Merge "EntropyMixer: Write entropy at shutdown / reboot / power" into jb-mr2-dev (0841c4cb) · Commits · e / os / android_frameworks_base

services/java/com/android/server/EntropyMixer.java

+19 −6

Original line number	Diff line number	Diff line
		@@ -23,6 +23,10 @@ import java.io.IOException;
		import java.io.OutputStream;
		import java.io.PrintWriter;

		import android.content.BroadcastReceiver;
		import android.content.Context;
		import android.content.Intent;
		import android.content.IntentFilter;
		import android.os.Binder;
		import android.os.Environment;
		import android.os.Handler;
		@@ -44,9 +48,6 @@ import android.util.Slog;
		* <p>This class was modeled after the script in
		* <a href="http://www.kernel.org/doc/man-pages/online/pages/man4/random.4.html">man
		* 4 random</a>.
		*
		* <p>TODO: Investigate attempting to write entropy data at shutdown time
		* instead of periodically.
		*/
		public class EntropyMixer extends Binder {
		private static final String TAG = "EntropyMixer";
		@@ -73,12 +74,19 @@ public class EntropyMixer extends Binder {
		}
		};

		public EntropyMixer() {
		this(getSystemDir() + "/entropy.dat", "/dev/urandom");
		private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
		@Override
		public void onReceive(Context context, Intent intent) {
		writeEntropy();
		}
		};

		public EntropyMixer(Context context) {
		this(context, getSystemDir() + "/entropy.dat", "/dev/urandom");
		}

		/** Test only interface, not for public use */
		public EntropyMixer(String entropyFile, String randomDevice) {
		public EntropyMixer(Context context, String entropyFile, String randomDevice) {
		if (randomDevice == null) { throw new NullPointerException("randomDevice"); }
		if (entropyFile == null) { throw new NullPointerException("entropyFile"); }

		@@ -88,6 +96,10 @@ public class EntropyMixer extends Binder {
		addDeviceSpecificEntropy();
		writeEntropy();
		scheduleEntropyWriter();
		IntentFilter broadcastFilter = new IntentFilter(Intent.ACTION_SHUTDOWN);
		broadcastFilter.addAction(Intent.ACTION_POWER_CONNECTED);
		broadcastFilter.addAction(Intent.ACTION_REBOOT);
		context.registerReceiver(mBroadcastReceiver, broadcastFilter);
		}

		private void scheduleEntropyWriter() {
		@@ -107,6 +119,7 @@ public class EntropyMixer extends Binder {

		private void writeEntropy() {
		try {
		Slog.i(TAG, "Writing entropy...");
		RandomBlock.fromFile(randomDevice).toFile(entropyFile, true);
		} catch (IOException e) {
		Slog.w(TAG, "Unable to write entropy", e);

services/java/com/android/server/SystemServer.java

+3 −3

Original line number	Diff line number	Diff line
		@@ -206,9 +206,6 @@ class ServerThread extends Thread {
		installer = new Installer();
		installer.ping();

		Slog.i(TAG, "Entropy Mixer");
		ServiceManager.addService("entropy", new EntropyMixer());

		Slog.i(TAG, "Power Manager");
		power = new PowerManagerService();
		ServiceManager.addService(Context.POWER_SERVICE, power);
		@@ -257,6 +254,9 @@ class ServerThread extends Thread {

		ActivityManagerService.setSystemProcess();

		Slog.i(TAG, "Entropy Mixer");
		ServiceManager.addService("entropy", new EntropyMixer(context));

		Slog.i(TAG, "User Service");
		ServiceManager.addService(Context.USER_SERVICE,
		UserManagerService.getInstance());

services/tests/servicestests/src/com/android/server/EntropyMixerTest.java

+1 −1

Original line number	Diff line number	Diff line
		@@ -34,7 +34,7 @@ public class EntropyMixerTest extends AndroidTestCase {
		assertEquals(0, FileUtils.readTextFile(file, 0, null).length());

		// The constructor has the side effect of writing to file
		new EntropyMixer("/dev/null", file.getCanonicalPath());
		new EntropyMixer(getContext(), "/dev/null", file.getCanonicalPath());

		assertTrue(FileUtils.readTextFile(file, 0, null).length() > 0);
		}