From dda75006e4e88320dfe8c4c274381aa30c6066ca Mon Sep 17 00:00:00 2001
From: Moxie Marlinspike <moxie@thoughtcrime.org>
Date: Sun, 5 Aug 2012 19:03:14 -0700
Subject: [PATCH] Remove some logging that could result in an information leak.

---
 .../securesms/protocol/WirePrefix.java        | 61 ++++++++-----------
 1 file changed, 27 insertions(+), 34 deletions(-)

diff --git a/src/org/thoughtcrime/securesms/protocol/WirePrefix.java b/src/org/thoughtcrime/securesms/protocol/WirePrefix.java
index ae9cd01ca..6561d1d8c 100644
--- a/src/org/thoughtcrime/securesms/protocol/WirePrefix.java
+++ b/src/org/thoughtcrime/securesms/protocol/WirePrefix.java
@@ -1,6 +1,6 @@
-/** 
+/**
  * Copyright (C) 2011 Whisper Systems
- * 
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
@@ -10,49 +10,47 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 package org.thoughtcrime.securesms.protocol;
 
+import org.thoughtcrime.securesms.util.Base64;
+
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 
-import org.thoughtcrime.securesms.util.Base64;
-
-import android.util.Log;
-
 /**
  * Calculates prefixes that identify a message as
  * being part of an encrypted session.  The idea was to
  * make calculating and identifying these prefixes somewhat
  * expensive, so that filtering them en-mass would come at a cost.
- * 
+ *
  * @author Moxie Marlinspike
  */
 
 public abstract class WirePrefix {
-	
+
   private static final int HASH_ITERATIONS = 1000;
   private static final int PREFIX_BYTES    = 3;
   public  static final int PREFIX_SIZE     = 4;
-	
+
   public abstract String calculatePrefix(String message);
-	
+
   public static boolean isKeyExchange(String message) {
     return verifyPrefix("?TSK", message);
   }
-	
+
   public static boolean isEncryptedMessage(String message) {
     return verifyPrefix("?TSM", message);
   }
-	
+
   public static String calculateKeyExchangePrefix(String message) {
     return calculatePrefix(("?TSK" + message).getBytes(), PREFIX_BYTES);
   }
-	
+
   public static String calculateEncryptedMesagePrefix(String message) {
     return calculatePrefix(("?TSM" + message).getBytes(), PREFIX_BYTES);
   }
@@ -60,27 +58,22 @@ public abstract class WirePrefix {
   private static boolean verifyPrefix(String prefixType, String message) {
     if (message.length() <= PREFIX_SIZE)
       return false;
-		
+
     String prefix           = message.substring(0, PREFIX_SIZE);
-    message                 = message.substring(PREFIX_SIZE);	
-		
-    Log.w("Prefix", "Calculating on message: " + message + "**");
-		
+    message                 = message.substring(PREFIX_SIZE);
+
     String calculatedPrefix = calculatePrefix((prefixType + message).getBytes(), PREFIX_BYTES);
-		
+
     assert(calculatedPrefix.length() == PREFIX_SIZE);
-		
-    Log.w("Prefix", "Received prefix: " + prefix);
-    Log.w("Prefix", "Calculated prefix: " + calculatedPrefix);
-		
-    return prefix.equals(calculatedPrefix);				
+
+    return prefix.equals(calculatedPrefix);
   }
-	
+
   private static String calculatePrefix(byte[] message, int byteCount) {
     try {
       MessageDigest md     = MessageDigest.getInstance("SHA1");
       byte[] runningDigest = message;
-			
+
       for (int i=0;i<HASH_ITERATIONS;i++) {
         runningDigest = md.digest(runningDigest);
       }
@@ -88,30 +81,30 @@ public abstract class WirePrefix {
       return Base64.encodeBytes(runningDigest, 0, byteCount);
     } catch (NoSuchAlgorithmException e) {
       throw new AssertionError(e);
-    }		
+    }
   }
-	
+
   public static String calculateEncryptedMmsSubject() {
     try {
       byte[] postfix = new byte[6];
       SecureRandom.getInstance("SHA1PRNG").nextBytes(postfix);
-			
+
       String postfixString = Base64.encodeBytes(postfix);
       String prefix        = calculatePrefix(postfixString.getBytes(), 6);
-			
+
       return prefix + postfixString;
     } catch (NoSuchAlgorithmException e) {
       throw new AssertionError(e);
     }
   }
-	
+
   public static boolean isEncryptedMmsSubject(String subject) {
     if (subject.length() < 9)
       return false;
-		
+
     String prefix  = subject.substring(0, 8);
     String postfix = subject.substring(8);
-		
+
     String calculatedPrefix = calculatePrefix(postfix.getBytes(), 6);
     return calculatedPrefix.equals(prefix);
   }