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/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
RCSID("$OpenBSD: auth.c,v 1.19 2001/03/02 18:54:31 deraadt Exp $");
#include "xmalloc.h"
#include "match.h"
#include "groupaccess.h"
#include "log.h"
#include "servconf.h"
#include "auth.h"
#include "auth-options.h"
#include "canohost.h"
/* import */
extern ServerOptions options;
/*
* Check if the user is allowed to log in via ssh. If user is listed
* in DenyUsers or one of user's groups is listed in DenyGroups, false
* will be returned. If AllowUsers isn't empty and user isn't listed
* there, or if AllowGroups isn't empty and one of user's groups isn't
* listed there, false will be returned.
* If the user's shell is not executable, false will be returned.
* Otherwise true is returned.
*/
int
allowed_user(struct passwd * pw)
{
struct stat st;
char *shell;
int i;
/* Shouldn't be called if pw is NULL, but better safe than sorry... */
if (!pw || !pw->pw_name)
return 0;
/*
* Get the shell from the password data. An empty shell field is
* legal, and means /bin/sh.
*/
shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
/* deny if shell does not exists or is not executable */
if (stat(shell, &st) != 0)
return 0;
if (!((st.st_mode & S_IFREG) && (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP))))
return 0;
/* Return false if user is listed in DenyUsers */
if (options.num_deny_users > 0) {
for (i = 0; i < options.num_deny_users; i++)
if (match_pattern(pw->pw_name, options.deny_users[i]))
return 0;
}
/* Return false if AllowUsers isn't empty and user isn't listed there */
if (options.num_allow_users > 0) {
for (i = 0; i < options.num_allow_users; i++)
if (match_pattern(pw->pw_name, options.allow_users[i]))
break;
/* i < options.num_allow_users iff we break for loop */
if (i >= options.num_allow_users)
return 0;
}
if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
/* Get the user's group access list (primary and supplementary) */
if (ga_init(pw->pw_name, pw->pw_gid) == 0)
return 0;
/* Return false if one of user's groups is listed in DenyGroups */
if (options.num_deny_groups > 0)
if (ga_match(options.deny_groups,
options.num_deny_groups)) {
ga_free();
return 0;
}
/*
* Return false if AllowGroups isn't empty and one of user's groups
* isn't listed there
*/
if (options.num_allow_groups > 0)
if (!ga_match(options.allow_groups,
options.num_allow_groups)) {
ga_free();
return 0;
}
ga_free();
}
/* We found no reason not to let this user try to log on... */
return 1;
}
Authctxt *
authctxt_new(void)
{
Authctxt *authctxt = xmalloc(sizeof(*authctxt));
memset(authctxt, 0, sizeof(*authctxt));
return authctxt;
}
void
auth_log(Authctxt *authctxt, int authenticated, char *method, char *info)
{
void (*authlog) (const char *fmt,...) = verbose;
char *authmsg;
/* Raise logging level */
if (authenticated == 1 ||
!authctxt->valid ||
authctxt->failures >= AUTH_FAIL_LOG ||
strcmp(method, "password") == 0)
authlog = log;
if (authctxt->postponed)
authmsg = "Postponed";
else
authmsg = authenticated ? "Accepted" : "Failed";
authlog("%s %s for %s%.100s from %.200s port %d%s",
authmsg,
method,
authctxt->valid ? "" : "illegal user ",
authctxt->valid && authctxt->pw->pw_uid == 0 ? "ROOT" : authctxt->user,
get_remote_ipaddr(),
get_remote_port(),
info);
}
/*
* Check whether root logins are disallowed.
*/
int
auth_root_allowed(char *method)
{
switch (options.permit_root_login) {
case PERMIT_YES:
return 1;
break;
case PERMIT_NO_PASSWD:
if (strcmp(method, "password") != 0)
return 1;
break;
case PERMIT_FORCED_ONLY:
if (forced_command) {
log("Root login accepted for forced command.");
return 1;
}
break;
}
log("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr());
return 0;
}
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