release/src/router/busybox/loginutils/passwd.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   4  */
   5 #include "libbb.h"
   6 #include <syslog.h>
   7
   8 static void nuke_str(char *str)
   9 {
  10         if (str) memset(str, 0, strlen(str));
  11 }
  12
  13 static char* new_password(const struct passwd *pw, uid_t myuid, int algo)
  14 {
  15         char salt[sizeof("$N$XXXXXXXX")]; /* "$N$XXXXXXXX" or "XX" */
  16         char *orig = (char*)"";
  17         char *newp = NULL;
  18         char *cp = NULL;
  19         char *ret = NULL; /* failure so far */
  20
  21         if (myuid && pw->pw_passwd[0]) {
  22                 char *encrypted;
  23
  24                 orig = bb_ask_stdin("Old password:"); /* returns ptr to static */
  25                 if (!orig)
  26                         goto err_ret;
  27                 encrypted = pw_encrypt(orig, pw->pw_passwd, 1); /* returns malloced str */
  28                 if (strcmp(encrypted, pw->pw_passwd) != 0) {
  29                         syslog(LOG_WARNING, "incorrect password for %s",
  30                                 pw->pw_name);
  31                         bb_do_delay(FAIL_DELAY);
  32                         puts("Incorrect password");
  33                         goto err_ret;
  34                 }
  35                 if (ENABLE_FEATURE_CLEAN_UP) free(encrypted);
  36         }
  37         orig = xstrdup(orig); /* or else bb_ask_stdin() will destroy it */
  38         newp = bb_ask_stdin("New password:"); /* returns ptr to static */
  39         if (!newp)
  40                 goto err_ret;
  41         newp = xstrdup(newp); /* we are going to bb_ask_stdin() again, so save it */
  42         if (ENABLE_FEATURE_PASSWD_WEAK_CHECK
  43          && obscure(orig, newp, pw) && myuid)
  44                 goto err_ret; /* non-root is not allowed to have weak passwd */
  45
  46         cp = bb_ask_stdin("Retype password:");
  47         if (!cp)
  48                 goto err_ret;
  49         if (strcmp(cp, newp)) {
  50                 puts("Passwords don't match");
  51                 goto err_ret;
  52         }
  53
  54         crypt_make_salt(salt, 1, 0); /* des */
  55         if (algo) { /* MD5 */
  56                 strcpy(salt, "$1$");
  57                 crypt_make_salt(salt + 3, 4, 0);
  58         }
  59         /* pw_encrypt returns malloced str */
  60         ret = pw_encrypt(newp, salt, 1);
  61         /* whee, success! */
  62
  63  err_ret:
  64         nuke_str(orig);
  65         if (ENABLE_FEATURE_CLEAN_UP) free(orig);
  66         nuke_str(newp);
  67         if (ENABLE_FEATURE_CLEAN_UP) free(newp);
  68         nuke_str(cp);
  69         return ret;
  70 }
  71
  72 int passwd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  73 int passwd_main(int argc UNUSED_PARAM, char **argv)
  74 {
  75         enum {
  76                 OPT_algo = 0x1, /* -a - password algorithm */
  77                 OPT_lock = 0x2, /* -l - lock account */
  78                 OPT_unlock = 0x4, /* -u - unlock account */
  79                 OPT_delete = 0x8, /* -d - delete password */
  80                 OPT_lud = 0xe,
  81                 STATE_ALGO_md5 = 0x10,
  82                 //STATE_ALGO_des = 0x20, not needed yet
  83         };
  84         unsigned opt;
  85         int rc;
  86         const char *opt_a = "";
  87         const char *filename;
  88         char *myname;
  89         char *name;
  90         char *newp;
  91         struct passwd *pw;
  92         uid_t myuid;
  93         struct rlimit rlimit_fsize;
  94         char c;
  95 #if ENABLE_FEATURE_SHADOWPASSWDS
  96         /* Using _r function to avoid pulling in static buffers */
  97         struct spwd spw;
  98         char buffer[256];
  99 #endif
 100
 101         logmode = LOGMODE_BOTH;
 102         openlog(applet_name, 0, LOG_AUTH);
 103         opt = getopt32(argv, "a:lud", &opt_a);
 104         //argc -= optind;
 105         argv += optind;
 106
 107         if (strcasecmp(opt_a, "des") != 0) /* -a */
 108                 opt |= STATE_ALGO_md5;
 109         //else
 110         //      opt |= STATE_ALGO_des;
 111         myuid = getuid();
 112         /* -l, -u, -d require root priv and username argument */
 113         if ((opt & OPT_lud) && (myuid || !argv[0]))
 114                 bb_show_usage();
 115
 116         /* Will complain and die if username not found */
 117         myname = xstrdup(xuid2uname(myuid));
 118         name = argv[0] ? argv[0] : myname;
 119
 120         pw = xgetpwnam(name);
 121         if (myuid && pw->pw_uid != myuid) {
 122                 /* LOGMODE_BOTH */
 123                 bb_error_msg_and_die("%s can't change password for %s", myname, name);
 124         }
 125
 126 #if ENABLE_FEATURE_SHADOWPASSWDS
 127         {
 128                 /* getspnam_r may return 0 yet set result to NULL.
 129                  * At least glibc 2.4 does this. Be extra paranoid here. */
 130                 struct spwd *result = NULL;
 131                 if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result)
 132                  || !result || strcmp(result->sp_namp, pw->pw_name) != 0) {
 133                         /* LOGMODE_BOTH */
 134                         bb_error_msg("no record of %s in %s, using %s",
 135                                         name, bb_path_shadow_file,
 136                                         bb_path_passwd_file);
 137                 } else {
 138                         pw->pw_passwd = result->sp_pwdp;
 139                 }
 140         }
 141 #endif
 142
 143         /* Decide what the new password will be */
 144         newp = NULL;
 145         c = pw->pw_passwd[0] - '!';
 146         if (!(opt & OPT_lud)) {
 147                 if (myuid && !c) { /* passwd starts with '!' */
 148                         /* LOGMODE_BOTH */
 149                         bb_error_msg_and_die("cannot change "
 150                                         "locked password for %s", name);
 151                 }
 152                 printf("Changing password for %s\n", name);
 153                 newp = new_password(pw, myuid, opt & STATE_ALGO_md5);
 154                 if (!newp) {
 155                         logmode = LOGMODE_STDIO;
 156                         bb_error_msg_and_die("password for %s is unchanged", name);
 157                 }
 158         } else if (opt & OPT_lock) {
 159                 if (!c) goto skip; /* passwd starts with '!' */
 160                 newp = xasprintf("!%s", pw->pw_passwd);
 161         } else if (opt & OPT_unlock) {
 162                 if (c) goto skip; /* not '!' */
 163                 /* pw->pw_passwd points to static storage,
 164                  * strdup'ing to avoid nasty surprizes */
 165                 newp = xstrdup(&pw->pw_passwd[1]);
 166         } else if (opt & OPT_delete) {
 167                 //newp = xstrdup("");
 168                 newp = (char*)"";
 169         }
 170
 171         rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * 30000;
 172         setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
 173         bb_signals(0
 174                 + (1 << SIGHUP)
 175                 + (1 << SIGINT)
 176                 + (1 << SIGQUIT)
 177                 , SIG_IGN);
 178         umask(077);
 179         xsetuid(0);
 180
 181 #if ENABLE_FEATURE_SHADOWPASSWDS
 182         filename = bb_path_shadow_file;
 183         rc = update_passwd(bb_path_shadow_file, name, newp, NULL);
 184         if (rc == 0) /* no lines updated, no errors detected */
 185 #endif
 186         {
 187                 filename = bb_path_passwd_file;
 188                 rc = update_passwd(bb_path_passwd_file, name, newp, NULL);
 189         }
 190         /* LOGMODE_BOTH */
 191         if (rc < 0)
 192                 bb_error_msg_and_die("cannot update password file %s",
 193                                 filename);
 194         bb_info_msg("Password for %s changed by %s", name, myname);
 195
 196         //if (ENABLE_FEATURE_CLEAN_UP) free(newp);
 197  skip:
 198         if (!newp) {
 199                 bb_error_msg_and_die("password for %s is already %slocked",
 200                         name, (opt & OPT_unlock) ? "un" : "");
 201         }
 202         if (ENABLE_FEATURE_CLEAN_UP) free(myname);
 203         return 0;
 204 }