1 /* vi: set sw=4 ts=4: */
2 /*
3 * chpasswd.c
4 *
5 * Written for SLIND (from passwd.c) by Alexander Shishkin <virtuoso@slind.org>
6 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
7 */
8 //config:config CHPASSWD
9 //config: bool "chpasswd"
10 //config: default y
11 //config: help
12 //config: Reads a file of user name and password pairs from standard input
13 //config: and uses this information to update a group of existing users.
14 //config:
15 //config:config FEATURE_DEFAULT_PASSWD_ALGO
16 //config: string "Default password encryption method (passwd -a, cryptpw -m parameter)"
17 //config: default "des"
18 //config: depends on PASSWD || CRYPTPW
19 //config: help
20 //config: Possible choices are "d[es]", "m[d5]", "s[ha256]" or "sha512".
21
22 //applet:IF_CHPASSWD(APPLET(chpasswd, BB_DIR_USR_SBIN, BB_SUID_DROP))
23
24 //kbuild:lib-$(CONFIG_CHPASSWD) += chpasswd.o
25
26 //usage:#define chpasswd_trivial_usage
27 //usage: IF_LONG_OPTS("[--md5|--encrypted|--crypt-method]") IF_NOT_LONG_OPTS("[-m|-e|-c]")
28 //usage:#define chpasswd_full_usage "\n\n"
29 //usage: "Read user:password from stdin and update /etc/passwd\n"
30 //usage: IF_LONG_OPTS(
31 //usage: "\n -e,--encrypted Supplied passwords are in encrypted form"
32 //usage: "\n -m,--md5 Use MD5 encryption instead of DES"
33 //usage: "\n -c,--crypt-method Use the specified method to encrypt the passwords"
34 //usage: )
35 //usage: IF_NOT_LONG_OPTS(
36 //usage: "\n -e Supplied passwords are in encrypted form"
37 //usage: "\n -m Use MD5 encryption instead of DES"
38 //usage: "\n -c Use the specified method to encrypt the passwords"
39 //usage: )
40
41 #include "libbb.h"
42
43 #if ENABLE_LONG_OPTS
44 static const char chpasswd_longopts[] ALIGN1 =
45 "encrypted\0" No_argument "e"
46 "md5\0" No_argument "m"
47 "crypt-method\0" Required_argument "c"
48 ;
49 #endif
50
51 #define OPT_ENC 1
52 #define OPT_MD5 2
53
54 int chpasswd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
chpasswd_main(int argc UNUSED_PARAM,char ** argv)55 int chpasswd_main(int argc UNUSED_PARAM, char **argv)
56 {
57 char *name;
58 const char *algo = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
59 int opt;
60
61 if (getuid() != 0)
62 bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
63
64 opt_complementary = "m--ec:e--mc:c--em";
65 IF_LONG_OPTS(applet_long_options = chpasswd_longopts;)
66 opt = getopt32(argv, "emc:", &algo);
67
68 while ((name = xmalloc_fgetline(stdin)) != NULL) {
69 char *free_me;
70 char *pass;
71 int rc;
72
73 pass = strchr(name, ':');
74 if (!pass)
75 bb_error_msg_and_die("missing new password");
76 *pass++ = '\0';
77
78 xuname2uid(name); /* dies if there is no such user */
79
80 free_me = NULL;
81 if (!(opt & OPT_ENC)) {
82 char salt[MAX_PW_SALT_LEN];
83
84 if (opt & OPT_MD5) {
85 /* Force MD5 if the -m flag is set */
86 algo = "md5";
87 }
88
89 crypt_make_pw_salt(salt, algo);
90 free_me = pass = pw_encrypt(pass, salt, 0);
91 }
92
93 /* This is rather complex: if user is not found in /etc/shadow,
94 * we try to find & change his passwd in /etc/passwd */
95 #if ENABLE_FEATURE_SHADOWPASSWDS
96 rc = update_passwd(bb_path_shadow_file, name, pass, NULL);
97 if (rc > 0) /* password in /etc/shadow was updated */
98 pass = (char*)"x";
99 if (rc >= 0)
100 /* 0 = /etc/shadow missing (not an error), >0 = passwd changed in /etc/shadow */
101 #endif
102 rc = update_passwd(bb_path_passwd_file, name, pass, NULL);
103 /* LOGMODE_BOTH logs to syslog also */
104 logmode = LOGMODE_BOTH;
105 if (rc < 0)
106 bb_error_msg_and_die("an error occurred updating password for %s", name);
107 if (rc)
108 bb_error_msg("password for '%s' changed", name);
109 logmode = LOGMODE_STDIO;
110 free(name);
111 free(free_me);
112 }
113 return EXIT_SUCCESS;
114 }
115