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/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Password authentication. This file contains the functions to check whether
* the password is valid for the user.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*
* Copyright (c) 1999 Dug Song. All rights reserved.
* 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-passwd.c,v 1.31 2004/01/30 09:48:57 markus Exp $");
#include "packet.h"
#include "log.h"
#include "servconf.h"
#include "auth.h"
#include "auth-options.h"
extern ServerOptions options;
int sys_auth_passwd(Authctxt *, const char *);
void
disable_forwarding(void)
{
no_port_forwarding_flag = 1;
no_agent_forwarding_flag = 1;
no_x11_forwarding_flag = 1;
}
/*
* Tries to authenticate the user using password. Returns true if
* authentication succeeds.
*/
int
auth_password(Authctxt *authctxt, const char *password)
{
struct passwd * pw = authctxt->pw;
int ok = authctxt->valid;
static int expire_checked = 0;
#ifndef HAVE_CYGWIN
if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
ok = 0;
#endif
if (*password == '\0' && options.permit_empty_passwd == 0)
return 0;
#ifdef KRB5
if (options.kerberos_authentication == 1) {
int ret = auth_krb5_password(authctxt, password);
if (ret == 1 || ret == 0)
return ret && ok;
/* Fall back to ordinary passwd authentication. */
}
#endif
#ifdef HAVE_CYGWIN
if (is_winnt) {
HANDLE hToken = cygwin_logon_user(pw, password);
if (hToken == INVALID_HANDLE_VALUE)
return 0;
cygwin_set_impersonation_token(hToken);
return ok;
}
#endif
#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
if (!expire_checked) {
expire_checked = 1;
if (auth_shadow_pwexpired(authctxt)) {
disable_forwarding();
authctxt->force_pwchange = 1;
}
}
#endif
return (sys_auth_passwd(authctxt, password) && ok);
}
#ifdef BSD_AUTH
int
sys_auth_passwd(Authctxt *authctxt, const char *password)
{
struct passwd *pw = authctxt->pw;
auth_session_t *as;
as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh",
(char *)password);
if (auth_getstate(as) & AUTH_PWEXPIRED) {
auth_close(as);
disable_forwarding();
authctxt->force_pwchange = 1;
return (1);
} else {
return (auth_close(as));
}
}
#elif !defined(CUSTOM_SYS_AUTH_PASSWD)
int
sys_auth_passwd(Authctxt *authctxt, const char *password)
{
struct passwd *pw = authctxt->pw;
char *encrypted_password;
/* Just use the supplied fake password if authctxt is invalid */
char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd;
/* Check for users with no password. */
if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0)
return (1);
/* Encrypt the candidate password using the proper salt. */
encrypted_password = xcrypt(password,
(pw_password[0] && pw_password[1]) ? pw_password : "xx");
/*
* Authentication is accepted if the encrypted passwords
* are identical.
*/
return (strcmp(encrypted_password, pw_password) == 0);
}
#endif
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