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Delete SecureRandomInitializer

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See
https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html

Android JellyBean (4.3) required a workaround for SecureRandom
initialization, which is no longer required as it was fixed in KitKat
(4.4) and we no longer support JellyBean.

Given we were previously initializing SecureRandom on a background
thread, I did some brief investigation into performance.

On my Pixel 3a:
Creating SecureRandom takes 0.2-1ms
Getting the first random number (which sets the seed) takes 0.03-0.1ms
Further random numbers take ~7us

Change-Id: I2a93d2607e86b488227feead5fdaaffa73ebe417
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2852318
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Joe Downing <joedow@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#876694}
This commit is contained in:
Michael Thiessen
2021-04-27 19:06:08 +00:00
committed by Chromium LUCI CQ
parent b824c0ba33
commit aedbb74f94
6 changed files with 2 additions and 98 deletions
base
BUILD.gn
android
java
src
org
chromium
base
SecureRandomInitializer.java
chrome
android
java
src
org
chromium
chrome
browser
externalnav
IntentWithRequestMetadataHandler.java
webapps
WebappAuthenticator.java
browser
android
crypto
java
src
org
chromium
chrome
browser
crypto
CipherFactory.java
remoting/android/java/src/org/chromium/chromoting
ThirdPartyTokenFetcher.java

1
base/BUILD.gn

@ -3849,7 +3849,6 @@ if (is_android) {
"android/java/src/org/chromium/base/PowerMonitor.java",
"android/java/src/org/chromium/base/Promise.java",
"android/java/src/org/chromium/base/RadioUtils.java",
"android/java/src/org/chromium/base/SecureRandomInitializer.java",
"android/java/src/org/chromium/base/StreamUtil.java",
"android/java/src/org/chromium/base/StrictModeContext.java",
"android/java/src/org/chromium/base/SysUtils.java",

35
base/android/java/src/org/chromium/base/SecureRandomInitializer.java

@ -1,35 +0,0 @@
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.base;
import android.annotation.SuppressLint;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.SecureRandom;
/**
* This class contains code to initialize a SecureRandom generator securely on Android platforms
* <= 4.3. See
* {@link http://android-developers.blogspot.com/2013/08/some-securerandom-thoughts.html}.
*/
// TODO(crbug.com/635567): Fix this properly.
@SuppressLint("SecureRandom")
public class SecureRandomInitializer {
private static final int NUM_RANDOM_BYTES = 16;
/**
* Safely initializes the random number generator, by seeding it with data from /dev/urandom.
*/
public static void initialize(SecureRandom generator) throws IOException {
try (FileInputStream fis = new FileInputStream("/dev/urandom")) {
byte[] seedBytes = new byte[NUM_RANDOM_BYTES];
if (fis.read(seedBytes) != seedBytes.length) {
throw new IOException("Failed to get enough random data.");
}
generator.setSeed(seedBytes);
}
}
}

38
chrome/android/java/src/org/chromium/chrome/browser/externalnav/IntentWithRequestMetadataHandler.java

@ -4,23 +4,16 @@
package org.chromium.chrome.browser.externalnav;
import android.annotation.SuppressLint;
import android.content.Intent;
import androidx.annotation.Nullable;
import org.chromium.base.IntentUtils;
import org.chromium.base.Log;
import org.chromium.base.SecureRandomInitializer;
import org.chromium.base.task.AsyncTask;
import org.chromium.base.task.BackgroundOnlyAsyncTask;
import org.chromium.chrome.browser.IntentHandler;
import org.chromium.url.Origin;
import java.io.IOException;
import java.security.SecureRandom;
import java.util.Arrays;
import java.util.concurrent.ExecutionException;
/**
* This class generates a token for the most recently launched external intent that has
@ -42,8 +35,7 @@ public class IntentWithRequestMetadataHandler {
private static final Object INSTANCE_LOCK = new Object();
private static IntentWithRequestMetadataHandler sIntentWithRequestMetadataHandler;
private SecureRandom mSecureRandom;
private AsyncTask<SecureRandom> mSecureRandomInitializer;
private SecureRandom mSecureRandom = new SecureRandom();
private RequestMetadata mRequestMetadata;
private byte[] mIntentToken;
private String mUri;
@ -89,25 +81,6 @@ public class IntentWithRequestMetadataHandler {
return sIntentWithRequestMetadataHandler;
}
private IntentWithRequestMetadataHandler() {
mSecureRandomInitializer = new BackgroundOnlyAsyncTask<SecureRandom>() {
// SecureRandomInitializer addresses the bug in SecureRandom that "TrulyRandom"
// warns about, so this lint warning can safely be suppressed.
@SuppressLint("TrulyRandom")
@Override
protected SecureRandom doInBackground() {
SecureRandom secureRandom = null;
try {
secureRandom = new SecureRandom();
SecureRandomInitializer.initialize(secureRandom);
} catch (IOException ioe) {
Log.e(TAG, "Cannot initialize SecureRandom", ioe);
}
return secureRandom;
}
}.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
}
/**
* Generate a new token for the intent and put the token and request metadata in the
* intent extra. This will invalidate the token on the previously launched intent with request
@ -117,15 +90,6 @@ public class IntentWithRequestMetadataHandler {
* @param metadata Request metadata to be put into the intent extra.
*/
public void onNewIntentWithRequestMetadata(Intent intent, RequestMetadata metadata) {
if (mSecureRandomInitializer != null) {
try {
mSecureRandom = mSecureRandomInitializer.get();
} catch (InterruptedException | ExecutionException e) {
Log.e(TAG, "Error fetching SecureRandom", e);
}
mSecureRandomInitializer = null;
}
if (mSecureRandom == null) return;
mIntentToken = new byte[32];
mSecureRandom.nextBytes(mIntentToken);
intent.putExtra(EXTRA_REQUEST_METADATA_TOKEN, mIntentToken);

8
chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappAuthenticator.java

@ -4,13 +4,11 @@
package org.chromium.chrome.browser.webapps;
import android.annotation.SuppressLint;
import android.content.Context;
import android.util.Log;
import org.chromium.base.ApiCompatibilityUtils;
import org.chromium.base.ContextUtils;
import org.chromium.base.SecureRandomInitializer;
import org.chromium.base.StrictModeContext;
import java.io.File;
@ -178,10 +176,7 @@ public class WebappAuthenticator {
/**
* Generates the authentication encryption key in a background thread (if necessary).
* SecureRandomInitializer addresses the bug in SecureRandom that "TrulyRandom" warns about, so
* this lint warning can safely be suppressed.
*/
@SuppressLint("TrulyRandom")
private static SecretKey generateMacKey() {
if (sKey != null) {
return sKey;
@ -189,10 +184,9 @@ public class WebappAuthenticator {
try {
KeyGenerator generator = KeyGenerator.getInstance(MAC_ALGORITHM_NAME);
SecureRandom random = new SecureRandom();
SecureRandomInitializer.initialize(random);
generator.init(MAC_KEY_BYTE_COUNT * 8, random);
return generator.generateKey();
} catch (NoSuchAlgorithmException | IOException e) {
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException(e);
}
}

9
chrome/browser/android/crypto/java/src/org/chromium/chrome/browser/crypto/CipherFactory.java

@ -4,7 +4,6 @@
package org.chromium.chrome.browser.crypto;
import android.annotation.SuppressLint;
import android.os.Bundle;
import androidx.annotation.AnyThread;
@ -13,7 +12,6 @@ import androidx.annotation.VisibleForTesting;
import org.chromium.base.ByteArrayGenerator;
import org.chromium.base.Log;
import org.chromium.base.ObserverList;
import org.chromium.base.SecureRandomInitializer;
import org.chromium.base.task.AsyncTask;
import org.chromium.base.task.PostTask;
import org.chromium.content_public.browser.UiThreadTaskTraits;
@ -193,9 +191,6 @@ public class CipherFactory {
*/
private Callable<CipherData> createGeneratorCallable() {
return new Callable<CipherData>() {
// SecureRandomInitializer addresses the bug in SecureRandom that "TrulyRandom"
// warns about, so this lint warning can safely be suppressed.
@SuppressLint("TrulyRandom")
@Override
public CipherData call() {
// Poll random data to generate initialization parameters for the Cipher.
@ -212,14 +207,10 @@ public class CipherFactory {
try {
SecureRandom random = new SecureRandom();
SecureRandomInitializer.initialize(random);
KeyGenerator generator = KeyGenerator.getInstance("AES");
generator.init(128, random);
return new CipherData(generator.generateKey(), iv);
} catch (IOException e) {
Log.e(TAG, "Couldn't get generator data.");
return null;
} catch (GeneralSecurityException e) {
Log.e(TAG, "Couldn't get generator instances.");
return null;

9
remoting/android/java/src/org/chromium/chromoting/ThirdPartyTokenFetcher.java

@ -4,7 +4,6 @@
package org.chromium.chromoting;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.ComponentName;
@ -16,9 +15,7 @@ import android.util.Base64;
import org.chromium.base.ContextUtils;
import org.chromium.base.Log;
import org.chromium.base.SecureRandomInitializer;
import java.io.IOException;
import java.security.SecureRandom;
import java.util.ArrayList;
@ -46,18 +43,12 @@ public class ThirdPartyTokenFetcher {
private static final String RESPONSE_TYPE = "code token";
/** This is used to securely generate an opaque 128 bit for the |mState| variable. */
@SuppressLint("TrulyRandom")
private static SecureRandom sSecureRandom;
// TODO(lambroslambrou): Refactor this class to only initialize a PRNG when ThirdPartyAuth is
// actually used.
static {
sSecureRandom = new SecureRandom();
try {
SecureRandomInitializer.initialize(sSecureRandom);
} catch (IOException e) {
throw new RuntimeException("Failed to initialize PRNG: " + e);
}
}
/** This is used to launch the third party login page in the browser. */