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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 Tuckerc52a2992004-02-06 16:38:16 +110039RCSID("$OpenBSD: auth-passwd.c,v 1.31 2004/01/30 09:48:57 markus Exp $");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100040
41#include "packet.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000042#include "log.h"
43#include "servconf.h"
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000044#include "auth.h"
Darren Tucker23bc8d02004-02-06 16:24:31 +110045#include "auth-options.h"
Damien Miller60396b02001-02-18 17:01:00 +110046
47extern ServerOptions options;
Darren Tucker23bc8d02004-02-06 16:24:31 +110048int sys_auth_passwd(Authctxt *, const char *);
49
Darren Tuckere3dba822004-02-10 12:50:19 +110050void
Darren Tucker23bc8d02004-02-06 16:24:31 +110051disable_forwarding(void)
52{
53 no_port_forwarding_flag = 1;
54 no_agent_forwarding_flag = 1;
55 no_x11_forwarding_flag = 1;
56}
Damien Miller60396b02001-02-18 17:01:00 +110057
Damien Miller95def091999-11-25 00:26:21 +110058/*
59 * Tries to authenticate the user using password. Returns true if
60 * authentication succeeds.
61 */
Damien Miller4af51302000-04-16 11:18:38 +100062int
Damien Miller60396b02001-02-18 17:01:00 +110063auth_password(Authctxt *authctxt, const char *password)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100064{
Ben Lindstrom0b478142002-05-10 02:40:15 +000065 struct passwd * pw = authctxt->pw;
Damien Millereab4bae2003-04-29 23:22:40 +100066 int ok = authctxt->valid;
Darren Tuckerb4dc6c22004-02-22 10:23:35 +110067 static int expire_checked = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100068
Damien Millerbac2d8a2000-09-05 16:13:06 +110069#ifndef HAVE_CYGWIN
Damien Miller3e3b5142003-11-17 21:13:40 +110070 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
Damien Millereab4bae2003-04-29 23:22:40 +100071 ok = 0;
Damien Millerbac2d8a2000-09-05 16:13:06 +110072#endif
Ben Lindstrom0b478142002-05-10 02:40:15 +000073 if (*password == '\0' && options.permit_empty_passwd == 0)
Damien Millereab4bae2003-04-29 23:22:40 +100074 return 0;
Ben Lindstrom0410e322003-07-24 06:52:13 +000075
Darren Tucker23bc8d02004-02-06 16:24:31 +110076#ifdef KRB5
Ben Lindstromec95ed92001-07-04 04:21:14 +000077 if (options.kerberos_authentication == 1) {
78 int ret = auth_krb5_password(authctxt, password);
79 if (ret == 1 || ret == 0)
Damien Miller856f0be2003-09-03 07:32:45 +100080 return ret && ok;
Ben Lindstromec95ed92001-07-04 04:21:14 +000081 /* Fall back to ordinary passwd authentication. */
82 }
Darren Tucker23bc8d02004-02-06 16:24:31 +110083#endif
84#ifdef HAVE_CYGWIN
Damien Millerbac2d8a2000-09-05 16:13:06 +110085 if (is_winnt) {
86 HANDLE hToken = cygwin_logon_user(pw, password);
87
88 if (hToken == INVALID_HANDLE_VALUE)
Damien Miller856f0be2003-09-03 07:32:45 +100089 return 0;
Damien Millerbac2d8a2000-09-05 16:13:06 +110090 cygwin_set_impersonation_token(hToken);
Damien Miller856f0be2003-09-03 07:32:45 +100091 return ok;
Damien Millerbac2d8a2000-09-05 16:13:06 +110092 }
Darren Tucker23bc8d02004-02-06 16:24:31 +110093#endif
Darren Tucker450a1582004-05-30 20:43:59 +100094#ifdef USE_PAM
95 if (options.use_pam)
96 return (sshpam_auth_passwd(authctxt, password) && ok);
97#endif
Darren Tuckercee6d4c2004-02-11 18:48:52 +110098#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
Darren Tuckerb4dc6c22004-02-22 10:23:35 +110099 if (!expire_checked) {
100 expire_checked = 1;
101 if (auth_shadow_pwexpired(authctxt)) {
102 disable_forwarding();
103 authctxt->force_pwchange = 1;
104 }
Darren Tucker9df3def2004-02-10 13:01:14 +1100105 }
106#endif
107
Darren Tucker23bc8d02004-02-06 16:24:31 +1100108 return (sys_auth_passwd(authctxt, password) && ok);
109}
110
111#ifdef BSD_AUTH
112int
113sys_auth_passwd(Authctxt *authctxt, const char *password)
114{
115 struct passwd *pw = authctxt->pw;
116 auth_session_t *as;
117
118 as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh",
119 (char *)password);
120 if (auth_getstate(as) & AUTH_PWEXPIRED) {
121 auth_close(as);
122 disable_forwarding();
123 authctxt->force_pwchange = 1;
124 return (1);
125 } else {
126 return (auth_close(as));
127 }
128}
Darren Tuckere3dba822004-02-10 12:50:19 +1100129#elif !defined(CUSTOM_SYS_AUTH_PASSWD)
Darren Tucker23bc8d02004-02-06 16:24:31 +1100130int
131sys_auth_passwd(Authctxt *authctxt, const char *password)
132{
133 struct passwd *pw = authctxt->pw;
134 char *encrypted_password;
135
Damien Miller856f0be2003-09-03 07:32:45 +1000136 /* Just use the supplied fake password if authctxt is invalid */
137 char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd;
Damien Miller8a1e6a62000-09-16 15:55:52 +1100138
139 /* Check for users with no password. */
Damien Miller5d07e6d2003-09-18 18:25:46 +1000140 if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0)
Darren Tucker23bc8d02004-02-06 16:24:31 +1100141 return (1);
Damien Miller2e1b0821999-12-25 10:11:29 +1100142
Darren Tucker23bc8d02004-02-06 16:24:31 +1100143 /* Encrypt the candidate password using the proper salt. */
144 encrypted_password = xcrypt(password,
145 (pw_password[0] && pw_password[1]) ? pw_password : "xx");
Damien Miller2e1b0821999-12-25 10:11:29 +1100146
Darren Tucker23bc8d02004-02-06 16:24:31 +1100147 /*
148 * Authentication is accepted if the encrypted passwords
149 * are identical.
150 */
151 return (strcmp(encrypted_password, pw_password) == 0);
Kevin Stevese683e762002-04-04 19:02:28 +0000152}
Darren Tucker23bc8d02004-02-06 16:24:31 +1100153#endif