1 /* 2 * Copyright (C) 2017 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 package com.android.voicemail.impl.transcribe.grpc; 17 18 import android.content.Context; 19 import android.content.pm.PackageInfo; 20 import android.content.pm.PackageManager; 21 import android.text.TextUtils; 22 import com.android.dialer.common.Assert; 23 import com.android.dialer.common.LogUtil; 24 import com.android.voicemail.impl.transcribe.TranscriptionConfigProvider; 25 import com.google.internal.communications.voicemailtranscription.v1.VoicemailTranscriptionServiceGrpc; 26 import io.grpc.CallOptions; 27 import io.grpc.Channel; 28 import io.grpc.ClientCall; 29 import io.grpc.ClientInterceptor; 30 import io.grpc.ClientInterceptors; 31 import io.grpc.ForwardingClientCall; 32 import io.grpc.ManagedChannel; 33 import io.grpc.ManagedChannelBuilder; 34 import io.grpc.Metadata; 35 import io.grpc.MethodDescriptor; 36 import io.grpc.okhttp.OkHttpChannelBuilder; 37 import java.security.MessageDigest; 38 39 /** 40 * Factory for creating grpc clients that talk to the transcription server. This allows all clients 41 * to share the same channel, which is relatively expensive to create. 42 */ 43 public class TranscriptionClientFactory { 44 private static final String DIGEST_ALGORITHM_SHA1 = "SHA1"; 45 private static final char[] HEX_UPPERCASE = { 46 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' 47 }; 48 49 private final TranscriptionConfigProvider configProvider; 50 private final ManagedChannel originalChannel; 51 private final String packageName; 52 private final String cert; 53 54 public TranscriptionClientFactory(Context context, TranscriptionConfigProvider configProvider) { 55 this(context, configProvider, getManagedChannel(configProvider)); 56 } 57 58 public TranscriptionClientFactory( 59 Context context, TranscriptionConfigProvider configProvider, ManagedChannel managedChannel) { 60 this.configProvider = configProvider; 61 this.packageName = context.getPackageName(); 62 this.cert = getCertificateFingerprint(context); 63 originalChannel = managedChannel; 64 } 65 66 public TranscriptionClient getClient() { 67 LogUtil.enterBlock("TranscriptionClientFactory.getClient"); 68 Assert.checkState(!originalChannel.isShutdown()); 69 Channel channel = 70 ClientInterceptors.intercept( 71 originalChannel, 72 new Interceptor( 73 packageName, cert, configProvider.getApiKey(), configProvider.getAuthToken())); 74 return new TranscriptionClient(VoicemailTranscriptionServiceGrpc.newBlockingStub(channel)); 75 } 76 77 public void shutdown() { 78 LogUtil.enterBlock("TranscriptionClientFactory.shutdown"); 79 originalChannel.shutdown(); 80 } 81 82 private static ManagedChannel getManagedChannel(TranscriptionConfigProvider configProvider) { 83 ManagedChannelBuilder<OkHttpChannelBuilder> builder = 84 OkHttpChannelBuilder.forTarget(configProvider.getServerAddress()); 85 // Only use plaintext for debugging 86 if (configProvider.shouldUsePlaintext()) { 87 // Just passing 'false' doesnt have the same effect as not setting this field 88 builder.usePlaintext(true); 89 } 90 return builder.build(); 91 } 92 93 private static String getCertificateFingerprint(Context context) { 94 try { 95 PackageInfo packageInfo = 96 context 97 .getPackageManager() 98 .getPackageInfo(context.getPackageName(), PackageManager.GET_SIGNATURES); 99 if (packageInfo != null 100 && packageInfo.signatures != null 101 && packageInfo.signatures.length > 0) { 102 MessageDigest messageDigest = MessageDigest.getInstance(DIGEST_ALGORITHM_SHA1); 103 if (messageDigest == null) { 104 LogUtil.w( 105 "TranscriptionClientFactory.getCertificateFingerprint", "error getting digest."); 106 return null; 107 } 108 byte[] bytes = messageDigest.digest(packageInfo.signatures[0].toByteArray()); 109 if (bytes == null) { 110 LogUtil.w( 111 "TranscriptionClientFactory.getCertificateFingerprint", "empty message digest."); 112 return null; 113 } 114 115 int length = bytes.length; 116 StringBuilder out = new StringBuilder(length * 2); 117 for (int i = 0; i < length; i++) { 118 out.append(HEX_UPPERCASE[(bytes[i] & 0xf0) >>> 4]); 119 out.append(HEX_UPPERCASE[bytes[i] & 0x0f]); 120 } 121 return out.toString(); 122 } else { 123 LogUtil.w( 124 "TranscriptionClientFactory.getCertificateFingerprint", 125 "failed to get package signature."); 126 } 127 } catch (Exception e) { 128 LogUtil.e( 129 "TranscriptionClientFactory.getCertificateFingerprint", 130 "error getting certificate fingerprint.", 131 e); 132 } 133 134 return null; 135 } 136 137 private static final class Interceptor implements ClientInterceptor { 138 private final String packageName; 139 private final String cert; 140 private final String apiKey; 141 private final String authToken; 142 143 private static final Metadata.Key<String> API_KEY_HEADER = 144 Metadata.Key.of("X-Goog-Api-Key", Metadata.ASCII_STRING_MARSHALLER); 145 private static final Metadata.Key<String> ANDROID_PACKAGE_HEADER = 146 Metadata.Key.of("X-Android-Package", Metadata.ASCII_STRING_MARSHALLER); 147 private static final Metadata.Key<String> ANDROID_CERT_HEADER = 148 Metadata.Key.of("X-Android-Cert", Metadata.ASCII_STRING_MARSHALLER); 149 private static final Metadata.Key<String> AUTHORIZATION_HEADER = 150 Metadata.Key.of("authorization", Metadata.ASCII_STRING_MARSHALLER); 151 152 public Interceptor(String packageName, String cert, String apiKey, String authToken) { 153 this.packageName = packageName; 154 this.cert = cert; 155 this.apiKey = apiKey; 156 this.authToken = authToken; 157 } 158 159 @Override 160 public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall( 161 MethodDescriptor<ReqT, RespT> method, CallOptions callOptions, Channel next) { 162 LogUtil.enterBlock( 163 "TranscriptionClientFactory.interceptCall, intercepted " + method.getFullMethodName()); 164 ClientCall<ReqT, RespT> call = next.newCall(method, callOptions); 165 166 call = 167 new ForwardingClientCall.SimpleForwardingClientCall<ReqT, RespT>(call) { 168 @Override 169 public void start(Listener<RespT> responseListener, Metadata headers) { 170 if (!TextUtils.isEmpty(packageName)) { 171 LogUtil.i( 172 "TranscriptionClientFactory.interceptCall", 173 "attaching package name: " + packageName); 174 headers.put(ANDROID_PACKAGE_HEADER, packageName); 175 } 176 if (!TextUtils.isEmpty(cert)) { 177 LogUtil.i("TranscriptionClientFactory.interceptCall", "attaching android cert"); 178 headers.put(ANDROID_CERT_HEADER, cert); 179 } 180 if (!TextUtils.isEmpty(apiKey)) { 181 LogUtil.i("TranscriptionClientFactory.interceptCall", "attaching API Key"); 182 headers.put(API_KEY_HEADER, apiKey); 183 } 184 if (!TextUtils.isEmpty(authToken)) { 185 LogUtil.i("TranscriptionClientFactory.interceptCall", "attaching auth token"); 186 headers.put(AUTHORIZATION_HEADER, "Bearer " + authToken); 187 } 188 super.start(responseListener, headers); 189 } 190 }; 191 return call; 192 } 193 } 194 } 195
