* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
-#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>
+#include "busybox.h"
#include <syslog.h>
-#include <time.h>
-#include <sys/resource.h>
-#include <errno.h>
-#include "busybox.h"
-static char crypt_passwd[128];
+static void nuke_str(char *str)
+{
+ if (str) memset(str, 0, strlen(str));
+}
-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 i64c(int i)
+{
+ i &= 0x3f;
+ 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 int get_algo(char *a)
+static void crypt_make_salt(char *p, int cnt)
+{
+ unsigned x = x; /* it's pointless to initialize it anyway :) */
+
+ x += getpid() + time(NULL) + clock();
+ do {
+ /* x = (x*1664525 + 1013904223) % 2^32 generator is lame
+ * (low-order bit is not "random", etc...),
+ * but for our purposes it is good enough */
+ x = x*1664525 + 1013904223;
+ /* BTW, Park and Miller's "minimal standard generator" is
+ * x = x*16807 % ((2^31)-1)
+ * It has no problem with visibly alternating lowest bit
+ * but is also weak in cryptographic sense + needs div,
+ * which needs more code (and slower) on many CPUs */
+ *p++ = i64c(x >> 16);
+ *p++ = i64c(x >> 22);
+ } while (--cnt);
+ *p = '\0';
+}
+
+
+static char* new_password(const struct passwd *pw, uid_t myuid, int algo)
{
- int x = 1; /* standard: MD5 */
+ char salt[sizeof("$N$XXXXXXXX")]; /* "$N$XXXXXXXX" or "XX" */
+ char *orig = "";
+ 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 (!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);
+ puts("Incorrect password");
+ goto err_ret;
+ }
+ }
+ 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;
+ }
+
+ /*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 */
+ /* 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 struct passwd *pw, const char *crypt_pw)
+static int update_passwd(const char *filename, const char *username,
+ const char *new_pw)
{
- 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);
+ 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);
}
-
- if (((fp = fopen(filename, "r+")) == 0) || (fstat(fileno(fp), &sb))) {
- /* return 0; */
- return 1;
+ 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(fileno(fp), F_SETLK, &lock) < 0) {
- fprintf(stderr, "%s: %s\n", filename, strerror(errno));
- return 1;
- }
+ if (fcntl(old_fd, F_SETLK, &lock) < 0)
+ bb_perror_msg("warning: cannot lock '%s'", filename);
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;
+ /* 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);
}
- 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;
+ 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! */
- 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);
- }
+ unlink_new:
+ if (ret) unlink(new_name);
- 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;
- }
+ 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;
+ return ret;
}
int passwd_main(int argc, char **argv)
{
- int amroot;
- char *cp;
- char *np;
- char *name;
+ 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;
+ char *opt_a = "";
+ const char *filename;
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;
-
- 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(bb_getpwuid(NULL, getuid(), -1));
- /* exits on error */
- if (optind < argc) {
- name = argv[optind];
- } else {
- name = myname;
- }
- if ((lflg || uflg || dflg) && (optind >= argc || !amroot)) {
+ char *name;
+ char *newp;
+ struct passwd *pw;
+ uid_t myuid;
+ struct rlimit rlimit_fsize;
+ char c;
+
+ logmode = LOGMODE_BOTH;
+ openlog(applet_name, LOG_NOWAIT, LOG_AUTH);
+ opt = getopt32(argc, 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))
bb_show_usage();
- }
+
+ myname = xstrdup(bb_getpwuid(NULL, myuid, -1));
+ name = argc ? argv[0] : myname;
+
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");
+ 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) {
+
+ filename = bb_path_passwd_file;
+#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;
-
- np = name;
- 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);
- }
- }
- 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);
+ if (!sp) {
+ /* LOGMODE_BOTH */
+ bb_error_msg("no record of %s in %s, using %s",
+ name, bb_path_shadow_file,
+ bb_path_passwd_file);
+ } else {
+ filename = bb_path_shadow_file;
+ pw->pw_passwd = sp->sp_pwdp;
}
- } 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] = '!';
+ }
+#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);
}
- } else if (uflg) {
- if (crypt_passwd[0] == '!') {
- memmove(crypt_passwd, &crypt_passwd[1],
- sizeof crypt_passwd - 1);
+ 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 (dflg) {
- crypt_passwd[0] = '\0';
+ } 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 '!' */
+ newp = xstrdup(&pw->pw_passwd[1]);
+ } else if (opt & OPT_delete) {
+ newp = xstrdup("");
}
- set_filesize_limit(30000);
+
+ 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);
umask(077);
- if (setuid(0)) {
- syslog(LOG_ERR, "can't setuid(0)");
- bb_error_msg_and_die( "Cannot change ID to root.\n");
+ xsetuid(0);
+ if (update_passwd(filename, name, newp) != 0) {
+ /* LOGMODE_BOTH */
+ bb_error_msg_and_die("cannot update password file %s",
+ filename);
}
- 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");
+ /* LOGMODE_BOTH */
+ 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);
-}
-
-
-
-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]) {
- 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);
- bb_do_delay(FAIL_DELAY);
- fprintf(stderr, "Incorrect password.\n");
- /* return -1; */
- return 1;
- }
- safe_strncpy(orig, clear, sizeof(orig));
- memset(clear, 0, strlen(clear));
- memset(cipher, 0, 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: ")))
- {
- 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) {
- printf("\nWarning: weak password (continuing).\n");
- } else {
- /* return -1; */
- return 1;
- }
- }
- if (!(cp = bb_askpass(0, "Re-enter new password: "))) {
- memset(orig, 0, sizeof orig);
- /* return -1; */
- return 1;
- }
- if (strcmp(cp, pass)) {
- fprintf(stderr, "Passwords do not match.\n");
- /* return -1; */
- return 1;
- }
- memset(cp, 0, strlen(cp));
- memset(orig, 0, sizeof(orig));
- memset(salt, 0, sizeof(salt));
-
- if (algo == 1) {
- strcpy(salt, "$1$");
- strcat(salt, crypt_make_salt());
- strcat(salt, crypt_make_salt());
- strcat(salt, crypt_make_salt());
- }
-
- strcat(salt, crypt_make_salt());
- cp = pw_encrypt(pass, salt);
-
- memset(pass, 0, sizeof pass);
- safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd));
- 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