mirror of
https://github.com/sheumann/hush.git
synced 2024-10-29 20:27:40 +00:00
407 lines
8.9 KiB
C
407 lines
8.9 KiB
C
/* 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>
|
|
#include <syslog.h>
|
|
#include <time.h>
|
|
#include <sys/resource.h>
|
|
#include <errno.h>
|
|
|
|
#include "busybox.h"
|
|
|
|
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);
|
|
|
|
|
|
int get_algo(char *a)
|
|
{
|
|
int x = 1; /* standard: MD5 */
|
|
|
|
if (strcasecmp(a, "des") == 0)
|
|
x = 0;
|
|
return x;
|
|
}
|
|
|
|
|
|
extern int update_passwd(const struct passwd *pw, char *crypt_pw)
|
|
{
|
|
char filename[1024];
|
|
char buf[1025];
|
|
char buffer[80];
|
|
char username[32];
|
|
char *pw_rest;
|
|
int has_shadow = 0;
|
|
int mask;
|
|
int continued;
|
|
FILE *fp;
|
|
FILE *out_fp;
|
|
struct stat sb;
|
|
struct flock lock;
|
|
|
|
if (access(bb_path_shadow_file, F_OK) == 0) {
|
|
has_shadow = 1;
|
|
}
|
|
if (has_shadow) {
|
|
snprintf(filename, sizeof filename, "%s", bb_path_shadow_file);
|
|
} else {
|
|
snprintf(filename, sizeof filename, "%s", bb_path_passwd_file);
|
|
}
|
|
|
|
if (((fp = fopen(filename, "r+")) == 0) || (fstat(fileno(fp), &sb))) {
|
|
/* return 0; */
|
|
return 1;
|
|
}
|
|
|
|
/* 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;
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
bzero(buffer, sizeof buffer);
|
|
}
|
|
|
|
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;
|
|
unsigned short ruid;
|
|
|
|
#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();
|
|
}
|
|
}
|
|
ruid = getuid();
|
|
pw = (struct passwd *) getpwuid(ruid);
|
|
if (!pw) {
|
|
bb_error_msg_and_die("Cannot determine your user name.");
|
|
}
|
|
myname = (char *) bb_xstrdup(pw->pw_name);
|
|
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);
|
|
}
|
|
}
|
|
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);
|
|
}
|
|
} else if (dflg) {
|
|
crypt_passwd[0] = '\0';
|
|
}
|
|
set_filesize_limit(30000);
|
|
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");
|
|
}
|
|
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: ")))
|
|
{
|
|
bzero(orig, sizeof orig);
|
|
/* return -1; */
|
|
return 1;
|
|
}
|
|
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;
|
|
}
|
|
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));
|
|
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);
|
|
}
|