auth-passwd.c revision 181110
12786Ssos/* $OpenBSD: auth-passwd.c,v 1.40 2006/08/03 03:34:41 deraadt Exp $ */ 22786Ssos/* 32786Ssos * Author: Tatu Ylonen <ylo@cs.hut.fi> 42786Ssos * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 52786Ssos * All rights reserved 62786Ssos * Password authentication. This file contains the functions to check whether 72786Ssos * the password is valid for the user. 86851Ssos * 92786Ssos * As far as I am concerned, the code I have written for this software 102786Ssos * can be used freely for any purpose. Any derived versions of this 112786Ssos * software must be clearly marked as such, and if the derived work is 122786Ssos * incompatible with the protocol description in the RFC file, it must be 132786Ssos * called by a name other than "ssh" or "Secure Shell". 142786Ssos * 152786Ssos * Copyright (c) 1999 Dug Song. All rights reserved. 162786Ssos * Copyright (c) 2000 Markus Friedl. All rights reserved. 172786Ssos * 184748Ssos * Redistribution and use in source and binary forms, with or without 196851Ssos * modification, are permitted provided that the following conditions 202786Ssos * are met: 212786Ssos * 1. Redistributions of source code must retain the above copyright 222786Ssos * notice, this list of conditions and the following disclaimer. 232786Ssos * 2. Redistributions in binary form must reproduce the above copyright 242786Ssos * notice, this list of conditions and the following disclaimer in the 252786Ssos * documentation and/or other materials provided with the distribution. 262786Ssos * 272786Ssos * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 282786Ssos * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 292786Ssos * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 302786Ssos * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 312786Ssos * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 322786Ssos * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 332786Ssos * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 342786Ssos * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 352786Ssos * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 362786Ssos * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 372786Ssos */ 382786Ssos 392786Ssos#include "includes.h" 402786Ssos 412786Ssos#include <sys/types.h> 422786Ssos 432786Ssos#include <pwd.h> 442786Ssos#include <stdio.h> 452786Ssos#include <string.h> 462786Ssos#include <stdarg.h> 472786Ssos 482786Ssos#include "packet.h" 492786Ssos#include "buffer.h" 502786Ssos#include "log.h" 512786Ssos#include "servconf.h" 522786Ssos#include "key.h" 532786Ssos#include "hostfile.h" 542786Ssos#include "auth.h" 552786Ssos#include "auth-options.h" 562786Ssos 572786Ssosextern Buffer loginmsg; 582786Ssosextern ServerOptions options; 592786Ssos 602786Ssos#ifdef HAVE_LOGIN_CAP 612786Ssosextern login_cap_t *lc; 626851Ssos#endif 632786Ssos 642786Ssos 652786Ssos#define DAY (24L * 60 * 60) /* 1 day in seconds */ 662786Ssos#define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ 672786Ssos 682786Ssosvoid 692786Ssosdisable_forwarding(void) 702786Ssos{ 712786Ssos no_port_forwarding_flag = 1; 722786Ssos no_agent_forwarding_flag = 1; 732786Ssos no_x11_forwarding_flag = 1; 742786Ssos} 752786Ssos 762786Ssos/* 772786Ssos * Tries to authenticate the user using password. Returns true if 782786Ssos * authentication succeeds. 792786Ssos */ 802786Ssosint 815994Ssosauth_password(Authctxt *authctxt, const char *password) 822786Ssos{ 832786Ssos struct passwd * pw = authctxt->pw; 842786Ssos int result, ok = authctxt->valid; 852786Ssos#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 862786Ssos static int expire_checked = 0; 872786Ssos#endif 886045Ssos 892786Ssos#ifndef HAVE_CYGWIN 902786Ssos if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 912786Ssos ok = 0; 922786Ssos#endif 932786Ssos if (*password == '\0' && options.permit_empty_passwd == 0) 942786Ssos return 0; 952786Ssos 962786Ssos#ifdef KRB5 972786Ssos if (options.kerberos_authentication == 1) { 982786Ssos int ret = auth_krb5_password(authctxt, password); 992786Ssos if (ret == 1 || ret == 0) 1002786Ssos return ret && ok; 1012786Ssos /* Fall back to ordinary passwd authentication. */ 1022786Ssos } 1032786Ssos#endif 1042786Ssos#ifdef HAVE_CYGWIN 1052786Ssos if (is_winnt) { 1062786Ssos HANDLE hToken = cygwin_logon_user(pw, password); 1072786Ssos 1086851Ssos if (hToken == INVALID_HANDLE_VALUE) 1092786Ssos return 0; 1106851Ssos cygwin_set_impersonation_token(hToken); 1116851Ssos return ok; 1126851Ssos } 113#endif 114#ifdef USE_PAM 115 if (options.use_pam) 116 return (sshpam_auth_passwd(authctxt, password) && ok); 117#endif 118#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 119 if (!expire_checked) { 120 expire_checked = 1; 121 if (auth_shadow_pwexpired(authctxt)) 122 authctxt->force_pwchange = 1; 123 } 124#endif 125 result = sys_auth_passwd(authctxt, password); 126 if (authctxt->force_pwchange) 127 disable_forwarding(); 128 return (result && ok); 129} 130 131#ifdef BSD_AUTH 132static void 133warn_expiry(Authctxt *authctxt, auth_session_t *as) 134{ 135 char buf[256]; 136 quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; 137 138 pwwarntime = acwarntime = TWO_WEEKS; 139 140 pwtimeleft = auth_check_change(as); 141 actimeleft = auth_check_expire(as); 142#ifdef HAVE_LOGIN_CAP 143 if (authctxt->valid) { 144 pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, 145 TWO_WEEKS); 146 acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, 147 TWO_WEEKS); 148 } 149#endif 150 if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { 151 daysleft = pwtimeleft / DAY + 1; 152 snprintf(buf, sizeof(buf), 153 "Your password will expire in %lld day%s.\n", 154 daysleft, daysleft == 1 ? "" : "s"); 155 buffer_append(&loginmsg, buf, strlen(buf)); 156 } 157 if (actimeleft != 0 && actimeleft < acwarntime) { 158 daysleft = actimeleft / DAY + 1; 159 snprintf(buf, sizeof(buf), 160 "Your account will expire in %lld day%s.\n", 161 daysleft, daysleft == 1 ? "" : "s"); 162 buffer_append(&loginmsg, buf, strlen(buf)); 163 } 164} 165 166int 167sys_auth_passwd(Authctxt *authctxt, const char *password) 168{ 169 struct passwd *pw = authctxt->pw; 170 auth_session_t *as; 171 static int expire_checked = 0; 172 173 as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", 174 (char *)password); 175 if (as == NULL) 176 return (0); 177 if (auth_getstate(as) & AUTH_PWEXPIRED) { 178 auth_close(as); 179 disable_forwarding(); 180 authctxt->force_pwchange = 1; 181 return (1); 182 } else { 183 if (!expire_checked) { 184 expire_checked = 1; 185 warn_expiry(authctxt, as); 186 } 187 return (auth_close(as)); 188 } 189} 190#elif !defined(CUSTOM_SYS_AUTH_PASSWD) 191int 192sys_auth_passwd(Authctxt *authctxt, const char *password) 193{ 194 struct passwd *pw = authctxt->pw; 195 char *encrypted_password; 196 197 /* Just use the supplied fake password if authctxt is invalid */ 198 char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; 199 200 /* Check for users with no password. */ 201 if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) 202 return (1); 203 204 /* Encrypt the candidate password using the proper salt. */ 205 encrypted_password = xcrypt(password, 206 (pw_password[0] && pw_password[1]) ? pw_password : "xx"); 207 208 /* 209 * Authentication is accepted if the encrypted passwords 210 * are identical. 211 */ 212 return (strcmp(encrypted_password, pw_password) == 0); 213} 214#endif 215