rlm_eap_sim.c

linux1.0内核的源代码,欢迎大家使用

/*
 * rlm_eap_sim.c    Handles that are called from eap for SIM
 *
 * The development of the EAP/SIM support was funded by Internet Foundation
 * Austria (http://www.nic.at/ipa).
 *
 * Version:     $Id: rlm_eap_sim.c,v 1.12 2004/03/19 02:20:35 mcr 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  Michael Richardson <[e-mail]>
 * Copyright 2003  The FreeRADIUS server project
 *
 */

#include "autoconf.h"

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

#include "../../eap.h"
#include "eap_types.h"
#include "eap_sim.h"

#include <rad_assert.h>

struct eap_sim_server_state {
	enum eapsim_serverstates state;
	struct eapsim_keys keys;
	int  sim_id;
};

/*
 * Add value pair to reply
 */
static void add_reply(VALUE_PAIR** vp,
		      const char* name, const char* value, int len)
{
	VALUE_PAIR *reply_attr;
	reply_attr = pairmake(name, "", T_OP_EQ);
	if (!reply_attr) {
		DEBUG("rlm_eap_sim: "
		      "add_reply failed to create attribute %s: %s\n",
		      name, librad_errstr);
		return;
	}

	memcpy(reply_attr->strvalue, value, len);
	reply_attr->length = len;
	pairadd(vp, reply_attr);
}

static void eap_sim_state_free(void *opaque)
{
	struct eap_sim_server_state *ess = (struct eap_sim_server_state *)opaque;

	if (!ess) return;

	free(ess);
}

/*
 *	build a reply to be sent.
 */
static int eap_sim_compose(EAP_HANDLER *handler)
{
	/* we will set the ID on requests, since we have to HMAC it */
	handler->eap_ds->set_request_id = 1;

	return map_eapsim_basictypes(handler->request->reply,
				     handler->eap_ds->request);
}

static int eap_sim_sendstart(EAP_HANDLER *handler)
{
	VALUE_PAIR **vps, *newvp;
	uint16_t *words;
	struct eap_sim_server_state *ess;

	rad_assert(handler->request != NULL);
	rad_assert(handler->request->reply);

	ess = (struct eap_sim_server_state *)handler->opaque;

	/* these are the outgoing attributes */
	vps = &handler->request->reply->vps;

	rad_assert(vps != NULL);

	/*
	 * add appropriate TLVs for the EAP things we wish to send.
	 */

	/* the version list. We support only version 1. */
	newvp = paircreate(ATTRIBUTE_EAP_SIM_BASE+PW_EAP_SIM_VERSION_LIST,
			PW_TYPE_OCTETS);
	words = (uint16_t *)newvp->strvalue;
	newvp->length = 3*sizeof(uint16_t);
	words[0] = htons(1*sizeof(uint16_t));
	words[1] = htons(EAP_SIM_VERSION);
	words[2] = 0;
	pairadd(vps, newvp);

	/* set the EAP_ID - new value */
	newvp = paircreate(ATTRIBUTE_EAP_ID, PW_TYPE_INTEGER);
	newvp->lvalue = ess->sim_id++;
	pairreplace(vps, newvp);

	/* record it in the ess */
	ess->keys.versionlistlen = 2;
	memcpy(ess->keys.versionlist, words+1, ess->keys.versionlistlen);

	/* the ANY_ID attribute. We do not support re-auth or pseudonym */
	newvp = paircreate(ATTRIBUTE_EAP_SIM_BASE+PW_EAP_SIM_FULLAUTH_ID_REQ,
			   PW_TYPE_OCTETS);
	newvp->length = 2;
	newvp->strvalue[0]=0;
	newvp->strvalue[0]=1;
	pairadd(vps, newvp);

	/* the SUBTYPE, set to start. */
	newvp = paircreate(ATTRIBUTE_EAP_SIM_SUBTYPE, PW_TYPE_INTEGER);
	newvp->lvalue = eapsim_start;
	pairreplace(vps, newvp);

	return 1;
}

static int eap_sim_getchalans(VALUE_PAIR *vps, int chalno,
			      struct eap_sim_server_state *ess)
{
	VALUE_PAIR *vp;

	rad_assert(chalno >= 0 && chalno < 3);

	vp = pairfind(vps, ATTRIBUTE_EAP_SIM_RAND1+chalno);
	if(vp == NULL) {
		/* bad, we can't find stuff! */
		DEBUG2("   eap-sim can not find sim-challenge%d",chalno+1);
		return 0;
	}
	if(vp->length != EAPSIM_RAND_SIZE) {
		DEBUG2("   eap-sim chal%d is not 8-bytes: %d", chalno+1,
		       vp->length);
		return 0;
	}
	memcpy(ess->keys.rand[chalno], vp->strvalue, EAPSIM_RAND_SIZE);

	vp = pairfind(vps, ATTRIBUTE_EAP_SIM_SRES1+chalno);
	if(vp == NULL) {
		/* bad, we can't find stuff! */
		DEBUG2("   eap-sim can not find sim-sres%d",chalno+1);
		return 0;
	}
	if(vp->length != EAPSIM_SRES_SIZE) {
		DEBUG2("   eap-sim sres%d is not 16-bytes: %d", chalno+1,
		       vp->length);
		return 0;
	}
	memcpy(ess->keys.sres[chalno], vp->strvalue, EAPSIM_SRES_SIZE);

	vp = pairfind(vps, ATTRIBUTE_EAP_SIM_KC1+chalno);
	if(vp == NULL) {
		/* bad, we can't find stuff! */
		DEBUG2("   eap-sim can not find sim-kc%d",chalno+1);
		return 0;
	}
	if(vp->length != EAPSIM_Kc_SIZE) {
		DEBUG2("   eap-sim kc%d is not 8-bytes: %d", chalno+1,
		       vp->length);
		return 0;
	}
	memcpy(ess->keys.Kc[chalno], vp->strvalue, EAPSIM_Kc_SIZE);

	return 1;
}

/*
 * this code sends the challenge itself.
 *
 * Challenges will come from one of three places eventually:
 *
 * 1  from attributes like ATTRIBUTE_EAP_SIM_RANDx
 *            (these might be retrived from a database)
 *
 * 2  from internally implemented SIM authenticators
 *            (a simple one based upon XOR will be provided)
 *
 * 3  from some kind of SS7 interface.
 *
 * For now, they only come from attributes.
 * It might be that the best way to do 2/3 will be with a different
 * module to generate/calculate things.
 *
 */
static int eap_sim_sendchallenge(EAP_HANDLER *handler)
{
	struct eap_sim_server_state *ess;
	VALUE_PAIR **invps, **outvps, *newvp;

	ess = (struct eap_sim_server_state *)handler->opaque;
	rad_assert(handler->request != NULL);
	rad_assert(handler->request->reply);

	/* invps is the data from the client.
	 * but, this is for non-protocol data here. We should
	 * already have consumed any client originated data.
	 */
	invps = &handler->request->packet->vps;

	/* outvps is the data to the client. */
	outvps= &handler->request->reply->vps;

	printf("+++> EAP-sim decoded packet:\n");
	vp_printlist(stdout, *invps);

	/* okay, we got the challenges! Put them into an attribute */
	newvp = paircreate(ATTRIBUTE_EAP_SIM_BASE+PW_EAP_SIM_RAND,
			   PW_TYPE_OCTETS);
	memset(newvp->strvalue,    0, 2); /* clear reserved bytes */
	memcpy(newvp->strvalue+2+EAPSIM_RAND_SIZE*0, ess->keys.rand[0], EAPSIM_RAND_SIZE);
	memcpy(newvp->strvalue+2+EAPSIM_RAND_SIZE*1, ess->keys.rand[1], EAPSIM_RAND_SIZE);
	memcpy(newvp->strvalue+2+EAPSIM_RAND_SIZE*2, ess->keys.rand[2], EAPSIM_RAND_SIZE);
	newvp->length = 2+EAPSIM_RAND_SIZE*3;
	pairadd(outvps, newvp);

	/* set the EAP_ID - new value */
	newvp = paircreate(ATTRIBUTE_EAP_ID, PW_TYPE_INTEGER);
	newvp->lvalue = ess->sim_id++;
	pairreplace(outvps, newvp);

	/* make a copy of the identity */
	ess->keys.identitylen = strlen(handler->identity);
	memcpy(ess->keys.identity, handler->identity, ess->keys.identitylen);

	/* all set, calculate keys! */
	eapsim_calculate_keys(&ess->keys);

#ifdef EAP_SIM_DEBUG_PRF
	eapsim_dump_mk(&ess->keys);
#endif

	/*
	 * need to include an AT_MAC attribute so that it will get
	 * calculated. The NONCE_MT and the MAC are both 16 bytes, so
	 * we store the NONCE_MT in the MAC for the encoder, which
	 * will pull it out before it does the operation.
	 */

	newvp = paircreate(ATTRIBUTE_EAP_SIM_BASE+PW_EAP_SIM_MAC,
			   PW_TYPE_OCTETS);
	memcpy(newvp->strvalue, ess->keys.nonce_mt, 16);
	newvp->length = 16;
	pairreplace(outvps, newvp);

	newvp = paircreate(ATTRIBUTE_EAP_SIM_KEY, PW_TYPE_OCTETS);
	memcpy(newvp->strvalue, ess->keys.K_aut, 16);
	newvp->length = 16;
	pairreplace(outvps, newvp);

	/* the SUBTYPE, set to challenge. */
	newvp = paircreate(ATTRIBUTE_EAP_SIM_SUBTYPE, PW_TYPE_INTEGER);
	newvp->lvalue = eapsim_challenge;
	pairreplace(outvps, newvp);

	return 1;
}

#ifndef EAPTLS_MPPE_KEY_LEN
#define EAPTLS_MPPE_KEY_LEN     32
#endif

/*
 * this code sends the success message.
 *
 * the only work to be done is the add the appropriate SEND/RECV
 * radius attributes derived from the MSK.
 *
 */
static int eap_sim_sendsuccess(EAP_HANDLER *handler)
{
        unsigned char *p;
	struct eap_sim_server_state *ess;
	VALUE_PAIR **outvps;
	VALUE_PAIR *newvp;

	/* outvps is the data to the client. */
	outvps= &handler->request->reply->vps;
	ess = (struct eap_sim_server_state *)handler->opaque;

	/* set the EAP_ID - new value */
	newvp = paircreate(ATTRIBUTE_EAP_ID, PW_TYPE_INTEGER);
	newvp->lvalue = ess->sim_id++;
	pairreplace(outvps, newvp);

	p = ess->keys.msk;
	add_reply(outvps, "MS-MPPE-Recv-Key", p, EAPTLS_MPPE_KEY_LEN);
	p += EAPTLS_MPPE_KEY_LEN;
	add_reply(outvps, "MS-MPPE-Send-Key", p, EAPTLS_MPPE_KEY_LEN);
	return 1;
}


/*
 * run the server state machine.
 */
static void eap_sim_stateenter(EAP_HANDLER *handler,
			       struct eap_sim_server_state *ess,
			       enum eapsim_serverstates newstate)
{
	switch(newstate) {
	case eapsim_server_start:
		/*
		 * send the EAP-SIM Start message, listing the
		 * versions that we support.
		 */
		eap_sim_sendstart(handler);
		break;

	case eapsim_server_challenge:
		/*
		 * send the EAP-SIM Challenge message.
		 */
		eap_sim_sendchallenge(handler);
		break;

	case eapsim_server_success:
		/*