/* 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"
+//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 Encryption method"
+//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/resource.h> /* setrlimit */
-static char crypt_passwd[128];
-
-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);
-
-
-static int get_algo(char *a)
+static void nuke_str(char *str)
{
- int x = 1; /* standard: MD5 */
-
- if (strcasecmp(a, "des") == 0)
- x = 0;
- return x;
+ if (str) memset(str, 0, strlen(str));
}
-
-static int update_passwd(const struct passwd *pw, const char *crypt_pw)
+static char* new_password(const struct passwd *pw, uid_t myuid, const char *algo)
{
- 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;
-
-#if ENABLE_FEATURE_SHADOWPASSWDS
- if (access(bb_path_shadow_file, F_OK) == 0) {
- snprintf(filename, sizeof filename, "%s", bb_path_shadow_file);
- } else
-#endif
- {
- snprintf(filename, sizeof filename, "%s", bb_path_passwd_file);
+ char salt[MAX_PW_SALT_LEN];
+ char *orig = (char*)"";
+ char *newp = NULL;
+ char *cp = NULL;
+ char *ret = NULL; /* failure so far */
+
+ if (myuid != 0 && pw->pw_passwd[0]) {
+ char *encrypted;
+
+ orig = bb_ask_stdin("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(LOGIN_FAIL_DELAY);
+ puts("Incorrect password");
+ goto err_ret;
+ }
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(encrypted);
}
-
- fp = fopen(filename, "r+");
- if (fp == 0 || fstat(fileno(fp), &sb)) {
- /* return 0; */
- return 1;
+ orig = xstrdup(orig); /* or else bb_ask_stdin() will destroy it */
+ newp = bb_ask_stdin("New password: "); /* returns ptr to static */
+ if (!newp)
+ goto err_ret;
+ newp = xstrdup(newp); /* we are going to bb_ask_stdin() again, so save it */
+ if (ENABLE_FEATURE_PASSWD_WEAK_CHECK
+ && obscure(orig, newp, pw)
+ && myuid != 0
+ ) {
+ goto err_ret; /* non-root is not allowed to have weak passwd */
}
- /* 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) {
- bb_perror_msg("%s", filename);
- return 1;
+ cp = bb_ask_stdin("Retype password: ");
+ if (!cp)
+ goto err_ret;
+ if (strcmp(cp, newp) != 0) {
+ puts("Passwords don't match");
+ goto err_ret;
}
- lock.l_type = F_UNLCK;
- 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;
- }
+ crypt_make_pw_salt(salt, algo);
- 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);
- }
- } else {
- fputs(buffer, out_fp);
- }
- if (buffer[strlen(buffer) - 1] == '\n') {
- continued = 0;
- } else {
- continued = 1;
- }
- memset(buffer, 0, sizeof buffer);
- }
+ /* pw_encrypt returns malloced str */
+ ret = pw_encrypt(newp, salt, 1);
+ /* whee, success! */
- 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;
- }
-}
+ 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)
+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,
+ 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 long opt;
- char *opt_a;
- int amroot;
- char *cp;
- char *np;
- char *name;
+ unsigned opt;
+ int rc;
+ const char *opt_a = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
+ const char *filename;
char *myname;
- int algo = 1;
- const struct passwd *pw;
+ 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
- amroot = (getuid() == 0);
- openlog("passwd", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
- opt = bb_getopt_ulflags(argc, argv, "a:lud", &opt_a);
- argc -= optind;
+ logmode = LOGMODE_BOTH;
+ openlog(applet_name, 0, LOG_AUTH);
+ opt = getopt32(argv, "a:lud", &opt_a);
+ //argc -= optind;
argv += optind;
- if (opt & OPT_algo) algo = get_algo(opt_a); // -a
- if ((opt & OPT_lud) && (!argc || !amroot))
+
+ myuid = getuid();
+ /* -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, getuid(), -1));
- name = myname;
- if (argc) name = argv[0];
+ /* 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);
+ 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);
}
- if (!amroot && pw->pw_uid != getuid()) {
- syslog(LOG_WARNING, "can't change pwd for '%s'", name);
- bb_error_msg_and_die("permission denied");
+
+#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 {
+ pw->pw_passwd = result->sp_pwdp;
+ }
}
- if (ENABLE_FEATURE_SHADOWPASSWDS) {
- struct spwd *sp = getspnam(name);
- if (!sp) bb_error_msg_and_die("unknown user %s", name);
- cp = sp->sp_pwdp;
- } else cp = pw->pw_passwd;
+#endif
- np = name;
- safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd));
+ /* Decide what the new password will be */
+ newp = NULL;
+ c = pw->pw_passwd[0] - '!';
if (!(opt & OPT_lud)) {
- 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", np);
- }
+ 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", name);
+ 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 (crypt_passwd[0] != '!') {
- memmove(&crypt_passwd[1], crypt_passwd,
- sizeof crypt_passwd - 1);
- crypt_passwd[sizeof crypt_passwd - 1] = '\0';
- crypt_passwd[0] = '!';
- }
+ if (!c)
+ goto skip; /* passwd starts with '!' */
+ newp = xasprintf("!%s", pw->pw_passwd);
} else if (opt & OPT_unlock) {
- if (crypt_passwd[0] == '!') {
- memmove(crypt_passwd, &crypt_passwd[1],
- sizeof crypt_passwd - 1);
- }
+ 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) {
- crypt_passwd[0] = '\0';
+ newp = (char*)"";
}
- set_filesize_limit(30000);
- signal(SIGHUP, SIG_IGN);
- signal(SIGINT, SIG_IGN);
- signal(SIGQUIT, SIG_IGN);
+
+ 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 (!update_passwd(pw, crypt_passwd)) {
- syslog(LOG_INFO, "password for '%s' changed by user '%s'", name,
- myname);
- puts("Password changed");
- } else {
- syslog(LOG_WARNING, "cannot update password file");
- bb_error_msg_and_die("cannot update password file");
- }
- if (ENABLE_FEATURE_CLEAN_UP) free(myname);
- 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 salt[12]; /* "$N$XXXXXXXX" or "XX" */
- char orig[200];
- char pass[200];
-
- if (!amroot && crypt_passwd[0]) {
- clear = bb_askpass(0, "Old password:");
- if (!clear) {
- /* 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);
- bb_do_delay(FAIL_DELAY);
- puts("Incorrect password");
- /* return -1; */
- return 1;
- }
- safe_strncpy(orig, clear, sizeof(orig));
- memset(clear, 0, strlen(clear));
- memset(cipher, 0, strlen(cipher));
- } else {
- orig[0] = '\0';
- }
- cp = bb_askpass(0, "Enter the new password (minimum of 5 characters).\n"
- "Please use a combination of upper and lower case letters and numbers.\n"
- "Enter new password: ");
- if (!cp ) {
- memset(orig, 0, sizeof orig);
- /* return -1; */
- return 1;
- }
- safe_strncpy(pass, cp, sizeof(pass));
- memset(cp, 0, strlen(cp));
- /* if (!obscure(orig, pass, pw)) { */
- if (obscure(orig, pass, pw)) {
- if (amroot) {
- puts("\nWarning: weak password (continuing)");
- } else {
- /* return -1; */
- return 1;
- }
- }
- cp = bb_askpass(0, "Re-enter new password: ");
- if (!cp) {
- memset(orig, 0, sizeof orig);
- /* return -1; */
- return 1;
- }
- if (strcmp(cp, pass)) {
- puts("Passwords do not match");
- /* return -1; */
- return 1;
+#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);
}
- memset(cp, 0, strlen(cp));
- memset(orig, 0, sizeof(orig));
- memset(salt, 0, sizeof(salt));
+ /* 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 (algo == 1) {
- strcpy(salt, "$1$");
- strcat(salt, crypt_make_salt());
- strcat(salt, crypt_make_salt());
- strcat(salt, crypt_make_salt());
+ /*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" : "");
}
- strcat(salt, crypt_make_salt());
- cp = pw_encrypt(pass, salt);
-
- memset(pass, 0, 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);
-}