/* vi: set sw=4 ts=4: */
/*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-
-#include "busybox.h"
+//config:config PASSWD
+//config: bool "passwd (21 kb)"
+//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-$(CONFIG_PASSWD) += passwd.o
+
+//usage:#define passwd_trivial_usage
+//usage: "[OPTIONS] [USER]"
+//usage:#define passwd_full_usage "\n\n"
+//usage: "Change USER's password (default: current user)"
+//usage: "\n"
+//usage: "\n -a ALG "CRYPT_METHODS_HELP_STR
+//usage: "\n -d Set password to ''"
+//usage: "\n -l Lock (disable) account"
+//usage: "\n -u Unlock (enable) account"
+
+#include "libbb.h"
#include <syslog.h>
-#include <sys/times.h> /* times() */
-
-
-static void nuke_str(char *str)
-{
- if (str) memset(str, 0, strlen(str));
-}
-
-static int i64c(int i)
+static char* new_password(const struct passwd *pw, uid_t myuid, const char *algo)
{
- if (i <= 0)
- return '.';
- if (i == 1)
- return '/';
- if (i < 12)
- return ('0' - 2 + i);
- if (i < 38)
- return ('A' - 12 + i);
- return ('a' - 38 + i);
-}
-
-
-static void crypt_make_salt(char *p, int cnt)
-{
-#if !defined(__GLIBC__)
- struct tms t;
-#define TIMES times(&t)
-#else
-/* glibc allows for times(NULL) a-la time() */
-#define TIMES times(NULL)
-#endif
- unsigned long x = x; /* it's pointless to initialize it anyway :) */
-
- x += getpid();
- do {
- /* clock() and times() variability is different between systems */
- /* hopefully at least one is good enough */
- x += time(NULL) + clock() + TIMES;
- *p++ = i64c(((x >> 18) ^ (x >> 6)) & 0x3f);
- *p++ = i64c(((x >> 12) ^ x) & 0x3f);
- usleep(100); /* or else time() etc won't change */
- } while (--cnt);
- *p = '\0';
-}
-
-
-static char* new_password(const struct passwd *pw, uid_t myuid, int algo)
-{
- char salt[sizeof("$N$XXXXXXXX")]; /* "$N$XXXXXXXX" or "XX" */
- char *orig = "";
+ char salt[MAX_PW_SALT_LEN];
+ char *orig = NULL;
char *newp = NULL;
- char *cipher = NULL;
char *cp = NULL;
char *ret = NULL; /* failure so far */
- if (myuid && pw->pw_passwd[0]) {
- orig = bb_askpass(0, "Old password:"); /* returns ptr to static */
+ if (myuid != 0 && pw->pw_passwd[0]) {
+ char *encrypted;
+
+ orig = bb_ask_noecho_stdin("Old password: "); /* returns malloced str */
if (!orig)
goto err_ret;
- cipher = pw_encrypt(orig, pw->pw_passwd); /* returns ptr to static */
- if (strcmp(cipher, pw->pw_passwd) != 0) {
- syslog(LOG_WARNING, "incorrect password for '%s'",
- pw->pw_name);
- bb_do_delay(FAIL_DELAY);
+ 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_askpass() will destroy it */
- newp = bb_askpass(0, "New password:"); /* returns ptr to static */
+ newp = bb_ask_noecho_stdin("New password: "); /* returns malloced str */
if (!newp)
goto err_ret;
- newp = xstrdup(newp); /* we are going to bb_askpass() again, so save it */
- if (obscure(orig, newp, pw) && myuid) {
- goto err_ret; /* non-root is not allowed to have weak passwd */
+ if (ENABLE_FEATURE_PASSWD_WEAK_CHECK
+ && obscure(orig, newp, pw) /* NB: passing NULL orig is ok */
+ && myuid != 0
+ ) {
+ goto err_ret; /* non-root is not allowed to have weak passwd */
}
- cp = bb_askpass(0, "Retype password:");
+ cp = bb_ask_noecho_stdin("Retype password: ");
if (!cp)
goto err_ret;
- if (strcmp(cp, newp)) {
+ if (strcmp(cp, newp) != 0) {
puts("Passwords don't match");
goto err_ret;
}
- /*memset(salt, 0, sizeof(salt)); - why?*/
- crypt_make_salt(salt, 1); /* des */
- if (algo) { /* MD5 */
- strcpy(salt, "$1$");
- crypt_make_salt(salt + 3, 4);
- }
- ret = xstrdup(pw_encrypt(newp, salt)); /* returns ptr to static */
+ 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(cipher);
- nuke_str(cp);
- return ret;
-}
-
-
-#if 0
-static int get_algo(char *a)
-{
- /* standard: MD5 */
- int x = 1;
- if (strcasecmp(a, "des") == 0)
- x = 0;
- return x;
-}
-#endif
-
-static int update_passwd(const char *filename, const char *username,
- const char *new_pw)
-{
- struct stat sb;
- struct flock lock;
- FILE *old_fp;
- FILE *new_fp;
- char *new_name;
- char *last_char;
- unsigned user_len;
- int old_fd;
- int new_fd;
- int i;
- int ret = 1; /* failure */
-
- logmode = LOGMODE_STDIO;
- /* New passwd file, "/etc/passwd+" for now */
- new_name = xasprintf("%s+", filename);
- last_char = &new_name[strlen(new_name)-1];
- username = xasprintf("%s:", username);
- user_len = strlen(username);
-
- old_fp = fopen(filename, "r+");
- if (!old_fp)
- goto free_mem;
- old_fd = fileno(old_fp);
-
- /* Try to create "/etc/passwd+". Wait if it exists. */
- i = 30;
- do {
- // FIXME: on last iteration try w/o O_EXCL but with O_TRUNC?
- new_fd = open(new_name, O_WRONLY|O_CREAT|O_EXCL,0600);
- if (new_fd >= 0) goto created;
- if (errno != EEXIST) break;
- usleep(100000); /* 0.1 sec */
- } while (--i);
- bb_perror_msg("cannot create '%s'", new_name);
- goto close_old_fp;
- created:
- if (!fstat(old_fd, &sb)) {
- fchmod(new_fd, sb.st_mode & 0777); /* ignore errors */
- fchown(new_fd, sb.st_uid, sb.st_gid);
- }
- new_fp = fdopen(new_fd, "w");
- if (!new_fp) {
- close(new_fd);
- goto unlink_new;
- }
-
- /* Backup file is "/etc/passwd-" */
- last_char[0] = '-';
- /* Delete old one, create new as a hardlink to current */
- i = (unlink(new_name) && errno != ENOENT);
- if (i || link(filename, new_name))
- bb_perror_msg("warning: cannot create backup copy '%s'", new_name);
- last_char[0] = '+';
-
- /* Lock the password file before updating */
- lock.l_type = F_WRLCK;
- lock.l_whence = SEEK_SET;
- lock.l_start = 0;
- lock.l_len = 0;
- if (fcntl(old_fd, F_SETLK, &lock) < 0)
- bb_perror_msg("warning: cannot lock '%s'", filename);
- lock.l_type = F_UNLCK;
-
- /* Read current password file, write updated one */
- while (1) {
- char *line = xmalloc_fgets(old_fp);
- if (!line) break; /* EOF/error */
- if (strncmp(username, line, user_len) == 0) {
- /* we have a match with "username:"... */
- const char *cp = line + user_len;
- /* now cp -> old passwd, skip it: */
- cp = strchr(cp, ':');
- if (!cp) cp = "";
- /* now cp -> ':' after old passwd or -> "" */
- fprintf(new_fp, "%s%s%s", username, new_pw, cp);
- /* Erase password in memory */
- } else
- fputs(line, new_fp);
- free(line);
- }
- fcntl(old_fd, F_SETLK, &lock);
-
- /* We do want all of them to execute, thus | instead of || */
- if ((ferror(old_fp) | fflush(new_fp) | fsync(new_fd) | fclose(new_fp))
- || rename(new_name, filename)
- ) {
- /* At least one of those failed */
- goto unlink_new;
- }
- ret = 0; /* whee, success! */
-
- unlink_new:
- if (ret) unlink(new_name);
-
- close_old_fp:
- fclose(old_fp);
-
- free_mem:
- if (ENABLE_FEATURE_CLEAN_UP) free(new_name);
- if (ENABLE_FEATURE_CLEAN_UP) free((char*)username);
- logmode = LOGMODE_BOTH;
+ nuke_str(cp);
+ if (ENABLE_FEATURE_CLEAN_UP) free(cp);
return ret;
}
-
-int passwd_main(int argc, char **argv)
+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 */
+ 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;
- char *opt_a = "";
+ int rc;
+ const char *opt_a = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
const char *filename;
char *myname;
char *name;
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(argc, argv, "a:lud", &opt_a);
- argc -= optind;
+ openlog(applet_name, 0, 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();
- if ((opt & OPT_lud) && (!argc || myuid))
+ /* -l, -u, -d require root priv and username argument */
+ if ((opt & OPT_lud) && (myuid != 0 || !argv[0]))
bb_show_usage();
- myname = xstrdup(bb_getpwuid(NULL, myuid, -1));
- name = argc ? argv[0] : myname;
+ /* Will complain and die if username not found */
+ myname = xstrdup(xuid2uname(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) {
+ 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);
}
- filename = bb_path_passwd_file;
- if (ENABLE_FEATURE_SHADOWPASSWDS) {
- struct spwd *sp = getspnam(name);
- if (!sp) {
- /* LOGMODE_BOTH */
- bb_error_msg("no record of %s in %s, using %s",
+#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 {
- filename = bb_path_shadow_file;
- pw->pw_passwd = sp->sp_pwdp;
+ 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 '!' */
+ if (myuid != 0 && !c) { /* passwd starts with '!' */
/* LOGMODE_BOTH */
- bb_error_msg_and_die("cannot change "
+ 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 & STATE_ALGO_md5);
+ 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 '!' */
+ if (!c)
+ goto skip; /* passwd starts with '!' */
newp = xasprintf("!%s", pw->pw_passwd);
} else if (opt & OPT_unlock) {
- if (c) goto skip; /* not '!' */
+ 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);
- signal(SIGHUP, SIG_IGN);
- signal(SIGINT, SIG_IGN);
- signal(SIGQUIT, SIG_IGN);
+ bb_signals(0
+ + (1 << SIGHUP)
+ + (1 << SIGINT)
+ + (1 << SIGQUIT)
+ , SIG_IGN);
umask(077);
xsetuid(0);
- if (update_passwd(filename, name, newp) != 0) {
- /* LOGMODE_BOTH */
- bb_error_msg_and_die("cannot update password file %s",
- filename);
+
+#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 */
- bb_info_msg("Password for %s changed by %s", name, myname);
+ if (rc < 0)
+ bb_error_msg_and_die("can't 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 (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);
+
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(myname);
return 0;
}
projects / oweals / busybox.git / blobdiff