1/* 2 * Copyright (C) 2016 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 17package com.android.packageinstaller; 18 19import static com.android.packageinstaller.PackageUtil.getMaxTargetSdkVersionForUid; 20 21import android.Manifest; 22import android.app.Activity; 23import android.app.ActivityManager; 24import android.app.AppGlobals; 25import android.app.IActivityManager; 26import android.content.ContentResolver; 27import android.content.Intent; 28import android.content.pm.ApplicationInfo; 29import android.content.pm.IPackageManager; 30import android.content.pm.PackageInstaller; 31import android.content.pm.PackageManager; 32import android.content.pm.ProviderInfo; 33import android.net.Uri; 34import android.os.Build; 35import android.os.Bundle; 36import android.os.RemoteException; 37import android.support.annotation.Nullable; 38import android.util.Log; 39 40import com.android.internal.annotations.VisibleForTesting; 41 42/** 43 * Select which activity is the first visible activity of the installation and forward the intent to 44 * it. 45 */ 46public class InstallStart extends Activity { 47 private static final String LOG_TAG = InstallStart.class.getSimpleName(); 48 49 private static final String DOWNLOADS_AUTHORITY = "downloads"; 50 private IActivityManager mIActivityManager; 51 private IPackageManager mIPackageManager; 52 private boolean mAbortInstall = false; 53 54 @Override 55 protected void onCreate(@Nullable Bundle savedInstanceState) { 56 super.onCreate(savedInstanceState); 57 mIPackageManager = AppGlobals.getPackageManager(); 58 Intent intent = getIntent(); 59 String callingPackage = getCallingPackage(); 60 61 // If the activity was started via a PackageInstaller session, we retrieve the calling 62 // package from that session 63 int sessionId = intent.getIntExtra(PackageInstaller.EXTRA_SESSION_ID, -1); 64 if (callingPackage == null && sessionId != -1) { 65 PackageInstaller packageInstaller = getPackageManager().getPackageInstaller(); 66 PackageInstaller.SessionInfo sessionInfo = packageInstaller.getSessionInfo(sessionId); 67 callingPackage = (sessionInfo != null) ? sessionInfo.getInstallerPackageName() : null; 68 } 69 70 final ApplicationInfo sourceInfo = getSourceInfo(callingPackage); 71 final int originatingUid = getOriginatingUid(sourceInfo); 72 boolean isTrustedSource = false; 73 if (sourceInfo != null 74 && (sourceInfo.privateFlags & ApplicationInfo.PRIVATE_FLAG_PRIVILEGED) != 0) { 75 isTrustedSource = intent.getBooleanExtra(Intent.EXTRA_NOT_UNKNOWN_SOURCE, false); 76 } 77 78 if (!isTrustedSource && originatingUid != PackageInstaller.SessionParams.UID_UNKNOWN) { 79 final int targetSdkVersion = getMaxTargetSdkVersionForUid(this, originatingUid); 80 if (targetSdkVersion < 0) { 81 Log.w(LOG_TAG, "Cannot get target sdk version for uid " + originatingUid); 82 // Invalid originating uid supplied. Abort install. 83 mAbortInstall = true; 84 } else if (targetSdkVersion >= Build.VERSION_CODES.O && !declaresAppOpPermission( 85 originatingUid, Manifest.permission.REQUEST_INSTALL_PACKAGES)) { 86 Log.e(LOG_TAG, "Requesting uid " + originatingUid + " needs to declare permission " 87 + Manifest.permission.REQUEST_INSTALL_PACKAGES); 88 mAbortInstall = true; 89 } 90 } 91 if (mAbortInstall) { 92 setResult(RESULT_CANCELED); 93 finish(); 94 return; 95 } 96 97 Intent nextActivity = new Intent(intent); 98 nextActivity.setFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT); 99 100 // The the installation source as the nextActivity thinks this activity is the source, hence 101 // set the originating UID and sourceInfo explicitly 102 nextActivity.putExtra(PackageInstallerActivity.EXTRA_CALLING_PACKAGE, callingPackage); 103 nextActivity.putExtra(PackageInstallerActivity.EXTRA_ORIGINAL_SOURCE_INFO, sourceInfo); 104 nextActivity.putExtra(Intent.EXTRA_ORIGINATING_UID, originatingUid); 105 106 if (PackageInstaller.ACTION_CONFIRM_PERMISSIONS.equals(intent.getAction())) { 107 nextActivity.setClass(this, PackageInstallerActivity.class); 108 } else { 109 Uri packageUri = intent.getData(); 110 111 if (packageUri != null && (packageUri.getScheme().equals(ContentResolver.SCHEME_FILE) 112 || packageUri.getScheme().equals(ContentResolver.SCHEME_CONTENT))) { 113 // Copy file to prevent it from being changed underneath this process 114 nextActivity.setClass(this, InstallStaging.class); 115 } else if (packageUri != null && packageUri.getScheme().equals( 116 PackageInstallerActivity.SCHEME_PACKAGE)) { 117 nextActivity.setClass(this, PackageInstallerActivity.class); 118 } else { 119 Intent result = new Intent(); 120 result.putExtra(Intent.EXTRA_INSTALL_RESULT, 121 PackageManager.INSTALL_FAILED_INVALID_URI); 122 setResult(RESULT_FIRST_USER, result); 123 124 nextActivity = null; 125 } 126 } 127 128 if (nextActivity != null) { 129 startActivity(nextActivity); 130 } 131 finish(); 132 } 133 134 private boolean declaresAppOpPermission(int uid, String permission) { 135 try { 136 final String[] packages = mIPackageManager.getAppOpPermissionPackages(permission); 137 if (packages == null) { 138 return false; 139 } 140 for (String packageName : packages) { 141 try { 142 if (uid == getPackageManager().getPackageUid(packageName, 0)) { 143 return true; 144 } 145 } catch (PackageManager.NameNotFoundException e) { 146 // Ignore and try the next package 147 } 148 } 149 } catch (RemoteException rexc) { 150 // If remote package manager cannot be reached, install will likely fail anyway. 151 } 152 return false; 153 } 154 155 /** 156 * @return the ApplicationInfo for the installation source (the calling package), if available 157 */ 158 private ApplicationInfo getSourceInfo(@Nullable String callingPackage) { 159 if (callingPackage != null) { 160 try { 161 return getPackageManager().getApplicationInfo(callingPackage, 0); 162 } catch (PackageManager.NameNotFoundException ex) { 163 // ignore 164 } 165 } 166 return null; 167 } 168 169 /** 170 * Get the originating uid if possible, or 171 * {@link android.content.pm.PackageInstaller.SessionParams#UID_UNKNOWN} if not available 172 * 173 * @param sourceInfo The source of this installation 174 * @return The UID of the installation source or UID_UNKNOWN 175 */ 176 private int getOriginatingUid(@Nullable ApplicationInfo sourceInfo) { 177 // The originating uid from the intent. We only trust/use this if it comes from either 178 // the document manager app or the downloads provider 179 final int uidFromIntent = getIntent().getIntExtra(Intent.EXTRA_ORIGINATING_UID, 180 PackageInstaller.SessionParams.UID_UNKNOWN); 181 182 final int callingUid; 183 if (sourceInfo != null) { 184 callingUid = sourceInfo.uid; 185 } else { 186 try { 187 callingUid = getIActivityManager() 188 .getLaunchedFromUid(getActivityToken()); 189 } catch (RemoteException ex) { 190 // Cannot reach ActivityManager. Aborting install. 191 Log.e(LOG_TAG, "Could not determine the launching uid."); 192 mAbortInstall = true; 193 return PackageInstaller.SessionParams.UID_UNKNOWN; 194 } 195 } 196 try { 197 if (mIPackageManager.checkUidPermission(Manifest.permission.MANAGE_DOCUMENTS, 198 callingUid) == PackageManager.PERMISSION_GRANTED) { 199 return uidFromIntent; 200 } 201 } catch (RemoteException rexc) { 202 // Ignore. Should not happen. 203 } 204 if (isSystemDownloadsProvider(callingUid)) { 205 return uidFromIntent; 206 } 207 // We don't trust uid from the intent. Use the calling uid instead. 208 return callingUid; 209 } 210 211 private boolean isSystemDownloadsProvider(int uid) { 212 final ProviderInfo downloadProviderPackage = getPackageManager().resolveContentProvider( 213 DOWNLOADS_AUTHORITY, 0); 214 if (downloadProviderPackage == null) { 215 // There seems to be no currently enabled downloads provider on the system. 216 return false; 217 } 218 final ApplicationInfo appInfo = downloadProviderPackage.applicationInfo; 219 return (appInfo.isSystemApp() && uid == appInfo.uid); 220 } 221 222 private IActivityManager getIActivityManager() { 223 if (mIActivityManager == null) { 224 return ActivityManager.getService(); 225 } 226 return mIActivityManager; 227 } 228 229 @VisibleForTesting 230 void injectIActivityManager(IActivityManager iActivityManager) { 231 mIActivityManager = iActivityManager; 232 } 233} 234