honour the pass phrase cache TTL by running a timer and removing expired cached pass phrases

1 files changed, 33 insertions, 5 deletions

diff --git a/src/org/thialfihar/android/apg/BaseActivity.java b/src/org/thialfihar/android/apg/BaseActivity.java
index 70ddb7402..244c4aee6 100644
--- a/src/org/thialfihar/android/apg/BaseActivity.java
+++ b/src/org/thialfihar/android/apg/BaseActivity.java
@@ -17,6 +17,8 @@
 package org.thialfihar.android.apg;

 

 import java.io.File;

+import java.util.Timer;

+import java.util.TimerTask;

 

 import org.bouncycastle2.bcpg.HashAlgorithmTags;

 import org.bouncycastle2.openpgp.PGPEncryptedData;

@@ -50,6 +52,8 @@ public class BaseActivity extends Activity
     private String mDeleteFile = null;

     protected static SharedPreferences mPreferences = null;

 

+    private static Timer mCacheTimer = new Timer();

+

     private Handler mHandler = new Handler() {

         @Override

         public void handleMessage(Message msg) {

@@ -65,6 +69,29 @@ public class BaseActivity extends Activity
             mPreferences = getPreferences(MODE_PRIVATE);

         }

         Apg.initialize(this);

+        if (mCacheTimer == null) {

+            setPassPhraseCacheTimer();

+        }

+    }

+

+    private void setPassPhraseCacheTimer() {

+        if (mCacheTimer != null) {

+            mCacheTimer.cancel();

+            mCacheTimer = null;

+        }

+        int ttl = getPassPhraseCacheTtl();

+        if (ttl == 0) {

+            // no timer needed

+            return;

+        }

+        // check every ttl/2 seconds, which shouldn't be heavy on the device (even if ttl = 15),

+        // and makes sure the longest a pass phrase survives int the cache is 1.5 * ttl

+        mCacheTimer = new Timer();

+        mCacheTimer.scheduleAtFixedRate(new TimerTask() {

+            public void run() {

+                Apg.cleanUpCache(BaseActivity.this.getPassPhraseCacheTtl());

+            }

+        }, 0, ttl * 1000 / 2);

     }

 

     @Override

@@ -98,7 +125,6 @@ public class BaseActivity extends Activity
 

     @Override

     protected Dialog onCreateDialog(int id) {

-

         // in case it is a progress dialog

         mProgressDialog = new ProgressDialog(this);

         mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);

@@ -354,14 +380,16 @@ public class BaseActivity extends Activity
         return mSecretKeyId;

     }

 

-    public int getPassPhraseCache() {

-        return mPreferences.getInt(Constants.pref.pass_phrase_cache_length, 300);

+    public int getPassPhraseCacheTtl() {

+        return mPreferences.getInt(Constants.pref.pass_phrase_cache_ttl, 300);

     }

 

-    public void setPassPhraseCache(int value) {

+    public void setPassPhraseCacheTtl(int value) {

         SharedPreferences.Editor editor = mPreferences.edit();

-        editor.putInt(Constants.pref.pass_phrase_cache_length, value);

+        editor.putInt(Constants.pref.pass_phrase_cache_ttl, value);

         editor.commit();

+

+        setPassPhraseCacheTimer();

     }

 

     public int getDefaultEncryptionAlgorithm() {