peap.c

free radius编程。完成AAA的实现

/*
 * peap.c  contains the interfaces that are called from eap
 *
 * Version:     $Id: peap.c,v 1.11 2004/03/12 18:23:14 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 "eap_tls.h"
#include "eap_peap.h"

/*
 *	Send protected EAP-Failure
 *
 *       Result-TLV = Failure
 */
static int eappeap_failure(EAP_HANDLER *handler, tls_session_t *tls_session)
{
	uint8_t tlv_packet[11];

	DEBUG2("  rlm_eap_peap: FAILURE");

	tlv_packet[0] = PW_EAP_REQUEST;
	tlv_packet[1] = handler->eap_ds->response->id +1;
	tlv_packet[2] = 0;
	tlv_packet[3] = 11;	/* length of this packet */
	tlv_packet[4] = PW_EAP_TLV;
	tlv_packet[5] = 0x80;
	tlv_packet[6] = EAP_TLV_ACK_RESULT;
	tlv_packet[7] = 0;
	tlv_packet[8] = 2;	/* length of the data portion */
	tlv_packet[9] = 0;
	tlv_packet[10] = EAP_TLV_FAILURE;

	record_plus(&tls_session->clean_in, tlv_packet, 11);

	/*
	 *	FIXME: Check the return code.
	 */
	tls_handshake_send(tls_session);
	record_init(&tls_session->clean_in);

	return 1;
}


/*
 *	Send protected EAP-Success
 *
 *       Result-TLV = Success
 */
static int eappeap_success(EAP_HANDLER *handler, tls_session_t *tls_session)
{
	uint8_t tlv_packet[11];

	DEBUG2("  rlm_eap_peap: SUCCESS");

	tlv_packet[0] = PW_EAP_REQUEST;
	tlv_packet[1] = handler->eap_ds->response->id +1;
	tlv_packet[2] = 0;
	tlv_packet[3] = 11;	/* length of this packet */
	tlv_packet[4] = PW_EAP_TLV;
	tlv_packet[5] = 0x80;	/* mandatory AVP */
	tlv_packet[6] = EAP_TLV_ACK_RESULT;
	tlv_packet[7] = 0;
	tlv_packet[8] = 2;	/* length of the data portion */
	tlv_packet[9] = 0;
	tlv_packet[10] = EAP_TLV_SUCCESS;

	record_plus(&tls_session->clean_in, tlv_packet, 11);

	/*
	 *	FIXME: Check the return code.
	 */
	tls_handshake_send(tls_session);
	record_init(&tls_session->clean_in);

	return 1;
}


/*
 *	Verify the tunneled EAP message.
 */
static int eapmessage_verify(const uint8_t *data, unsigned int data_len)
{
	const eap_packet_t *eap_packet = (const eap_packet_t *) data;
	uint8_t eap_type;
	char identity[256];

	if (!data || (data_len <= 1)) {
		return 0;
	}

	eap_type = *data;
	switch (eap_type) {
	case PW_EAP_IDENTITY:
		memcpy(identity, data + 1, data_len - 1);
		identity[data_len - 1] = '\0';
		DEBUG2("  rlm_eap_peap: Identity - %s", identity);
		return 1;
		break;

		/*
		 *	If the first byte of the packet is
		 *	EAP-Response, and the EAP data is a TLV,
		 *	then it looks OK...
		 */
	case PW_EAP_RESPONSE:
		if (eap_packet->data[0] == PW_EAP_TLV) {
			DEBUG2("  rlm_eap_peap: Received EAP-TLV response.");
			return 1;
		}
		DEBUG2("  rlm_eap_peap: Got something weird.");
		break;


		/*
		 *	We normally do Microsoft MS-CHAPv2 (26), versus
		 *	Cisco MS-CHAPv2 (29).
		 */
	case PW_EAP_MSCHAPV2:
	default:
		DEBUG2("  rlm_eap_peap: EAP type %s",
		       eaptype_type2name(eap_type,
					 identity, sizeof(identity)));
		return 1;
		break;
	}

	return 0;
}

/*
 *	Convert a pseudo-EAP packet to a list of VALUE_PAIR's.
 */
static VALUE_PAIR *eap2vp(EAP_DS *eap_ds,
			  const uint8_t *data, unsigned int data_len)
{
	VALUE_PAIR *vp = NULL;

	/*
	 *	Sanity check this...
	 */
	if (data_len + EAP_HEADER_LEN > MAX_STRING_LEN) {
		radlog(L_ERR, "rlm_eap_peap: EAP Response packet is too large.  Code must be fixed to handle this.");
		return NULL;
	}

	vp = paircreate(PW_EAP_MESSAGE, PW_TYPE_OCTETS);
	if (!vp) {
		DEBUG2("  rlm_eap_peap: Failure in creating VP");
		return NULL;
	}

	/*
	 *	Hand-build an EAP packet from the crap in PEAP version 0.
	 */
	vp->strvalue[0] = PW_EAP_RESPONSE;
	vp->strvalue[1] = eap_ds->response->id;
	vp->strvalue[2] = 0;
	vp->strvalue[3] = EAP_HEADER_LEN + data_len;

	memcpy(vp->strvalue + EAP_HEADER_LEN, data, data_len);
	vp->length = EAP_HEADER_LEN + data_len;

	return vp;
}


/*
 *	Convert a list of VALUE_PAIR's to an EAP packet, through the
 *	simple expedient of dumping the EAP message
 */
static int vp2eap(tls_session_t *tls_session, VALUE_PAIR *vp)
{
	if (vp->next != NULL) {
		radlog(L_ERR, "rlm_eap_peap: EAP Request packet is too large.  Code must be fixed to handle this.");
		return 0;
	}

	/*
	 *	Skip the id, code, and length.  Just write the EAP
	 *	type & data to the client.
	 */
#ifndef NDEBUG
	if (debug_flag > 2) {
		int i;
		int total = vp->length - 4;

		if (debug_flag > 0) for (i = 0; i < total; i++) {
			if ((i & 0x0f) == 0) printf("  PEAP tunnel data out %04x: ", i);

			printf("%02x ", vp->strvalue[i + 4]);

			if ((i & 0x0f) == 0x0f) printf("\n");
		}
		if ((total & 0x0f) != 0) printf("\n");
	}
#endif

	/*
	 *	Send the EAP data, WITHOUT the header.
	 */
#if 1
	record_plus(&tls_session->clean_in, vp->strvalue + EAP_HEADER_LEN,
		vp->length - EAP_HEADER_LEN);
#else
	record_plus(&tls_session->clean_in, vp->strvalue, vp->length);
#endif
	tls_handshake_send(tls_session);
	record_init(&tls_session->clean_in);

	return 1;
}


/*
 *	See if there's a TLV in the response.
 */
static int eappeap_check_tlv(const uint8_t *data)
{
	const eap_packet_t *eap_packet = (const eap_packet_t *) data;

	/*
	 *	Look for success or failure.
	 */
	if ((eap_packet->code == PW_EAP_RESPONSE) &&
	    (eap_packet->data[0] == PW_EAP_TLV)) {
		if (data[10] == EAP_TLV_SUCCESS) {
			return 1;
		}

		if (data[10] == EAP_TLV_FAILURE) {
			DEBUG2("  rlm_eap_peap: Client rejected our response.  The password is probably incorrect.");
			return 0;
		}
	}

	return 0;
}


/*
 *	Use a reply packet to determine what to do.
 */
static int process_reply(EAP_HANDLER *handler, tls_session_t *tls_session,
			 REQUEST *request, RADIUS_PACKET *reply)
{
	int rcode = RLM_MODULE_REJECT;
	VALUE_PAIR *vp;
	peap_tunnel_t *t = tls_session->opaque;

#ifndef NDEBUG
	if (debug_flag > 0) {
		printf("  PEAP: Processing from tunneled session code %p %d\n",
		       reply, reply->code);
		
		for (vp = reply->vps; vp != NULL; vp = vp->next) {
			putchar('\t');vp_print(stdout, vp);putchar('\n');
		}
	}
#endif

	switch (reply->code) {
	case PW_AUTHENTICATION_ACK:
		DEBUG2("  PEAP: Tunneled authentication was successful.");
		t->status = PEAP_STATUS_SENT_TLV_SUCCESS;
		eappeap_success(handler, tls_session);
		rcode = RLM_MODULE_HANDLED;

		/*
		 *	If we've been told to use the attributes from
		 *	the reply, then do so.
		 *
		 *	WARNING: This may leak information about the
		 *	tunneled user!
		 */
		if (t->use_tunneled_reply) {
			/*
			 *	Clean up the tunneled reply.
			 */
			pairdelete(&reply->vps, PW_PROXY_STATE);
			pairdelete(&reply->vps, PW_EAP_MESSAGE);

			pairadd(&request->reply->vps, reply->vps);
			reply->vps = NULL;
		}
		break;

	case PW_AUTHENTICATION_REJECT:
		DEBUG2("  PEAP: Tunneled authentication was rejected.");
		t->status = PEAP_STATUS_SENT_TLV_FAILURE;
		eappeap_failure(handler, tls_session);
		rcode = RLM_MODULE_HANDLED;
		break;

	case PW_ACCESS_CHALLENGE:
		DEBUG2("  PEAP: Got tunneled Access-Challenge");

		/*
		 *	Keep the State attribute, if necessary.
		 *
		 *	Get rid of the old State, too.
		 */
		pairfree(&t->state);
		pairmove2(&t->state, &(reply->vps), PW_STATE);

		/*
		 *	PEAP takes only EAP-Message attributes inside
		 *	of the tunnel.  Any Reply-Message in the
		 *	Access-Challenge is ignored.
		 */
		vp = NULL;
		pairmove2(&vp, &(reply->vps), PW_EAP_MESSAGE);

		/*
		 *	Handle the ACK, by tunneling any necessary reply
		 *	VP's back to the client.
		 */
		if (vp) {
			vp2eap(tls_session, vp);
			pairfree(&vp);
		}

		rcode = RLM_MODULE_HANDLED;
		break;

	default:
		DEBUG2("  PEAP: Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
		rcode = RLM_MODULE_REJECT;
		break;
	}

	return rcode;
}


/*
 *	Do post-proxy processing,
 */
static int eappeap_postproxy(EAP_HANDLER *handler, void *data)
{
	int rcode;
	tls_session_t *tls_session = (tls_session_t *) data;
	REQUEST *fake;

	DEBUG2("  PEAP: Passing reply from proxy back into the tunnel.");

	/*
	 *	If there was a fake request associated with the proxied
	 *	request, do more processing of it.
	 */
	fake = (REQUEST *) request_data_get(handler->request,
					    handler->request->proxy,
					    REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
	
	/*
	 *	Do the callback, if it exists, and if it was a success.
	 */
	if (fake && (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
		VALUE_PAIR *vp;
		REQUEST *request = handler->request;

		/*
		 *	Terrible hacks.
		 */
		rad_assert(fake->packet == NULL);
		fake->packet = request->proxy;
		request->proxy = NULL;

		rad_assert(fake->reply == NULL);
		fake->reply = request->proxy_reply;
		request->proxy_reply = NULL;

		/*
		 *	Perform a post-auth stage, which will get the EAP
		 *	handler, too...
		 */
		fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
		DEBUG2("  PEAP: Passing reply back for EAP-MS-CHAP-V2 %p %d",
		       fake, fake->reply->code);
		rcode = module_post_proxy(fake);

		/*
		 *	FIXME: If rcode returns fail, do something
		 *	intelligent...
		 */
		DEBUG2("  POST-PROXY %d", rcode);
		rcode = rad_postauth(fake);
		DEBUG2("  POST-AUTH %d", rcode);

#ifndef NDEBUG
		if (debug_flag > 0) {
			printf("  PEAP: Final reply from tunneled session code %d\n",
			       fake->reply->code);
			
			for (vp = fake->reply->vps; vp != NULL; vp = vp->next) {
				putchar('\t');vp_print(stdout, vp);putchar('\n');
			}
		}
#endif

		/*
		 *	Terrible hacks.
		 */
		request->proxy = fake->packet;
		fake->packet = NULL;
		request->proxy_reply = fake->reply;
		fake->reply = NULL;

		/*
		 *	And we're done with this request.
		 */

		switch (rcode) {
                case RLM_MODULE_FAIL:
			request_free(&fake);
			eaptls_fail(handler->eap_ds, 0);
			return 0;
			break;
			
                default:  /* Don't Do Anything */
			DEBUG2(" PEAP: Got reply %d",
			       request->proxy_reply->code);
			break;
		}	
	}
	request_free(&fake);	/* robust if fake == NULL */

	/*
	 *	If there was no EAP-Message in the reply packet, then
	 *	we know that we're supposed to re-run the "authenticate"
	 *	stage, in order to get the right kind of handling...
	 */

	/*
	 *	Process the reply from the home server.
	 */

	rcode = process_reply(handler, tls_session, handler->request,
			      handler->request->proxy_reply);

	/*
	 *	The proxy code uses the reply from the home server as
	 *	the basis for the reply to the NAS.  We don't want that,
	 *	so we toss it, after we've had our way with it.
	 */
	pairfree(&handler->request->proxy_reply->vps);

	switch (rcode) {
	case RLM_MODULE_REJECT:
		DEBUG2("  PEAP: Reply was rejected");
		eaptls_fail(handler->eap_ds, 0);
		return 0;

	case RLM_MODULE_HANDLED:
		DEBUG2("  PEAP: Reply was handled");
		eaptls_request(handler->eap_ds, tls_session);
		return 1;

	case RLM_MODULE_OK: