eap_peap.c

hostapd源代码

/*
 * hostapd / EAP-PEAP (draft-josefsson-pppext-eap-tls-eap-07.txt)
 * Copyright (c) 2004-2005, Jouni Malinen <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "hostapd.h"
#include "common.h"
#include "eap_i.h"
#include "eap_tls_common.h"
#include "tls.h"


/* Maximum supported PEAP version
 * 0 = Microsoft's PEAP version 0; draft-kamath-pppext-peapv0-00.txt
 * 1 = draft-josefsson-ppext-eap-tls-eap-05.txt
 * 2 = draft-josefsson-ppext-eap-tls-eap-07.txt
 */
#define EAP_PEAP_VERSION 1


static void eap_peap_reset(struct eap_sm *sm, void *priv);


struct eap_peap_data {
	struct eap_ssl_data ssl;
	enum {
		START, PHASE1, PHASE2_START, PHASE2_ID, PHASE2_METHOD,
		PHASE2_TLV, SUCCESS_REQ, FAILURE_REQ, SUCCESS, FAILURE
	} state;

	int peap_version;
	const struct eap_method *phase2_method;
	void *phase2_priv;
	int force_version;
};


static const char * eap_peap_state_txt(int state)
{
	switch (state) {
	case START:
		return "START";
	case PHASE1:
		return "PHASE1";
	case PHASE2_START:
		return "PHASE2_START";
	case PHASE2_ID:
		return "PHASE2_ID";
	case PHASE2_METHOD:
		return "PHASE2_METHOD";
	case PHASE2_TLV:
		return "PHASE2_TLV";
	case SUCCESS_REQ:
		return "SUCCESS_REQ";
	case FAILURE_REQ:
		return "FAILURE_REQ";
	case SUCCESS:
		return "SUCCESS";
	case FAILURE:
		return "FAILURE";
	default:
		return "Unknown?!";
	}
}


static void eap_peap_state(struct eap_peap_data *data, int state)
{
	wpa_printf(MSG_DEBUG, "EAP-PEAP: %s -> %s",
		   eap_peap_state_txt(data->state),
		   eap_peap_state_txt(state));
	data->state = state;
}


static EapType eap_peap_req_success(struct eap_sm *sm,
				    struct eap_peap_data *data)
{
	if (data->state == FAILURE || data->state == FAILURE_REQ) {
		eap_peap_state(data, FAILURE);
		return EAP_TYPE_NONE;
	}

	if (data->peap_version == 0) {
		sm->tlv_request = TLV_REQ_SUCCESS;
		eap_peap_state(data, PHASE2_TLV);
		return EAP_TYPE_TLV;
	} else {
		eap_peap_state(data, SUCCESS_REQ);
		return EAP_TYPE_NONE;
	}
}


static EapType eap_peap_req_failure(struct eap_sm *sm,
				    struct eap_peap_data *data)
{
	if (data->state == FAILURE || data->state == FAILURE_REQ ||
	    data->state == SUCCESS_REQ ||
	    (data->phase2_method &&
	     data->phase2_method->method == EAP_TYPE_TLV)) {
		eap_peap_state(data, FAILURE);
		return EAP_TYPE_NONE;
	}

	if (data->peap_version == 0) {
		sm->tlv_request = TLV_REQ_FAILURE;
		eap_peap_state(data, PHASE2_TLV);
		return EAP_TYPE_TLV;
	} else {
		eap_peap_state(data, FAILURE_REQ);
		return EAP_TYPE_NONE;
	}
}


static void * eap_peap_init(struct eap_sm *sm)
{
	struct eap_peap_data *data;

	data = wpa_zalloc(sizeof(*data));
	if (data == NULL)
		return NULL;
	data->peap_version = EAP_PEAP_VERSION;
	data->force_version = -1;
	if (sm->user && sm->user->force_version >= 0) {
		data->force_version = sm->user->force_version;
		wpa_printf(MSG_DEBUG, "EAP-PEAP: forcing version %d",
			   data->force_version);
		data->peap_version = data->force_version;
	}
	data->state = START;

	if (eap_tls_ssl_init(sm, &data->ssl, 0)) {
		wpa_printf(MSG_INFO, "EAP-PEAP: Failed to initialize SSL.");
		eap_peap_reset(sm, data);
		return NULL;
	}

	return data;
}


static void eap_peap_reset(struct eap_sm *sm, void *priv)
{
	struct eap_peap_data *data = priv;
	if (data == NULL)
		return;
	if (data->phase2_priv && data->phase2_method)
		data->phase2_method->reset(sm, data->phase2_priv);
	eap_tls_ssl_deinit(sm, &data->ssl);
	free(data);
}


static u8 * eap_peap_build_start(struct eap_sm *sm, struct eap_peap_data *data,
				 int id, size_t *reqDataLen)
{
	struct eap_hdr *req;
	u8 *pos;

	*reqDataLen = sizeof(*req) + 2;
	req = malloc(*reqDataLen);
	if (req == NULL) {
		wpa_printf(MSG_ERROR, "EAP-PEAP: Failed to allocate memory for"
			   " request");
		eap_peap_state(data, FAILURE);
		return NULL;
	}

	req->code = EAP_CODE_REQUEST;
	req->identifier = id;
	req->length = htons(*reqDataLen);
	pos = (u8 *) (req + 1);
	*pos++ = EAP_TYPE_PEAP;
	*pos = EAP_TLS_FLAGS_START | data->peap_version;

	eap_peap_state(data, PHASE1);

	return (u8 *) req;
}


static u8 * eap_peap_build_req(struct eap_sm *sm, struct eap_peap_data *data,
			       int id, size_t *reqDataLen)
{
	int res;
	u8 *req;

	res = eap_tls_buildReq_helper(sm, &data->ssl, EAP_TYPE_PEAP,
				      data->peap_version, id, &req,
				      reqDataLen);

	if (tls_connection_established(sm->ssl_ctx, data->ssl.conn)) {
		wpa_printf(MSG_DEBUG, "EAP-PEAP: Phase1 done, starting "
			   "Phase2");
		eap_peap_state(data, PHASE2_START);
	}

	if (res == 1)
		return eap_tls_build_ack(reqDataLen, id, EAP_TYPE_PEAP,
					 data->peap_version);
	return req;
}


static u8 * eap_peap_encrypt(struct eap_sm *sm, struct eap_peap_data *data,
			     int id, u8 *plain, size_t plain_len,
			     size_t *out_len)
{
	int res;
	u8 *pos;
	struct eap_hdr *req;

	/* TODO: add support for fragmentation, if needed. This will need to
	 * add TLS Message Length field, if the frame is fragmented. */
	req = malloc(sizeof(struct eap_hdr) + 2 + data->ssl.tls_out_limit);
	if (req == NULL)
		return NULL;

	req->code = EAP_CODE_REQUEST;
	req->identifier = id;

	pos = (u8 *) (req + 1);
	*pos++ = EAP_TYPE_PEAP;
	*pos++ = data->peap_version;

	res = tls_connection_encrypt(sm->ssl_ctx, data->ssl.conn,
				     plain, plain_len,
				     pos, data->ssl.tls_out_limit);
	if (res < 0) {
		wpa_printf(MSG_INFO, "EAP-PEAP: Failed to encrypt Phase 2 "
			   "data");
		free(req);
		return NULL;
	}

	*out_len = sizeof(struct eap_hdr) + 2 + res;
	req->length = host_to_be16(*out_len);
	return (u8 *) req;
}


static u8 * eap_peap_build_phase2_req(struct eap_sm *sm,
				      struct eap_peap_data *data,
				      int id, size_t *reqDataLen)
{
	u8 *req, *buf, *encr_req;
	size_t req_len;

	buf = req = data->phase2_method->buildReq(sm, data->phase2_priv, id,
						  &req_len);
	if (req == NULL)
		return NULL;

	wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: Encrypting Phase 2 data",
			req, req_len);

	if (data->peap_version == 0 &&
	    data->phase2_method->method != EAP_TYPE_TLV) {
		req += sizeof(struct eap_hdr);
		req_len -= sizeof(struct eap_hdr);
	}

	encr_req = eap_peap_encrypt(sm, data, id, req, req_len, reqDataLen);
	free(buf);

	return encr_req;
}


static u8 * eap_peap_build_phase2_term(struct eap_sm *sm,
				       struct eap_peap_data *data,
				       int id, size_t *reqDataLen, int success)
{
	u8 *encr_req;
	size_t req_len;
	struct eap_hdr *hdr;

	req_len = sizeof(*hdr);
	hdr = wpa_zalloc(req_len);
	if (hdr == NULL)
		return NULL;

	hdr->code = success ? EAP_CODE_SUCCESS : EAP_CODE_FAILURE;
	hdr->identifier = id;
	hdr->length = htons(req_len);

	wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: Encrypting Phase 2 data",
			(u8 *) hdr, req_len);

	encr_req = eap_peap_encrypt(sm, data, id, (u8 *) hdr, req_len,
				    reqDataLen);
	free(hdr);

	return encr_req;
}


static u8 * eap_peap_buildReq(struct eap_sm *sm, void *priv, int id,
			      size_t *reqDataLen)
{
	struct eap_peap_data *data = priv;

	switch (data->state) {
	case START:
		return eap_peap_build_start(sm, data, id, reqDataLen);
	case PHASE1:
		return eap_peap_build_req(sm, data, id, reqDataLen);
	case PHASE2_ID:
	case PHASE2_METHOD:
	case PHASE2_TLV:
		return eap_peap_build_phase2_req(sm, data, id, reqDataLen);
	case SUCCESS_REQ:
		return eap_peap_build_phase2_term(sm, data, id, reqDataLen, 1);
	case FAILURE_REQ:
		return eap_peap_build_phase2_term(sm, data, id, reqDataLen, 0);
	default:
		wpa_printf(MSG_DEBUG, "EAP-PEAP: %s - unexpected state %d",
			   __func__, data->state);
		return NULL;
	}
}


static Boolean eap_peap_check(struct eap_sm *sm, void *priv,
			      u8 *respData, size_t respDataLen)
{
	struct eap_hdr *resp;
	u8 *pos;
	size_t len;

	resp = (struct eap_hdr *) respData;
	pos = (u8 *) (resp + 1);
	if (respDataLen < sizeof(*resp) + 2 || *pos != EAP_TYPE_PEAP ||
	    (len = ntohs(resp->length)) > respDataLen) {
		wpa_printf(MSG_INFO, "EAP-PEAP: Invalid frame");
		return TRUE;
	}

	return FALSE;
}


static int eap_peap_phase2_init(struct eap_sm *sm, struct eap_peap_data *data,
				EapType eap_type)
{
	if (data->phase2_priv && data->phase2_method) {
		data->phase2_method->reset(sm, data->phase2_priv);
		data->phase2_method = NULL;
		data->phase2_priv = NULL;
	}
	data->phase2_method = eap_sm_get_eap_methods(EAP_VENDOR_IETF,
						     eap_type);
	if (!data->phase2_method)