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.
45 #include "auth-options.h"
47 extern Buffer loginmsg;
48 extern ServerOptions options;
51 extern login_cap_t *lc;
55 #define DAY (24L * 60 * 60) /* 1 day in seconds */
56 #define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */
59 disable_forwarding(void)
61 no_port_forwarding_flag = 1;
62 no_agent_forwarding_flag = 1;
63 no_x11_forwarding_flag = 1;
67 * Tries to authenticate the user using password. Returns true if
68 * authentication succeeds.
71 auth_password(Authctxt *authctxt, const char *password)
73 struct passwd * pw = authctxt->pw;
74 int result, ok = authctxt->valid;
75 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
76 static int expire_checked = 0;
80 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
83 if (*password == '\0' && options.permit_empty_passwd == 0)
87 if (options.kerberos_authentication == 1) {
88 int ret = auth_krb5_password(authctxt, password);
89 if (ret == 1 || ret == 0)
91 /* Fall back to ordinary passwd authentication. */
96 HANDLE hToken = cygwin_logon_user(pw, password);
98 if (hToken == INVALID_HANDLE_VALUE)
100 cygwin_set_impersonation_token(hToken);
106 return (sshpam_auth_passwd(authctxt, password) && ok);
108 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
109 if (!expire_checked) {
111 if (auth_shadow_pwexpired(authctxt))
112 authctxt->force_pwchange = 1;
115 result = sys_auth_passwd(authctxt, password);
116 if (authctxt->force_pwchange)
117 disable_forwarding();
118 return (result && ok);
123 warn_expiry(Authctxt *authctxt, auth_session_t *as)
126 quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime;
128 pwwarntime = acwarntime = TWO_WEEKS;
130 pwtimeleft = auth_check_change(as);
131 actimeleft = auth_check_expire(as);
132 #ifdef HAVE_LOGIN_CAP
133 if (authctxt->valid) {
134 pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS,
136 acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS,
140 if (pwtimeleft != 0 && pwtimeleft < pwwarntime) {
141 daysleft = pwtimeleft / DAY + 1;
142 snprintf(buf, sizeof(buf),
143 "Your password will expire in %lld day%s.\n",
144 daysleft, daysleft == 1 ? "" : "s");
145 buffer_append(&loginmsg, buf, strlen(buf));
147 if (actimeleft != 0 && actimeleft < acwarntime) {
148 daysleft = actimeleft / DAY + 1;
149 snprintf(buf, sizeof(buf),
150 "Your account will expire in %lld day%s.\n",
151 daysleft, daysleft == 1 ? "" : "s");
152 buffer_append(&loginmsg, buf, strlen(buf));
157 sys_auth_passwd(Authctxt *authctxt, const char *password)
159 struct passwd *pw = authctxt->pw;
161 static int expire_checked = 0;
163 as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh",
167 if (auth_getstate(as) & AUTH_PWEXPIRED) {
169 disable_forwarding();
170 authctxt->force_pwchange = 1;
173 if (!expire_checked) {
175 warn_expiry(authctxt, as);
177 return (auth_close(as));
180 #elif !defined(CUSTOM_SYS_AUTH_PASSWD)
182 sys_auth_passwd(Authctxt *authctxt, const char *password)
184 struct passwd *pw = authctxt->pw;
185 char *encrypted_password;
187 /* Just use the supplied fake password if authctxt is invalid */
188 char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd;
190 /* Check for users with no password. */
191 if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0)
194 /* Encrypt the candidate password using the proper salt. */
195 encrypted_password = xcrypt(password,
196 (pw_password[0] && pw_password[1]) ? pw_password : "xx");
199 * Authentication is accepted if the encrypted passwords
202 return (strcmp(encrypted_password, pw_password) == 0);