auth-passwd.c revision 322341
187189Spdeuskar/* $OpenBSD: auth-passwd.c,v 1.44 2014/07/15 15:54:14 millert Exp $ */ 287189Spdeuskar/* 3146662Stackerman * Author: Tatu Ylonen <ylo@cs.hut.fi> 487189Spdeuskar * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 587189Spdeuskar * All rights reserved 6103895Spdeuskar * Password authentication. This file contains the functions to check whether 7103895Spdeuskar * the password is valid for the user. 887189Spdeuskar * 9103895Spdeuskar * As far as I am concerned, the code I have written for this software 10103895Spdeuskar * can be used freely for any purpose. Any derived versions of this 1187189Spdeuskar * software must be clearly marked as such, and if the derived work is 12103895Spdeuskar * incompatible with the protocol description in the RFC file, it must be 13103895Spdeuskar * called by a name other than "ssh" or "Secure Shell". 14103895Spdeuskar * 1587189Spdeuskar * Copyright (c) 1999 Dug Song. All rights reserved. 1687189Spdeuskar * Copyright (c) 2000 Markus Friedl. All rights reserved. 17103895Spdeuskar * 18103895Spdeuskar * Redistribution and use in source and binary forms, with or without 1987189Spdeuskar * modification, are permitted provided that the following conditions 2087189Spdeuskar * are met: 2187189Spdeuskar * 1. Redistributions of source code must retain the above copyright 2287189Spdeuskar * notice, this list of conditions and the following disclaimer. 23103895Spdeuskar * 2. Redistributions in binary form must reproduce the above copyright 24103895Spdeuskar * notice, this list of conditions and the following disclaimer in the 25103895Spdeuskar * documentation and/or other materials provided with the distribution. 26103895Spdeuskar * 27103895Spdeuskar * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 28103895Spdeuskar * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 29103895Spdeuskar * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 30103895Spdeuskar * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 3187189Spdeuskar * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 3287189Spdeuskar * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 3387189Spdeuskar * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 3490628Spdeuskar * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 3590628Spdeuskar * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 36150968Sglebius * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37150968Sglebius */ 38150968Sglebius 39150968Sglebius#include "includes.h" 4087189Spdeuskar 4187189Spdeuskar#include <sys/types.h> 4287189Spdeuskar 4387189Spdeuskar#include <pwd.h> 4487189Spdeuskar#include <stdio.h> 4587189Spdeuskar#include <string.h> 4687189Spdeuskar#include <stdarg.h> 4787189Spdeuskar 4887189Spdeuskar#include "packet.h" 4987189Spdeuskar#include "buffer.h" 5087189Spdeuskar#include "log.h" 51152740Sglebius#include "misc.h" 5287189Spdeuskar#include "servconf.h" 5387189Spdeuskar#include "key.h" 5487189Spdeuskar#include "hostfile.h" 5587189Spdeuskar#include "auth.h" 5687189Spdeuskar#include "auth-options.h" 5787189Spdeuskar 5887189Spdeuskarextern Buffer loginmsg; 5987189Spdeuskarextern ServerOptions options; 6087189Spdeuskar 6187189Spdeuskar#ifdef HAVE_LOGIN_CAP 6287189Spdeuskarextern login_cap_t *lc; 63112472Spdeuskar#endif 6487189Spdeuskar 6587189Spdeuskar 66108229Spdeuskar#define DAY (24L * 60 * 60) /* 1 day in seconds */ 67146662Stackerman#define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ 68146662Stackerman 69146662Stackerman#define MAX_PASSWORD_LEN 1024 70146662Stackerman 71146662Stackermanvoid 72146662Stackermandisable_forwarding(void) 73146662Stackerman{ 74146662Stackerman no_port_forwarding_flag = 1; 75146662Stackerman no_agent_forwarding_flag = 1; 76146662Stackerman no_x11_forwarding_flag = 1; 77146662Stackerman} 78146662Stackerman 79146662Stackerman/* 80146662Stackerman * Tries to authenticate the user using password. Returns true if 81146662Stackerman * authentication succeeds. 82146662Stackerman */ 83146662Stackermanint 84146662Stackermanauth_password(Authctxt *authctxt, const char *password) 85146662Stackerman{ 86146662Stackerman struct passwd * pw = authctxt->pw; 87146662Stackerman int result, ok = authctxt->valid; 88146662Stackerman#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 89146662Stackerman static int expire_checked = 0; 90146662Stackerman#endif 91146662Stackerman 92146662Stackerman if (strlen(password) > MAX_PASSWORD_LEN) 93146662Stackerman return 0; 94146662Stackerman 95146662Stackerman#ifndef HAVE_CYGWIN 96146662Stackerman if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 97146662Stackerman ok = 0; 98146662Stackerman#endif 99146662Stackerman if (*password == '\0' && options.permit_empty_passwd == 0) 100146662Stackerman return 0; 101146662Stackerman 102146662Stackerman#ifdef KRB5 103146662Stackerman if (options.kerberos_authentication == 1) { 104146662Stackerman int ret = auth_krb5_password(authctxt, password); 105146662Stackerman if (ret == 1 || ret == 0) 106146662Stackerman return ret && ok; 107146662Stackerman /* Fall back to ordinary passwd authentication. */ 108146662Stackerman } 109146662Stackerman#endif 110152740Sglebius#ifdef HAVE_CYGWIN 111152740Sglebius { 112152740Sglebius HANDLE hToken = cygwin_logon_user(pw, password); 113152740Sglebius 114152740Sglebius if (hToken == INVALID_HANDLE_VALUE) 115152740Sglebius return 0; 116152740Sglebius cygwin_set_impersonation_token(hToken); 117152740Sglebius return ok; 118146662Stackerman } 119146662Stackerman#endif 120152740Sglebius#ifdef USE_PAM 121146662Stackerman if (options.use_pam) 122108229Spdeuskar return (sshpam_auth_passwd(authctxt, password) && ok); 123108229Spdeuskar#endif 12487189Spdeuskar#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 12587189Spdeuskar if (!expire_checked) { 12687189Spdeuskar expire_checked = 1; 12787189Spdeuskar if (auth_shadow_pwexpired(authctxt)) 12887189Spdeuskar authctxt->force_pwchange = 1; 12987189Spdeuskar } 13087189Spdeuskar#endif 13197785Spdeuskar result = sys_auth_passwd(authctxt, password); 13287189Spdeuskar if (authctxt->force_pwchange) 13387189Spdeuskar disable_forwarding(); 13487189Spdeuskar return (result && ok); 13587189Spdeuskar} 13687189Spdeuskar 13793914Spdeuskar#ifdef BSD_AUTH 13893914Spdeuskarstatic void 13993914Spdeuskarwarn_expiry(Authctxt *authctxt, auth_session_t *as) 14093914Spdeuskar{ 141153729Sglebius char buf[256]; 142153729Sglebius quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; 14392739Salfred 14492739Salfred pwwarntime = acwarntime = TWO_WEEKS; 145153729Sglebius 146112472Spdeuskar pwtimeleft = auth_check_change(as); 14792739Salfred actimeleft = auth_check_expire(as); 14892739Salfred#ifdef HAVE_LOGIN_CAP 149120364Ssam if (authctxt->valid) { 15092739Salfred pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, 15192739Salfred TWO_WEEKS); 15293914Spdeuskar acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, 15392739Salfred TWO_WEEKS); 15493914Spdeuskar } 15592739Salfred#endif 15692739Salfred if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { 15793914Spdeuskar daysleft = pwtimeleft / DAY + 1; 15892739Salfred snprintf(buf, sizeof(buf), 15993914Spdeuskar "Your password will expire in %lld day%s.\n", 16092739Salfred daysleft, daysleft == 1 ? "" : "s"); 16193914Spdeuskar buffer_append(&loginmsg, buf, strlen(buf)); 16292739Salfred } 16393914Spdeuskar if (actimeleft != 0 && actimeleft < acwarntime) { 16493914Spdeuskar daysleft = actimeleft / DAY + 1; 16592739Salfred snprintf(buf, sizeof(buf), 16692739Salfred "Your account will expire in %lld day%s.\n", 16792739Salfred daysleft, daysleft == 1 ? "" : "s"); 16892739Salfred buffer_append(&loginmsg, buf, strlen(buf)); 16993914Spdeuskar } 17093914Spdeuskar} 171107242Sluigi 172153474Syongariint 173153474Syongarisys_auth_passwd(Authctxt *authctxt, const char *password) 174153474Syongari{ 17592739Salfred struct passwd *pw = authctxt->pw; 176112472Spdeuskar auth_session_t *as; 177108229Spdeuskar static int expire_checked = 0; 178102452Spdeuskar 179108229Spdeuskar as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", 180108229Spdeuskar (char *)password); 181108229Spdeuskar if (as == NULL) 18292739Salfred return (0); 18392739Salfred if (auth_getstate(as) & AUTH_PWEXPIRED) { 18492739Salfred auth_close(as); 18592739Salfred disable_forwarding(); 18692739Salfred authctxt->force_pwchange = 1; 187108229Spdeuskar return (1); 188106649Spdeuskar } else { 189112472Spdeuskar if (!expire_checked) { 190140859Syar expire_checked = 1; 191137609Srwatson warn_expiry(authctxt, as); 192112472Spdeuskar } 193112472Spdeuskar return (auth_close(as)); 194112472Spdeuskar } 195112472Spdeuskar} 196112472Spdeuskar#elif !defined(CUSTOM_SYS_AUTH_PASSWD) 197121106Sdeischenint 198114554Spdeuskarsys_auth_passwd(Authctxt *authctxt, const char *password) 199114554Spdeuskar{ 200114554Spdeuskar struct passwd *pw = authctxt->pw; 201115878Spdeuskar char *encrypted_password; 202115878Spdeuskar 203115878Spdeuskar /* Just use the supplied fake password if authctxt is invalid */ 204115878Spdeuskar char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; 205152225Syongari 206119509Spdeuskar /* Check for users with no password. */ 207119509Spdeuskar if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) 208118314Sjdp return (1); 209118314Sjdp 210118314Sjdp /* Encrypt the candidate password using the proper salt. */ 211118314Sjdp encrypted_password = xcrypt(password, 212150789Sglebius (pw_password[0] && pw_password[1]) ? pw_password : "xx"); 213150789Sglebius 214150789Sglebius /* 21597785Spdeuskar * Authentication is accepted if the encrypted passwords 21687189Spdeuskar * are identical. 21787189Spdeuskar */ 21887189Spdeuskar return encrypted_password != NULL && 21987189Spdeuskar strcmp(encrypted_password, pw_password) == 0; 22087189Spdeuskar} 22197785Spdeuskar#endif 22297785Spdeuskar