xrdp/sesman/libsesman/sesman_access.c

186 lines
4.9 KiB
C

/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Jay Sorg 2004-2015
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
*
* @file sesman_access.c
* @brief User access control code
* @author Simone Fedele
*
*/
#if defined(HAVE_CONFIG_H)
#include <config_ac.h>
#endif
#include <stdio.h>
#include "arch.h"
#include "sesman_access.h"
#include "sesman_config.h"
#include "log.h"
#include "os_calls.h"
/******************************************************************************/
/**
* Root user login check
*
* @param cfg_sec Sesman security config
* @param user user name
* @return 0 if user is root and root accesses are not allowed
*/
static int
root_login_check(const struct config_security *cfg_sec,
const char *user)
{
int rv = 0;
if (cfg_sec->allow_root)
{
rv = 1;
}
else
{
// Check the UID of the user isn't 0
int uid;
if (g_getuser_info_by_name(user, &uid, NULL, NULL, NULL, NULL) != 0)
{
LOG(LOG_LEVEL_ERROR, "Can't get UID for user %s", user);
}
else if (0 == uid)
{
LOG(LOG_LEVEL_ERROR,
"ROOT login attempted, but root login is disabled");
}
else
{
rv = 1;
}
}
return rv;
}
/******************************************************************************/
/**
* Common access control for group checks
* @param group Group name
* @param param Where group comes from (e.g. "TerminalServerUsers")
* @param always_check_group 0 if a missing group allows a login
* @param user Username
* @return != 0 if the access is allowed */
static int
access_login_allowed_common(const char *group, const char *param,
int always_check_group,
const char *user)
{
int rv = 0;
int gid;
int ok;
if (group == NULL || group[0] == '\0')
{
/* Group is not defined. Default access depends on whether
* we must have the group or not */
if (always_check_group)
{
LOG(LOG_LEVEL_ERROR,
"%s group is not defined. Access denied for %s",
param, user);
}
else
{
LOG(LOG_LEVEL_INFO,
"%s group is not defined. Access granted for %s",
param, user);
rv = 1;
}
}
else if (g_getgroup_info(group, &gid) != 0)
{
/* Group is defined but doesn't exist. Default access depends
* on whether we must have the group or not */
if (always_check_group)
{
LOG(LOG_LEVEL_ERROR,
"%s group %s doesn't exist. Access denied for %s",
param, group, user);
}
else
{
LOG(LOG_LEVEL_INFO,
"%s group %s doesn't exist. Access granted for %s",
param, group, user);
rv = 1;
}
}
else if (0 != g_check_user_in_group(user, gid, &ok))
{
LOG(LOG_LEVEL_ERROR, "Error checking %s group %s. "
"Access denied for %s", param, group, user);
}
else if (!ok)
{
LOG(LOG_LEVEL_ERROR, "User %s is not in %s group %s. Access denied",
user, param, group);
}
else
{
LOG(LOG_LEVEL_INFO, "User %s is in %s group %s. Access granted",
user, param, group);
rv = 1;
}
return rv;
}
/******************************************************************************/
int
access_login_allowed(const struct config_security *cfg_sec, const char *user)
{
int rv = 0;
if (root_login_check(cfg_sec, user))
{
rv = access_login_allowed_common(cfg_sec->ts_users,
"TerminalServerUsers",
cfg_sec->ts_always_group_check,
user);
}
return rv;
}
/******************************************************************************/
int
access_login_mng_allowed(const struct config_security *cfg_sec,
const char *user)
{
int rv = 0;
if (root_login_check(cfg_sec, user))
{
rv = access_login_allowed_common(cfg_sec->ts_admins,
"TerminalServerAdmins",
1,
user);
}
return rv;
}