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/* $Header: /home/morgan/pam/Linux-PAM-0.59/modules/pam_unix/RCS/pam_unix_auth.c,v 1.1 1996/11/09 19:44:35 morgan Exp morgan $ */
/*
* Copyright Alexander O. Yuriev, 1996. All rights reserved.
* NIS+ support by Thorsten Kukuk <kukuk@weber.uni-paderborn.de>
*
* 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, and the entire permission notice in its entirety,
* including the disclaimer of warranties.
* 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.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* ALTERNATIVELY, this product may be distributed under the terms of
* the GNU Public License, in which case the provisions of the GPL are
* required INSTEAD OF the above restrictions. (This clause is
* necessary due to a potential bad interaction between the GPL and
* the restrictions contained in a BSD-style copyright.)
*
* THIS SOFTWARE IS PROVIDED ``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.
*/
/*
* $Log: pam_unix_auth.c,v $
*
* Revision 1.9 1996/05/26 04:13:04 morgan
* added static support
*
* Revision 1.8 1996/05/21 03:51:58 morgan
* added "const" to rcsid[] definition
*
* Revision 1.7 1996/04/19 03:25:57 alex
* minor corrections.
*
* Revision 1.6 1996/04/17 01:05:05 alex
* _pam_auth_unix() cleaned up - non-authentication code is made into funcs
* and mostly moved out to support.c.
*
* Revision 1.5 1996/04/16 21:12:46 alex
* unix authentication works on Bach again. This is a tranitional stage.
* I really don't like that _pam_unix_auth() grew into a monster that does
* prompts etc etc. They should go into other functions.
*
* Revision 1.4 1996/04/07 08:06:12 morgan
* tidied up a little
*
* Revision 1.3 1996/04/07 07:34:07 morgan
* added conversation support. Now the module is capable of obtaining a
* username and a password all by itself.
*
* Revision 1.2 1996/03/29 02:31:19 morgan
* Marek Michalkiewicz's small patches for shadow support.
*
* Revision 1.1 1996/03/09 09:10:57 morgan
* Initial revision
*
*/
#ifdef linux
# define _GNU_SOURCE
# include <features.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define __USE_BSD
#include <unistd.h>
#include <pwd.h>
#include <sys/types.h>
#ifndef NDEBUG
#include <syslog.h>
#endif /* NDEBUG */
#ifdef HAVE_SHADOW_H
#include <shadow.h>
#endif /* HAVE_SHADOW_H */
#ifndef LINUX
#include <security/pam_appl.h>
#endif /* LINUX */
#define _PAM_EXTERN_FUNCTIONS
#include <security/pam_modules.h>
static const char rcsid[] = "$Id: pam_unix_auth.c,v 1.1 1996/11/09 19:44:35 morgan Exp morgan $ pam_unix authentication functions. alex@bach.cis.temple.edu";
/* Define function phototypes */
extern char *crypt(const char *key, const char *salt); /* This should have
been in unistd.h
but it is not */
extern int converse( pam_handle_t *pamh,
int nargs,
struct pam_message **message,
struct pam_response **response );
extern int _set_auth_tok( pam_handle_t *pamh,
int flags, int argc,
const char **argv );
static int _pam_auth_unix( pam_handle_t *pamh,
int flags, int argc,
const char **argv );
static int _pam_set_credentials_unix ( pam_handle_t *pamh,
int flags,
int argc,
const char ** argv ) ;
/* Fun starts here :)
*
* _pam_auth_unix() actually performs UNIX/shadow authentication
*
* First, if shadow support is available, attempt to perform
* authentication using shadow passwords. If shadow is not
* available, or user does not have a shadow password, fallback
* onto a normal UNIX authentication
*/
static int _pam_auth_unix( pam_handle_t *pamh,
int flags,
int argc,
const char **argv )
{
int retval;
struct passwd *pw;
const char *name;
char *p, *pp;
const char *salt;
#ifdef HAVE_SHADOW_H
struct spwd *sp;
#endif
/* get the user'name' */
if ( (retval = pam_get_user( pamh, &name, "login: ") ) != PAM_SUCCESS )
return retval;
/*
* at some point we will have to make this module pay
* attention to arguments, like 'pam_first_pass' etc...
*/
pw = getpwnam ( name );
/* For NIS+, root cannot get password for lesser user */
if (pw) {
uid_t save_euid, save_uid;
save_uid = getuid ();
save_euid = geteuid();
if (setreuid (0,pw->pw_uid) >= 0) {
pw = getpwnam ( name );
setreuid (save_uid,save_euid);
}
}
if ( pw && (!pw->pw_passwd || pw->pw_passwd[0] == '\0') &&
!(flags & PAM_DISALLOW_NULL_AUTHTOK)) {
return PAM_SUCCESS;
}
pam_get_item( pamh, PAM_AUTHTOK, (void*) &p );
if ( !p )
{
retval = _set_auth_tok( pamh, flags, argc, argv );
if ( retval != PAM_SUCCESS )
return retval;
}
/*
We have to call pam_get_item() again because value of p should
change
*/
pam_get_item( pamh, PAM_AUTHTOK, (void*) &p );
if (pw)
{
#ifdef HAVE_SHADOW_H
/*
* Support for shadow passwords on Linux and SVR4-based
* systems. Shadow passwords are optional on Linux - if
* there is no shadow password, use the non-shadow one.
*/
sp = getspnam( name );
if (sp && (!strcmp(pw->pw_passwd,"x")))
{
/* TODO: check if password has expired etc. */
salt = sp->sp_pwdp;
}
else
#endif
salt = pw->pw_passwd;
}
else
return PAM_USER_UNKNOWN;
/* The 'always-encrypt' method does not make sense in PAM
because the framework requires return of a different
error code for non-existant users -- alex */
if ( ( !pw->pw_passwd ) && ( !p ) )
if ( flags && PAM_DISALLOW_NULL_AUTHTOK )
return PAM_SUCCESS;
else
return PAM_AUTH_ERR;
pp = crypt(p, salt);
if ( strcmp( pp, salt ) == 0 )
return PAM_SUCCESS;
return PAM_AUTH_ERR;
}
/*
* The only thing _pam_set_credentials_unix() does is initialization of
* UNIX group IDs.
*
* Well, everybody but me on linux-pam is convinced that it should not
* initialize group IDs, so I am not doing it but don't say that I haven't
* warned you. -- AOY
*/
static int _pam_set_credentials_unix ( pam_handle_t *pamh,
int flags,
int argc,
const char **argv )
{ /* FIX ME: incorrect error code */
return PAM_SUCCESS; /* This is a wrong result code. From what I
remember from reafing one of the guides
there's an error-level saying 'N/A func'
-- AOY
*/
}
/*
* PAM framework looks for these entry-points to pass control to the
* authentication module.
*/
PAM_EXTERN
int pam_sm_authenticate( pam_handle_t *pamh,
int flags,
int argc,
const char **argv )
{
return _pam_auth_unix( pamh, flags, argc, argv );
}
PAM_EXTERN
int pam_sm_setcred( pam_handle_t *pamh,
int flags,
int argc,
const char **argv)
{
return _pam_set_credentials_unix ( pamh, flags, argc, argv ) ;
}
/* static module data */
#ifdef PAM_STATIC
struct pam_module _pam_unix_auth_modstruct = {
"pam_unix_auth",
pam_sm_authenticate,
pam_sm_setcred,
NULL,
NULL,
NULL,
NULL,
};
#endif
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