2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * Password authentication. This file contains the functions to check whether
6 * the password is valid for the user.
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".
14 * Copyright (c) 1999 Dug Song. All rights reserved.
15 * Copyright (c) 2000 Markus Friedl. All rights reserved.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
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.
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.
39 RCSID("$OpenBSD: auth-passwd.c,v 1.31 2004/01/30 09:48:57 markus Exp $");
45 #include "auth-options.h"
47 extern ServerOptions options;
48 int sys_auth_passwd(Authctxt *, const char *);
51 disable_forwarding(void)
53 no_port_forwarding_flag = 1;
54 no_agent_forwarding_flag = 1;
55 no_x11_forwarding_flag = 1;
59 * Tries to authenticate the user using password. Returns true if
60 * authentication succeeds.
63 auth_password(Authctxt *authctxt, const char *password)
65 struct passwd * pw = authctxt->pw;
66 int ok = authctxt->valid;
67 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
68 static int expire_checked = 0;
72 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
75 if (*password == '\0' && options.permit_empty_passwd == 0)
79 if (options.kerberos_authentication == 1) {
80 int ret = auth_krb5_password(authctxt, password);
81 if (ret == 1 || ret == 0)
83 /* Fall back to ordinary passwd authentication. */
88 HANDLE hToken = cygwin_logon_user(pw, password);
90 if (hToken == INVALID_HANDLE_VALUE)
92 cygwin_set_impersonation_token(hToken);
98 return (sshpam_auth_passwd(authctxt, password) && ok);
100 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
101 if (!expire_checked) {
103 if (auth_shadow_pwexpired(authctxt)) {
104 disable_forwarding();
105 authctxt->force_pwchange = 1;
110 return (sys_auth_passwd(authctxt, password) && ok);
115 sys_auth_passwd(Authctxt *authctxt, const char *password)
117 struct passwd *pw = authctxt->pw;
120 as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh",
122 if (auth_getstate(as) & AUTH_PWEXPIRED) {
124 disable_forwarding();
125 authctxt->force_pwchange = 1;
128 return (auth_close(as));
131 #elif !defined(CUSTOM_SYS_AUTH_PASSWD)
133 sys_auth_passwd(Authctxt *authctxt, const char *password)
135 struct passwd *pw = authctxt->pw;
136 char *encrypted_password;
138 /* Just use the supplied fake password if authctxt is invalid */
139 char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd;
141 /* Check for users with no password. */
142 if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0)
145 /* Encrypt the candidate password using the proper salt. */
146 encrypted_password = xcrypt(password,
147 (pw_password[0] && pw_password[1]) ? pw_password : "xx");
150 * Authentication is accepted if the encrypted passwords
153 return (strcmp(encrypted_password, pw_password) == 0);