1 /* $OpenBSD: auth-passwd.c,v 1.43 2007/09/21 08:15:29 djm Exp $ */
2 /*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * Password authentication. This file contains the functions to check whether
7 * the password is valid for the user.
8 *
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 *
15 * Copyright (c) 1999 Dug Song. All rights reserved.
16 * 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.
37 */
38
39 #include <sys/types.h>
40
41 #include <login_cap.h>
42 #include <pwd.h>
43 #include <stdio.h>
44 #include <string.h>
45 #include <stdarg.h>
46 #include <unistd.h>
47
48 #include "packet.h"
49 #include "buffer.h"
50 #include "log.h"
51 #include "servconf.h"
52 #include "key.h"
53 #include "hostfile.h"
54 #include "auth.h"
55 #include "auth-options.h"
56
57 __RCSID("$MirOS: src/usr.bin/ssh/auth-passwd.c,v 1.9 2008/03/02 21:14:18 tg Exp $");
58
59 extern Buffer loginmsg;
60 extern ServerOptions options;
61 int sys_auth_passwd(Authctxt *, const char *);
62
63 extern login_cap_t *lc;
64
65 #define DAY (24L * 60 * 60) /* 1 day in seconds */
66 #define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */
67
68 #ifdef BSD_AUTH
69 static void
disable_forwarding(void)70 disable_forwarding(void)
71 {
72 no_port_forwarding_flag = 1;
73 no_agent_forwarding_flag = 1;
74 no_x11_forwarding_flag = 1;
75 }
76 #endif
77
78 /*
79 * Tries to authenticate the user using password. Returns true if
80 * authentication succeeds.
81 */
82 int
auth_password(Authctxt * authctxt,const char * password)83 auth_password(Authctxt *authctxt, const char *password)
84 {
85 struct passwd * pw = authctxt->pw;
86 int ok = authctxt->valid;
87
88 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
89 ok = 0;
90 if (*password == '\0' && options.permit_empty_passwd == 0)
91 return 0;
92 return (sys_auth_passwd(authctxt, password) && ok);
93 }
94
95 #ifdef BSD_AUTH
96 static void
warn_expiry(Authctxt * authctxt,auth_session_t * as)97 warn_expiry(Authctxt *authctxt, auth_session_t *as)
98 {
99 char buf[256];
100 quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime;
101
102 pwwarntime = acwarntime = TWO_WEEKS;
103
104 pwtimeleft = auth_check_change(as);
105 actimeleft = auth_check_expire(as);
106 if (authctxt->valid) {
107 pwwarntime = login_getcaptime(lc, (char *)"password-warn",
108 TWO_WEEKS, TWO_WEEKS);
109 acwarntime = login_getcaptime(lc, (char *)"expire-warn",
110 TWO_WEEKS, TWO_WEEKS);
111 }
112 if (pwtimeleft != 0 && pwtimeleft < pwwarntime) {
113 daysleft = pwtimeleft / DAY + 1;
114 snprintf(buf, sizeof(buf),
115 "Your password will expire in %lld day%s.\n",
116 daysleft, daysleft == 1 ? "" : "s");
117 buffer_append(&loginmsg, buf, strlen(buf));
118 }
119 if (actimeleft != 0 && actimeleft < acwarntime) {
120 daysleft = actimeleft / DAY + 1;
121 snprintf(buf, sizeof(buf),
122 "Your account will expire in %lld day%s.\n",
123 daysleft, daysleft == 1 ? "" : "s");
124 buffer_append(&loginmsg, buf, strlen(buf));
125 }
126 }
127
128 int
sys_auth_passwd(Authctxt * authctxt,const char * password)129 sys_auth_passwd(Authctxt *authctxt, const char *password)
130 {
131 struct passwd *pw = authctxt->pw;
132 auth_session_t *as;
133 static int expire_checked = 0;
134
135 as = auth_usercheck(pw->pw_name, authctxt->style, (char *)"auth-ssh",
136 (char *)password);
137 if (as == NULL)
138 return (0);
139 if (auth_getstate(as) & AUTH_PWEXPIRED) {
140 auth_close(as);
141 disable_forwarding();
142 authctxt->force_pwchange = 1;
143 return (1);
144 } else {
145 if (!expire_checked) {
146 expire_checked = 1;
147 warn_expiry(authctxt, as);
148 }
149 return (auth_close(as));
150 }
151 }
152 #else
153 int
sys_auth_passwd(Authctxt * authctxt,const char * password)154 sys_auth_passwd(Authctxt *authctxt, const char *password)
155 {
156 struct passwd *pw = authctxt->pw;
157 char *encrypted_password;
158
159 /* Check for users with no password. */
160 if (strcmp(password, "") == 0 && strcmp(pw->pw_passwd, "") == 0)
161 return (1);
162
163 /* Encrypt the candidate password using the proper salt. */
164 encrypted_password = crypt(password,
165 (pw->pw_passwd[0] && pw->pw_passwd[1]) ?
166 pw->pw_passwd : "xx");
167
168 /*
169 * Authentication is accepted if the encrypted passwords
170 * are identical.
171 */
172 return (strcmp(encrypted_password, pw->pw_passwd) == 0);
173 }
174 #endif
175