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Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
Damien Miller95def091999-11-25 00:26:21 +11002 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11005 * Password authentication. This file contains the functions to check whether
6 * the password is valid for the user.
Damien Millere4340be2000-09-16 13:29:08 +11007 *
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose. Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
13 *
Damien Millere4340be2000-09-16 13:29:08 +110014 * Copyright (c) 1999 Dug Song. All rights reserved.
Damien Millere4340be2000-09-16 13:29:08 +110015 * Copyright (c) 2000 Markus Friedl. All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Damien Miller95def091999-11-25 00:26:21 +110036 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100037
38#include "includes.h"
Darren Tucker218f1782005-01-24 22:50:47 +110039RCSID("$OpenBSD: auth-passwd.c,v 1.33 2005/01/24 11:47:13 dtucker Exp $");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100040
41#include "packet.h"
Darren Tucker5c14c732005-01-24 21:55:49 +110042#include "buffer.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000043#include "log.h"
44#include "servconf.h"
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000045#include "auth.h"
Darren Tucker23bc8d02004-02-06 16:24:31 +110046#include "auth-options.h"
Damien Miller60396b02001-02-18 17:01:00 +110047
Darren Tucker5c14c732005-01-24 21:55:49 +110048extern Buffer loginmsg;
Damien Miller60396b02001-02-18 17:01:00 +110049extern ServerOptions options;
Darren Tucker23bc8d02004-02-06 16:24:31 +110050int sys_auth_passwd(Authctxt *, const char *);
51
Darren Tucker5c14c732005-01-24 21:55:49 +110052#ifdef HAVE_LOGIN_CAP
53extern login_cap_t *lc;
54#endif
55
56
57#define DAY (24L * 60 * 60) /* 1 day in seconds */
58#define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */
59
Darren Tuckere3dba822004-02-10 12:50:19 +110060void
Darren Tucker23bc8d02004-02-06 16:24:31 +110061disable_forwarding(void)
62{
63 no_port_forwarding_flag = 1;
64 no_agent_forwarding_flag = 1;
65 no_x11_forwarding_flag = 1;
66}
Damien Miller60396b02001-02-18 17:01:00 +110067
Damien Miller95def091999-11-25 00:26:21 +110068/*
69 * Tries to authenticate the user using password. Returns true if
70 * authentication succeeds.
71 */
Damien Miller4af51302000-04-16 11:18:38 +100072int
Damien Miller60396b02001-02-18 17:01:00 +110073auth_password(Authctxt *authctxt, const char *password)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100074{
Ben Lindstrom0b478142002-05-10 02:40:15 +000075 struct passwd * pw = authctxt->pw;
Darren Tucker92170a82005-02-09 17:08:23 +110076 int result, ok = authctxt->valid;
Ben Lindstrome35bf122004-06-22 03:37:11 +000077#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
Darren Tuckerb4dc6c22004-02-22 10:23:35 +110078 static int expire_checked = 0;
Ben Lindstrome35bf122004-06-22 03:37:11 +000079#endif
Damien Millerd4a8b7e1999-10-27 13:42:43 +100080
Damien Millerbac2d8a2000-09-05 16:13:06 +110081#ifndef HAVE_CYGWIN
Damien Miller3e3b5142003-11-17 21:13:40 +110082 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
Damien Millereab4bae2003-04-29 23:22:40 +100083 ok = 0;
Damien Millerbac2d8a2000-09-05 16:13:06 +110084#endif
Ben Lindstrom0b478142002-05-10 02:40:15 +000085 if (*password == '\0' && options.permit_empty_passwd == 0)
Damien Millereab4bae2003-04-29 23:22:40 +100086 return 0;
Ben Lindstrom0410e322003-07-24 06:52:13 +000087
Darren Tucker23bc8d02004-02-06 16:24:31 +110088#ifdef KRB5
Ben Lindstromec95ed92001-07-04 04:21:14 +000089 if (options.kerberos_authentication == 1) {
90 int ret = auth_krb5_password(authctxt, password);
91 if (ret == 1 || ret == 0)
Damien Miller856f0be2003-09-03 07:32:45 +100092 return ret && ok;
Ben Lindstromec95ed92001-07-04 04:21:14 +000093 /* Fall back to ordinary passwd authentication. */
94 }
Darren Tucker23bc8d02004-02-06 16:24:31 +110095#endif
96#ifdef HAVE_CYGWIN
Damien Millerbac2d8a2000-09-05 16:13:06 +110097 if (is_winnt) {
98 HANDLE hToken = cygwin_logon_user(pw, password);
99
100 if (hToken == INVALID_HANDLE_VALUE)
Damien Miller856f0be2003-09-03 07:32:45 +1000101 return 0;
Damien Millerbac2d8a2000-09-05 16:13:06 +1100102 cygwin_set_impersonation_token(hToken);
Damien Miller856f0be2003-09-03 07:32:45 +1000103 return ok;
Damien Millerbac2d8a2000-09-05 16:13:06 +1100104 }
Darren Tucker23bc8d02004-02-06 16:24:31 +1100105#endif
Darren Tucker450a1582004-05-30 20:43:59 +1000106#ifdef USE_PAM
107 if (options.use_pam)
108 return (sshpam_auth_passwd(authctxt, password) && ok);
109#endif
Darren Tuckercee6d4c2004-02-11 18:48:52 +1100110#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
Darren Tuckerb4dc6c22004-02-22 10:23:35 +1100111 if (!expire_checked) {
112 expire_checked = 1;
Darren Tucker92170a82005-02-09 17:08:23 +1100113 if (auth_shadow_pwexpired(authctxt))
Darren Tuckerb4dc6c22004-02-22 10:23:35 +1100114 authctxt->force_pwchange = 1;
Darren Tucker9df3def2004-02-10 13:01:14 +1100115 }
116#endif
Darren Tucker92170a82005-02-09 17:08:23 +1100117 result = sys_auth_passwd(authctxt, password);
118 if (authctxt->force_pwchange)
119 disable_forwarding();
120 return (result && ok);
Darren Tucker23bc8d02004-02-06 16:24:31 +1100121}
122
123#ifdef BSD_AUTH
Darren Tucker5c14c732005-01-24 21:55:49 +1100124static void
125warn_expiry(Authctxt *authctxt, auth_session_t *as)
126{
127 char buf[256];
128 quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime;
129
130 pwwarntime = acwarntime = TWO_WEEKS;
131
132 pwtimeleft = auth_check_change(as);
133 actimeleft = auth_check_expire(as);
Darren Tucker218f1782005-01-24 22:50:47 +1100134#ifdef HAVE_LOGIN_CAP
Darren Tucker5c14c732005-01-24 21:55:49 +1100135 if (authctxt->valid) {
136 pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS,
137 TWO_WEEKS);
138 acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS,
139 TWO_WEEKS);
140 }
141#endif
142 if (pwtimeleft != 0 && pwtimeleft < pwwarntime) {
143 daysleft = pwtimeleft / DAY + 1;
144 snprintf(buf, sizeof(buf),
145 "Your password will expire in %lld day%s.\n",
146 daysleft, daysleft == 1 ? "" : "s");
147 buffer_append(&loginmsg, buf, strlen(buf));
148 }
149 if (actimeleft != 0 && actimeleft < acwarntime) {
150 daysleft = actimeleft / DAY + 1;
151 snprintf(buf, sizeof(buf),
152 "Your account will expire in %lld day%s.\n",
153 daysleft, daysleft == 1 ? "" : "s");
154 buffer_append(&loginmsg, buf, strlen(buf));
155 }
156}
157
Darren Tucker23bc8d02004-02-06 16:24:31 +1100158int
159sys_auth_passwd(Authctxt *authctxt, const char *password)
160{
161 struct passwd *pw = authctxt->pw;
162 auth_session_t *as;
Darren Tucker5c14c732005-01-24 21:55:49 +1100163 static int expire_checked = 0;
Darren Tucker23bc8d02004-02-06 16:24:31 +1100164
165 as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh",
166 (char *)password);
167 if (auth_getstate(as) & AUTH_PWEXPIRED) {
168 auth_close(as);
169 disable_forwarding();
170 authctxt->force_pwchange = 1;
171 return (1);
172 } else {
Darren Tucker5c14c732005-01-24 21:55:49 +1100173 if (!expire_checked) {
174 expire_checked = 1;
175 warn_expiry(authctxt, as);
176 }
Darren Tucker23bc8d02004-02-06 16:24:31 +1100177 return (auth_close(as));
178 }
179}
Darren Tuckere3dba822004-02-10 12:50:19 +1100180#elif !defined(CUSTOM_SYS_AUTH_PASSWD)
Darren Tucker23bc8d02004-02-06 16:24:31 +1100181int
182sys_auth_passwd(Authctxt *authctxt, const char *password)
183{
184 struct passwd *pw = authctxt->pw;
185 char *encrypted_password;
186
Damien Miller856f0be2003-09-03 07:32:45 +1000187 /* Just use the supplied fake password if authctxt is invalid */
188 char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd;
Damien Miller8a1e6a62000-09-16 15:55:52 +1100189
190 /* Check for users with no password. */
Damien Miller5d07e6d2003-09-18 18:25:46 +1000191 if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0)
Darren Tucker23bc8d02004-02-06 16:24:31 +1100192 return (1);
Damien Miller2e1b0821999-12-25 10:11:29 +1100193
Darren Tucker23bc8d02004-02-06 16:24:31 +1100194 /* Encrypt the candidate password using the proper salt. */
195 encrypted_password = xcrypt(password,
196 (pw_password[0] && pw_password[1]) ? pw_password : "xx");
Damien Miller2e1b0821999-12-25 10:11:29 +1100197
Darren Tucker23bc8d02004-02-06 16:24:31 +1100198 /*
199 * Authentication is accepted if the encrypted passwords
200 * are identical.
201 */
202 return (strcmp(encrypted_password, pw_password) == 0);
Kevin Stevese683e762002-04-04 19:02:28 +0000203}
Darren Tucker23bc8d02004-02-06 16:24:31 +1100204#endif