1181111Sdes/* $OpenBSD: auth-passwd.c,v 1.43 2007/09/21 08:15:29 djm Exp $ */ 257429Smarkm/* 357429Smarkm * Author: Tatu Ylonen <ylo@cs.hut.fi> 457429Smarkm * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 557429Smarkm * All rights reserved 657429Smarkm * Password authentication. This file contains the functions to check whether 757429Smarkm * the password is valid for the user. 865674Skris * 965674Skris * As far as I am concerned, the code I have written for this software 1065674Skris * can be used freely for any purpose. Any derived versions of this 1165674Skris * software must be clearly marked as such, and if the derived work is 1265674Skris * incompatible with the protocol description in the RFC file, it must be 1365674Skris * called by a name other than "ssh" or "Secure Shell". 1465674Skris * 1565674Skris * Copyright (c) 1999 Dug Song. All rights reserved. 1665674Skris * Copyright (c) 2000 Markus Friedl. All rights reserved. 1765674Skris * 1865674Skris * Redistribution and use in source and binary forms, with or without 1965674Skris * modification, are permitted provided that the following conditions 2065674Skris * are met: 2165674Skris * 1. Redistributions of source code must retain the above copyright 2265674Skris * notice, this list of conditions and the following disclaimer. 2365674Skris * 2. Redistributions in binary form must reproduce the above copyright 2465674Skris * notice, this list of conditions and the following disclaimer in the 2565674Skris * documentation and/or other materials provided with the distribution. 2665674Skris * 2765674Skris * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 2865674Skris * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 2965674Skris * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 3065674Skris * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 3165674Skris * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 3265674Skris * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 3365674Skris * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 3465674Skris * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 3565674Skris * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 3665674Skris * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 3757429Smarkm */ 3857429Smarkm 3957429Smarkm#include "includes.h" 4057429Smarkm 41162856Sdes#include <sys/types.h> 42162856Sdes 43162856Sdes#include <pwd.h> 44162856Sdes#include <stdio.h> 45162856Sdes#include <string.h> 46162856Sdes#include <stdarg.h> 47162856Sdes 4857429Smarkm#include "packet.h" 49147005Sdes#include "buffer.h" 5076262Sgreen#include "log.h" 5157429Smarkm#include "servconf.h" 52162856Sdes#include "key.h" 53162856Sdes#include "hostfile.h" 5476262Sgreen#include "auth.h" 55126277Sdes#include "auth-options.h" 5676262Sgreen 57147005Sdesextern Buffer loginmsg; 58124211Sdesextern ServerOptions options; 59124211Sdes 60147005Sdes#ifdef HAVE_LOGIN_CAP 61147005Sdesextern login_cap_t *lc; 62147005Sdes#endif 63147005Sdes 64147005Sdes 65147005Sdes#define DAY (24L * 60 * 60) /* 1 day in seconds */ 66147005Sdes#define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ 67147005Sdes 68126277Sdesvoid 69126277Sdesdisable_forwarding(void) 70126277Sdes{ 71126277Sdes no_port_forwarding_flag = 1; 72126277Sdes no_agent_forwarding_flag = 1; 73126277Sdes no_x11_forwarding_flag = 1; 74126277Sdes} 75126277Sdes 7657429Smarkm/* 7757429Smarkm * Tries to authenticate the user using password. Returns true if 7857429Smarkm * authentication succeeds. 7957429Smarkm */ 8065674Skrisint 8176262Sgreenauth_password(Authctxt *authctxt, const char *password) 8257429Smarkm{ 8376262Sgreen struct passwd * pw = authctxt->pw; 84147005Sdes int result, ok = authctxt->valid; 85137019Sdes#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 86126277Sdes static int expire_checked = 0; 87137019Sdes#endif 8857429Smarkm 8998941Sdes#ifndef HAVE_CYGWIN 90126277Sdes if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 91124211Sdes ok = 0; 9298941Sdes#endif 9357429Smarkm if (*password == '\0' && options.permit_empty_passwd == 0) 9457429Smarkm return 0; 95113911Sdes 96126277Sdes#ifdef KRB5 9773400Sassar if (options.kerberos_authentication == 1) { 9892559Sdes int ret = auth_krb5_password(authctxt, password); 9992559Sdes if (ret == 1 || ret == 0) 100124211Sdes return ret && ok; 10157565Smarkm /* Fall back to ordinary passwd authentication. */ 10257565Smarkm } 103126277Sdes#endif 104126277Sdes#ifdef HAVE_CYGWIN 105197679Sdes { 10698941Sdes HANDLE hToken = cygwin_logon_user(pw, password); 10798941Sdes 10898941Sdes if (hToken == INVALID_HANDLE_VALUE) 10998941Sdes return 0; 11098941Sdes cygwin_set_impersonation_token(hToken); 111124211Sdes return ok; 11298941Sdes } 113126277Sdes#endif 114137019Sdes#ifdef USE_PAM 115137019Sdes if (options.use_pam) 116137019Sdes return (sshpam_auth_passwd(authctxt, password) && ok); 117137019Sdes#endif 118126277Sdes#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 119126277Sdes if (!expire_checked) { 120126277Sdes expire_checked = 1; 121147005Sdes if (auth_shadow_pwexpired(authctxt)) 122126277Sdes authctxt->force_pwchange = 1; 123126277Sdes } 124126277Sdes#endif 125147005Sdes result = sys_auth_passwd(authctxt, password); 126147005Sdes if (authctxt->force_pwchange) 127147005Sdes disable_forwarding(); 128147005Sdes return (result && ok); 129126277Sdes} 130124211Sdes 131126277Sdes#ifdef BSD_AUTH 132147005Sdesstatic void 133147005Sdeswarn_expiry(Authctxt *authctxt, auth_session_t *as) 134147005Sdes{ 135147005Sdes char buf[256]; 136147005Sdes quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; 137147005Sdes 138147005Sdes pwwarntime = acwarntime = TWO_WEEKS; 139147005Sdes 140147005Sdes pwtimeleft = auth_check_change(as); 141147005Sdes actimeleft = auth_check_expire(as); 142147005Sdes#ifdef HAVE_LOGIN_CAP 143147005Sdes if (authctxt->valid) { 144147005Sdes pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, 145147005Sdes TWO_WEEKS); 146147005Sdes acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, 147147005Sdes TWO_WEEKS); 148147005Sdes } 149147005Sdes#endif 150147005Sdes if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { 151147005Sdes daysleft = pwtimeleft / DAY + 1; 152147005Sdes snprintf(buf, sizeof(buf), 153147005Sdes "Your password will expire in %lld day%s.\n", 154147005Sdes daysleft, daysleft == 1 ? "" : "s"); 155147005Sdes buffer_append(&loginmsg, buf, strlen(buf)); 156147005Sdes } 157147005Sdes if (actimeleft != 0 && actimeleft < acwarntime) { 158147005Sdes daysleft = actimeleft / DAY + 1; 159147005Sdes snprintf(buf, sizeof(buf), 160147005Sdes "Your account will expire in %lld day%s.\n", 161147005Sdes daysleft, daysleft == 1 ? "" : "s"); 162147005Sdes buffer_append(&loginmsg, buf, strlen(buf)); 163147005Sdes } 164147005Sdes} 165147005Sdes 166126277Sdesint 167126277Sdessys_auth_passwd(Authctxt *authctxt, const char *password) 168126277Sdes{ 169126277Sdes struct passwd *pw = authctxt->pw; 170126277Sdes auth_session_t *as; 171147005Sdes static int expire_checked = 0; 172124211Sdes 173126277Sdes as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", 174126277Sdes (char *)password); 175149753Sdes if (as == NULL) 176149753Sdes return (0); 177126277Sdes if (auth_getstate(as) & AUTH_PWEXPIRED) { 178126277Sdes auth_close(as); 179126277Sdes disable_forwarding(); 180126277Sdes authctxt->force_pwchange = 1; 181126277Sdes return (1); 182126277Sdes } else { 183147005Sdes if (!expire_checked) { 184147005Sdes expire_checked = 1; 185147005Sdes warn_expiry(authctxt, as); 186147005Sdes } 187126277Sdes return (auth_close(as)); 18857429Smarkm } 189126277Sdes} 190126277Sdes#elif !defined(CUSTOM_SYS_AUTH_PASSWD) 191126277Sdesint 192126277Sdessys_auth_passwd(Authctxt *authctxt, const char *password) 193126277Sdes{ 194126277Sdes struct passwd *pw = authctxt->pw; 195126277Sdes char *encrypted_password; 196126277Sdes 197124211Sdes /* Just use the supplied fake password if authctxt is invalid */ 198124211Sdes char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; 19998941Sdes 20057429Smarkm /* Check for users with no password. */ 201124211Sdes if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) 202126277Sdes return (1); 20398941Sdes 204126277Sdes /* Encrypt the candidate password using the proper salt. */ 205126277Sdes encrypted_password = xcrypt(password, 206126277Sdes (pw_password[0] && pw_password[1]) ? pw_password : "xx"); 20798941Sdes 208126277Sdes /* 209126277Sdes * Authentication is accepted if the encrypted passwords 210126277Sdes * are identical. 211126277Sdes */ 212240075Sdes return encrypted_password != NULL && 213240075Sdes strcmp(encrypted_password, pw_password) == 0; 21457429Smarkm} 215126277Sdes#endif 216