eap_ttls.c

一个Linux下无线网卡的设置工具

		avp_length &= 0xffffff;
		wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP: code=%d flags=0x%02x "
			   "length=%d", (int) avp_code, avp_flags,
			   (int) avp_length);
		if (avp_length > left) {
			wpa_printf(MSG_WARNING, "EAP-TTLS: AVP overflow "
				   "(len=%d, left=%d) - dropped",
				   (int) avp_length, left);
			retval = -1;
			goto done;
		}
		dpos = (u8 *) (avp + 1);
		dlen = avp_length - sizeof(*avp);
		if (avp_flags & AVP_FLAGS_VENDOR) {
			if (dlen < 4) {
				wpa_printf(MSG_WARNING, "EAP-TTLS: vendor AVP "
					   "underflow");
				retval = -1;
				goto done;
			}
			vendor_id = be_to_host32(* (u32 *) dpos);
			wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP vendor_id %d",
				   (int) vendor_id);
			dpos += 4;
			dlen -= 4;
		}

		wpa_hexdump(MSG_DEBUG, "EAP-TTLS: AVP data", dpos, dlen);

		if (vendor_id == 0 && avp_code == RADIUS_ATTR_EAP_MESSAGE) {
			wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP - EAP Message");
			if (eapdata == NULL) {
				eapdata = malloc(dlen);
				if (eapdata == NULL) {
					retval = -1;
					wpa_printf(MSG_WARNING, "EAP-TTLS: "
						   "failed to allocate memory "
						   "for Phase 2 EAP data");
					goto done;
				}
				memcpy(eapdata, dpos, dlen);
				eap_len = dlen;
			} else {
				u8 *neweap = realloc(eapdata, eap_len + dlen);
				if (neweap == NULL) {
					retval = -1;
					wpa_printf(MSG_WARNING, "EAP-TTLS: "
						   "failed to allocate memory "
						   "for Phase 2 EAP data");
					goto done;
				}
				memcpy(neweap + eap_len, dpos, dlen);
				eapdata = neweap;
				eap_len += dlen;
			}
		} else if (vendor_id == 0 &&
			   avp_code == RADIUS_ATTR_REPLY_MESSAGE) {
			/* This is an optional message that can be displayed to
			 * the user. */
			wpa_hexdump_ascii(MSG_DEBUG,
					  "EAP-TTLS: AVP - Reply-Message",
					  dpos, dlen);
		} else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
			   avp_code == RADIUS_ATTR_MS_CHAP2_SUCCESS) {
			wpa_hexdump_ascii(MSG_DEBUG, "EAP-TTLS: "
					  "MS-CHAP2-Success", dpos, dlen);
			if (dlen != 43) {
				wpa_printf(MSG_WARNING, "EAP-TTLS: Unexpected "
					   "MS-CHAP2-Success length "
					   "(len=%lu, expected 43)",
					   (unsigned long) dlen);
				retval = -1;
				break;
			}
			mschapv2 = dpos;
		} else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
			   avp_code == RADIUS_ATTR_MS_CHAP_ERROR) {
			wpa_hexdump_ascii(MSG_DEBUG, "EAP-TTLS: "
					  "MS-CHAP-Error", dpos, dlen);
			mschapv2_error = 1;
		} else if (avp_flags & AVP_FLAGS_MANDATORY) {
			wpa_printf(MSG_WARNING, "EAP-TTLS: Unsupported "
				   "mandatory AVP code %d vendor_id %d - "
				   "dropped", (int) avp_code, (int) vendor_id);
			retval = -1;
			goto done;
		} else {
			wpa_printf(MSG_DEBUG, "EAP-TTLS: Ignoring unsupported "
				   "AVP code %d vendor_id %d",
				   (int) avp_code, (int) vendor_id);
		}

		pad = (4 - (avp_length & 3)) & 3;
		pos += avp_length + pad;
		left -= avp_length + pad;
	}

	switch (data->phase2_type) {
	case EAP_TTLS_PHASE2_EAP:
		if (eapdata == NULL) {
			wpa_printf(MSG_WARNING, "EAP-TTLS: No EAP Message in "
				   "the packet - dropped");
			retval = -1;
			goto done;
		}

		wpa_hexdump(MSG_DEBUG, "EAP-TTLS: Phase 2 EAP",
			    eapdata, eap_len);
		hdr = (struct eap_hdr *) eapdata;

		if (eap_len < sizeof(*hdr)) {
			wpa_printf(MSG_WARNING, "EAP-TTLS: Too short Phase 2 "
				   "EAP frame (len=%lu, expected %lu or more) "
				   "- dropped", (unsigned long) eap_len,
				   (unsigned long) sizeof(*hdr));
			retval = -1;
			goto done;
		}
		len = be_to_host16(hdr->length);
		if (len > eap_len) {
			wpa_printf(MSG_INFO, "EAP-TTLS: Length mismatch in "
				   "Phase 2 EAP frame (EAP hdr len=%d, EAP "
				   "data len in AVP=%lu)", len,
				   (unsigned long) eap_len);
			retval = -1;
			goto done;
		}
		wpa_printf(MSG_DEBUG, "EAP-TTLS: received Phase 2: code=%d "
			   "identifier=%d length=%d",
			   hdr->code, hdr->identifier, len);
	process_eap:
		switch (hdr->code) {
		case EAP_CODE_REQUEST:
			if (eap_ttls_phase2_request(sm, data, ret, req, hdr,
						    &resp, &resp_len)) {
				wpa_printf(MSG_INFO, "EAP-TTLS: Phase2 "
					   "Request processing failed");
				retval = -1;
				goto done;
			}
			break;
		default:
			wpa_printf(MSG_INFO, "EAP-TTLS: Unexpected code=%d in "
				   "Phase 2 EAP header", hdr->code);
			retval = -1;
			break;
		}
		break;
	case EAP_TTLS_PHASE2_MSCHAPV2:
		if (mschapv2_error) {
			wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Received "
				   "MS-CHAP-Error - failed");
			ret->methodState = METHOD_DONE;
			ret->decision = DECISION_FAIL;
			*out_data = eap_tls_build_ack(&data->ssl, out_len,
						      req->identifier,
						      EAP_TYPE_TTLS, 0);
			break;
		}

		if (mschapv2 == NULL) {
			wpa_printf(MSG_WARNING, "EAP-TTLS: no MS-CHAP2-Success"
				   " AVP received for Phase2 MSCHAPV2");
			retval = -1;
			break;
		}
		if (mschapv2[0] != data->ident) {
			wpa_printf(MSG_WARNING, "EAP-TTLS: Ident mismatch "
				   "for Phase 2 MSCHAPV2 (received Ident "
				   "0x%02x, expected 0x%02x)",
				   mschapv2[0], data->ident);
			retval = -1;
			break;
		}
		if (!data->auth_response_valid ||
		    mschapv2[1] != 'S' || mschapv2[2] != '=' ||
		    hexstr2bin((char *) (mschapv2 + 3), recv_response, 20) ||
		    memcmp(data->auth_response, recv_response, 20) != 0) {
			wpa_printf(MSG_WARNING, "EAP-TTLS: Invalid "
				   "authenticator response in Phase 2 "
				   "MSCHAPV2 success request");
			retval = -1;
			break;
		}

		wpa_printf(MSG_INFO, "EAP-TTLS: Phase 2 MSCHAPV2 "
			   "authentication succeeded");
		ret->methodState = METHOD_DONE;
		ret->decision = DECISION_UNCOND_SUCC;
		data->phase2_success = 1;

		/* Reply with empty data; authentication server will reply
		 * with EAP-Success after this. */
		retval = 1;
		goto done;
	case EAP_TTLS_PHASE2_MSCHAP:
	case EAP_TTLS_PHASE2_PAP:
	case EAP_TTLS_PHASE2_CHAP:
		/* EAP-TTLS/{MSCHAP,PAP,CHAP} should not send any TLS tunneled
		 * requests to the supplicant */
		wpa_printf(MSG_INFO, "EAP-TTLS: Phase 2 received unexpected "
			   "tunneled data");
		retval = -1;
		break;
	}

	if (resp) {
		wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Encrypting Phase 2 data",
				resp, resp_len);

		if (eap_ttls_encrypt(sm, data, req->identifier,
				     resp, resp_len, out_data, out_len)) {
			wpa_printf(MSG_INFO, "EAP-TTLS: Failed to encrypt "
				   "a Phase 2 frame");
		}
		free(resp);
	} else if (config->pending_req_identity ||
		   config->pending_req_password ||
		   config->pending_req_otp ||
		   config->pending_req_new_password) {
		free(data->pending_phase2_req);
		data->pending_phase2_req = malloc(len_decrypted);
		if (data->pending_phase2_req) {
			memcpy(data->pending_phase2_req, in_decrypted,
			       len_decrypted);
			data->pending_phase2_req_len = len_decrypted;
		}
	}

done:
	free(in_decrypted);
	free(eapdata);

	if (retval < 0) {
		ret->methodState = METHOD_DONE;
		ret->decision = DECISION_FAIL;
	}

	return retval;
}


static u8 * eap_ttls_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_ttls_data *data = priv;

	pos = eap_tls_process_init(sm, &data->ssl, EAP_TYPE_TTLS, 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-TTLS: Start");
		/* draft-ietf-pppext-eap-ttls-03.txt, Ch. 8.1:
		 * EAP-TTLS Start packet may, in a future specification, be
		 * allowed to contain data. Client based on this draft version
		 * must ignore such data but must not reject the Start packet.
		 */
		left = 0;
	}

	resp = NULL;
	if (tls_connection_established(sm->ssl_ctx, data->ssl.conn) &&
	    !data->resuming) {
		res = eap_ttls_decrypt(sm, data, ret, req, pos, left,
				       &resp, respDataLen);
	} else {
		res = eap_tls_process_helper(sm, &data->ssl, EAP_TYPE_TTLS, 0,
					     id, pos, left,
					     &resp, respDataLen);

		if (tls_connection_established(sm->ssl_ctx, data->ssl.conn)) {
			wpa_printf(MSG_DEBUG,
				   "EAP-TTLS: TLS done, proceed to Phase 2");
			if (data->resuming) {
				wpa_printf(MSG_DEBUG, "EAP-TTLS: fast reauth -"
					   " may skip Phase 2");
				ret->decision = DECISION_COND_SUCC;
				ret->methodState = METHOD_MAY_CONT;
			}
			data->phase2_start = 1;
			free(data->key_data);
			data->key_data =
				eap_tls_derive_key(sm, &data->ssl,
						   "ttls keying material",
						   EAP_TLS_KEY_LEN);
			if (data->key_data) {
				wpa_hexdump_key(MSG_DEBUG,
						"EAP-TTLS: Derived key",
						data->key_data,
						EAP_TLS_KEY_LEN);
			} else {
				wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to "
					   "derive key");
			}

			if (*respDataLen == 0) {
				if (eap_ttls_decrypt(sm, data, ret, req, NULL,
						     0, &resp, respDataLen)) {
					wpa_printf(MSG_WARNING, "EAP-TTLS: "
						   "failed to process early "
						   "start for Phase 2");
				}
				res = 0;
			}
			data->resuming = 0;
		}
	}

	if (ret->methodState == METHOD_DONE) {
		ret->allowNotifications = FALSE;
		if (ret->decision == DECISION_UNCOND_SUCC ||
		    ret->decision == DECISION_COND_SUCC) {
			wpa_printf(MSG_DEBUG, "EAP-TTLS: Authentication "
				   "completed successfully");
			data->phase2_success = 1;
		}
	} else if (sm->workaround && ret->methodState == METHOD_MAY_CONT &&
		   (ret->decision == DECISION_UNCOND_SUCC ||
		    ret->decision == DECISION_COND_SUCC)) {
			wpa_printf(MSG_DEBUG, "EAP-TTLS: Authentication "
				   "completed successfully (EAP workaround)");
			data->phase2_success = 1;
	}

	if (res == 1) {
		return eap_tls_build_ack(&data->ssl, respDataLen, id,
					 EAP_TYPE_TTLS, 0);
	}
	return resp;
}


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


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


static void * eap_ttls_init_for_reauth(struct eap_sm *sm, void *priv)
{
	struct eap_ttls_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_start = 0;
	data->phase2_success = 0;
	data->resuming = 1;
	data->reauth = 1;
	return priv;
}


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

	len = eap_tls_status(sm, &data->ssl, buf, buflen, verbose);
	switch (data->phase2_type) {
	case EAP_TTLS_PHASE2_EAP:
		len += snprintf(buf + len, buflen - len,
				"EAP-TTLS Phase2 method=EAP-%s\n",
				data->phase2_method ? data->phase2_method->name
				: "?");
		break;
	case EAP_TTLS_PHASE2_MSCHAPV2:
		len += snprintf(buf + len, buflen - len,
				"EAP-TTLS Phase2 method=MSCHAPV2\n");
		break;
	case EAP_TTLS_PHASE2_MSCHAP:
		len += snprintf(buf + len, buflen - len,
				"EAP-TTLS Phase2 method=MSCHAP\n");
		break;
	case EAP_TTLS_PHASE2_PAP:
		len += snprintf(buf + len, buflen - len,
				"EAP-TTLS Phase2 method=PAP\n");
		break;
	case EAP_TTLS_PHASE2_CHAP:
		len += snprintf(buf + len, buflen - len,
				"EAP-TTLS Phase2 method=CHAP\n");
		break;
	}

	return len;
}


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


static u8 * eap_ttls_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
	struct eap_ttls_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_ttls =
{
	.method = EAP_TYPE_TTLS,
	.name = "TTLS",
	.init = eap_ttls_init,
	.deinit = eap_ttls_deinit,
	.process = eap_ttls_process,
	.isKeyAvailable = eap_ttls_isKeyAvailable,
	.getKey = eap_ttls_getKey,
	.get_status = eap_ttls_get_status,
	.has_reauth_data = eap_ttls_has_reauth_data,
	.deinit_for_reauth = eap_ttls_deinit_for_reauth,
	.init_for_reauth = eap_ttls_init_for_reauth,
};