/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.os; import android.annotation.SystemApi; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.os.UserManager; import android.text.TextUtils; import android.util.Log; import java.io.ByteArrayInputStream; import java.io.BufferedReader; import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.io.InputStream; import java.io.RandomAccessFile; import java.security.GeneralSecurityException; import java.security.PublicKey; import java.security.Signature; import java.security.SignatureException; import java.security.cert.CertificateFactory; import java.security.cert.X509Certificate; import java.util.Enumeration; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Locale; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; import com.android.internal.logging.MetricsLogger; import sun.security.pkcs.PKCS7; import sun.security.pkcs.SignerInfo; /** * RecoverySystem contains methods for interacting with the Android * recovery system (the separate partition that can be used to install * system updates, wipe user data, etc.) */ public class RecoverySystem { private static final String TAG = "RecoverySystem"; /** * Default location of zip file containing public keys (X509 * certs) authorized to sign OTA updates. */ private static final File DEFAULT_KEYSTORE = new File("/system/etc/security/otacerts.zip"); /** Send progress to listeners no more often than this (in ms). */ private static final long PUBLISH_PROGRESS_INTERVAL_MS = 500; /** Used to communicate with recovery. See bootable/recovery/recovery.cpp. */ private static final File RECOVERY_DIR = new File("/cache/recovery"); private static final File LOG_FILE = new File(RECOVERY_DIR, "log"); private static final File LAST_INSTALL_FILE = new File(RECOVERY_DIR, "last_install"); private static final String LAST_PREFIX = "last_"; /** * The recovery image uses this file to identify the location (i.e. blocks) * of an OTA package on the /data partition. The block map file is * generated by uncrypt. * * @hide */ public static final File BLOCK_MAP_FILE = new File(RECOVERY_DIR, "block.map"); /** * UNCRYPT_PACKAGE_FILE stores the filename to be uncrypt'd, which will be * read by uncrypt. * * @hide */ public static final File UNCRYPT_PACKAGE_FILE = new File(RECOVERY_DIR, "uncrypt_file"); // Length limits for reading files. private static final int LOG_FILE_MAX_LENGTH = 64 * 1024; // Prevent concurrent execution of requests. private static final Object sRequestLock = new Object(); private final IRecoverySystem mService; /** * Interface definition for a callback to be invoked regularly as * verification proceeds. */ public interface ProgressListener { /** * Called periodically as the verification progresses. * * @param progress the approximate percentage of the * verification that has been completed, ranging from 0 * to 100 (inclusive). */ public void onProgress(int progress); } /** @return the set of certs that can be used to sign an OTA package. */ private static HashSet getTrustedCerts(File keystore) throws IOException, GeneralSecurityException { HashSet trusted = new HashSet(); if (keystore == null) { keystore = DEFAULT_KEYSTORE; } ZipFile zip = new ZipFile(keystore); try { CertificateFactory cf = CertificateFactory.getInstance("X.509"); Enumeration entries = zip.entries(); while (entries.hasMoreElements()) { ZipEntry entry = entries.nextElement(); InputStream is = zip.getInputStream(entry); try { trusted.add((X509Certificate) cf.generateCertificate(is)); } finally { is.close(); } } } finally { zip.close(); } return trusted; } /** * Verify the cryptographic signature of a system update package * before installing it. Note that the package is also verified * separately by the installer once the device is rebooted into * the recovery system. This function will return only if the * package was successfully verified; otherwise it will throw an * exception. * * Verification of a package can take significant time, so this * function should not be called from a UI thread. Interrupting * the thread while this function is in progress will result in a * SecurityException being thrown (and the thread's interrupt flag * will be cleared). * * @param packageFile the package to be verified * @param listener an object to receive periodic progress * updates as verification proceeds. May be null. * @param deviceCertsZipFile the zip file of certificates whose * public keys we will accept. Verification succeeds if the * package is signed by the private key corresponding to any * public key in this file. May be null to use the system default * file (currently "/system/etc/security/otacerts.zip"). * * @throws IOException if there were any errors reading the * package or certs files. * @throws GeneralSecurityException if verification failed */ public static void verifyPackage(File packageFile, ProgressListener listener, File deviceCertsZipFile) throws IOException, GeneralSecurityException { final long fileLen = packageFile.length(); final RandomAccessFile raf = new RandomAccessFile(packageFile, "r"); try { final long startTimeMillis = System.currentTimeMillis(); if (listener != null) { listener.onProgress(0); } raf.seek(fileLen - 6); byte[] footer = new byte[6]; raf.readFully(footer); if (footer[2] != (byte)0xff || footer[3] != (byte)0xff) { throw new SignatureException("no signature in file (no footer)"); } final int commentSize = (footer[4] & 0xff) | ((footer[5] & 0xff) << 8); final int signatureStart = (footer[0] & 0xff) | ((footer[1] & 0xff) << 8); byte[] eocd = new byte[commentSize + 22]; raf.seek(fileLen - (commentSize + 22)); raf.readFully(eocd); // Check that we have found the start of the // end-of-central-directory record. if (eocd[0] != (byte)0x50 || eocd[1] != (byte)0x4b || eocd[2] != (byte)0x05 || eocd[3] != (byte)0x06) { throw new SignatureException("no signature in file (bad footer)"); } for (int i = 4; i < eocd.length-3; ++i) { if (eocd[i ] == (byte)0x50 && eocd[i+1] == (byte)0x4b && eocd[i+2] == (byte)0x05 && eocd[i+3] == (byte)0x06) { throw new SignatureException("EOCD marker found after start of EOCD"); } } // Parse the signature PKCS7 block = new PKCS7(new ByteArrayInputStream(eocd, commentSize+22-signatureStart, signatureStart)); // Take the first certificate from the signature (packages // should contain only one). X509Certificate[] certificates = block.getCertificates(); if (certificates == null || certificates.length == 0) { throw new SignatureException("signature contains no certificates"); } X509Certificate cert = certificates[0]; PublicKey signatureKey = cert.getPublicKey(); SignerInfo[] signerInfos = block.getSignerInfos(); if (signerInfos == null || signerInfos.length == 0) { throw new SignatureException("signature contains no signedData"); } SignerInfo signerInfo = signerInfos[0]; // Check that the public key of the certificate contained // in the package equals one of our trusted public keys. boolean verified = false; HashSet trusted = getTrustedCerts( deviceCertsZipFile == null ? DEFAULT_KEYSTORE : deviceCertsZipFile); for (X509Certificate c : trusted) { if (c.getPublicKey().equals(signatureKey)) { verified = true; break; } } if (!verified) { throw new SignatureException("signature doesn't match any trusted key"); } // The signature cert matches a trusted key. Now verify that // the digest in the cert matches the actual file data. raf.seek(0); final ProgressListener listenerForInner = listener; SignerInfo verifyResult = block.verify(signerInfo, new InputStream() { // The signature covers all of the OTA package except the // archive comment and its 2-byte length. long toRead = fileLen - commentSize - 2; long soFar = 0; int lastPercent = 0; long lastPublishTime = startTimeMillis; @Override public int read() throws IOException { throw new UnsupportedOperationException(); } @Override public int read(byte[] b, int off, int len) throws IOException { if (soFar >= toRead) { return -1; } if (Thread.currentThread().isInterrupted()) { return -1; } int size = len; if (soFar + size > toRead) { size = (int)(toRead - soFar); } int read = raf.read(b, off, size); soFar += read; if (listenerForInner != null) { long now = System.currentTimeMillis(); int p = (int)(soFar * 100 / toRead); if (p > lastPercent && now - lastPublishTime > PUBLISH_PROGRESS_INTERVAL_MS) { lastPercent = p; lastPublishTime = now; listenerForInner.onProgress(lastPercent); } } return read; } }); final boolean interrupted = Thread.interrupted(); if (listener != null) { listener.onProgress(100); } if (interrupted) { throw new SignatureException("verification was interrupted"); } if (verifyResult == null) { throw new SignatureException("signature digest verification failed"); } } finally { raf.close(); } } /** * Process a given package with uncrypt. No-op if the package is not on the * /data partition. * * @param Context the Context to use * @param packageFile the package to be processed * @param listener an object to receive periodic progress updates as * processing proceeds. May be null. * @param handler the Handler upon which the callbacks will be * executed. * * @throws IOException if there were any errors processing the package file. * * @hide */ @SystemApi public static void processPackage(Context context, File packageFile, final ProgressListener listener, final Handler handler) throws IOException { String filename = packageFile.getCanonicalPath(); if (!filename.startsWith("/data/")) { return; } RecoverySystem rs = (RecoverySystem) context.getSystemService(Context.RECOVERY_SERVICE); IRecoverySystemProgressListener progressListener = null; if (listener != null) { final Handler progressHandler; if (handler != null) { progressHandler = handler; } else { progressHandler = new Handler(context.getMainLooper()); } progressListener = new IRecoverySystemProgressListener.Stub() { int lastProgress = 0; long lastPublishTime = System.currentTimeMillis(); @Override public void onProgress(final int progress) { final long now = System.currentTimeMillis(); progressHandler.post(new Runnable() { @Override public void run() { if (progress > lastProgress && now - lastPublishTime > PUBLISH_PROGRESS_INTERVAL_MS) { lastProgress = progress; lastPublishTime = now; listener.onProgress(progress); } } }); } }; } if (!rs.uncrypt(filename, progressListener)) { throw new IOException("process package failed"); } } /** * Process a given package with uncrypt. No-op if the package is not on the * /data partition. * * @param Context the Context to use * @param packageFile the package to be processed * @param listener an object to receive periodic progress updates as * processing proceeds. May be null. * * @throws IOException if there were any errors processing the package file. * * @hide */ @SystemApi public static void processPackage(Context context, File packageFile, final ProgressListener listener) throws IOException { processPackage(context, packageFile, listener, null); } /** * Reboots the device in order to install the given update * package. * Requires the {@link android.Manifest.permission#REBOOT} permission. * * @param context the Context to use * @param packageFile the update package to install. Must be on * a partition mountable by recovery. (The set of partitions * known to recovery may vary from device to device. Generally, * /cache and /data are safe.) * * @throws IOException if writing the recovery command file * fails, or if the reboot itself fails. */ public static void installPackage(Context context, File packageFile) throws IOException { installPackage(context, packageFile, false); } /** * If the package hasn't been processed (i.e. uncrypt'd), set up * UNCRYPT_PACKAGE_FILE and delete BLOCK_MAP_FILE to trigger uncrypt during the * reboot. * * @param context the Context to use * @param packageFile the update package to install. Must be on a * partition mountable by recovery. * @param processed if the package has been processed (uncrypt'd). * * @throws IOException if writing the recovery command file fails, or if * the reboot itself fails. * * @hide */ @SystemApi public static void installPackage(Context context, File packageFile, boolean processed) throws IOException { synchronized (sRequestLock) { LOG_FILE.delete(); // Must delete the file in case it was created by system server. UNCRYPT_PACKAGE_FILE.delete(); String filename = packageFile.getCanonicalPath(); Log.w(TAG, "!!! REBOOTING TO INSTALL " + filename + " !!!"); // If the package name ends with "_s.zip", it's a security update. boolean securityUpdate = filename.endsWith("_s.zip"); // If the package is on the /data partition, the package needs to // be processed (i.e. uncrypt'd). The caller specifies if that has // been done in 'processed' parameter. if (filename.startsWith("/data/")) { if (processed) { if (!BLOCK_MAP_FILE.exists()) { Log.e(TAG, "Package claimed to have been processed but failed to find " + "the block map file."); throw new IOException("Failed to find block map file"); } } else { FileWriter uncryptFile = new FileWriter(UNCRYPT_PACKAGE_FILE); try { uncryptFile.write(filename + "\n"); } finally { uncryptFile.close(); } // UNCRYPT_PACKAGE_FILE needs to be readable and writable // by system server. if (!UNCRYPT_PACKAGE_FILE.setReadable(true, false) || !UNCRYPT_PACKAGE_FILE.setWritable(true, false)) { Log.e(TAG, "Error setting permission for " + UNCRYPT_PACKAGE_FILE); } BLOCK_MAP_FILE.delete(); } // If the package is on the /data partition, use the block map // file as the package name instead. filename = "@/cache/recovery/block.map"; } final String filenameArg = "--update_package=" + filename + "\n"; final String localeArg = "--locale=" + Locale.getDefault().toString() + "\n"; final String securityArg = "--security\n"; String command = filenameArg + localeArg; if (securityUpdate) { command += securityArg; } RecoverySystem rs = (RecoverySystem) context.getSystemService( Context.RECOVERY_SERVICE); if (!rs.setupBcb(command)) { throw new IOException("Setup BCB failed"); } // Having set up the BCB (bootloader control block), go ahead and reboot PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE); pm.reboot(PowerManager.REBOOT_RECOVERY_UPDATE); throw new IOException("Reboot failed (no permissions?)"); } } /** * Schedule to install the given package on next boot. The caller needs to * ensure that the package must have been processed (uncrypt'd) if needed. * It sets up the command in BCB (bootloader control block), which will * be read by the bootloader and the recovery image. * * @param Context the Context to use. * @param packageFile the package to be installed. * * @throws IOException if there were any errors setting up the BCB. * * @hide */ @SystemApi public static void scheduleUpdateOnBoot(Context context, File packageFile) throws IOException { String filename = packageFile.getCanonicalPath(); boolean securityUpdate = filename.endsWith("_s.zip"); // If the package is on the /data partition, use the block map file as // the package name instead. if (filename.startsWith("/data/")) { filename = "@/cache/recovery/block.map"; } final String filenameArg = "--update_package=" + filename + "\n"; final String localeArg = "--locale=" + Locale.getDefault().toString() + "\n"; final String securityArg = "--security\n"; String command = filenameArg + localeArg; if (securityUpdate) { command += securityArg; } RecoverySystem rs = (RecoverySystem) context.getSystemService(Context.RECOVERY_SERVICE); if (!rs.setupBcb(command)) { throw new IOException("schedule update on boot failed"); } } /** * Cancel any scheduled update by clearing up the BCB (bootloader control * block). * * @param Context the Context to use. * * @throws IOException if there were any errors clearing up the BCB. * * @hide */ @SystemApi public static void cancelScheduledUpdate(Context context) throws IOException { RecoverySystem rs = (RecoverySystem) context.getSystemService(Context.RECOVERY_SERVICE); if (!rs.clearBcb()) { throw new IOException("cancel scheduled update failed"); } } /** * Reboots the device and wipes the user data and cache * partitions. This is sometimes called a "factory reset", which * is something of a misnomer because the system partition is not * restored to its factory state. Requires the * {@link android.Manifest.permission#REBOOT} permission. * * @param context the Context to use * * @throws IOException if writing the recovery command file * fails, or if the reboot itself fails. * @throws SecurityException if the current user is not allowed to wipe data. */ public static void rebootWipeUserData(Context context) throws IOException { rebootWipeUserData(context, false, context.getPackageName()); } /** {@hide} */ public static void rebootWipeUserData(Context context, String reason) throws IOException { rebootWipeUserData(context, false, reason); } /** {@hide} */ public static void rebootWipeUserData(Context context, boolean shutdown) throws IOException { rebootWipeUserData(context, shutdown, context.getPackageName()); } /** * Reboots the device and wipes the user data and cache * partitions. This is sometimes called a "factory reset", which * is something of a misnomer because the system partition is not * restored to its factory state. Requires the * {@link android.Manifest.permission#REBOOT} permission. * * @param context the Context to use * @param shutdown if true, the device will be powered down after * the wipe completes, rather than being rebooted * back to the regular system. * * @throws IOException if writing the recovery command file * fails, or if the reboot itself fails. * @throws SecurityException if the current user is not allowed to wipe data. * * @hide */ public static void rebootWipeUserData(Context context, boolean shutdown, String reason) throws IOException { UserManager um = (UserManager) context.getSystemService(Context.USER_SERVICE); if (um.hasUserRestriction(UserManager.DISALLOW_FACTORY_RESET)) { throw new SecurityException("Wiping data is not allowed for this user."); } final ConditionVariable condition = new ConditionVariable(); Intent intent = new Intent("android.intent.action.MASTER_CLEAR_NOTIFICATION"); intent.addFlags(Intent.FLAG_RECEIVER_FOREGROUND); context.sendOrderedBroadcastAsUser(intent, UserHandle.SYSTEM, android.Manifest.permission.MASTER_CLEAR, new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { condition.open(); } }, null, 0, null, null); // Block until the ordered broadcast has completed. condition.block(); String shutdownArg = null; if (shutdown) { shutdownArg = "--shutdown_after"; } String reasonArg = null; if (!TextUtils.isEmpty(reason)) { reasonArg = "--reason=" + sanitizeArg(reason); } final String localeArg = "--locale=" + Locale.getDefault().toString(); bootCommand(context, shutdownArg, "--wipe_data", reasonArg, localeArg); } /** * Reboot into the recovery system to wipe the /cache partition. * @throws IOException if something goes wrong. */ public static void rebootWipeCache(Context context) throws IOException { rebootWipeCache(context, context.getPackageName()); } /** {@hide} */ public static void rebootWipeCache(Context context, String reason) throws IOException { String reasonArg = null; if (!TextUtils.isEmpty(reason)) { reasonArg = "--reason=" + sanitizeArg(reason); } final String localeArg = "--locale=" + Locale.getDefault().toString(); bootCommand(context, "--wipe_cache", reasonArg, localeArg); } /** * Reboot into the recovery system with the supplied argument. * @param args to pass to the recovery utility. * @throws IOException if something goes wrong. */ private static void bootCommand(Context context, String... args) throws IOException { synchronized (sRequestLock) { LOG_FILE.delete(); StringBuilder command = new StringBuilder(); for (String arg : args) { if (!TextUtils.isEmpty(arg)) { command.append(arg); command.append("\n"); } } // Write the command into BCB (bootloader control block). RecoverySystem rs = (RecoverySystem) context.getSystemService( Context.RECOVERY_SERVICE); rs.setupBcb(command.toString()); // Having set up the BCB, go ahead and reboot. PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE); pm.reboot(PowerManager.REBOOT_RECOVERY); throw new IOException("Reboot failed (no permissions?)"); } } // Read last_install; then report time (in seconds) and I/O (in MiB) for // this update to tron. // Only report on the reboots immediately after an OTA update. private static void parseLastInstallLog(Context context) { try (BufferedReader in = new BufferedReader(new FileReader(LAST_INSTALL_FILE))) { String line = null; int bytesWrittenInMiB = -1, bytesStashedInMiB = -1; int timeTotal = -1; int sourceVersion = -1; while ((line = in.readLine()) != null) { // Here is an example of lines in last_install: // ... // time_total: 101 // bytes_written_vendor: 51074 // bytes_stashed_vendor: 200 int numIndex = line.indexOf(':'); if (numIndex == -1 || numIndex + 1 >= line.length()) { continue; } String numString = line.substring(numIndex + 1).trim(); long parsedNum; try { parsedNum = Long.parseLong(numString); } catch (NumberFormatException ignored) { Log.e(TAG, "Failed to parse numbers in " + line); continue; } final int MiB = 1024 * 1024; int scaled; try { if (line.startsWith("bytes")) { scaled = Math.toIntExact(parsedNum / MiB); } else { scaled = Math.toIntExact(parsedNum); } } catch (ArithmeticException ignored) { Log.e(TAG, "Number overflows in " + line); continue; } if (line.startsWith("time")) { timeTotal = scaled; } else if (line.startsWith("source_build")) { sourceVersion = scaled; } else if (line.startsWith("bytes_written")) { bytesWrittenInMiB = (bytesWrittenInMiB == -1) ? scaled : bytesWrittenInMiB + scaled; } else if (line.startsWith("bytes_stashed")) { bytesStashedInMiB = (bytesStashedInMiB == -1) ? scaled : bytesStashedInMiB + scaled; } } // Don't report data to tron if corresponding entry isn't found in last_install. if (timeTotal != -1) { MetricsLogger.histogram(context, "ota_time_total", timeTotal); } if (sourceVersion != -1) { MetricsLogger.histogram(context, "ota_source_version", sourceVersion); } if (bytesWrittenInMiB != -1) { MetricsLogger.histogram(context, "ota_written_in_MiBs", bytesWrittenInMiB); } if (bytesStashedInMiB != -1) { MetricsLogger.histogram(context, "ota_stashed_in_MiBs", bytesStashedInMiB); } } catch (IOException e) { Log.e(TAG, "Failed to read lines in last_install", e); } } /** * Called after booting to process and remove recovery-related files. * @return the log file from recovery, or null if none was found. * * @hide */ public static String handleAftermath(Context context) { // Record the tail of the LOG_FILE String log = null; try { log = FileUtils.readTextFile(LOG_FILE, -LOG_FILE_MAX_LENGTH, "...\n"); } catch (FileNotFoundException e) { Log.i(TAG, "No recovery log file"); } catch (IOException e) { Log.e(TAG, "Error reading recovery log", e); } if (log != null) { parseLastInstallLog(context); } // Only remove the OTA package if it's partially processed (uncrypt'd). boolean reservePackage = BLOCK_MAP_FILE.exists(); if (!reservePackage && UNCRYPT_PACKAGE_FILE.exists()) { String filename = null; try { filename = FileUtils.readTextFile(UNCRYPT_PACKAGE_FILE, 0, null); } catch (IOException e) { Log.e(TAG, "Error reading uncrypt file", e); } // Remove the OTA package on /data that has been (possibly // partially) processed. (Bug: 24973532) if (filename != null && filename.startsWith("/data")) { if (UNCRYPT_PACKAGE_FILE.delete()) { Log.i(TAG, "Deleted: " + filename); } else { Log.e(TAG, "Can't delete: " + filename); } } } // We keep the update logs (beginning with LAST_PREFIX), and optionally // the block map file (BLOCK_MAP_FILE) for a package. BLOCK_MAP_FILE // will be created at the end of a successful uncrypt. If seeing this // file, we keep the block map file and the file that contains the // package name (UNCRYPT_PACKAGE_FILE). This is to reduce the work for // GmsCore to avoid re-downloading everything again. String[] names = RECOVERY_DIR.list(); for (int i = 0; names != null && i < names.length; i++) { if (names[i].startsWith(LAST_PREFIX)) continue; if (reservePackage && names[i].equals(BLOCK_MAP_FILE.getName())) continue; if (reservePackage && names[i].equals(UNCRYPT_PACKAGE_FILE.getName())) continue; recursiveDelete(new File(RECOVERY_DIR, names[i])); } return log; } /** * Internally, delete a given file or directory recursively. */ private static void recursiveDelete(File name) { if (name.isDirectory()) { String[] files = name.list(); for (int i = 0; files != null && i < files.length; i++) { File f = new File(name, files[i]); recursiveDelete(f); } } if (!name.delete()) { Log.e(TAG, "Can't delete: " + name); } else { Log.i(TAG, "Deleted: " + name); } } /** * Talks to RecoverySystemService via Binder to trigger uncrypt. */ private boolean uncrypt(String packageFile, IRecoverySystemProgressListener listener) { try { return mService.uncrypt(packageFile, listener); } catch (RemoteException unused) { } return false; } /** * Talks to RecoverySystemService via Binder to set up the BCB. */ private boolean setupBcb(String command) { try { return mService.setupBcb(command); } catch (RemoteException unused) { } return false; } /** * Talks to RecoverySystemService via Binder to clear up the BCB. */ private boolean clearBcb() { try { return mService.clearBcb(); } catch (RemoteException unused) { } return false; } /** * Internally, recovery treats each line of the command file as a separate * argv, so we only need to protect against newlines and nulls. */ private static String sanitizeArg(String arg) { arg = arg.replace('\0', '?'); arg = arg.replace('\n', '?'); return arg; } /** * @removed Was previously made visible by accident. */ public RecoverySystem() { mService = null; } /** * @hide */ public RecoverySystem(IRecoverySystem service) { mService = service; } }