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
|
/* $OpenBSD: local_passwd.c,v 1.46 2015/11/26 19:01:47 deraadt Exp $ */
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* 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, this list of conditions and the following disclaimer.
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <util.h>
#include <login_cap.h>
#define UNCHANGED_MSG "Password unchanged.\n"
static uid_t uid;
extern int pwd_check(login_cap_t *, char *);
extern int pwd_gettries(login_cap_t *);
int local_passwd(char *, int);
char *getnewpasswd(struct passwd *, login_cap_t *, int);
void kbintr(int);
int
local_passwd(char *uname, int authenticated)
{
struct passwd *pw, *opw;
login_cap_t *lc;
sigset_t fullset;
time_t period;
int i, pfd, tfd = -1;
int pwflags = _PASSWORD_OMITV7;
if (!(pw = getpwnam(uname))) {
warnx("unknown user %s.", uname);
return(1);
}
if (pledge("stdio rpath wpath cpath getpw tty id proc exec", NULL) == -1)
err(1, "pledge");
if ((opw = pw_dup(pw)) == NULL) {
warn(NULL);
return(1);
}
if ((lc = login_getclass(pw->pw_class)) == NULL) {
warnx("unable to get login class for user %s.", uname);
free(opw);
return(1);
}
uid = authenticated ? pw->pw_uid : getuid();
if (uid && uid != pw->pw_uid) {
warnx("login/uid mismatch, username argument required.");
free(opw);
return(1);
}
/* Get the new password. */
pw->pw_passwd = getnewpasswd(pw, lc, authenticated);
if (pledge("stdio rpath wpath cpath getpw id proc exec", NULL) == -1)
err(1, "pledge");
/* Reset password change time based on login.conf. */
period = (time_t)login_getcaptime(lc, "passwordtime",
(quad_t)0, (quad_t)0);
if (period > 0) {
pw->pw_change = time(NULL) + period;
} else {
/*
* If the pw change time is the same we only need
* to update the spwd.db file.
*/
if (pw->pw_change != 0)
pw->pw_change = 0;
else
pwflags = _PASSWORD_SECUREONLY;
}
/* Drop user's real uid and block all signals to avoid a DoS. */
setuid(0);
sigfillset(&fullset);
sigdelset(&fullset, SIGINT);
sigprocmask(SIG_BLOCK, &fullset, NULL);
if (pledge("stdio rpath wpath cpath proc exec", NULL) == -1)
err(1, "pledge");
/* Get a lock on the passwd file and open it. */
pw_init();
for (i = 1; (tfd = pw_lock(0)) == -1; i++) {
if (i == 4)
(void)fputs("Attempting to lock password file, "
"please wait or press ^C to abort", stderr);
(void)signal(SIGINT, kbintr);
if (i % 16 == 0)
fputc('.', stderr);
usleep(250000);
(void)signal(SIGINT, SIG_IGN);
}
if (i >= 4)
fputc('\n', stderr);
pfd = open(_PATH_MASTERPASSWD, O_RDONLY | O_CLOEXEC, 0);
if (pfd < 0)
pw_error(_PATH_MASTERPASSWD, 1, 1);
/* Update master.passwd file and rebuild spwd.db. */
pw_copy(pfd, tfd, pw, opw);
free(opw);
if (pw_mkdb(uname, pwflags) < 0)
pw_error(NULL, 0, 1);
return(0);
}
char *
getnewpasswd(struct passwd *pw, login_cap_t *lc, int authenticated)
{
static char hash[_PASSWORD_LEN];
char *p, *pref;
int tries, pwd_tries;
char buf[1024];
sig_t saveint, savequit;
saveint = signal(SIGINT, kbintr);
savequit = signal(SIGQUIT, kbintr);
if (!authenticated) {
(void)printf("Changing password for %s.\n", pw->pw_name);
if (uid != 0 && pw->pw_passwd[0] != '\0') {
p = getpass("Old password:");
if (p == NULL || *p == '\0') {
(void)printf(UNCHANGED_MSG);
pw_abort();
exit(p == NULL ? 1 : 0);
}
if (crypt_checkpass(p, pw->pw_passwd) != 0) {
errno = EACCES;
pw_error(NULL, 1, 1);
}
}
}
pwd_tries = pwd_gettries(lc);
for (buf[0] = '\0', tries = 0;;) {
p = getpass("New password:");
if (p == NULL || *p == '\0') {
(void)printf(UNCHANGED_MSG);
pw_abort();
exit(p == NULL ? 1 : 0);
}
if (strcmp(p, "s/key") == 0) {
printf("That password collides with a system feature. Choose another.\n");
continue;
}
if ((tries++ < pwd_tries || pwd_tries == 0) &&
pwd_check(lc, p) == 0)
continue;
strlcpy(buf, p, sizeof(buf));
p = getpass("Retype new password:");
if (p != NULL && strcmp(buf, p) == 0)
break;
(void)printf("Mismatch; try again, EOF to quit.\n");
}
(void)signal(SIGINT, saveint);
(void)signal(SIGQUIT, savequit);
pref = login_getcapstr(lc, "localcipher", NULL, NULL);
if (crypt_newhash(buf, pref, hash, sizeof(hash)) != 0) {
(void)printf("Couldn't generate hash.\n");
pw_error(NULL, 0, 0);
}
free(pref);
return hash;
}
/* ARGSUSED */
void
kbintr(int signo)
{
write(STDOUT_FILENO, "\n", 1);
write(STDOUT_FILENO, UNCHANGED_MSG, sizeof(UNCHANGED_MSG) - 1);
_exit(0);
}
|
