Allow to pass large blobs and a new content provider to simplify this

Since AIDL is not for passing large data, a blob can be passed to APG by
a Uri. This Uri is opened as a file by APG and read/written to. Note the
file is overwritten by APG, so make sure it is a copy if you want to
keep the original.

With the ApgServiceBlobProvider, Apg has an own ContentProvider that can
be used like mentioned above. For now the data is stored in the dir
where APG stores other files and NOT DELETED after en/decryption. This
is tbd. It can only be accessed by an application with the permission
"org.thialfihar.android.apg.permission.STORE_BLOBS".

ApgCon has been updated accordingly and can handle blobs with `setBlob`
and `getBlobResult`. That is a really easy way to en/decrypt large data.

Note that encrypting by blob should only be used for large files (1MB+).
On all other cases, the data should be passed as as String through the
AIDl-Interface, so no temporary file must be created.

See ApgCon for a complete example of how to connect to the AIDL and use
it. Or use it in your own project!

1 files changed, 86 insertions, 11 deletions

diff --git a/src/org/thialfihar/android/apg/utils/ApgCon.java b/src/org/thialfihar/android/apg/utils/ApgCon.java
index 475f7e9a9..c46ccf6b1 100644
--- a/src/org/thialfihar/android/apg/utils/ApgCon.java
+++ b/src/org/thialfihar/android/apg/utils/ApgCon.java
@@ -16,22 +16,27 @@
 
 package org.thialfihar.android.apg.utils;
 
-import java.lang.reflect.InvocationTargetException;
-import java.util.ArrayList;
+import org.thialfihar.android.apg.IApgService;
+import org.thialfihar.android.apg.utils.ApgConInterface.OnCallFinishListener;
 
-import android.content.Context;
 import android.content.ComponentName;
-import android.content.ServiceConnection;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
 import android.content.Intent;
+import android.content.ServiceConnection;
 import android.content.pm.PackageManager;
 import android.content.pm.ServiceInfo;
+import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.util.Log;
 
-import org.thialfihar.android.apg.IApgService;
-import org.thialfihar.android.apg.utils.ApgConInterface.OnCallFinishListener;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
 
 /**
  * A APG-AIDL-Wrapper
@@ -46,7 +51,7 @@ import org.thialfihar.android.apg.utils.ApgConInterface.OnCallFinishListener;
  * </p>
  * 
  * @author Markus Doits <markus.doits@googlemail.com>
- * @version 1.0rc1
+ * @version 1.1rc1
  * 
  */
 public class ApgCon {
@@ -54,7 +59,8 @@ public class ApgCon {
     private static final boolean LOCAL_LOGD = true;
 
     private final static String TAG = "ApgCon";
-    private final static int API_VERSION = 1; // aidl api-version it expects
+    private final static int API_VERSION = 2; // aidl api-version it expects
+    private final static String BLOB_URI = "content://org.thialfihar.android.apg.provider.apgserviceblobprovider";
     
     /**
      * How many seconds to wait for a connection to AGP when connecting.
@@ -80,7 +86,6 @@ public class ApgCon {
 
     }
 
-
     private final Context mContext;
     private final error mConnectionStatus;
     private boolean mAsyncRunning = false;
@@ -187,9 +192,9 @@ public class ApgCon {
                             mWarningList.add("(LOCAL) Could not determine ApgService API");
                             tmpError = error.APG_API_MISSMATCH;
                         } else if (inf.metaData.getInt("api_version") != API_VERSION) {
-                            Log.w(TAG, "Found ApgService API version" + inf.metaData.getInt("api_version") + " but exspected " + API_VERSION);
+                            Log.w(TAG, "Found ApgService API version " + inf.metaData.getInt("api_version") + " but exspected " + API_VERSION);
                             Log.w(TAG, "This probably won't work!");
-                            mWarningList.add("(LOCAL) Found ApgService API version" + inf.metaData.getInt("api_version") + " but exspected " + API_VERSION);
+                            mWarningList.add("(LOCAL) Found ApgService API version " + inf.metaData.getInt("api_version") + " but exspected " + API_VERSION);
                             tmpError = error.APG_API_MISSMATCH;
                         } else {
                             if( LOCAL_LOGV ) Log.v(TAG, "Found api_version " + API_VERSION + ", everything should work");
@@ -495,6 +500,41 @@ public class ApgCon {
         }
         mArgs.putIntegerArrayList(key, list);
     }
+    
+    /**
+     * Set up binary data to en/decrypt
+     * 
+     * @param is
+     *          InputStream to get the data from
+     */
+    public void setBlob(InputStream is) {
+        if( LOCAL_LOGD ) Log.d(TAG, "setBlob() called");
+        // 1. get the new contentUri
+        ContentResolver cr = mContext.getContentResolver();
+        Uri contentUri = cr.insert(Uri.parse(BLOB_URI), new ContentValues());
+        
+        // 2. insert binary data
+        OutputStream os = null;
+        try {
+            os = cr.openOutputStream(contentUri, "w");
+        } catch( Exception e ) {
+            Log.e(TAG, "... exception on setBlob", e);
+        }
+        
+        byte[] buffer = new byte[8];
+        int len = 0;
+        try {
+            while( (len = is.read(buffer)) != -1) {
+                os.write(buffer, 0, len);
+            }
+            if(LOCAL_LOGD) Log.d(TAG, "... write finished, now closing");
+            os.close();
+        } catch (Exception e) {
+            Log.e(TAG, "... error on writing buffer", e);
+        }
+        
+        mArgs.putString("BLOB", contentUri.toString() );
+    }
 
     /**
      * Clears all arguments
@@ -628,18 +668,53 @@ public class ApgCon {
      * {@link #hasNextError()} is false.
      * </p>
      * 
+     * <p>
+     * Note: When handling binary data with {@link #setBlob(InputStream)}, you
+     * get your result with {@link #getBlobResult()}.
+     * </p>
+     * 
      * @return the mResult of the last {@link #call(String)} or
      *         {@link #callAsync(String)}.
      * 
      * @see #reset()
      * @see #clearResult()
      * @see #getResultBundle()
+     * @see #getBlobResult()
      */
     public String getResult() {
         return mResult.getString(ret.RESULT.name());
     }
 
     /**
+     * Get the binary result
+     * 
+     * <p>
+     * This gets your binary result. It only works if you called {@link #setBlob(InputStream)} before.
+     * 
+     * If you did not call encrypt nor decrypt, this will be the same data as you inputed.
+     * </p>
+     * 
+     * @return InputStream of the binary data which was en/decrypted
+     * 
+     * @see #setBlob(InputStream)
+     * @see #getResult()
+     */
+    public InputStream getBlobResult() {
+        if(mArgs.containsKey("BLOB")) {
+            ContentResolver cr = mContext.getContentResolver();
+            InputStream in = null;
+            try {
+                in = cr.openInputStream(Uri.parse(mArgs.getString("BLOB")));
+            } catch( Exception e ) {
+                Log.e(TAG, "Could not return blob in result", e);
+            }
+            return in;
+        } else {
+            return null;
+        }
+    }
+
+    /**
      * Get the result bundle
      * 
      * <p>