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
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
|
/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config PASSWD
//config: bool "passwd"
//config: default y
//config: select FEATURE_SYSLOG
//config: help
//config: passwd changes passwords for user and group accounts. A normal user
//config: may only change the password for his/her own account, the super user
//config: may change the password for any account. The administrator of a group
//config: may change the password for the group.
//config:
//config: Note that Busybox binary must be setuid root for this applet to
//config: work properly.
//config:
//config:config FEATURE_PASSWD_WEAK_CHECK
//config: bool "Check new passwords for weakness"
//config: default y
//config: depends on PASSWD
//config: help
//config: With this option passwd will refuse new passwords which are "weak".
//applet:/* Needs to be run by root or be suid root - needs to change /etc/{passwd,shadow}: */
//applet:IF_PASSWD(APPLET(passwd, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
//kbuild:lib-$(CONFIG_PASSWD) += passwd.o
//usage:#define passwd_trivial_usage
//usage: "[OPTIONS] [USER]"
//usage:#define passwd_full_usage "\n\n"
//usage: "Change USER's password (default: current user)"
//usage: "\n"
//usage: "\n -a ALG "CRYPT_METHODS_HELP_STR
//usage: "\n -d Set password to ''"
//usage: "\n -l Lock (disable) account"
//usage: "\n -u Unlock (enable) account"
#include "libbb.h"
#include <syslog.h>
#include <sys/resource.h> /* setrlimit */
static char* new_password(const struct passwd *pw, uid_t myuid, const char *algo)
{
char salt[MAX_PW_SALT_LEN];
char *orig = (char*)"";
char *newp = NULL;
char *cp = NULL;
char *ret = NULL; /* failure so far */
if (myuid != 0 && pw->pw_passwd[0]) {
char *encrypted;
orig = bb_ask_stdin("Old password: "); /* returns ptr to static */
if (!orig)
goto err_ret;
encrypted = pw_encrypt(orig, pw->pw_passwd, 1); /* returns malloced str */
if (strcmp(encrypted, pw->pw_passwd) != 0) {
syslog(LOG_WARNING, "incorrect password for %s", pw->pw_name);
bb_do_delay(LOGIN_FAIL_DELAY);
puts("Incorrect password");
goto err_ret;
}
if (ENABLE_FEATURE_CLEAN_UP)
free(encrypted);
}
orig = xstrdup(orig); /* or else bb_ask_stdin() will destroy it */
newp = bb_ask_stdin("New password: "); /* returns ptr to static */
if (!newp)
goto err_ret;
newp = xstrdup(newp); /* we are going to bb_ask_stdin() again, so save it */
if (ENABLE_FEATURE_PASSWD_WEAK_CHECK
&& obscure(orig, newp, pw)
&& myuid != 0
) {
goto err_ret; /* non-root is not allowed to have weak passwd */
}
cp = bb_ask_stdin("Retype password: ");
if (!cp)
goto err_ret;
if (strcmp(cp, newp) != 0) {
puts("Passwords don't match");
goto err_ret;
}
crypt_make_pw_salt(salt, algo);
/* pw_encrypt returns malloced str */
ret = pw_encrypt(newp, salt, 1);
/* whee, success! */
err_ret:
nuke_str(orig);
if (ENABLE_FEATURE_CLEAN_UP) free(orig);
nuke_str(newp);
if (ENABLE_FEATURE_CLEAN_UP) free(newp);
nuke_str(cp);
return ret;
}
int passwd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int passwd_main(int argc UNUSED_PARAM, char **argv)
{
enum {
OPT_algo = (1 << 0), /* -a - password algorithm */
OPT_lock = (1 << 1), /* -l - lock account */
OPT_unlock = (1 << 2), /* -u - unlock account */
OPT_delete = (1 << 3), /* -d - delete password */
OPT_lud = OPT_lock | OPT_unlock | OPT_delete,
};
unsigned opt;
int rc;
const char *opt_a = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
const char *filename;
char *myname;
char *name;
char *newp;
struct passwd *pw;
uid_t myuid;
struct rlimit rlimit_fsize;
char c;
#if ENABLE_FEATURE_SHADOWPASSWDS
/* Using _r function to avoid pulling in static buffers */
struct spwd spw;
char buffer[256];
#endif
logmode = LOGMODE_BOTH;
openlog(applet_name, 0, LOG_AUTH);
opt = getopt32(argv, "a:lud", &opt_a);
//argc -= optind;
argv += optind;
myuid = getuid();
/* -l, -u, -d require root priv and username argument */
if ((opt & OPT_lud) && (myuid != 0 || !argv[0]))
bb_show_usage();
/* Will complain and die if username not found */
myname = xstrdup(xuid2uname(myuid));
name = argv[0] ? argv[0] : myname;
pw = xgetpwnam(name);
if (myuid != 0 && pw->pw_uid != myuid) {
/* LOGMODE_BOTH */
bb_error_msg_and_die("%s can't change password for %s", myname, name);
}
#if ENABLE_FEATURE_SHADOWPASSWDS
{
/* getspnam_r may return 0 yet set result to NULL.
* At least glibc 2.4 does this. Be extra paranoid here. */
struct spwd *result = NULL;
errno = 0;
if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result) != 0
|| !result /* no error, but no record found either */
|| strcmp(result->sp_namp, pw->pw_name) != 0 /* paranoia */
) {
if (errno != ENOENT) {
/* LOGMODE_BOTH */
bb_perror_msg("no record of %s in %s, using %s",
name, bb_path_shadow_file,
bb_path_passwd_file);
}
/* else: /etc/shadow does not exist,
* apparently we are on a shadow-less system,
* no surprise there */
} else {
pw->pw_passwd = result->sp_pwdp;
}
}
#endif
/* Decide what the new password will be */
newp = NULL;
c = pw->pw_passwd[0] - '!';
if (!(opt & OPT_lud)) {
if (myuid != 0 && !c) { /* passwd starts with '!' */
/* LOGMODE_BOTH */
bb_error_msg_and_die("can't change "
"locked password for %s", name);
}
printf("Changing password for %s\n", name);
newp = new_password(pw, myuid, opt_a);
if (!newp) {
logmode = LOGMODE_STDIO;
bb_error_msg_and_die("password for %s is unchanged", name);
}
} else if (opt & OPT_lock) {
if (!c)
goto skip; /* passwd starts with '!' */
newp = xasprintf("!%s", pw->pw_passwd);
} else if (opt & OPT_unlock) {
if (c)
goto skip; /* not '!' */
/* pw->pw_passwd points to static storage,
* strdup'ing to avoid nasty surprizes */
newp = xstrdup(&pw->pw_passwd[1]);
} else if (opt & OPT_delete) {
newp = (char*)"";
}
rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * 30000;
setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
bb_signals(0
+ (1 << SIGHUP)
+ (1 << SIGINT)
+ (1 << SIGQUIT)
, SIG_IGN);
umask(077);
xsetuid(0);
#if ENABLE_FEATURE_SHADOWPASSWDS
filename = bb_path_shadow_file;
rc = update_passwd(bb_path_shadow_file, name, newp, NULL);
if (rc > 0)
/* password in /etc/shadow was updated */
newp = (char*) "x";
if (rc >= 0)
/* 0 = /etc/shadow missing (not an error), >0 = passwd changed in /etc/shadow */
#endif
{
filename = bb_path_passwd_file;
rc = update_passwd(bb_path_passwd_file, name, newp, NULL);
}
/* LOGMODE_BOTH */
if (rc < 0)
bb_error_msg_and_die("can't update password file %s", filename);
bb_error_msg("password for %s changed by %s", name, myname);
/*if (ENABLE_FEATURE_CLEAN_UP) free(newp); - can't, it may be non-malloced */
skip:
if (!newp) {
bb_error_msg_and_die("password for %s is already %slocked",
name, (opt & OPT_unlock) ? "un" : "");
}
if (ENABLE_FEATURE_CLEAN_UP)
free(myname);
return 0;
}
|
