1323124Sdes/* $OpenBSD: auth-passwd.c,v 1.45 2016/07/21 01:39:35 dtucker 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" 51295367Sdes#include "misc.h" 5257429Smarkm#include "servconf.h" 53162856Sdes#include "key.h" 54162856Sdes#include "hostfile.h" 5576262Sgreen#include "auth.h" 56126277Sdes#include "auth-options.h" 5776262Sgreen 58147005Sdesextern Buffer loginmsg; 59124211Sdesextern ServerOptions options; 60124211Sdes 61147005Sdes#ifdef HAVE_LOGIN_CAP 62147005Sdesextern login_cap_t *lc; 63147005Sdes#endif 64147005Sdes 65147005Sdes 66147005Sdes#define DAY (24L * 60 * 60) /* 1 day in seconds */ 67147005Sdes#define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ 68147005Sdes 69322341Sdelphij#define MAX_PASSWORD_LEN 1024 70322341Sdelphij 71126277Sdesvoid 72126277Sdesdisable_forwarding(void) 73126277Sdes{ 74126277Sdes no_port_forwarding_flag = 1; 75126277Sdes no_agent_forwarding_flag = 1; 76126277Sdes no_x11_forwarding_flag = 1; 77126277Sdes} 78126277Sdes 7957429Smarkm/* 8057429Smarkm * Tries to authenticate the user using password. Returns true if 8157429Smarkm * authentication succeeds. 8257429Smarkm */ 8365674Skrisint 8476262Sgreenauth_password(Authctxt *authctxt, const char *password) 8557429Smarkm{ 8676262Sgreen struct passwd * pw = authctxt->pw; 87147005Sdes int result, ok = authctxt->valid; 88137019Sdes#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 89126277Sdes static int expire_checked = 0; 90137019Sdes#endif 9157429Smarkm 92322341Sdelphij if (strlen(password) > MAX_PASSWORD_LEN) 93322341Sdelphij return 0; 94322341Sdelphij 9598941Sdes#ifndef HAVE_CYGWIN 96126277Sdes if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 97124211Sdes ok = 0; 9898941Sdes#endif 9957429Smarkm if (*password == '\0' && options.permit_empty_passwd == 0) 10057429Smarkm return 0; 101113911Sdes 102126277Sdes#ifdef KRB5 10373400Sassar if (options.kerberos_authentication == 1) { 10492559Sdes int ret = auth_krb5_password(authctxt, password); 10592559Sdes if (ret == 1 || ret == 0) 106124211Sdes return ret && ok; 10757565Smarkm /* Fall back to ordinary passwd authentication. */ 10857565Smarkm } 109126277Sdes#endif 110126277Sdes#ifdef HAVE_CYGWIN 111197679Sdes { 11298941Sdes HANDLE hToken = cygwin_logon_user(pw, password); 11398941Sdes 11498941Sdes if (hToken == INVALID_HANDLE_VALUE) 11598941Sdes return 0; 11698941Sdes cygwin_set_impersonation_token(hToken); 117124211Sdes return ok; 11898941Sdes } 119126277Sdes#endif 120137019Sdes#ifdef USE_PAM 121137019Sdes if (options.use_pam) 122137019Sdes return (sshpam_auth_passwd(authctxt, password) && ok); 123137019Sdes#endif 124126277Sdes#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 125126277Sdes if (!expire_checked) { 126126277Sdes expire_checked = 1; 127147005Sdes if (auth_shadow_pwexpired(authctxt)) 128126277Sdes authctxt->force_pwchange = 1; 129126277Sdes } 130126277Sdes#endif 131147005Sdes result = sys_auth_passwd(authctxt, password); 132147005Sdes if (authctxt->force_pwchange) 133147005Sdes disable_forwarding(); 134147005Sdes return (result && ok); 135126277Sdes} 136124211Sdes 137126277Sdes#ifdef BSD_AUTH 138147005Sdesstatic void 139147005Sdeswarn_expiry(Authctxt *authctxt, auth_session_t *as) 140147005Sdes{ 141147005Sdes char buf[256]; 142147005Sdes quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; 143147005Sdes 144147005Sdes pwwarntime = acwarntime = TWO_WEEKS; 145147005Sdes 146147005Sdes pwtimeleft = auth_check_change(as); 147147005Sdes actimeleft = auth_check_expire(as); 148147005Sdes#ifdef HAVE_LOGIN_CAP 149147005Sdes if (authctxt->valid) { 150147005Sdes pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, 151147005Sdes TWO_WEEKS); 152147005Sdes acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, 153147005Sdes TWO_WEEKS); 154147005Sdes } 155147005Sdes#endif 156147005Sdes if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { 157147005Sdes daysleft = pwtimeleft / DAY + 1; 158147005Sdes snprintf(buf, sizeof(buf), 159147005Sdes "Your password will expire in %lld day%s.\n", 160147005Sdes daysleft, daysleft == 1 ? "" : "s"); 161147005Sdes buffer_append(&loginmsg, buf, strlen(buf)); 162147005Sdes } 163147005Sdes if (actimeleft != 0 && actimeleft < acwarntime) { 164147005Sdes daysleft = actimeleft / DAY + 1; 165147005Sdes snprintf(buf, sizeof(buf), 166147005Sdes "Your account will expire in %lld day%s.\n", 167147005Sdes daysleft, daysleft == 1 ? "" : "s"); 168147005Sdes buffer_append(&loginmsg, buf, strlen(buf)); 169147005Sdes } 170147005Sdes} 171147005Sdes 172126277Sdesint 173126277Sdessys_auth_passwd(Authctxt *authctxt, const char *password) 174126277Sdes{ 175126277Sdes struct passwd *pw = authctxt->pw; 176126277Sdes auth_session_t *as; 177147005Sdes static int expire_checked = 0; 178124211Sdes 179126277Sdes as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", 180126277Sdes (char *)password); 181149753Sdes if (as == NULL) 182149753Sdes return (0); 183126277Sdes if (auth_getstate(as) & AUTH_PWEXPIRED) { 184126277Sdes auth_close(as); 185126277Sdes disable_forwarding(); 186126277Sdes authctxt->force_pwchange = 1; 187126277Sdes return (1); 188126277Sdes } else { 189147005Sdes if (!expire_checked) { 190147005Sdes expire_checked = 1; 191147005Sdes warn_expiry(authctxt, as); 192147005Sdes } 193126277Sdes return (auth_close(as)); 19457429Smarkm } 195126277Sdes} 196126277Sdes#elif !defined(CUSTOM_SYS_AUTH_PASSWD) 197126277Sdesint 198126277Sdessys_auth_passwd(Authctxt *authctxt, const char *password) 199126277Sdes{ 200126277Sdes struct passwd *pw = authctxt->pw; 201323124Sdes char *encrypted_password, *salt = NULL; 202126277Sdes 203124211Sdes /* Just use the supplied fake password if authctxt is invalid */ 204124211Sdes char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; 20598941Sdes 20657429Smarkm /* Check for users with no password. */ 207124211Sdes if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) 208126277Sdes return (1); 20998941Sdes 210323124Sdes /* 211323124Sdes * Encrypt the candidate password using the proper salt, or pass a 212323124Sdes * NULL and let xcrypt pick one. 213323124Sdes */ 214323124Sdes if (authctxt->valid && pw_password[0] && pw_password[1]) 215323124Sdes salt = pw_password; 216323124Sdes encrypted_password = xcrypt(password, salt); 21798941Sdes 218126277Sdes /* 219126277Sdes * Authentication is accepted if the encrypted passwords 220126277Sdes * are identical. 221126277Sdes */ 222240075Sdes return encrypted_password != NULL && 223240075Sdes strcmp(encrypted_password, pw_password) == 0; 22457429Smarkm} 225126277Sdes#endif 226