auth-passwd.c revision 126277
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 126277 2004-02-26 10:52:33Z 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; 68126277Sdes static int expire_checked = 0; 6957429Smarkm 7098941Sdes#ifndef HAVE_CYGWIN 71126277Sdes if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 72124211Sdes ok = 0; 7398941Sdes#endif 7457429Smarkm if (*password == '\0' && options.permit_empty_passwd == 0) 7557429Smarkm return 0; 76113911Sdes 77124211Sdes#if defined(HAVE_OSF_SIA) 78126277Sdes /* 79126277Sdes * XXX: any reason this is before krb? could be moved to 80126277Sdes * sys_auth_passwd()? -dt 81126277Sdes */ 82124211Sdes return auth_sia_password(authctxt, password) && ok; 83126277Sdes#endif 84126277Sdes#ifdef KRB5 8573400Sassar if (options.kerberos_authentication == 1) { 8692559Sdes int ret = auth_krb5_password(authctxt, password); 8792559Sdes if (ret == 1 || ret == 0) 88124211Sdes return ret && ok; 8957565Smarkm /* Fall back to ordinary passwd authentication. */ 9057565Smarkm } 91126277Sdes#endif 92126277Sdes#ifdef HAVE_CYGWIN 9398941Sdes if (is_winnt) { 9498941Sdes HANDLE hToken = cygwin_logon_user(pw, password); 9598941Sdes 9698941Sdes if (hToken == INVALID_HANDLE_VALUE) 9798941Sdes return 0; 9898941Sdes cygwin_set_impersonation_token(hToken); 99124211Sdes return ok; 10098941Sdes } 101126277Sdes#endif 102126277Sdes#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 103126277Sdes if (!expire_checked) { 104126277Sdes expire_checked = 1; 105126277Sdes if (auth_shadow_pwexpired(authctxt)) { 106126277Sdes disable_forwarding(); 107126277Sdes authctxt->force_pwchange = 1; 108124211Sdes } 109126277Sdes } 110126277Sdes#endif 111126277Sdes 112126277Sdes return (sys_auth_passwd(authctxt, password) && ok); 113126277Sdes} 114124211Sdes 115126277Sdes#ifdef BSD_AUTH 116126277Sdesint 117126277Sdessys_auth_passwd(Authctxt *authctxt, const char *password) 118126277Sdes{ 119126277Sdes struct passwd *pw = authctxt->pw; 120126277Sdes auth_session_t *as; 121124211Sdes 122126277Sdes as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", 123126277Sdes (char *)password); 124126277Sdes if (auth_getstate(as) & AUTH_PWEXPIRED) { 125126277Sdes auth_close(as); 126126277Sdes disable_forwarding(); 127126277Sdes authctxt->force_pwchange = 1; 128126277Sdes return (1); 129126277Sdes } else { 130126277Sdes return (auth_close(as)); 13157429Smarkm } 132126277Sdes} 133126277Sdes#elif !defined(CUSTOM_SYS_AUTH_PASSWD) 134126277Sdesint 135126277Sdessys_auth_passwd(Authctxt *authctxt, const char *password) 136126277Sdes{ 137126277Sdes struct passwd *pw = authctxt->pw; 138126277Sdes char *encrypted_password; 139126277Sdes 140124211Sdes /* Just use the supplied fake password if authctxt is invalid */ 141124211Sdes char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; 14298941Sdes 14357429Smarkm /* Check for users with no password. */ 144124211Sdes if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) 145126277Sdes return (1); 14698941Sdes 147126277Sdes /* Encrypt the candidate password using the proper salt. */ 148126277Sdes encrypted_password = xcrypt(password, 149126277Sdes (pw_password[0] && pw_password[1]) ? pw_password : "xx"); 15098941Sdes 151126277Sdes /* 152126277Sdes * Authentication is accepted if the encrypted passwords 153126277Sdes * are identical. 154126277Sdes */ 155126277Sdes return (strcmp(encrypted_password, pw_password) == 0); 15657429Smarkm} 157126277Sdes#endif 158