1 files changed, 0 insertions, 177 deletions
diff --git a/services/java/com/android/server/EntropyMixer.java b/services/java/com/android/server/EntropyMixer.java
deleted file mode 100644
index fbb66f9..0000000
--- a/services/java/com/android/server/EntropyMixer.java
+++ /dev/null
@@ -1,177 +0,0 @@
-/*
- * Copyright (C) 2009 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 com.android.server;
-
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-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;
-import android.os.Message;
-import android.os.SystemProperties;
-import android.util.Slog;
-
-/**
- * A service designed to load and periodically save &quot;randomness&quot;
- * for the Linux kernel.
- *
- * <p>When a Linux system starts up, the entropy pool associated with
- * {@code /dev/random} may be in a fairly predictable state.  Applications which
- * depend strongly on randomness may find {@code /dev/random} or
- * {@code /dev/urandom} returning predictable data.  In order to counteract
- * this effect, it's helpful to carry the entropy pool information across
- * shutdowns and startups.
- *
- * <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>.
- */
-public class EntropyMixer extends Binder {
-    private static final String TAG = "EntropyMixer";
-    private static final int ENTROPY_WHAT = 1;
-    private static final int ENTROPY_WRITE_PERIOD = 3 * 60 * 60 * 1000;  // 3 hrs
-    private static final long START_TIME = System.currentTimeMillis();
-    private static final long START_NANOTIME = System.nanoTime();
-
-    private final String randomDevice;
-    private final String entropyFile;
-
-    /**
-     * Handler that periodically updates the entropy on disk.
-     */
-    private final Handler mHandler = new Handler() {
-        @Override
-        public void handleMessage(Message msg) {
-            if (msg.what != ENTROPY_WHAT) {
-                Slog.e(TAG, "Will not process invalid message");
-                return;
-            }
-            writeEntropy();
-            scheduleEntropyWriter();
-        }
-    };
-
-    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(Context context, String entropyFile, String randomDevice) {
-        if (randomDevice == null) { throw new NullPointerException("randomDevice"); }
-        if (entropyFile == null) { throw new NullPointerException("entropyFile"); }
-
-        this.randomDevice = randomDevice;
-        this.entropyFile = entropyFile;
-        loadInitialEntropy();
-        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() {
-        mHandler.removeMessages(ENTROPY_WHAT);
-        mHandler.sendEmptyMessageDelayed(ENTROPY_WHAT, ENTROPY_WRITE_PERIOD);
-    }
-
-    private void loadInitialEntropy() {
-        try {
-            RandomBlock.fromFile(entropyFile).toFile(randomDevice, false);
-        } catch (FileNotFoundException e) {
-            Slog.w(TAG, "No existing entropy file -- first boot?");
-        } catch (IOException e) {
-            Slog.w(TAG, "Failure loading existing entropy file", e);
-        }
-    }
-
-    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);
-        }
-    }
-
-    /**
-     * Add additional information to the kernel entropy pool.  The
-     * information isn't necessarily "random", but that's ok.  Even
-     * sending non-random information to {@code /dev/urandom} is useful
-     * because, while it doesn't increase the "quality" of the entropy pool,
-     * it mixes more bits into the pool, which gives us a higher degree
-     * of uncertainty in the generated randomness.  Like nature, writes to
-     * the random device can only cause the quality of the entropy in the
-     * kernel to stay the same or increase.
-     *
-     * <p>For maximum effect, we try to target information which varies
-     * on a per-device basis, and is not easily observable to an
-     * attacker.
-     */
-    private void addDeviceSpecificEntropy() {
-        PrintWriter out = null;
-        try {
-            out = new PrintWriter(new FileOutputStream(randomDevice));
-            out.println("Copyright (C) 2009 The Android Open Source Project");
-            out.println("All Your Randomness Are Belong To Us");
-            out.println(START_TIME);
-            out.println(START_NANOTIME);
-            out.println(SystemProperties.get("ro.serialno"));
-            out.println(SystemProperties.get("ro.bootmode"));
-            out.println(SystemProperties.get("ro.baseband"));
-            out.println(SystemProperties.get("ro.carrier"));
-            out.println(SystemProperties.get("ro.bootloader"));
-            out.println(SystemProperties.get("ro.hardware"));
-            out.println(SystemProperties.get("ro.revision"));
-            out.println(SystemProperties.get("ro.build.fingerprint"));
-            out.println(new Object().hashCode());
-            out.println(System.currentTimeMillis());
-            out.println(System.nanoTime());
-        } catch (IOException e) {
-            Slog.w(TAG, "Unable to add device specific data to the entropy pool", e);
-        } finally {
-            if (out != null) {
-                out.close();
-            }
-        }
-    }
-
-    private static String getSystemDir() {
-        File dataDir = Environment.getDataDirectory();
-        File systemDir = new File(dataDir, "system");
-        systemDir.mkdirs();
-        return systemDir.toString();
-    }
-}