions and the following disclaimer. 2265674Skris * 2. Redistributions in binary form must reproduce the above copyright 2365674Skris * notice, this list of conditions and the following disclaimer in the 2465674Skris * documentation and/or other materials provided with the distribution. 2565674Skris * 2665674Skris * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 2765674Skris * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 2865674Skris * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 2965674Skris * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 3065674Skris * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 3165674Skris * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 3265674Skris * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 3365674Skris * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 3465674Skris * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 3565674Skris * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 3657429Smarkm */ 3757429Smarkm 3857429Smarkm#include "includes.h" 39126277SdesRCSID("$OpenBSD: auth-passwd.c,v 1.31 2004/01/30 09:48:57 markus Exp $"); 4099748SdesRCSID("$FreeBSD: head/crypto/openssh/auth-passwd.c 137019 2004-10-28 16:11:31Z des $"); 4157429Smarkm 4257429Smarkm#include "packet.h" 4376262Sgreen#include "log.h" 4457429Smarkm#include "servconf.h" 4576262Sgreen#include "auth.h" 46126277Sdes#include "auth-options.h" 4776262Sgreen 48124211Sdesextern ServerOptions options; 49126277Sdesint sys_auth_passwd(Authctxt *, const char *); 50124211Sdes 51126277Sdesvoid 52126277Sdesdisable_forwarding(void) 53126277Sdes{ 54126277Sdes no_port_forwarding_flag = 1; 55126277Sdes no_agent_forwarding_flag = 1; 56126277Sdes no_x11_forwarding_flag = 1; 57126277Sdes} 58126277Sdes 5957429Smarkm/* 6057429Smarkm * Tries to authenticate the user using password. Returns true if 6157429Smarkm * authentication succeeds. 6257429Smarkm */ 6365674Skrisint 6476262Sgreenauth_password(Authctxt *authctxt, const char *password) 6557429Smarkm{ 6676262Sgreen struct passwd * pw = authctxt->pw; 67124211Sdes int ok = authctxt->valid; 68137019Sdes#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 69126277Sdes static int expire_checked = 0; 70137019Sdes#endif 7157429Smarkm 7298941Sdes#ifndef HAVE_CYGWIN 73126277Sdes if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 74124211Sdes ok = 0; 7598941Sdes#endif 7657429Smarkm if (*password == '\0' && options.permit_empty_passwd == 0) 7757429Smarkm return 0; 78113911Sdes 79126277Sdes#ifdef KRB5 8073400Sassar if (options.kerberos_authentication == 1) { 8192559Sdes int ret = auth_krb5_password(authctxt, password); 8292559Sdes if (ret == 1 || ret == 0) 83124211Sdes return ret && ok; 8457565Smarkm /* Fall back to ordinary passwd authentication. */ 8557565Smarkm } 86126277Sdes#endif 87126277Sdes#ifdef HAVE_CYGWIN 8898941Sdes if (is_winnt) { 8998941Sdes HANDLE hToken = cygwin_logon_user(pw, password); 9098941Sdes 9198941Sdes if (hToken == INVALID_HANDLE_VALUE) 9298941Sdes return 0; 9398941Sdes cygwin_set_impersonation_token(hToken); 94124211Sdes return ok; 9598941Sdes } 96126277Sdes#endif 97137019Sdes#ifdef USE_PAM 98137019Sdes if (options.use_pam) 99137019Sdes return (sshpam_auth_passwd(authctxt, password) && ok); 100137019Sdes#endif 101126277Sdes#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 102126277Sdes if (!expire_checked) { 103126277Sdes expire_checked = 1; 104126277Sdes if (auth_shadow_pwexpired(authctxt)) { 105126277Sdes disable_forwarding(); 106126277Sdes authctxt->force_pwchange = 1; 107124211Sdes } 108126277Sdes } 109126277Sdes#endif 110126277Sdes 111126277Sdes return (sys_auth_passwd(authctxt, password) && ok); 112126277Sdes} 113124211Sdes 114126277Sdes#ifdef BSD_AUTH 115126277Sdesint 116126277Sdessys_auth_passwd(Authctxt *authctxt, const char *password) 117126277Sdes{ 118126277Sdes struct passwd *pw = authctxt->pw; 119126277Sdes auth_session_t *as; 120124211Sdes 121126277Sdes as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", 122126277Sdes (char *)password); 123126277Sdes if (auth_getstate(as) & AUTH_PWEXPIRED) { 124126277Sdes auth_close(as); 125126277Sdes disable_forwarding(); 126126277Sdes authctxt->force_pwchange = 1; 127126277Sdes return (1); 128126277Sdes } else { 129126277Sdes return (auth_close(as)); 13057429Smarkm } 131126277Sdes} 132126277Sdes#elif !defined(CUSTOM_SYS_AUTH_PASSWD) 133126277Sdesint 134126277Sdessys_auth_passwd(Authctxt *authctxt, const char *password) 135126277Sdes{ 136126277Sdes struct passwd *pw = authctxt->pw; 137126277Sdes char *encrypted_password; 138126277Sdes 139124211Sdes /* Just use the supplied fake password if authctxt is invalid */ 140124211Sdes char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; 14198941Sdes 14257429Smarkm /* Check for users with no password. */ 143124211Sdes if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) 144126277Sdes return (1); 14598941Sdes 146126277Sdes /* Encrypt the candidate password using the proper salt. */ 147126277Sdes encrypted_password = xcrypt(password, 148126277Sdes (pw_password[0] && pw_password[1]) ? pw_password : "xx"); 14998941Sdes 150126277Sdes /* 151126277Sdes * Authentication is accepted if the encrypted passwords 152126277Sdes * are identical. 153126277Sdes */ 154126277Sdes return (strcmp(encrypted_password, pw_password) == 0); 15557429Smarkm} 156126277Sdes#endif 157