eap_peap.c

一个Linux下无线网卡的设置工具

		ret->methodState = METHOD_DONE;
		return 1;
	}

	buf_len = in_len;
	if (data->ssl.tls_in_total > buf_len)
		buf_len = data->ssl.tls_in_total;
	in_decrypted = malloc(buf_len);
	if (in_decrypted == NULL) {
		free(data->ssl.tls_in);
		data->ssl.tls_in = NULL;
		data->ssl.tls_in_len = 0;
		wpa_printf(MSG_WARNING, "EAP-PEAP: failed to allocate memory "
			   "for decryption");
		return -1;
	}

	len_decrypted = tls_connection_decrypt(sm->ssl_ctx, data->ssl.conn,
					       msg, msg_len,
					       in_decrypted, buf_len);
	free(data->ssl.tls_in);
	data->ssl.tls_in = NULL;
	data->ssl.tls_in_len = 0;
	if (len_decrypted < 0) {
		wpa_printf(MSG_INFO, "EAP-PEAP: Failed to decrypt Phase 2 "
			   "data");
		free(in_decrypted);
		return 0;
	}

continue_req:
	wpa_hexdump(MSG_DEBUG, "EAP-PEAP: Decrypted Phase 2 EAP", in_decrypted,
		    len_decrypted);

	hdr = (struct eap_hdr *) in_decrypted;
	if (len_decrypted == 5 && hdr->code == EAP_CODE_REQUEST &&
	    be_to_host16(hdr->length) == 5 &&
	    in_decrypted[4] == EAP_TYPE_IDENTITY) {
		/* At least FreeRADIUS seems to send full EAP header with
		 * EAP Request Identity */
		skip_change = 1;
	}
	if (len_decrypted >= 5 && hdr->code == EAP_CODE_REQUEST &&
	    in_decrypted[4] == EAP_TYPE_TLV) {
		skip_change = 1;
	}

	if (data->peap_version == 0 && !skip_change) {
		struct eap_hdr *nhdr = malloc(sizeof(struct eap_hdr) +
					      len_decrypted);
		if (nhdr == NULL) {
			free(in_decrypted);
			return 0;
		}
		memcpy((u8 *) (nhdr + 1), in_decrypted, len_decrypted);
		free(in_decrypted);
		nhdr->code = req->code;
		nhdr->identifier = req->identifier;
		nhdr->length = host_to_be16(sizeof(struct eap_hdr) +
					    len_decrypted);

		len_decrypted += sizeof(struct eap_hdr);
		in_decrypted = (u8 *) nhdr;
	}
	hdr = (struct eap_hdr *) in_decrypted;
	if (len_decrypted < sizeof(*hdr)) {
		free(in_decrypted);
		wpa_printf(MSG_INFO, "EAP-PEAP: Too short Phase 2 "
			   "EAP frame (len=%d)", len_decrypted);
		return 0;
	}
	len = be_to_host16(hdr->length);
	if (len > len_decrypted) {
		free(in_decrypted);
		wpa_printf(MSG_INFO, "EAP-PEAP: Length mismatch in "
			   "Phase 2 EAP frame (len=%d hdr->length=%d)",
			   len_decrypted, len);
		return 0;
	}
	if (len < len_decrypted) {
		wpa_printf(MSG_INFO, "EAP-PEAP: Odd.. Phase 2 EAP header has "
			   "shorter length than full decrypted data (%d < %d)",
			   len, len_decrypted);
		if (sm->workaround && len == 4 && len_decrypted == 5 &&
		    in_decrypted[4] == EAP_TYPE_IDENTITY) {
			/* Radiator 3.9 seems to set Phase 2 EAP header to use
			 * incorrect length for the EAP-Request Identity
			 * packet, so fix the inner header to interoperate..
			 * This was fixed in 2004-06-23 patch for Radiator and
			 * this workaround can be removed at some point. */
			wpa_printf(MSG_INFO, "EAP-PEAP: workaround -> replace "
				   "Phase 2 EAP header len (%d) with real "
				   "decrypted len (%d)", len, len_decrypted);
			len = len_decrypted;
			hdr->length = host_to_be16(len);
		}
	}
	wpa_printf(MSG_DEBUG, "EAP-PEAP: received Phase 2: code=%d "
		   "identifier=%d length=%d", hdr->code, hdr->identifier, len);
	switch (hdr->code) {
	case EAP_CODE_REQUEST:
		if (eap_peap_phase2_request(sm, data, ret, req, hdr,
					    &resp, &resp_len)) {
			free(in_decrypted);
			wpa_printf(MSG_INFO, "EAP-PEAP: Phase2 Request "
				   "processing failed");
			return 0;
		}
		break;
	case EAP_CODE_SUCCESS:
		wpa_printf(MSG_DEBUG, "EAP-PEAP: Phase 2 Success");
		if (data->peap_version == 1) {
			/* EAP-Success within TLS tunnel is used to indicate
			 * shutdown of the TLS channel. The authentication has
			 * been completed. */
			wpa_printf(MSG_DEBUG, "EAP-PEAP: Version 1 - "
				   "EAP-Success within TLS tunnel - "
				   "authentication completed");
			ret->decision = DECISION_UNCOND_SUCC;
			ret->methodState = METHOD_DONE;
			data->phase2_success = 1;
			if (data->peap_outer_success == 2) {
				free(in_decrypted);
				wpa_printf(MSG_DEBUG, "EAP-PEAP: Use TLS ACK "
					   "to finish authentication");
				return 1;
			} else if (data->peap_outer_success == 1) {
				/* Reply with EAP-Success within the TLS
				 * channel to complete the authentication. */
				resp_len = sizeof(struct eap_hdr);
				resp = malloc(resp_len);
				if (resp) {
					memset(resp, 0, resp_len);
					rhdr = (struct eap_hdr *) resp;
					rhdr->code = EAP_CODE_SUCCESS;
					rhdr->identifier = hdr->identifier;
					rhdr->length = host_to_be16(resp_len);
				}
			} else {
				/* No EAP-Success expected for Phase 1 (outer,
				 * unencrypted auth), so force EAP state
				 * machine to SUCCESS state. */
				sm->peap_done = TRUE;
			}
		} else {
			/* FIX: ? */
		}
		break;
	case EAP_CODE_FAILURE:
		wpa_printf(MSG_DEBUG, "EAP-PEAP: Phase 2 Failure");
		ret->decision = DECISION_FAIL;
		ret->methodState = METHOD_MAY_CONT;
		ret->allowNotifications = FALSE;
		/* Reply with EAP-Failure within the TLS channel to complete
		 * failure reporting. */
		resp_len = sizeof(struct eap_hdr);
		resp = malloc(resp_len);
		if (resp) {
			memset(resp, 0, resp_len);
			rhdr = (struct eap_hdr *) resp;
			rhdr->code = EAP_CODE_FAILURE;
			rhdr->identifier = hdr->identifier;
			rhdr->length = host_to_be16(resp_len);
		}
		break;
	default:
		wpa_printf(MSG_INFO, "EAP-PEAP: Unexpected code=%d in "
			   "Phase 2 EAP header", hdr->code);
		break;
	}

	free(in_decrypted);

	if (resp) {
		u8 *resp_pos;
		size_t resp_send_len;
		int skip_change = 0;

		wpa_hexdump_key(MSG_DEBUG, "EAP-PEAP: Encrypting Phase 2 data",
				resp, resp_len);
		/* PEAP version changes */
		if (resp_len >= 5 && resp[0] == EAP_CODE_RESPONSE &&
		    resp[4] == EAP_TYPE_TLV)
			skip_change = 1;
		if (data->peap_version == 0 && !skip_change) {
			resp_pos = resp + sizeof(struct eap_hdr);
			resp_send_len = resp_len - sizeof(struct eap_hdr);
		} else {
			resp_pos = resp;
			resp_send_len = resp_len;
		}

		if (eap_peap_encrypt(sm, data, req->identifier,
				     resp_pos, resp_send_len,
				     out_data, out_len)) {
			wpa_printf(MSG_INFO, "EAP-PEAP: Failed to encrypt "
				   "a Phase 2 frame");
		}
		free(resp);
	}

	return 0;
}


static u8 * eap_peap_process(struct eap_sm *sm, void *priv,
			     struct eap_method_ret *ret,
			     const u8 *reqData, size_t reqDataLen,
			     size_t *respDataLen)
{
	const struct eap_hdr *req;
	size_t left;
	int res;
	u8 flags, *resp, id;
	const u8 *pos;
	struct eap_peap_data *data = priv;

	pos = eap_tls_process_init(sm, &data->ssl, EAP_TYPE_PEAP, ret,
				   reqData, reqDataLen, &left, &flags);
	if (pos == NULL)
		return NULL;
	req = (const struct eap_hdr *) reqData;
	id = req->identifier;

	if (flags & EAP_TLS_FLAGS_START) {
		wpa_printf(MSG_DEBUG, "EAP-PEAP: Start (server ver=%d, own "
			   "ver=%d)", flags & EAP_PEAP_VERSION_MASK,
			data->peap_version);
		if ((flags & EAP_PEAP_VERSION_MASK) < data->peap_version)
			data->peap_version = flags & EAP_PEAP_VERSION_MASK;
		if (data->force_peap_version >= 0 &&
		    data->force_peap_version != data->peap_version) {
			wpa_printf(MSG_WARNING, "EAP-PEAP: Failed to select "
				   "forced PEAP version %d",
				   data->force_peap_version);
			ret->methodState = METHOD_DONE;
			ret->decision = DECISION_FAIL;
			ret->allowNotifications = FALSE;
			return NULL;
		}
		wpa_printf(MSG_DEBUG, "EAP-PEAP: Using PEAP version %d",
			   data->peap_version);
		left = 0; /* make sure that this frame is empty, even though it
			   * should always be, anyway */
	}

	resp = NULL;
	if (tls_connection_established(sm->ssl_ctx, data->ssl.conn) &&
	    !data->resuming) {
		res = eap_peap_decrypt(sm, data, ret, req, pos, left,
				       &resp, respDataLen);
	} else {
		res = eap_tls_process_helper(sm, &data->ssl, EAP_TYPE_PEAP,
					     data->peap_version, id, pos, left,
					     &resp, respDataLen);

		if (tls_connection_established(sm->ssl_ctx, data->ssl.conn)) {
			char *label;
			wpa_printf(MSG_DEBUG,
				   "EAP-PEAP: TLS done, proceed to Phase 2");
			free(data->key_data);
			/* draft-josefsson-ppext-eap-tls-eap-05.txt
			 * specifies that PEAPv1 would use "client PEAP
			 * encryption" as the label. However, most existing
			 * PEAPv1 implementations seem to be using the old
			 * label, "client EAP encryption", instead. Use the old
			 * label by default, but allow it to be configured with
			 * phase1 parameter peaplabel=1. */
			if (data->peap_version > 1 || data->force_new_label)
				label = "client PEAP encryption";
			else
				label = "client EAP encryption";
			wpa_printf(MSG_DEBUG, "EAP-PEAP: using label '%s' in "
				   "key derivation", label);
			data->key_data =
				eap_tls_derive_key(sm, &data->ssl, label,
						   EAP_TLS_KEY_LEN);
			if (data->key_data) {
				wpa_hexdump_key(MSG_DEBUG, 
						"EAP-PEAP: Derived key",
						data->key_data,
						EAP_TLS_KEY_LEN);
			} else {
				wpa_printf(MSG_DEBUG, "EAP-PEAP: Failed to "
					   "derive key");
			}

			if (sm->workaround && data->resuming) {
				/*
				 * At least few RADIUS servers (Aegis v1.1.6;
				 * but not v1.1.4; and Cisco ACS) seem to be
				 * terminating PEAPv1 (Aegis) or PEAPv0 (Cisco
				 * ACS) session resumption with outer
				 * EAP-Success. This does not seem to follow
				 * draft-josefsson-pppext-eap-tls-eap-05.txt
				 * section 4.2, so only allow this if EAP
				 * workarounds are enabled.
				 */
				wpa_printf(MSG_DEBUG, "EAP-PEAP: Workaround - "
					   "allow outer EAP-Success to "
					   "terminate PEAP resumption");
				ret->decision = DECISION_COND_SUCC;
				data->phase2_success = 1;
			}

			data->resuming = 0;
		}
	}

	if (ret->methodState == METHOD_DONE) {
		ret->allowNotifications = FALSE;
	}

	if (res == 1) {
		return eap_tls_build_ack(&data->ssl, respDataLen, id,
					 EAP_TYPE_PEAP, data->peap_version);
	}

	return resp;
}


static Boolean eap_peap_has_reauth_data(struct eap_sm *sm, void *priv)
{
	struct eap_peap_data *data = priv;
	return tls_connection_established(sm->ssl_ctx, data->ssl.conn) &&
		data->phase2_success;
}


static void eap_peap_deinit_for_reauth(struct eap_sm *sm, void *priv)
{
	struct eap_peap_data *data = priv;
	free(data->pending_phase2_req);
	data->pending_phase2_req = NULL;
}


static void * eap_peap_init_for_reauth(struct eap_sm *sm, void *priv)
{
	struct eap_peap_data *data = priv;
	free(data->key_data);
	data->key_data = NULL;
	if (eap_tls_reauth_init(sm, &data->ssl)) {
		free(data);
		return NULL;
	}
	data->phase2_success = 0;
	data->resuming = 1;
	sm->peap_done = FALSE;
	return priv;
}


static int eap_peap_get_status(struct eap_sm *sm, void *priv, char *buf,
			       size_t buflen, int verbose)
{
	struct eap_peap_data *data = priv;
	int len;

	len = eap_tls_status(sm, &data->ssl, buf, buflen, verbose);
	if (data->phase2_method) {
		len += snprintf(buf + len, buflen - len,
				"EAP-PEAPv%d Phase2 method=%s\n",
				data->peap_version, data->phase2_method->name);
	}
	return len;
}


static Boolean eap_peap_isKeyAvailable(struct eap_sm *sm, void *priv)
{
	struct eap_peap_data *data = priv;
	return data->key_data != NULL && data->phase2_success;
}


static u8 * eap_peap_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
	struct eap_peap_data *data = priv;
	u8 *key;

	if (data->key_data == NULL || !data->phase2_success)
		return NULL;

	key = malloc(EAP_TLS_KEY_LEN);
	if (key == NULL)
		return NULL;

	*len = EAP_TLS_KEY_LEN;
	memcpy(key, data->key_data, EAP_TLS_KEY_LEN);

	return key;
}


const struct eap_method eap_method_peap =
{
	.method = EAP_TYPE_PEAP,
	.name = "PEAP",
	.init = eap_peap_init,
	.deinit = eap_peap_deinit,
	.process = eap_peap_process,
	.isKeyAvailable = eap_peap_isKeyAvailable,
	.getKey = eap_peap_getKey,
	.get_status = eap_peap_get_status,
	.has_reauth_data = eap_peap_has_reauth_data,
	.deinit_for_reauth = eap_peap_deinit_for_reauth,
	.init_for_reauth = eap_peap_init_for_reauth,
};