From 4f8ff39c1e2448d44ac900e04f9348f9d2aeaaf5 Mon Sep 17 00:00:00 2001
From: Doug Zongker <dougz@android.com>
Date: Wed, 3 Feb 2010 10:36:40 -0800
Subject: [PATCH] use device serial number to seed RNG for generating
 ANDROID_ID

Change-Id: I1bcc55f1309cb908803bc42084846a046041eda6
---
 .../providers/settings/SettingsProvider.java        | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
index 265d138641361..4080a6ae76321 100644
--- a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
+++ b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
@@ -17,9 +17,10 @@
 package com.android.providers.settings;
 
 import java.io.FileNotFoundException;
-import java.util.Random;
-import java.security.SecureRandom;
+import java.io.UnsupportedEncodingException;
 import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.Random;
 
 import android.backup.BackupManager;
 import android.content.ContentProvider;
@@ -197,6 +198,14 @@ public class SettingsProvider extends ContentProvider {
             final String value = c.moveToNext() ? c.getString(0) : null;
             if (value == null) {
                 final SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
+                String serial = SystemProperties.get("ro.serialno");
+                if (serial != null) {
+                    try {
+                        random.setSeed(serial.getBytes("UTF-8"));
+                    } catch (UnsupportedEncodingException ignore) {
+                        // stick with default seed
+                    }
+                }
                 final String newAndroidIdValue = Long.toHexString(random.nextLong());
                 Log.d(TAG, "Generated and saved new ANDROID_ID");
                 final ContentValues values = new ContentValues();