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Damien Miller733124b2007-10-26 14:25:12 +10001/* $OpenBSD: auth-passwd.c,v 1.43 2007/09/21 08:15:29 djm Exp $ */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002/*
Damien Miller95def091999-11-25 00:26:21 +11003 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11006 * Password authentication. This file contains the functions to check whether
7 * the password is valid for the user.
Damien Millere4340be2000-09-16 13:29:08 +11008 *
9 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
14 *
Damien Millere4340be2000-09-16 13:29:08 +110015 * Copyright (c) 1999 Dug Song. All rights reserved.
Damien Millere4340be2000-09-16 13:29:08 +110016 * Copyright (c) 2000 Markus Friedl. All rights reserved.
17 *
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
20 * are met:
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
28 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
29 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
31 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
32 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
36 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Damien Miller95def091999-11-25 00:26:21 +110037 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100038
39#include "includes.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100040
Damien Miller9f2abc42006-07-10 20:53:08 +100041#include <sys/types.h>
42
43#include <pwd.h>
Damien Millera7a73ee2006-08-05 11:37:59 +100044#include <stdio.h>
Damien Millere3476ed2006-07-24 14:13:33 +100045#include <string.h>
Damien Millerd7834352006-08-05 12:39:39 +100046#include <stdarg.h>
Damien Miller9f2abc42006-07-10 20:53:08 +100047
Damien Millerd4a8b7e1999-10-27 13:42:43 +100048#include "packet.h"
Darren Tucker5c14c732005-01-24 21:55:49 +110049#include "buffer.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000050#include "log.h"
51#include "servconf.h"
Damien Millerd7834352006-08-05 12:39:39 +100052#include "key.h"
53#include "hostfile.h"
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000054#include "auth.h"
Darren Tucker23bc8d02004-02-06 16:24:31 +110055#include "auth-options.h"
Damien Miller60396b02001-02-18 17:01:00 +110056
Darren Tucker5c14c732005-01-24 21:55:49 +110057extern Buffer loginmsg;
Damien Miller60396b02001-02-18 17:01:00 +110058extern ServerOptions options;
Darren Tucker23bc8d02004-02-06 16:24:31 +110059
Darren Tucker5c14c732005-01-24 21:55:49 +110060#ifdef HAVE_LOGIN_CAP
61extern login_cap_t *lc;
62#endif
63
64
65#define DAY (24L * 60 * 60) /* 1 day in seconds */
66#define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */
67
Darren Tuckere3dba822004-02-10 12:50:19 +110068void
Darren Tucker23bc8d02004-02-06 16:24:31 +110069disable_forwarding(void)
70{
71 no_port_forwarding_flag = 1;
72 no_agent_forwarding_flag = 1;
73 no_x11_forwarding_flag = 1;
74}
Damien Miller60396b02001-02-18 17:01:00 +110075
Damien Miller95def091999-11-25 00:26:21 +110076/*
77 * Tries to authenticate the user using password. Returns true if
78 * authentication succeeds.
79 */
Damien Miller4af51302000-04-16 11:18:38 +100080int
Damien Miller60396b02001-02-18 17:01:00 +110081auth_password(Authctxt *authctxt, const char *password)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100082{
Ben Lindstrom0b478142002-05-10 02:40:15 +000083 struct passwd * pw = authctxt->pw;
Darren Tucker92170a82005-02-09 17:08:23 +110084 int result, ok = authctxt->valid;
Ben Lindstrome35bf122004-06-22 03:37:11 +000085#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
Darren Tuckerb4dc6c22004-02-22 10:23:35 +110086 static int expire_checked = 0;
Ben Lindstrome35bf122004-06-22 03:37:11 +000087#endif
Damien Millerd4a8b7e1999-10-27 13:42:43 +100088
Damien Millerbac2d8a2000-09-05 16:13:06 +110089#ifndef HAVE_CYGWIN
Damien Miller3e3b5142003-11-17 21:13:40 +110090 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
Damien Millereab4bae2003-04-29 23:22:40 +100091 ok = 0;
Damien Millerbac2d8a2000-09-05 16:13:06 +110092#endif
Ben Lindstrom0b478142002-05-10 02:40:15 +000093 if (*password == '\0' && options.permit_empty_passwd == 0)
Damien Millereab4bae2003-04-29 23:22:40 +100094 return 0;
Ben Lindstrom0410e322003-07-24 06:52:13 +000095
Darren Tucker23bc8d02004-02-06 16:24:31 +110096#ifdef KRB5
Ben Lindstromec95ed92001-07-04 04:21:14 +000097 if (options.kerberos_authentication == 1) {
98 int ret = auth_krb5_password(authctxt, password);
99 if (ret == 1 || ret == 0)
Damien Miller856f0be2003-09-03 07:32:45 +1000100 return ret && ok;
Ben Lindstromec95ed92001-07-04 04:21:14 +0000101 /* Fall back to ordinary passwd authentication. */
102 }
Darren Tucker23bc8d02004-02-06 16:24:31 +1100103#endif
104#ifdef HAVE_CYGWIN
Damien Millerbac2d8a2000-09-05 16:13:06 +1100105 if (is_winnt) {
106 HANDLE hToken = cygwin_logon_user(pw, password);
107
108 if (hToken == INVALID_HANDLE_VALUE)
Damien Miller856f0be2003-09-03 07:32:45 +1000109 return 0;
Damien Millerbac2d8a2000-09-05 16:13:06 +1100110 cygwin_set_impersonation_token(hToken);
Damien Miller856f0be2003-09-03 07:32:45 +1000111 return ok;
Damien Millerbac2d8a2000-09-05 16:13:06 +1100112 }
Darren Tucker23bc8d02004-02-06 16:24:31 +1100113#endif
Darren Tucker450a1582004-05-30 20:43:59 +1000114#ifdef USE_PAM
115 if (options.use_pam)
116 return (sshpam_auth_passwd(authctxt, password) && ok);
117#endif
Darren Tuckercee6d4c2004-02-11 18:48:52 +1100118#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
Darren Tuckerb4dc6c22004-02-22 10:23:35 +1100119 if (!expire_checked) {
120 expire_checked = 1;
Darren Tucker92170a82005-02-09 17:08:23 +1100121 if (auth_shadow_pwexpired(authctxt))
Darren Tuckerb4dc6c22004-02-22 10:23:35 +1100122 authctxt->force_pwchange = 1;
Darren Tucker9df3def2004-02-10 13:01:14 +1100123 }
124#endif
Darren Tucker92170a82005-02-09 17:08:23 +1100125 result = sys_auth_passwd(authctxt, password);
126 if (authctxt->force_pwchange)
127 disable_forwarding();
128 return (result && ok);
Darren Tucker23bc8d02004-02-06 16:24:31 +1100129}
130
131#ifdef BSD_AUTH
Darren Tucker5c14c732005-01-24 21:55:49 +1100132static 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);
Darren Tucker218f1782005-01-24 22:50:47 +1100142#ifdef HAVE_LOGIN_CAP
Darren Tucker5c14c732005-01-24 21:55:49 +1100143 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
Darren Tucker23bc8d02004-02-06 16:24:31 +1100166int
167sys_auth_passwd(Authctxt *authctxt, const char *password)
168{
169 struct passwd *pw = authctxt->pw;
170 auth_session_t *as;
Darren Tucker5c14c732005-01-24 21:55:49 +1100171 static int expire_checked = 0;
Darren Tucker23bc8d02004-02-06 16:24:31 +1100172
173 as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh",
174 (char *)password);
Damien Miller47655ee2005-07-26 21:54:11 +1000175 if (as == NULL)
176 return (0);
Darren Tucker23bc8d02004-02-06 16:24:31 +1100177 if (auth_getstate(as) & AUTH_PWEXPIRED) {
178 auth_close(as);
179 disable_forwarding();
180 authctxt->force_pwchange = 1;
181 return (1);
182 } else {
Darren Tucker5c14c732005-01-24 21:55:49 +1100183 if (!expire_checked) {
184 expire_checked = 1;
185 warn_expiry(authctxt, as);
186 }
Darren Tucker23bc8d02004-02-06 16:24:31 +1100187 return (auth_close(as));
188 }
189}
Darren Tuckere3dba822004-02-10 12:50:19 +1100190#elif !defined(CUSTOM_SYS_AUTH_PASSWD)
Darren Tucker23bc8d02004-02-06 16:24:31 +1100191int
192sys_auth_passwd(Authctxt *authctxt, const char *password)
193{
194 struct passwd *pw = authctxt->pw;
195 char *encrypted_password;
196
Damien Miller856f0be2003-09-03 07:32:45 +1000197 /* Just use the supplied fake password if authctxt is invalid */
198 char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd;
Damien Miller8a1e6a62000-09-16 15:55:52 +1100199
200 /* Check for users with no password. */
Damien Miller5d07e6d2003-09-18 18:25:46 +1000201 if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0)
Darren Tucker23bc8d02004-02-06 16:24:31 +1100202 return (1);
Damien Miller2e1b0821999-12-25 10:11:29 +1100203
Darren Tucker23bc8d02004-02-06 16:24:31 +1100204 /* Encrypt the candidate password using the proper salt. */
205 encrypted_password = xcrypt(password,
206 (pw_password[0] && pw_password[1]) ? pw_password : "xx");
Damien Miller2e1b0821999-12-25 10:11:29 +1100207
Darren Tucker23bc8d02004-02-06 16:24:31 +1100208 /*
209 * Authentication is accepted if the encrypted passwords
210 * are identical.
211 */
212 return (strcmp(encrypted_password, pw_password) == 0);
Kevin Stevese683e762002-04-04 19:02:28 +0000213}
Darren Tucker23bc8d02004-02-06 16:24:31 +1100214#endif