rlm_eap_mschapv2.c

free radius编程。完成AAA的实现

/*
 * rlm_eap_mschapv2.c    Handles that are called from eap
 *
 * Version:     $Id: rlm_eap_mschapv2.c,v 1.8 2004/04/19 20:15:30 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  The FreeRADIUS server project
 */

#include "autoconf.h"

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

#include "eap_mschapv2.h"

#include <rad_assert.h>

typedef struct rlm_eap_mschapv2_t {
        int with_ntdomain_hack;
} rlm_eap_mschapv2_t;

static CONF_PARSER module_config[] = {
	{ "with_ntdomain_hack",     PW_TYPE_BOOLEAN,
	  offsetof(rlm_eap_mschapv2_t,with_ntdomain_hack), NULL, "no" },

	{ NULL, -1, 0, NULL, NULL }		/* end the list */
};


/*
 *	Detach the module.
 */
static int mschapv2_detach(void *arg)
{
	rlm_eap_mschapv2_t *inst = (rlm_eap_mschapv2_t *) arg;

	free(inst);

	return 0;
}


/*
 *	Attach the module.
 */
static int mschapv2_attach(CONF_SECTION *cs, void **instance)
{
	rlm_eap_mschapv2_t *inst;

	inst = malloc(sizeof(*inst));
	if (!inst) {
		radlog(L_ERR, "rlm_eap_mschapv2: out of memory");
		return -1;
	}
	memset(inst, 0, sizeof(*inst));

	/*
	 *	Parse the configuration attributes.
	 */
	if (cf_section_parse(cs, inst, module_config) < 0) {
		mschapv2_detach(inst);
		return -1;
	}

	*instance = inst;

	return 0;
}


/*
 *	Compose the response.
 */
static int eapmschapv2_compose(EAP_HANDLER *handler, VALUE_PAIR *reply)
{
	uint8_t *ptr;
	int16_t length;
	mschapv2_header_t *hdr;
	EAP_DS *eap_ds = handler->eap_ds;

	eap_ds->request->code = PW_EAP_REQUEST;
	eap_ds->request->type.type = PW_EAP_MSCHAPV2;

	switch (reply->attribute) {
	case PW_MSCHAP_CHALLENGE:
		/*
		 *   0                   1                   2                   3
		 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 *  |     Code      |   Identifier  |            Length             |
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 *  |     Type      |   OpCode      |  MS-CHAPv2-ID |  MS-Length...
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 *  |   MS-Length   |  Value-Size   |  Challenge...
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 *  |                             Challenge...
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 *  |                             Name...
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 */
		length = MSCHAPV2_HEADER_LEN + MSCHAPV2_CHALLENGE_LEN + strlen(handler->identity);
		eap_ds->request->type.data = malloc(length);
		/*
		 *	Allocate room for the EAP-MS-CHAPv2 data.
		 */
		if (eap_ds->request->type.data == NULL) {
			radlog(L_ERR, "rlm_eap_mschapv2: out of memory");
			return 0;
		}
		eap_ds->request->type.length = length;

		ptr = eap_ds->request->type.data;
		hdr = eap_ds->request->type.data;

		hdr->opcode = PW_EAP_MSCHAPV2_CHALLENGE;
		hdr->mschapv2_id = eap_ds->response->id + 1;
		length = htons(length);
		memcpy(hdr->ms_length, &length, sizeof(uint16_t));
		hdr->value_size = MSCHAPV2_CHALLENGE_LEN;

		ptr += MSCHAPV2_HEADER_LEN;

		/*
		 *	Copy the Challenge, success, or error over.
		 */
		memcpy(ptr, reply->strvalue, reply->length);
		memcpy((ptr + reply->length), handler->identity, strlen(handler->identity));
		break;

	case PW_MSCHAP2_SUCCESS:
		/*
		 *   0                   1                   2                   3
		 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 *  |     Code      |   Identifier  |            Length             |
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 *  |     Type      |   OpCode      |  MS-CHAPv2-ID |  MS-Length...
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 *  |   MS-Length   |                    Message...
		 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
		 */
		DEBUG2("MSCHAP Success\n");
		length = 46;
		eap_ds->request->type.data = malloc(length);
		memset(eap_ds->request->type.data, 0, length);
		/*
		 *	Allocate room for the EAP-MS-CHAPv2 data.
		 */
		if (eap_ds->request->type.data == NULL) {
			radlog(L_ERR, "rlm_eap_mschapv2: out of memory");
			return 0;
		}
		eap_ds->request->type.length = length;

		eap_ds->request->type.data[0] = PW_EAP_MSCHAPV2_SUCCESS;
		eap_ds->request->type.data[1] = eap_ds->response->id;
		length = htons(length);
		memcpy((eap_ds->request->type.data + 2), &length, sizeof(uint16_t));
		memcpy((eap_ds->request->type.data + 4), reply->strvalue + 1, 42);
		break;

	case PW_MSCHAP_ERROR:
		DEBUG2("MSCHAP Failure\n");
		length = 4 + MSCHAPV2_FAILURE_MESSAGE_LEN;
		eap_ds->request->type.data = malloc(length);
		memset(eap_ds->request->type.data, 0, length);

		/*
		 *	Allocate room for the EAP-MS-CHAPv2 data.
		 */
		if (eap_ds->request->type.data == NULL) {
			radlog(L_ERR, "rlm_eap_mschapv2: out of memory");
			return 0;
		}
		eap_ds->request->type.length = length;

		eap_ds->request->type.data[0] = PW_EAP_MSCHAPV2_FAILURE;
		eap_ds->request->type.data[1] = eap_ds->response->id;
		length = htons(length);
		memcpy((eap_ds->request->type.data + 2), &length, sizeof(uint16_t));
		memcpy((eap_ds->request->type.data + 4), MSCHAPV2_FAILURE_MESSAGE, MSCHAPV2_FAILURE_MESSAGE_LEN);
		break;

	default:
		radlog(L_ERR, "rlm_eap_mschapv2: Internal sanity check failed");
		return 0;
		break;
	}

	return 1;
}


/*
 *	Initiate the EAP-MSCHAPV2 session by sending a challenge to the peer.
 */
static int mschapv2_initiate(void *type_data, EAP_HANDLER *handler)
{
	int		i;
	VALUE_PAIR	*challenge;
	mschapv2_opaque_t *data;

	type_data = type_data;	/* -Wunused */

	challenge = pairmake("MS-CHAP-Challenge", "0x00", T_OP_EQ);
	if (!challenge) {
		radlog(L_ERR, "rlm_eap_mschapv2: out of memory");
		return 0;
	}

	/*
	 *	Get a random challenge.
	 */
	challenge->length = MSCHAPV2_CHALLENGE_LEN;
	for (i = 0; i < MSCHAPV2_CHALLENGE_LEN; i++) {
		challenge->strvalue[i] = lrad_rand();
	}
	radlog(L_INFO, "rlm_eap_mschapv2: Issuing Challenge");

	/*
	 *	Keep track of the challenge.
	 */
	data = malloc(sizeof(mschapv2_opaque_t));
	rad_assert(data != NULL);

	/*
	 *	We're at the stage where we're challenging the user.
	 */
	data->code = PW_EAP_MSCHAPV2_CHALLENGE;
	memcpy(data->challenge, challenge->strvalue, MSCHAPV2_CHALLENGE_LEN);

	handler->opaque = data;
	handler->free_opaque = free;

	/*
	 *	Compose the EAP-MSCHAPV2 packet out of the data structure,
	 *	and free it.
	 */
	eapmschapv2_compose(handler, challenge);
	pairfree(&challenge);

	/*
	 *	The EAP session doesn't have enough information to
	 *	proxy the "inside EAP" protocol.  Disable EAP proxying.
	 */
	handler->request->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;

	/*
	 *	We don't need to authorize the user at this point.
	 *
	 *	We also don't need to keep the challenge, as it's
	 *	stored in 'handler->eap_ds', which will be given back
	 *	to us...
	 */
	handler->stage = AUTHENTICATE;

	return 1;
}


/*
 *	Do post-proxy processing,
 *	0 = fail
 *	1 = OK.
 *
 *	Called from rlm_eap.c, eap_postproxy().
 */
static int mschap_postproxy(EAP_HANDLER *handler, void *tunnel_data)
{
	VALUE_PAIR *response = NULL;
	mschapv2_opaque_t *data;

	data = (mschapv2_opaque_t *) handler->opaque;
	rad_assert(data != NULL);

	tunnel_data = tunnel_data; /* -Wunused */

	DEBUG2("  rlm_eap_mschapv2: Passing reply from proxy back into the tunnel %p %d.",
	       handler->request, handler->request->reply->code);

	/*
	 *	There is only a limited number of possibilities.
	 */
	switch (handler->request->reply->code) {
	case PW_AUTHENTICATION_ACK:
		DEBUG("  rlm_eap_mschapv2: Authentication succeeded.");
		/*
		 *	Move the attribute, so it doesn't go into
		 *	the reply.
		 */
		pairmove2(&response,
			  &handler->request->reply->vps,
			  PW_MSCHAP2_SUCCESS);
		break;

	default:
	case PW_AUTHENTICATION_REJECT:
		DEBUG("  rlm_eap_mschapv2: Authentication did not succeed.");
		return 0;
	}

	/*
	 *	No response, die.
	 */
	if (!response) {
		radlog(L_ERR, "rlm_eap_mschapv2: No MS-CHAPv2-Success or MS-CHAP-Error was found.");
		return 0;
	}