source: branches/3.2/mindi-busybox/loginutils/passwd.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
File size: 6.0 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
4 */
5
6//usage:#define passwd_trivial_usage
7//usage:       "[OPTIONS] [USER]"
8//usage:#define passwd_full_usage "\n\n"
9//usage:       "Change USER's password (default: current user)"
10//usage:     "\n"
11//usage:     "\n    -a ALG  Encryption method"
12//usage:     "\n    -d  Set password to ''"
13//usage:     "\n    -l  Lock (disable) account"
14//usage:     "\n    -u  Unlock (enable) account"
15
16#include "libbb.h"
17#include <syslog.h>
18#include <sys/resource.h> /* setrlimit */
19
20static void nuke_str(char *str)
21{
22    if (str) memset(str, 0, strlen(str));
23}
24
25static char* new_password(const struct passwd *pw, uid_t myuid, const char *algo)
26{
27    char salt[MAX_PW_SALT_LEN];
28    char *orig = (char*)"";
29    char *newp = NULL;
30    char *cp = NULL;
31    char *ret = NULL; /* failure so far */
32
33    if (myuid != 0 && pw->pw_passwd[0]) {
34        char *encrypted;
35
36        orig = bb_ask_stdin("Old password: "); /* returns ptr to static */
37        if (!orig)
38            goto err_ret;
39        encrypted = pw_encrypt(orig, pw->pw_passwd, 1); /* returns malloced str */
40        if (strcmp(encrypted, pw->pw_passwd) != 0) {
41            syslog(LOG_WARNING, "incorrect password for %s", pw->pw_name);
42            bb_do_delay(LOGIN_FAIL_DELAY);
43            puts("Incorrect password");
44            goto err_ret;
45        }
46        if (ENABLE_FEATURE_CLEAN_UP)
47            free(encrypted);
48    }
49    orig = xstrdup(orig); /* or else bb_ask_stdin() will destroy it */
50    newp = bb_ask_stdin("New password: "); /* returns ptr to static */
51    if (!newp)
52        goto err_ret;
53    newp = xstrdup(newp); /* we are going to bb_ask_stdin() again, so save it */
54    if (ENABLE_FEATURE_PASSWD_WEAK_CHECK
55     && obscure(orig, newp, pw)
56     && myuid != 0
57    ) {
58        goto err_ret; /* non-root is not allowed to have weak passwd */
59    }
60
61    cp = bb_ask_stdin("Retype password: ");
62    if (!cp)
63        goto err_ret;
64    if (strcmp(cp, newp) != 0) {
65        puts("Passwords don't match");
66        goto err_ret;
67    }
68
69    crypt_make_pw_salt(salt, algo);
70
71    /* pw_encrypt returns malloced str */
72    ret = pw_encrypt(newp, salt, 1);
73    /* whee, success! */
74
75 err_ret:
76    nuke_str(orig);
77    if (ENABLE_FEATURE_CLEAN_UP) free(orig);
78
79    nuke_str(newp);
80    if (ENABLE_FEATURE_CLEAN_UP) free(newp);
81
82    nuke_str(cp);
83    return ret;
84}
85
86int passwd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
87int passwd_main(int argc UNUSED_PARAM, char **argv)
88{
89    enum {
90        OPT_algo   = (1 << 0), /* -a - password algorithm */
91        OPT_lock   = (1 << 1), /* -l - lock account */
92        OPT_unlock = (1 << 2), /* -u - unlock account */
93        OPT_delete = (1 << 3), /* -d - delete password */
94        OPT_lud    = OPT_lock | OPT_unlock | OPT_delete,
95    };
96    unsigned opt;
97    int rc;
98    const char *opt_a = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
99    const char *filename;
100    char *myname;
101    char *name;
102    char *newp;
103    struct passwd *pw;
104    uid_t myuid;
105    struct rlimit rlimit_fsize;
106    char c;
107#if ENABLE_FEATURE_SHADOWPASSWDS
108    /* Using _r function to avoid pulling in static buffers */
109    struct spwd spw;
110    char buffer[256];
111#endif
112
113    logmode = LOGMODE_BOTH;
114    openlog(applet_name, 0, LOG_AUTH);
115    opt = getopt32(argv, "a:lud", &opt_a);
116    //argc -= optind;
117    argv += optind;
118
119    myuid = getuid();
120    /* -l, -u, -d require root priv and username argument */
121    if ((opt & OPT_lud) && (myuid != 0 || !argv[0]))
122        bb_show_usage();
123
124    /* Will complain and die if username not found */
125    myname = xstrdup(xuid2uname(myuid));
126    name = argv[0] ? argv[0] : myname;
127
128    pw = xgetpwnam(name);
129    if (myuid != 0 && pw->pw_uid != myuid) {
130        /* LOGMODE_BOTH */
131        bb_error_msg_and_die("%s can't change password for %s", myname, name);
132    }
133
134#if ENABLE_FEATURE_SHADOWPASSWDS
135    {
136        /* getspnam_r may return 0 yet set result to NULL.
137         * At least glibc 2.4 does this. Be extra paranoid here. */
138        struct spwd *result = NULL;
139        errno = 0;
140        if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result) != 0
141         || !result /* no error, but no record found either */
142         || strcmp(result->sp_namp, pw->pw_name) != 0 /* paranoia */
143        ) {
144            if (errno != ENOENT) {
145                /* LOGMODE_BOTH */
146                bb_perror_msg("no record of %s in %s, using %s",
147                    name, bb_path_shadow_file,
148                    bb_path_passwd_file);
149            }
150            /* else: /etc/shadow does not exist,
151             * apparently we are on a shadow-less system,
152             * no surprise there */
153        } else {
154            pw->pw_passwd = result->sp_pwdp;
155        }
156    }
157#endif
158
159    /* Decide what the new password will be */
160    newp = NULL;
161    c = pw->pw_passwd[0] - '!';
162    if (!(opt & OPT_lud)) {
163        if (myuid != 0 && !c) { /* passwd starts with '!' */
164            /* LOGMODE_BOTH */
165            bb_error_msg_and_die("can't change "
166                    "locked password for %s", name);
167        }
168        printf("Changing password for %s\n", name);
169        newp = new_password(pw, myuid, opt_a);
170        if (!newp) {
171            logmode = LOGMODE_STDIO;
172            bb_error_msg_and_die("password for %s is unchanged", name);
173        }
174    } else if (opt & OPT_lock) {
175        if (!c)
176            goto skip; /* passwd starts with '!' */
177        newp = xasprintf("!%s", pw->pw_passwd);
178    } else if (opt & OPT_unlock) {
179        if (c)
180            goto skip; /* not '!' */
181        /* pw->pw_passwd points to static storage,
182         * strdup'ing to avoid nasty surprizes */
183        newp = xstrdup(&pw->pw_passwd[1]);
184    } else if (opt & OPT_delete) {
185        newp = (char*)"";
186    }
187
188    rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * 30000;
189    setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
190    bb_signals(0
191        + (1 << SIGHUP)
192        + (1 << SIGINT)
193        + (1 << SIGQUIT)
194        , SIG_IGN);
195    umask(077);
196    xsetuid(0);
197
198#if ENABLE_FEATURE_SHADOWPASSWDS
199    filename = bb_path_shadow_file;
200    rc = update_passwd(bb_path_shadow_file, name, newp, NULL);
201    if (rc > 0)
202        /* password in /etc/shadow was updated */
203        newp = (char*) "x";
204    if (rc >= 0)
205        /* 0 = /etc/shadow missing (not an error), >0 = passwd changed in /etc/shadow */
206#endif
207    {
208        filename = bb_path_passwd_file;
209        rc = update_passwd(bb_path_passwd_file, name, newp, NULL);
210    }
211    /* LOGMODE_BOTH */
212    if (rc < 0)
213        bb_error_msg_and_die("can't update password file %s", filename);
214    bb_info_msg("Password for %s changed by %s", name, myname);
215
216    /*if (ENABLE_FEATURE_CLEAN_UP) free(newp); - can't, it may be non-malloced */
217 skip:
218    if (!newp) {
219        bb_error_msg_and_die("password for %s is already %slocked",
220            name, (opt & OPT_unlock) ? "un" : "");
221    }
222
223    if (ENABLE_FEATURE_CLEAN_UP)
224        free(myname);
225    return 0;
226}
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