rlm_eap_leap.c

radius服务器

/*
 * rlm_eap_leap.c    Handles that are called from eap
 *
 * Version:     $Id: rlm_eap_leap.c,v 1.8 2004/02/26 19:04:30 aland Exp $
 *
 *   This program 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 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program 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 this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Copyright 2003 Alan DeKok <[e-mail]>
 */

#include "autoconf.h"

#include <stdio.h>
#include <stdlib.h>

#include "eap_leap.h"


/*
 * send an initial eap-leap request
 * ie access challenge to the user/peer.

 * Frame eap reply packet.
 * len = header + type + leap_typedata
 * leap_typedata = value_size + value
 */
static int leap_initiate(void *instance, EAP_HANDLER *handler)
{
	leap_session_t	*session;
	LEAP_PACKET	*reply;

	DEBUG2("  rlm_eap_leap: Stage 2");

	/*
	 *	LEAP requires a User-Name attribute
	 */
	if (!handler->request->username) {
		DEBUG2("  rlm_eap_leap: User-Name is required for EAP-LEAP authentication.");
		return 0;
	}

	reply = eapleap_initiate(handler->eap_ds, handler->request->username);
	if (reply == NULL)
		return 0;

	eapleap_compose(handler->eap_ds, reply);

	handler->opaque = malloc(sizeof(leap_session_t));
	if (!handler->opaque) {
	  radlog(L_ERR, "rlm_eap_leap: Out of memory");
	  eapleap_free(&reply);
	  return 0;
	}

	/*
	 *	Remember which stage we're in, and which challenge
	 *	we sent to the AP.  The later stages will take care
	 *	of filling in the peer response.
	 */
	session = (leap_session_t *) handler->opaque;
	handler->free_opaque = free; /* just malloc'd memory */

	session->stage = 4;	/* the next stage we're in */
	memcpy(session->peer_challenge, reply->challenge, reply->count);

	DEBUG2("  rlm_eap_leap: Successfully initiated");

	/*
	 *	The next stage to process the packet.
	 */
	handler->stage = AUTHENTICATE;

	eapleap_free(&reply);
	return 1;
}

static int leap_authenticate(void *instance, EAP_HANDLER *handler)
{
	int		rcode;
	leap_session_t	*session;
	LEAP_PACKET	*packet;
	LEAP_PACKET	*reply;
	char*		username;
	VALUE_PAIR	*password;

	if (!handler->opaque) {
		radlog(L_ERR, "rlm_eap_leap: Cannot authenticate without LEAP history");
		return 0;
	}
	session = (leap_session_t *) handler->opaque;
	reply = NULL;

	/*
	 *	Extract the LEAP packet.
	 */
	if (!(packet = eapleap_extract(handler->eap_ds)))
		return 0;

	username = (char *)handler->request->username->strvalue;

	/*
	 *	The password is never sent over the wire.
	 *	Always get the configured password, for each user.
	 */
	password = pairfind(handler->request->config_items, PW_PASSWORD);
	if (!password) password = pairfind(handler->request->config_items, PW_NT_PASSWORD);
	if (!password) {
		radlog(L_INFO, "rlm_eap_leap: No User-Password or NT-Password configured for this user");
		eapleap_free(&packet);
		return 0;
	}

	/*
	 *	We've already sent the AP challenge.  This packet
	 *	should contain the NtChallengeResponse
	 */
	switch (session->stage) {
	case 4:			/* Verify NtChallengeResponse */
		DEBUG2("  rlm_eap_leap: Stage 4");
		rcode = eapleap_stage4(packet, password, session);
		session->stage = 6;

		/*
		 *	We send EAP-Success or EAP-Fail, and not
		 *	any LEAP packet.  So we return here.
		 */
		if (!rcode) {
			handler->eap_ds->request->code = PW_EAP_FAILURE;
			eapleap_free(&packet);
			return 0;
		}

		handler->eap_ds->request->code = PW_EAP_SUCCESS;

		/*
		 *	Do this only for Success.
		 */
		handler->eap_ds->request->id = handler->eap_ds->response->id + 1;
		handler->eap_ds->set_request_id = 1;

		/*
		 *	LEAP requires a challenge in stage 4, not
		 *	an Access-Accept, which is normally returned
		 *	by eap_compose() in eap.c, when the EAP reply code
		 *	is EAP_SUCCESS.
		 */
		handler->request->reply->code = PW_ACCESS_CHALLENGE;
		return 1;
		break;

	case 6:			/* Issue session key */
		DEBUG2("  rlm_eap_leap: Stage 6");
		reply = eapleap_stage6(packet, handler->request,
				       handler->request->username, password,
				       session, &handler->request->reply->vps);
		break;

		/*
		 *	Stages 1, 3, and 5 are requests from the AP.
		 *	Stage 2 is handled by initiate()
		 */
	default:
		radlog(L_ERR, "  rlm_eap_leap: Internal sanity check failed on stage");
		break;
	}

	eapleap_free(&packet);

	/*
	 *	Process the packet.  We don't care about any previous
	 *	EAP packets, as
	 */
	if (!reply) {
		return 0;
	}

	eapleap_compose(handler->eap_ds, reply);

	eapleap_free(&reply);
	return 1;
}

/*
 *	The module name should be the only globally exported symbol.
 *	That is, everything else should be 'static'.
 */
EAP_TYPE rlm_eap_leap = {
	"eap_leap",
	NULL,			/* attach */
	leap_initiate,		/* Start the initial request, after Identity */
	NULL,			/* authorization */
	leap_authenticate,	/* authentication */
	NULL,			/* detach */
};