1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
/*
* pam_pwhistory module
*
* Copyright (c) 2008, 2012 Thorsten Kukuk
* Author: Thorsten Kukuk <kukuk@thkukuk.de>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, and the entire permission notice in its entirety,
* including the disclaimer of warranties.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* ALTERNATIVELY, this product may be distributed under the terms of
* the GNU Public License, in which case the provisions of the GPL are
* required INSTEAD OF the above restrictions. (This clause is
* necessary due to a potential bad interaction between the GPL and
* the restrictions contained in a BSD-style copyright.)
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#if defined(HAVE_CONFIG_H)
#include <config.h>
#endif
#include <pwd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <shadow.h>
#include <syslog.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <security/pam_modules.h>
#include <security/pam_modutil.h>
#include <security/pam_ext.h>
#include <security/_pam_macros.h>
#include "opasswd.h"
#include "pam_inline.h"
#define DEFAULT_BUFLEN 2048
struct options_t {
int debug;
int enforce_for_root;
int remember;
int tries;
};
typedef struct options_t options_t;
static void
parse_option (pam_handle_t *pamh, const char *argv, options_t *options)
{
const char *str;
if (strcasecmp (argv, "try_first_pass") == 0)
/* ignore */;
else if (strcasecmp (argv, "use_first_pass") == 0)
/* ignore */;
else if (strcasecmp (argv, "use_authtok") == 0)
/* ignore, handled by pam_get_authtok */;
else if (strcasecmp (argv, "debug") == 0)
options->debug = 1;
else if ((str = pam_str_skip_icase_prefix(argv, "remember=")) != NULL)
{
options->remember = strtol(str, NULL, 10);
if (options->remember < 0)
options->remember = 0;
if (options->remember > 400)
options->remember = 400;
}
else if ((str = pam_str_skip_icase_prefix(argv, "retry=")) != NULL)
{
options->tries = strtol(str, NULL, 10);
if (options->tries < 0)
options->tries = 1;
}
else if (strcasecmp (argv, "enforce_for_root") == 0)
options->enforce_for_root = 1;
else if (pam_str_skip_icase_prefix(argv, "authtok_type=") != NULL)
{ /* ignore, for pam_get_authtok */; }
else
pam_syslog (pamh, LOG_ERR, "pam_pwhistory: unknown option: %s", argv);
}
/* This module saves the current crypted password in /etc/security/opasswd
and then compares the new password with all entries in this file. */
int
pam_sm_chauthtok (pam_handle_t *pamh, int flags, int argc, const char **argv)
{
struct passwd *pwd;
const char *newpass;
const char *user;
int retval, tries;
options_t options;
memset (&options, 0, sizeof (options));
/* Set some default values, which could be overwritten later. */
options.remember = 10;
options.tries = 1;
/* Parse parameters for module */
for ( ; argc-- > 0; argv++)
parse_option (pamh, *argv, &options);
if (options.debug)
pam_syslog (pamh, LOG_DEBUG, "pam_sm_chauthtok entered");
if (options.remember == 0)
return PAM_IGNORE;
retval = pam_get_user (pamh, &user, NULL);
if (retval != PAM_SUCCESS)
return retval;
if (flags & PAM_PRELIM_CHECK)
{
if (options.debug)
pam_syslog (pamh, LOG_DEBUG,
"pam_sm_chauthtok(PAM_PRELIM_CHECK)");
return PAM_SUCCESS;
}
pwd = pam_modutil_getpwnam (pamh, user);
if (pwd == NULL)
return PAM_USER_UNKNOWN;
if ((strcmp(pwd->pw_passwd, "x") == 0) ||
((pwd->pw_passwd[0] == '#') &&
(pwd->pw_passwd[1] == '#') &&
(strcmp(pwd->pw_name, pwd->pw_passwd + 2) == 0)))
{
struct spwd *spw = pam_modutil_getspnam (pamh, user);
if (spw == NULL)
return PAM_USER_UNKNOWN;
retval = save_old_pass (pamh, user, pwd->pw_uid, spw->sp_pwdp,
options.remember, options.debug);
if (retval != PAM_SUCCESS)
return retval;
}
else
{
retval = save_old_pass (pamh, user, pwd->pw_uid, pwd->pw_passwd,
options.remember, options.debug);
if (retval != PAM_SUCCESS)
return retval;
}
newpass = NULL;
tries = 0;
while ((newpass == NULL) && (tries < options.tries))
{
retval = pam_get_authtok (pamh, PAM_AUTHTOK, &newpass, NULL);
if (retval != PAM_SUCCESS && retval != PAM_TRY_AGAIN)
{
if (retval == PAM_CONV_AGAIN)
retval = PAM_INCOMPLETE;
return retval;
}
tries++;
if (options.debug)
{
if (newpass)
pam_syslog (pamh, LOG_DEBUG, "got new auth token");
else
pam_syslog (pamh, LOG_DEBUG, "got no auth token");
}
if (newpass == NULL || retval == PAM_TRY_AGAIN)
continue;
if (options.debug)
pam_syslog (pamh, LOG_DEBUG, "check against old password file");
if (check_old_pass (pamh, user, newpass,
options.debug) != PAM_SUCCESS)
{
if (getuid() || options.enforce_for_root ||
(flags & PAM_CHANGE_EXPIRED_AUTHTOK))
{
pam_error (pamh,
_("Password has been already used. Choose another."));
newpass = NULL;
/* Remove password item, else following module will use it */
pam_set_item (pamh, PAM_AUTHTOK, (void *) NULL);
}
else
pam_info (pamh,
_("Password has been already used."));
}
}
if (newpass == NULL && tries >= options.tries)
{
if (options.debug)
pam_syslog (pamh, LOG_DEBUG, "Aborted, too many tries");
return PAM_MAXTRIES;
}
return PAM_SUCCESS;
}
|
