1 /* 2 * Copyright (C) 2019 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.car.trust; 18 19 import android.util.Log; 20 21 import com.android.car.BLEStreamProtos.VersionExchangeProto.BLEVersionExchange; 22 23 /** 24 * Resolver of version exchanges between this device and a client device. 25 */ 26 class BLEVersionExchangeResolver { 27 private static final String TAG = "BLEVersionExchangeResolver"; 28 29 // Currently, only version 1 of the messaging and security supported. 30 private static final int MESSAGING_VERSION = 1; 31 private static final int SECURITY_VERSION = 1; 32 33 /** 34 * Return whether or not the given version exchange proto has the a version that is currently 35 * supported by this device. 36 * 37 * @param versionExchange The version exchange proto to resolve 38 * @return {@code true} if there is a supported version. 39 */ hasSupportedVersion(BLEVersionExchange versionExchange)40 static boolean hasSupportedVersion(BLEVersionExchange versionExchange) { 41 int minMessagingVersion = versionExchange.getMinSupportedMessagingVersion(); 42 int minSecurityVersion = versionExchange.getMinSupportedSecurityVersion(); 43 44 if (Log.isLoggable(TAG, Log.DEBUG)) { 45 Log.d(TAG, "Checking for supported version on (minMessagingVersion: " 46 + minMessagingVersion + ", minSecurityVersion: " + minSecurityVersion + ")"); 47 } 48 49 // Only one supported version, so ensure the minimum version matches. 50 return minMessagingVersion == MESSAGING_VERSION && minSecurityVersion == SECURITY_VERSION; 51 } 52 53 /** 54 * Returns a version exchange proto with the maximum and minimum protocol and security versions 55 * this device currently supports. 56 */ makeVersionExchange()57 static BLEVersionExchange makeVersionExchange() { 58 return BLEVersionExchange.newBuilder() 59 .setMinSupportedMessagingVersion(MESSAGING_VERSION) 60 .setMaxSupportedMessagingVersion(MESSAGING_VERSION) 61 .setMinSupportedSecurityVersion(SECURITY_VERSION) 62 .setMinSupportedSecurityVersion(SECURITY_VERSION) 63 .build(); 64 } 65 BLEVersionExchangeResolver()66 private BLEVersionExchangeResolver() {} 67 } 68