diff -r 000000000000 -r 6474c204b198 mobile/android/base/sync/middleware/Crypto5MiddlewareRepository.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/sync/middleware/Crypto5MiddlewareRepository.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,74 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.sync.middleware;
+
+import org.mozilla.gecko.sync.crypto.KeyBundle;
+import org.mozilla.gecko.sync.repositories.IdentityRecordFactory;
+import org.mozilla.gecko.sync.repositories.RecordFactory;
+import org.mozilla.gecko.sync.repositories.Repository;
+import org.mozilla.gecko.sync.repositories.RepositorySession;
+import org.mozilla.gecko.sync.repositories.delegates.RepositorySessionCleanDelegate;
+import org.mozilla.gecko.sync.repositories.delegates.RepositorySessionCreationDelegate;
+
+import android.content.Context;
+
+/**
+ * Wrap an existing repository in middleware that encrypts and decrypts records
+ * passing through.
+ *
+ * @author rnewman
+ *
+ */
+public class Crypto5MiddlewareRepository extends MiddlewareRepository {
+
+  public RecordFactory recordFactory = new IdentityRecordFactory();
+
+  public class Crypto5MiddlewareRepositorySessionCreationDelegate extends MiddlewareRepository.SessionCreationDelegate {
+    private Crypto5MiddlewareRepository repository;
+    private RepositorySessionCreationDelegate outerDelegate;
+
+    public Crypto5MiddlewareRepositorySessionCreationDelegate(Crypto5MiddlewareRepository repository, RepositorySessionCreationDelegate outerDelegate) {
+      this.repository = repository;
+      this.outerDelegate = outerDelegate;
+    }
+    public void onSessionCreateFailed(Exception ex) {
+      this.outerDelegate.onSessionCreateFailed(ex);
+    }
+
+    @Override
+    public void onSessionCreated(RepositorySession session) {
+      // Do some work, then report success with the wrapping session.
+      Crypto5MiddlewareRepositorySession cryptoSession;
+      try {
+        // Synchronous, baby.
+        cryptoSession = new Crypto5MiddlewareRepositorySession(session, this.repository, recordFactory);
+      } catch (Exception ex) {
+        this.outerDelegate.onSessionCreateFailed(ex);
+        return;
+      }
+      this.outerDelegate.onSessionCreated(cryptoSession);
+    }
+  }
+
+  public KeyBundle keyBundle;
+  private Repository inner;
+
+  public Crypto5MiddlewareRepository(Repository inner, KeyBundle keys) {
+    super();
+    this.inner = inner;
+    this.keyBundle = keys;
+  }
+  @Override
+  public void createSession(RepositorySessionCreationDelegate delegate, Context context) {
+    Crypto5MiddlewareRepositorySessionCreationDelegate delegateWrapper = new Crypto5MiddlewareRepositorySessionCreationDelegate(this, delegate);
+    inner.createSession(delegateWrapper, context);
+  }
+
+  @Override
+  public void clean(boolean success, RepositorySessionCleanDelegate delegate,
+                    Context context) {
+    this.inner.clean(success, delegate, context);
+  }
+}