ubase/util/passwd.c
sin 924fc8449b Disable core dumps in case passwd(1) crashes
Avoids leaking the shadow db.
2014-06-10 11:44:33 +01:00

183 lines
3.0 KiB
C

/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <pwd.h>
#include <shadow.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/resource.h>
#include <sys/time.h>
#include "../passwd.h"
#include "../text.h"
#include "../util.h"
/* Returns -1 on error, 0 for incorrect password
* and 1 if all went OK */
int
pw_check(struct passwd *pw, const char *pass)
{
char *cryptpass, *p;
struct spwd *spw;
p = pw->pw_passwd;
if (p[0] == '!' || p[0] == '*') {
weprintf("denied\n");
return -1;
}
if (pw->pw_passwd[0] == '\0') {
if (pass[0] == '\0')
return 1;
weprintf("incorrect password\n");
return 0;
}
if (pw->pw_passwd[0] == 'x' && pw->pw_passwd[1] == '\0') {
errno = 0;
spw = getspnam(pw->pw_name);
if (errno) {
weprintf("getspnam: %s:", pw->pw_name);
return -1;
} else if (!spw) {
weprintf("who are you?\n");
return -1;
}
p = spw->sp_pwdp;
if (p[0] == '!' || p[0] == '*') {
weprintf("denied\n");
return -1;
}
}
cryptpass = crypt(pass, p);
if (!cryptpass) {
weprintf("crypt:");
return -1;
}
if (strcmp(cryptpass, p) != 0) {
weprintf("incorrect password\n");
return 0;
}
return 1;
}
int
pw_copy(int ffd, int tfd, const struct passwd *newpw)
{
struct passwd pw;
char *buf = NULL, *p;
size_t size = 0;
FILE *from, *to;
from = fdopen(ffd, "r");
if (!from) {
weprintf("fdopen:");
return -1;
}
to = fdopen(tfd, "w");
if (!to) {
weprintf("fdopen:");
return -1;
}
while (agetline(&buf, &size, from) != -1) {
p = strdup(buf);
if (!p) {
weprintf("strdup:");
return -1;
}
if (newpw) {
if (pw_scan(p, &pw) < 0)
return -1;
if (strcmp(pw.pw_name, newpw->pw_name) == 0) {
fprintf(to, "%s:%s:%u:%u:%s:%s:%s\n",
newpw->pw_name,
newpw->pw_passwd,
newpw->pw_uid,
newpw->pw_gid,
newpw->pw_gecos,
newpw->pw_dir,
newpw->pw_shell);
continue;
}
}
fprintf(to, "%s", buf);
free(p);
}
fflush(to);
free(buf);
return 0;
}
int
pw_init(void)
{
struct rlimit rlim;
rlim.rlim_cur = 0;
rlim.rlim_max = 0;
if (setrlimit(RLIMIT_CORE, &rlim) < 0)
eprintf("setrlimit:");
return 0;
}
int
pw_scan(char *bp, struct passwd *pw)
{
char *p;
memset(pw, 0, sizeof(*pw));
/* login name */
p = strsep(&bp, ":");
if (!p || *p == '\0')
goto corrupt;
pw->pw_name = p;
/* passwd */
p = strsep(&bp, ":");
if (!p)
goto corrupt;
pw->pw_passwd = p;
/* uid */
p = strsep(&bp, ":");
if (!p)
goto corrupt;
pw->pw_uid = estrtol(p, 10);
/* gid */
p = strsep(&bp, ":");
if (!p)
goto corrupt;
pw->pw_gid = estrtol(p, 10);
/* user name or comment */
p = strsep(&bp, ":");
if (!p)
goto corrupt;
pw->pw_gecos = p;
/* home directory */
p = strsep(&bp, ":");
if (!p)
goto corrupt;
pw->pw_dir = p;
/* optional shell */
p = strsep(&bp, ":");
if (!p)
goto corrupt;
pw->pw_shell = p;
/* look for redundant entries */
p = strsep(&bp, ":");
if (p)
goto corrupt;
return 0;
corrupt:
weprintf("corrupted passwd entry\n");
return -1;
}