diff options
Diffstat (limited to 'loginutils/passwd.c')
| -rw-r--r-- | loginutils/passwd.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/loginutils/passwd.c b/loginutils/passwd.c new file mode 100644 index 0000000..99fb76e --- /dev/null +++ b/loginutils/passwd.c @@ -0,0 +1,207 @@ +/* vi: set sw=4 ts=4: */ +/* + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ + +#include "libbb.h" +#include <syslog.h> + +static void nuke_str(char *str) +{ + if (str) memset(str, 0, strlen(str)); +} + +static char* new_password(const struct passwd *pw, uid_t myuid, int algo) +{ + char salt[sizeof("$N$XXXXXXXX")]; /* "$N$XXXXXXXX" or "XX" */ + char *orig = (char*)""; + char *newp = NULL; + char *cp = NULL; + char *ret = NULL; /* failure so far */ + + if (myuid && pw->pw_passwd[0]) { + char *encrypted; + + orig = bb_askpass(0, "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(FAIL_DELAY); + puts("Incorrect password"); + goto err_ret; + } + if (ENABLE_FEATURE_CLEAN_UP) free(encrypted); + } + orig = xstrdup(orig); /* or else bb_askpass() will destroy it */ + newp = bb_askpass(0, "New password:"); /* returns ptr to static */ + if (!newp) + goto err_ret; + newp = xstrdup(newp); /* we are going to bb_askpass() again, so save it */ + if (ENABLE_FEATURE_PASSWD_WEAK_CHECK + && obscure(orig, newp, pw) && myuid) + goto err_ret; /* non-root is not allowed to have weak passwd */ + + cp = bb_askpass(0, "Retype password:"); + if (!cp) + goto err_ret; + if (strcmp(cp, newp)) { + puts("Passwords don't match"); + goto err_ret; + } + + crypt_make_salt(salt, 1, 0); /* des */ + if (algo) { /* MD5 */ + strcpy(salt, "$1$"); + crypt_make_salt(salt + 3, 4, 0); + } + /* 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 = 0x1, /* -a - password algorithm */ + OPT_lock = 0x2, /* -l - lock account */ + OPT_unlock = 0x4, /* -u - unlock account */ + OPT_delete = 0x8, /* -d - delete password */ + OPT_lud = 0xe, + STATE_ALGO_md5 = 0x10, + //STATE_ALGO_des = 0x20, not needed yet + }; + unsigned opt; + int rc; + const char *opt_a = ""; + 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, LOG_NOWAIT, LOG_AUTH); + opt = getopt32(argv, "a:lud", &opt_a); + //argc -= optind; + argv += optind; + + if (strcasecmp(opt_a, "des") != 0) /* -a */ + opt |= STATE_ALGO_md5; + //else + // opt |= STATE_ALGO_des; + myuid = getuid(); + /* -l, -u, -d require root priv and username argument */ + if ((opt & OPT_lud) && (myuid || !argv[0])) + bb_show_usage(); + + /* Will complain and die if username not found */ + myname = xstrdup(bb_getpwuid(NULL, -1, myuid)); + name = argv[0] ? argv[0] : myname; + + pw = getpwnam(name); + if (!pw) + bb_error_msg_and_die("unknown user %s", name); + if (myuid && 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; + if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result) + || !result || strcmp(result->sp_namp, pw->pw_name) != 0) { + /* LOGMODE_BOTH */ + bb_error_msg("no record of %s in %s, using %s", + name, bb_path_shadow_file, + bb_path_passwd_file); + } 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 && !c) { /* passwd starts with '!' */ + /* LOGMODE_BOTH */ + bb_error_msg_and_die("cannot change " + "locked password for %s", name); + } + printf("Changing password for %s\n", name); + newp = new_password(pw, myuid, opt & STATE_ALGO_md5); + 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 = xstrdup(""); + 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); + if (rc == 0) /* no lines updated, no errors detected */ +#endif + { + filename = bb_path_passwd_file; + rc = update_passwd(bb_path_passwd_file, name, newp); + } + /* LOGMODE_BOTH */ + if (rc < 0) + bb_error_msg_and_die("cannot update password file %s", + filename); + bb_info_msg("Password for %s changed by %s", name, myname); + + //if (ENABLE_FEATURE_CLEAN_UP) free(newp); + 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; +} |