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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/auth.h>
#include <grub/list.h>
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/env.h>
#include <grub/normal.h>
#include <grub/time.h>
#include <grub/i18n.h>
struct grub_auth_user
{
struct grub_auth_user *next;
struct grub_auth_user **prev;
char *name;
grub_auth_callback_t callback;
void *arg;
int authenticated;
};
static struct grub_auth_user *users = NULL;
grub_err_t
grub_auth_register_authentication (const char *user,
grub_auth_callback_t callback,
void *arg)
{
struct grub_auth_user *cur;
cur = grub_named_list_find (GRUB_AS_NAMED_LIST (users), user);
if (!cur)
cur = grub_zalloc (sizeof (*cur));
if (!cur)
return grub_errno;
cur->callback = callback;
cur->arg = arg;
if (! cur->name)
{
cur->name = grub_strdup (user);
if (!cur->name)
{
grub_free (cur);
return grub_errno;
}
grub_list_push (GRUB_AS_LIST_P (&users), GRUB_AS_LIST (cur));
}
return GRUB_ERR_NONE;
}
grub_err_t
grub_auth_unregister_authentication (const char *user)
{
struct grub_auth_user *cur;
cur = grub_named_list_find (GRUB_AS_NAMED_LIST (users), user);
if (!cur)
return grub_error (GRUB_ERR_BAD_ARGUMENT, "user '%s' not found", user);
if (!cur->authenticated)
{
grub_free (cur->name);
grub_list_remove (GRUB_AS_LIST (cur));
grub_free (cur);
}
else
{
cur->callback = NULL;
cur->arg = NULL;
}
return GRUB_ERR_NONE;
}
grub_err_t
grub_auth_authenticate (const char *user)
{
struct grub_auth_user *cur;
cur = grub_named_list_find (GRUB_AS_NAMED_LIST (users), user);
if (!cur)
cur = grub_zalloc (sizeof (*cur));
if (!cur)
return grub_errno;
cur->authenticated = 1;
if (! cur->name)
{
cur->name = grub_strdup (user);
if (!cur->name)
{
grub_free (cur);
return grub_errno;
}
grub_list_push (GRUB_AS_LIST_P (&users), GRUB_AS_LIST (cur));
}
return GRUB_ERR_NONE;
}
grub_err_t
grub_auth_deauthenticate (const char *user)
{
struct grub_auth_user *cur;
cur = grub_named_list_find (GRUB_AS_NAMED_LIST (users), user);
if (!cur)
return grub_error (GRUB_ERR_BAD_ARGUMENT, "user '%s' not found", user);
if (!cur->callback)
{
grub_free (cur->name);
grub_list_remove (GRUB_AS_LIST (cur));
grub_free (cur);
}
else
cur->authenticated = 0;
return GRUB_ERR_NONE;
}
static int
is_authenticated (const char *userlist)
{
const char *superusers;
struct grub_auth_user *user;
superusers = grub_env_get ("superusers");
if (!superusers)
return 1;
FOR_LIST_ELEMENTS (user, users)
{
if (!(user->authenticated))
continue;
if ((userlist && grub_strword (userlist, user->name))
|| grub_strword (superusers, user->name))
return 1;
}
return 0;
}
static int
grub_username_get (char buf[], unsigned buf_size)
{
unsigned cur_len = 0;
int key;
while (1)
{
key = grub_getkey ();
if (key == '\n' || key == '\r')
break;
if (key == '\e')
{
cur_len = 0;
break;
}
if (key == '\b')
{
if (cur_len)
{
cur_len--;
grub_printf ("\b \b");
}
continue;
}
if (!grub_isprint (key))
continue;
if (cur_len + 2 < buf_size)
{
buf[cur_len++] = key;
grub_printf ("%c", key);
}
}
grub_memset (buf + cur_len, 0, buf_size - cur_len);
grub_xputs ("\n");
grub_refresh ();
return (key != '\e');
}
grub_err_t
grub_auth_check_authentication (const char *userlist)
{
char login[1024];
struct grub_auth_user *cur = NULL;
static unsigned long punishment_delay = 1;
char entered[GRUB_AUTH_MAX_PASSLEN];
struct grub_auth_user *user;
grub_memset (login, 0, sizeof (login));
if (is_authenticated (userlist))
{
punishment_delay = 1;
return GRUB_ERR_NONE;
}
grub_puts_ (N_("Enter username: "));
if (!grub_username_get (login, sizeof (login) - 1))
goto access_denied;
grub_puts_ (N_("Enter password: "));
if (!grub_password_get (entered, GRUB_AUTH_MAX_PASSLEN))
goto access_denied;
FOR_LIST_ELEMENTS (user, users)
{
if (grub_strcmp (login, user->name) == 0)
cur = user;
}
if (!cur || ! cur->callback)
goto access_denied;
cur->callback (login, entered, cur->arg);
if (is_authenticated (userlist))
{
punishment_delay = 1;
return GRUB_ERR_NONE;
}
access_denied:
grub_sleep (punishment_delay);
if (punishment_delay < GRUB_ULONG_MAX / 2)
punishment_delay *= 2;
return GRUB_ACCESS_DENIED;
}
static grub_err_t
grub_cmd_authenticate (struct grub_command *cmd __attribute__ ((unused)),
int argc, char **args)
{
return grub_auth_check_authentication ((argc >= 1) ? args[0] : "");
}
static grub_command_t cmd;
void
grub_normal_auth_init (void)
{
cmd = grub_register_command ("authenticate",
grub_cmd_authenticate,
N_("[USERLIST]"),
N_("Check whether user is in USERLIST."));
}
void
grub_normal_auth_fini (void)
{
grub_unregister_command (cmd);
}