Joseph Wen | 6a34bb2 | 2015-02-25 14:00:39 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2015 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.statementservice; |
| 18 | |
| 19 | import android.content.BroadcastReceiver; |
| 20 | import android.content.Context; |
| 21 | import android.content.Intent; |
| 22 | import android.content.pm.PackageManager; |
| 23 | import android.content.pm.PackageManager.NameNotFoundException; |
| 24 | import android.os.Bundle; |
| 25 | import android.os.Handler; |
| 26 | import android.os.ResultReceiver; |
| 27 | import android.util.Log; |
| 28 | import android.util.Patterns; |
| 29 | |
| 30 | import com.android.statementservice.retriever.Utils; |
| 31 | |
| 32 | import java.net.MalformedURLException; |
| 33 | import java.net.URL; |
| 34 | import java.util.ArrayList; |
| 35 | import java.util.Collections; |
| 36 | import java.util.List; |
| 37 | import java.util.regex.Pattern; |
| 38 | |
| 39 | /** |
| 40 | * Receives {@link Intent#ACTION_INTENT_FILTER_NEEDS_VERIFICATION} broadcast and calls |
| 41 | * {@link DirectStatementService} to verify the request. Calls |
| 42 | * {@link PackageManager#verifyIntentFilter} to notify {@link PackageManager} the result of the |
| 43 | * verification. |
| 44 | * |
| 45 | * This implementation of the API will send a HTTP request for each host specified in the query. |
| 46 | * To avoid overwhelming the network at app install time, {@code MAX_HOSTS_PER_REQUEST} limits |
| 47 | * the maximum number of hosts in a query. If a query contains more than |
| 48 | * {@code MAX_HOSTS_PER_REQUEST} hosts, it will fail immediately without making any HTTP request |
| 49 | * and call {@link PackageManager#verifyIntentFilter} with |
| 50 | * {@link PackageManager#INTENT_FILTER_VERIFICATION_FAILURE}. |
| 51 | */ |
| 52 | public final class IntentFilterVerificationReceiver extends BroadcastReceiver { |
| 53 | private static final String TAG = IntentFilterVerificationReceiver.class.getSimpleName(); |
| 54 | |
| 55 | private static final Integer MAX_HOSTS_PER_REQUEST = 10; |
| 56 | |
| 57 | private static final String HANDLE_ALL_URLS_RELATION |
| 58 | = "delegate_permission/common.handle_all_urls"; |
| 59 | |
| 60 | private static final String ANDROID_ASSET_FORMAT = "{\"namespace\": \"android_app\", " |
| 61 | + "\"package_name\": \"%s\", \"sha256_cert_fingerprints\": [\"%s\"]}"; |
| 62 | private static final String WEB_ASSET_FORMAT = "{\"namespace\": \"web\", \"site\": \"%s\"}"; |
| 63 | private static final Pattern ANDROID_PACKAGE_NAME_PATTERN = |
| 64 | Pattern.compile("^[a-zA-Z_][a-zA-Z0-9_]*(\\.[a-zA-Z_][a-zA-Z0-9_]*)*$"); |
| 65 | private static final String TOO_MANY_HOSTS_FORMAT = |
| 66 | "Request contains %d hosts which is more than the allowed %d."; |
| 67 | |
| 68 | private static void sendErrorToPackageManager(PackageManager packageManager, |
| 69 | int verificationId) { |
| 70 | packageManager.verifyIntentFilter(verificationId, |
| 71 | PackageManager.INTENT_FILTER_VERIFICATION_FAILURE, |
| 72 | Collections.<String>emptyList()); |
| 73 | } |
| 74 | |
| 75 | @Override |
| 76 | public void onReceive(Context context, Intent intent) { |
| 77 | final String action = intent.getAction(); |
| 78 | if (Intent.ACTION_INTENT_FILTER_NEEDS_VERIFICATION.equals(action)) { |
| 79 | Bundle inputExtras = intent.getExtras(); |
| 80 | if (inputExtras != null) { |
| 81 | Intent serviceIntent = new Intent(context, DirectStatementService.class); |
| 82 | serviceIntent.setAction(DirectStatementService.CHECK_ALL_ACTION); |
| 83 | |
| 84 | int verificationId = inputExtras.getInt( |
| 85 | PackageManager.EXTRA_INTENT_FILTER_VERIFICATION_ID); |
| 86 | String scheme = inputExtras.getString( |
| 87 | PackageManager.EXTRA_INTENT_FILTER_VERIFICATION_URI_SCHEME); |
| 88 | String hosts = inputExtras.getString( |
| 89 | PackageManager.EXTRA_INTENT_FILTER_VERIFICATION_HOSTS); |
| 90 | String packageName = inputExtras.getString( |
| 91 | PackageManager.EXTRA_INTENT_FILTER_VERIFICATION_PACKAGE_NAME); |
| 92 | |
| 93 | Log.i(TAG, "Verify IntentFilter for " + hosts); |
| 94 | |
| 95 | Bundle extras = new Bundle(); |
| 96 | extras.putString(DirectStatementService.EXTRA_RELATION, HANDLE_ALL_URLS_RELATION); |
| 97 | |
| 98 | String[] hostList = hosts.split(" "); |
| 99 | if (hostList.length > MAX_HOSTS_PER_REQUEST) { |
| 100 | Log.w(TAG, String.format(TOO_MANY_HOSTS_FORMAT, |
| 101 | hostList.length, MAX_HOSTS_PER_REQUEST)); |
| 102 | sendErrorToPackageManager(context.getPackageManager(), verificationId); |
| 103 | return; |
| 104 | } |
| 105 | |
| 106 | try { |
| 107 | ArrayList<String> sourceAssets = new ArrayList<String>(); |
| 108 | for (String host : hostList) { |
Christopher Tate | d268a22 | 2016-02-19 16:48:28 -0800 | [diff] [blame] | 109 | // "*.example.tld" is validated via https://example.tld |
| 110 | if (host.startsWith("*.")) { |
| 111 | host = host.substring(2); |
| 112 | } |
Joseph Wen | 6a34bb2 | 2015-02-25 14:00:39 -0500 | [diff] [blame] | 113 | sourceAssets.add(createWebAssetString(scheme, host)); |
| 114 | } |
| 115 | extras.putStringArrayList(DirectStatementService.EXTRA_SOURCE_ASSET_DESCRIPTORS, |
| 116 | sourceAssets); |
| 117 | } catch (MalformedURLException e) { |
| 118 | Log.w(TAG, "Error when processing input host: " + e.getMessage()); |
| 119 | sendErrorToPackageManager(context.getPackageManager(), verificationId); |
| 120 | return; |
| 121 | } |
| 122 | try { |
| 123 | extras.putString(DirectStatementService.EXTRA_TARGET_ASSET_DESCRIPTOR, |
| 124 | createAndroidAssetString(context, packageName)); |
| 125 | } catch (NameNotFoundException e) { |
| 126 | Log.w(TAG, "Error when processing input Android package: " + e.getMessage()); |
| 127 | sendErrorToPackageManager(context.getPackageManager(), verificationId); |
| 128 | return; |
| 129 | } |
| 130 | extras.putParcelable(DirectStatementService.EXTRA_RESULT_RECEIVER, |
| 131 | new IsAssociatedResultReceiver( |
| 132 | new Handler(), context.getPackageManager(), verificationId)); |
| 133 | |
| 134 | serviceIntent.putExtras(extras); |
| 135 | context.startService(serviceIntent); |
| 136 | } |
| 137 | } else { |
| 138 | Log.w(TAG, "Intent action not supported: " + action); |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | private String createAndroidAssetString(Context context, String packageName) |
| 143 | throws NameNotFoundException { |
| 144 | if (!ANDROID_PACKAGE_NAME_PATTERN.matcher(packageName).matches()) { |
| 145 | throw new NameNotFoundException("Input package name is not valid."); |
| 146 | } |
| 147 | |
| 148 | List<String> certFingerprints = |
| 149 | Utils.getCertFingerprintsFromPackageManager(packageName, context); |
| 150 | |
| 151 | return String.format(ANDROID_ASSET_FORMAT, packageName, |
| 152 | Utils.joinStrings("\", \"", certFingerprints)); |
| 153 | } |
| 154 | |
| 155 | private String createWebAssetString(String scheme, String host) throws MalformedURLException { |
| 156 | if (!Patterns.DOMAIN_NAME.matcher(host).matches()) { |
| 157 | throw new MalformedURLException("Input host is not valid."); |
| 158 | } |
| 159 | if (!scheme.equals("http") && !scheme.equals("https")) { |
| 160 | throw new MalformedURLException("Input scheme is not valid."); |
| 161 | } |
| 162 | |
| 163 | return String.format(WEB_ASSET_FORMAT, new URL(scheme, host, "").toString()); |
| 164 | } |
| 165 | |
| 166 | /** |
| 167 | * Receives the result of {@code StatementService.CHECK_ACTION} from |
| 168 | * {@link DirectStatementService} and passes it back to {@link PackageManager}. |
| 169 | */ |
| 170 | private static class IsAssociatedResultReceiver extends ResultReceiver { |
| 171 | |
| 172 | private final int mVerificationId; |
| 173 | private final PackageManager mPackageManager; |
| 174 | |
| 175 | public IsAssociatedResultReceiver(Handler handler, PackageManager packageManager, |
| 176 | int verificationId) { |
| 177 | super(handler); |
| 178 | mVerificationId = verificationId; |
| 179 | mPackageManager = packageManager; |
| 180 | } |
| 181 | |
| 182 | @Override |
| 183 | protected void onReceiveResult(int resultCode, Bundle resultData) { |
| 184 | if (resultCode == DirectStatementService.RESULT_SUCCESS) { |
| 185 | if (resultData.getBoolean(DirectStatementService.IS_ASSOCIATED)) { |
| 186 | mPackageManager.verifyIntentFilter(mVerificationId, |
| 187 | PackageManager.INTENT_FILTER_VERIFICATION_SUCCESS, |
| 188 | Collections.<String>emptyList()); |
| 189 | } else { |
| 190 | mPackageManager.verifyIntentFilter(mVerificationId, |
| 191 | PackageManager.INTENT_FILTER_VERIFICATION_FAILURE, |
| 192 | resultData.getStringArrayList(DirectStatementService.FAILED_SOURCES)); |
| 193 | } |
| 194 | } else { |
| 195 | sendErrorToPackageManager(mPackageManager, mVerificationId); |
| 196 | } |
| 197 | } |
| 198 | } |
| 199 | } |