michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko.sync.middleware;
michael@0: 
michael@0: import java.io.UnsupportedEncodingException;
michael@0: import java.util.concurrent.ExecutorService;
michael@0: 
michael@0: import org.mozilla.gecko.sync.CryptoRecord;
michael@0: import org.mozilla.gecko.sync.crypto.CryptoException;
michael@0: import org.mozilla.gecko.sync.crypto.KeyBundle;
michael@0: import org.mozilla.gecko.sync.repositories.InactiveSessionException;
michael@0: import org.mozilla.gecko.sync.repositories.NoStoreDelegateException;
michael@0: import org.mozilla.gecko.sync.repositories.RecordFactory;
michael@0: import org.mozilla.gecko.sync.repositories.RepositorySession;
michael@0: import org.mozilla.gecko.sync.repositories.delegates.RepositorySessionFetchRecordsDelegate;
michael@0: import org.mozilla.gecko.sync.repositories.delegates.RepositorySessionStoreDelegate;
michael@0: import org.mozilla.gecko.sync.repositories.domain.Record;
michael@0: 
michael@0: /**
michael@0:  * It's a RepositorySession that accepts Records as input, producing CryptoRecords
michael@0:  * for submission to a remote service.
michael@0:  * Takes a RecordFactory as a parameter. This is in charge of taking decrypted CryptoRecords
michael@0:  * as input and producing some expected kind of Record as output for local use.
michael@0:  *
michael@0:  *
michael@0: 
michael@0: 
michael@0: 
michael@0:                  +------------------------------------+
michael@0:                  |    Server11RepositorySession       |
michael@0:                  +-------------------------+----------+
michael@0:                            ^               |
michael@0:                            |               |
michael@0:                         Encrypted CryptoRecords
michael@0:                            |               |
michael@0:                            |               v
michael@0:                  +---------+--------------------------+
michael@0:                  | Crypto5MiddlewareRepositorySession |
michael@0:                  +------------------------------------+
michael@0:                            ^               |
michael@0:                            |               |  Decrypted CryptoRecords
michael@0:                            |               |
michael@0:                            |            +---------------+
michael@0:                            |            | RecordFactory |
michael@0:                            |            +--+------------+
michael@0:                            |               |
michael@0:                           Local Record instances
michael@0:                            |               |
michael@0:                            |               v
michael@0:                  +---------+--------------------------+
michael@0:                  |  Local RepositorySession instance  |
michael@0:                  +------------------------------------+
michael@0: 
michael@0: 
michael@0:  * @author rnewman
michael@0:  *
michael@0:  */
michael@0: public class Crypto5MiddlewareRepositorySession extends MiddlewareRepositorySession {
michael@0:   private KeyBundle keyBundle;
michael@0:   private RecordFactory recordFactory;
michael@0: 
michael@0:   public Crypto5MiddlewareRepositorySession(RepositorySession session, Crypto5MiddlewareRepository repository, RecordFactory recordFactory) {
michael@0:     super(session, repository);
michael@0:     this.keyBundle = repository.keyBundle;
michael@0:     this.recordFactory = recordFactory;
michael@0:   }
michael@0: 
michael@0:   public class DecryptingTransformingFetchDelegate implements RepositorySessionFetchRecordsDelegate {
michael@0:     private RepositorySessionFetchRecordsDelegate next;
michael@0:     private KeyBundle keyBundle;
michael@0:     private RecordFactory recordFactory;
michael@0: 
michael@0:     DecryptingTransformingFetchDelegate(RepositorySessionFetchRecordsDelegate next, KeyBundle bundle, RecordFactory recordFactory) {
michael@0:       this.next = next;
michael@0:       this.keyBundle = bundle;
michael@0:       this.recordFactory = recordFactory;
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public void onFetchFailed(Exception ex, Record record) {
michael@0:       next.onFetchFailed(ex, record);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public void onFetchedRecord(Record record) {
michael@0:       CryptoRecord r;
michael@0:       try {
michael@0:         r = (CryptoRecord) record;
michael@0:       } catch (ClassCastException e) {
michael@0:         next.onFetchFailed(e, record);
michael@0:         return;
michael@0:       }
michael@0:       r.keyBundle = keyBundle;
michael@0:       try {
michael@0:         r.decrypt();
michael@0:       } catch (Exception e) {
michael@0:         next.onFetchFailed(e, r);
michael@0:         return;
michael@0:       }
michael@0:       Record transformed;
michael@0:       try {
michael@0:         transformed = this.recordFactory.createRecord(r);
michael@0:       } catch (Exception e) {
michael@0:         next.onFetchFailed(e, r);
michael@0:         return;
michael@0:       }
michael@0:       next.onFetchedRecord(transformed);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public void onFetchCompleted(final long fetchEnd) {
michael@0:       next.onFetchCompleted(fetchEnd);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public RepositorySessionFetchRecordsDelegate deferredFetchDelegate(ExecutorService executor) {
michael@0:       // Synchronously perform *our* work, passing through appropriately.
michael@0:       RepositorySessionFetchRecordsDelegate deferredNext = next.deferredFetchDelegate(executor);
michael@0:       return new DecryptingTransformingFetchDelegate(deferredNext, keyBundle, recordFactory);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   private DecryptingTransformingFetchDelegate makeUnwrappingDelegate(RepositorySessionFetchRecordsDelegate inner) {
michael@0:     if (inner == null) {
michael@0:       throw new IllegalArgumentException("Inner delegate cannot be null!");
michael@0:     }
michael@0:     return new DecryptingTransformingFetchDelegate(inner, this.keyBundle, this.recordFactory);
michael@0:   }
michael@0: 
michael@0:   @Override
michael@0:   public void fetchSince(long timestamp,
michael@0:                          RepositorySessionFetchRecordsDelegate delegate) {
michael@0:     inner.fetchSince(timestamp, makeUnwrappingDelegate(delegate));
michael@0:   }
michael@0: 
michael@0:   @Override
michael@0:   public void fetch(String[] guids,
michael@0:                     RepositorySessionFetchRecordsDelegate delegate) throws InactiveSessionException {
michael@0:     inner.fetch(guids, makeUnwrappingDelegate(delegate));
michael@0:   }
michael@0: 
michael@0:   @Override
michael@0:   public void fetchAll(RepositorySessionFetchRecordsDelegate delegate) {
michael@0:     inner.fetchAll(makeUnwrappingDelegate(delegate));
michael@0:   }
michael@0: 
michael@0:   @Override
michael@0:   public void setStoreDelegate(RepositorySessionStoreDelegate delegate) {
michael@0:     // TODO: it remains to be seen how this will work.
michael@0:     inner.setStoreDelegate(delegate);
michael@0:     this.delegate = delegate;             // So we can handle errors without involving inner.
michael@0:   }
michael@0: 
michael@0:   @Override
michael@0:   public void store(Record record) throws NoStoreDelegateException {
michael@0:     if (delegate == null) {
michael@0:       throw new NoStoreDelegateException();
michael@0:     }
michael@0:     CryptoRecord rec = record.getEnvelope();
michael@0:     rec.keyBundle = this.keyBundle;
michael@0:     try {
michael@0:       rec.encrypt();
michael@0:     } catch (UnsupportedEncodingException e) {
michael@0:       delegate.onRecordStoreFailed(e, record.guid);
michael@0:       return;
michael@0:     } catch (CryptoException e) {
michael@0:       delegate.onRecordStoreFailed(e, record.guid);
michael@0:       return;
michael@0:     }
michael@0:     // Allow the inner session to do delegate handling.
michael@0:     inner.store(rec);
michael@0:   }
michael@0: }