/* vi: set sw=4 ts=4: */
-#include <fcntl.h>
-#include <stdio.h>
-#include <string.h>
-#include <signal.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <utime.h>
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+//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 <time.h>
-#include <sys/resource.h>
-#include <errno.h>
-#include "busybox.h"
+static char* new_password(const struct passwd *pw, uid_t myuid, const char *algo)
+{
+ char salt[MAX_PW_SALT_LEN];
+ char *orig = NULL;
+ char *newp = NULL;
+ char *cp = NULL;
+ char *ret = NULL; /* failure so far */
+
+ if (myuid != 0 && pw->pw_passwd[0]) {
+ char *encrypted;
+
+ orig = bb_ask_noecho_stdin("Old password: "); /* returns malloced str */
+ 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(LOGIN_FAIL_DELAY);
+ puts("Incorrect password");
+ goto err_ret;
+ }
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(encrypted);
+ }
+ newp = bb_ask_noecho_stdin("New password: "); /* returns malloced str */
+ if (!newp)
+ goto err_ret;
+ 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 */
+ }
-static char crypt_passwd[128];
+ cp = bb_ask_noecho_stdin("Retype password: ");
+ if (!cp)
+ goto err_ret;
+ if (strcmp(cp, newp) != 0) {
+ puts("Passwords don't match");
+ goto err_ret;
+ }
-static int create_backup(const char *backup, FILE * fp);
-static int new_password(const struct passwd *pw, int amroot, int algo);
-static void set_filesize_limit(int blocks);
+ crypt_make_pw_salt(salt, algo);
+ /* pw_encrypt returns malloced str */
+ ret = pw_encrypt(newp, salt, 1);
+ /* whee, success! */
-static int get_algo(char *a)
-{
- int x = 1; /* standard: MD5 */
+ err_ret:
+ nuke_str(orig);
+ if (ENABLE_FEATURE_CLEAN_UP) free(orig);
- if (strcasecmp(a, "des") == 0)
- x = 0;
- return x;
-}
+ nuke_str(newp);
+ if (ENABLE_FEATURE_CLEAN_UP) free(newp);
+ nuke_str(cp);
+ if (ENABLE_FEATURE_CLEAN_UP) free(cp);
+ return ret;
+}
-static int update_passwd(const struct passwd *pw, char *crypt_pw)
+int passwd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int passwd_main(int argc UNUSED_PARAM, char **argv)
{
- char filename[1024];
- char buf[1025];
- char buffer[80];
- char username[32];
- char *pw_rest;
- int mask;
- int continued;
- FILE *fp;
- FILE *out_fp;
- struct stat sb;
- struct flock lock;
-
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
- if (access(bb_path_shadow_file, F_OK) == 0) {
- snprintf(filename, sizeof filename, "%s", bb_path_shadow_file);
- } else
+ enum {
+ 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;
+ int rc;
+ const char *opt_a = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
+ 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
- {
- snprintf(filename, sizeof filename, "%s", bb_path_passwd_file);
- }
- if (((fp = fopen(filename, "r+")) == 0) || (fstat(fileno(fp), &sb))) {
- /* return 0; */
- return 1;
- }
+ logmode = LOGMODE_BOTH;
+ openlog(applet_name, 0, LOG_AUTH);
+ opt = getopt32(argv, "a:lud", &opt_a);
+ //argc -= optind;
+ argv += optind;
- /* 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(fileno(fp), F_SETLK, &lock) < 0) {
- fprintf(stderr, "%s: %s\n", filename, strerror(errno));
- return 1;
- }
- lock.l_type = F_UNLCK;
+ myuid = getuid();
+ /* -l, -u, -d require root priv and username argument */
+ if ((opt & OPT_lud) && (myuid != 0 || !argv[0]))
+ bb_show_usage();
- snprintf(buf, sizeof buf, "%s-", filename);
- if (create_backup(buf, fp)) {
- fcntl(fileno(fp), F_SETLK, &lock);
- fclose(fp);
- return 1;
- }
- snprintf(buf, sizeof buf, "%s+", filename);
- mask = umask(0777);
- out_fp = fopen(buf, "w");
- umask(mask);
- if ((!out_fp) || (fchmod(fileno(out_fp), sb.st_mode & 0777))
- || (fchown(fileno(out_fp), sb.st_uid, sb.st_gid))) {
- fcntl(fileno(fp), F_SETLK, &lock);
- fclose(fp);
- fclose(out_fp);
- return 1;
+ /* Will complain and die if username not found */
+ myname = xstrdup(xuid2uname(myuid));
+ name = argv[0] ? argv[0] : myname;
+
+ 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);
}
- continued = 0;
- snprintf(username, sizeof username, "%s:", pw->pw_name);
- rewind(fp);
- while (!feof(fp)) {
- fgets(buffer, sizeof buffer, fp);
- if (!continued) { // Check to see if we're updating this line.
- if (strncmp(username, buffer, strlen(username)) == 0) { // we have a match.
- pw_rest = strchr(buffer, ':');
- *pw_rest++ = '\0';
- pw_rest = strchr(pw_rest, ':');
- fprintf(out_fp, "%s:%s%s", buffer, crypt_pw, pw_rest);
- } else {
- fputs(buffer, out_fp);
+#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 {
- fputs(buffer, out_fp);
- }
- if (buffer[strlen(buffer) - 1] == '\n') {
- continued = 0;
- } else {
- continued = 1;
+ pw->pw_passwd = result->sp_pwdp;
}
- bzero(buffer, sizeof buffer);
}
+#endif
- if (fflush(out_fp) || fsync(fileno(out_fp)) || fclose(out_fp)) {
- unlink(buf);
- fcntl(fileno(fp), F_SETLK, &lock);
- fclose(fp);
- return 1;
- }
- if (rename(buf, filename) < 0) {
- fcntl(fileno(fp), F_SETLK, &lock);
- fclose(fp);
- return 1;
- } else {
- fcntl(fileno(fp), F_SETLK, &lock);
- fclose(fp);
- return 0;
- }
-}
-
-
-extern int passwd_main(int argc, char **argv)
-{
- int amroot;
- char *cp;
- char *np;
- char *name;
- char *myname;
- int flag;
- int algo = 1; /* -a - password algorithm */
- int lflg = 0; /* -l - lock account */
- int uflg = 0; /* -u - unlock account */
- int dflg = 0; /* -d - delete password */
- const struct passwd *pw;
-
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
- const struct spwd *sp;
-#endif /* CONFIG_FEATURE_SHADOWPASSWDS */
- amroot = (getuid() == 0);
- openlog("passwd", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
- while ((flag = getopt(argc, argv, "a:dlu")) != EOF) {
- switch (flag) {
- case 'a':
- algo = get_algo(optarg);
- break;
- case 'd':
- dflg++;
- break;
- case 'l':
- lflg++;
- break;
- case 'u':
- uflg++;
- break;
- default:
- bb_show_usage();
- }
- }
- myname = (char *) bb_xstrdup(my_getpwuid(NULL, getuid(), -1));
- /* exits on error */
- if (optind < argc) {
- name = argv[optind];
- } else {
- name = myname;
- }
- if ((lflg || uflg || dflg) && (optind >= argc || !amroot)) {
- bb_show_usage();
- }
- pw = getpwnam(name);
- if (!pw) {
- bb_error_msg_and_die("Unknown user %s\n", name);
- }
- if (!amroot && pw->pw_uid != getuid()) {
- syslog(LOG_WARNING, "can't change pwd for `%s'", name);
- bb_error_msg_and_die("Permission denied.\n");
- }
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
- sp = getspnam(name);
- if (!sp) {
- sp = (struct spwd *) pwd_to_spwd(pw);
- }
- cp = sp->sp_pwdp;
- np = sp->sp_namp;
-#else
- cp = pw->pw_passwd;
- np = name;
-#endif /* CONFIG_FEATURE_SHADOWPASSWDS */
-
- safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd));
- if (!(dflg || lflg || uflg)) {
- if (!amroot) {
- if (cp[0] == '!') {
- syslog(LOG_WARNING, "password locked for `%s'", np);
- bb_error_msg_and_die( "The password for `%s' cannot be changed.\n", np);
- }
+ /* Decide what the new password will be */
+ newp = NULL;
+ c = pw->pw_passwd[0] - '!';
+ if (!(opt & OPT_lud)) {
+ if (myuid != 0 && !c) { /* passwd starts with '!' */
+ /* LOGMODE_BOTH */
+ bb_error_msg_and_die("can't change "
+ "locked password for %s", name);
}
printf("Changing password for %s\n", name);
- if (new_password(pw, amroot, algo)) {
- bb_error_msg_and_die( "The password for %s is unchanged.\n", name);
- }
- } else if (lflg) {
- if (crypt_passwd[0] != '!') {
- memmove(&crypt_passwd[1], crypt_passwd,
- sizeof crypt_passwd - 1);
- crypt_passwd[sizeof crypt_passwd - 1] = '\0';
- crypt_passwd[0] = '!';
- }
- } else if (uflg) {
- if (crypt_passwd[0] == '!') {
- memmove(crypt_passwd, &crypt_passwd[1],
- sizeof crypt_passwd - 1);
+ 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 (dflg) {
- crypt_passwd[0] = '\0';
- }
- set_filesize_limit(30000);
- signal(SIGHUP, SIG_IGN);
- signal(SIGINT, SIG_IGN);
- signal(SIGQUIT, SIG_IGN);
+ } 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 = (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);
- if (setuid(0)) {
- syslog(LOG_ERR, "can't setuid(0)");
- bb_error_msg_and_die( "Cannot change ID to root.\n");
- }
- if (!update_passwd(pw, crypt_passwd)) {
- syslog(LOG_INFO, "password for `%s' changed by user `%s'", name,
- myname);
- printf("Password changed.\n");
- } else {
- syslog(LOG_WARNING, "an error occurred updating the password file");
- bb_error_msg_and_die("An error occurred updating the password file.\n");
- }
- return (0);
-}
-
-
-
-static int create_backup(const char *backup, FILE * fp)
-{
- struct stat sb;
- struct utimbuf ub;
- FILE *bkfp;
- int c, mask;
-
- if (fstat(fileno(fp), &sb))
- /* return -1; */
- return 1;
-
- mask = umask(077);
- bkfp = fopen(backup, "w");
- umask(mask);
- if (!bkfp)
- /* return -1; */
- return 1;
-
- /* TODO: faster copy, not one-char-at-a-time. --marekm */
- rewind(fp);
- while ((c = getc(fp)) != EOF) {
- if (putc(c, bkfp) == EOF)
- break;
- }
- if (c != EOF || fflush(bkfp)) {
- fclose(bkfp);
- /* return -1; */
- return 1;
- }
- if (fclose(bkfp))
- /* return -1; */
- return 1;
-
- ub.actime = sb.st_atime;
- ub.modtime = sb.st_mtime;
- utime(backup, &ub);
- return 0;
-}
-
-static int i64c(int i)
-{
- if (i <= 0)
- return ('.');
- if (i == 1)
- return ('/');
- if (i >= 2 && i < 12)
- return ('0' - 2 + i);
- if (i >= 12 && i < 38)
- return ('A' - 12 + i);
- if (i >= 38 && i < 63)
- return ('a' - 38 + i);
- return ('z');
-}
-
-static char *crypt_make_salt(void)
-{
- time_t now;
- static unsigned long x;
- static char result[3];
-
- time(&now);
- x += now + getpid() + clock();
- result[0] = i64c(((x >> 18) ^ (x >> 6)) & 077);
- result[1] = i64c(((x >> 12) ^ x) & 077);
- result[2] = '\0';
- return result;
-}
-
-
-static int new_password(const struct passwd *pw, int amroot, int algo)
-{
- char *clear;
- char *cipher;
- char *cp;
- char orig[200];
- char pass[200];
- time_t start, now;
-
- if (!amroot && crypt_passwd[0]) {
- if (!(clear = bb_askpass(0, "Old password:"))) {
- /* return -1; */
- return 1;
- }
- cipher = pw_encrypt(clear, crypt_passwd);
- if (strcmp(cipher, crypt_passwd) != 0) {
- syslog(LOG_WARNING, "incorrect password for `%s'",
- pw->pw_name);
- time(&start);
- now = start;
- while (difftime(now, start) < FAIL_DELAY) {
- sleep(FAIL_DELAY);
- time(&now);
- }
- fprintf(stderr, "Incorrect password.\n");
- /* return -1; */
- return 1;
- }
- safe_strncpy(orig, clear, sizeof(orig));
- bzero(clear, strlen(clear));
- bzero(cipher, strlen(cipher));
- } else {
- orig[0] = '\0';
- }
- if (! (cp=bb_askpass(0, "Enter the new password (minimum of 5, maximum of 8 characters)\n"
- "Please use a combination of upper and lower case letters and numbers.\n"
- "Enter new password: ")))
+ xsetuid(0);
+
+#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
{
- bzero(orig, sizeof orig);
- /* return -1; */
- return 1;
+ filename = bb_path_passwd_file;
+ rc = update_passwd(bb_path_passwd_file, name, newp, NULL);
}
- safe_strncpy(pass, cp, sizeof(pass));
- bzero(cp, strlen(cp));
- /* if (!obscure(orig, pass, pw)) { */
- if (obscure(orig, pass, pw)) {
- if (amroot) {
- printf("\nWarning: weak password (continuing).\n");
- } else {
- /* return -1; */
- return 1;
- }
- }
- if (!(cp = bb_askpass(0, "Re-enter new password: "))) {
- bzero(orig, sizeof orig);
- /* return -1; */
- return 1;
- }
- if (strcmp(cp, pass)) {
- fprintf(stderr, "Passwords do not match.\n");
- /* return -1; */
- return 1;
+ /* LOGMODE_BOTH */
+ 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); - 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" : "");
}
- bzero(cp, strlen(cp));
- bzero(orig, sizeof(orig));
- if (algo == 1) {
- cp = pw_encrypt(pass, "$1$");
- } else
- cp = pw_encrypt(pass, crypt_make_salt());
- bzero(pass, sizeof pass);
- safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd));
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(myname);
return 0;
}
-
-static void set_filesize_limit(int blocks)
-{
- struct rlimit rlimit_fsize;
-
- rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * blocks;
- setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
-}
projects / oweals / busybox.git / blobdiff