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.crypto;
michael@0: 
michael@0: import org.mozilla.gecko.background.common.log.Logger;
michael@0: import org.mozilla.gecko.sync.CollectionKeys;
michael@0: import org.mozilla.gecko.sync.CryptoRecord;
michael@0: 
michael@0: import android.content.SharedPreferences;
michael@0: 
michael@0: public class PersistedCrypto5Keys {
michael@0:   public static final String LOG_TAG = "PersistedC5Keys";
michael@0: 
michael@0:   public static final String CRYPTO5_KEYS_SERVER_RESPONSE_BODY = "crypto5KeysServerResponseBody";
michael@0:   public static final String CRYPTO5_KEYS_LAST_MODIFIED        = "crypto5KeysLastModified";
michael@0: 
michael@0:   protected SharedPreferences prefs;
michael@0:   protected KeyBundle syncKeyBundle;
michael@0: 
michael@0:   public PersistedCrypto5Keys(SharedPreferences prefs, KeyBundle syncKeyBundle) {
michael@0:     if (syncKeyBundle == null) {
michael@0:       throw new IllegalArgumentException("Null syncKeyBundle passed in to PersistedCrypto5Keys constructor.");
michael@0:     }
michael@0:     this.prefs = prefs;
michael@0:     this.syncKeyBundle = syncKeyBundle;
michael@0:   }
michael@0: 
michael@0:   /**
michael@0:    * Get persisted crypto/keys.
michael@0:    * <p>
michael@0:    * crypto/keys is fetched from an encrypted JSON-encoded <code>CryptoRecord</code>.
michael@0:    *
michael@0:    * @return A <code>CollectionKeys</code> instance or <code>null</code> if none
michael@0:    *         is currently persisted.
michael@0:    */
michael@0:   public CollectionKeys keys() {
michael@0:     String keysJSON = prefs.getString(CRYPTO5_KEYS_SERVER_RESPONSE_BODY, null);
michael@0:     if (keysJSON == null) {
michael@0:       return null;
michael@0:     }
michael@0:     try {
michael@0:       CryptoRecord cryptoRecord = CryptoRecord.fromJSONRecord(keysJSON);
michael@0:       CollectionKeys keys = new CollectionKeys();
michael@0:       keys.setKeyPairsFromWBO(cryptoRecord, syncKeyBundle);
michael@0:       return keys;
michael@0:     } catch (Exception e) {
michael@0:       Logger.warn(LOG_TAG, "Got exception decrypting persisted crypto/keys.", e);
michael@0:       return null;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   /**
michael@0:    * Persist crypto/keys.
michael@0:    * <p>
michael@0:    * crypto/keys is stored as an encrypted JSON-encoded <code>CryptoRecord</code>.
michael@0:    *
michael@0:    * @param keys
michael@0:    *          The <code>CollectionKeys</code> object to persist, which should
michael@0:    *          have the same default key bundle as the sync key bundle.
michael@0:    */
michael@0:   public void persistKeys(CollectionKeys keys) {
michael@0:     if (keys == null) {
michael@0:       Logger.debug(LOG_TAG, "Clearing persisted crypto/keys.");
michael@0:       prefs.edit().remove(CRYPTO5_KEYS_SERVER_RESPONSE_BODY).commit();
michael@0:       return;
michael@0:     }
michael@0:     try {
michael@0:       CryptoRecord cryptoRecord = keys.asCryptoRecord();
michael@0:       cryptoRecord.keyBundle = syncKeyBundle;
michael@0:       cryptoRecord.encrypt();
michael@0:       String keysJSON = cryptoRecord.toJSONString();
michael@0:       Logger.debug(LOG_TAG, "Persisting crypto/keys.");
michael@0:       prefs.edit().putString(CRYPTO5_KEYS_SERVER_RESPONSE_BODY, keysJSON).commit();
michael@0:     } catch (Exception e) {
michael@0:       Logger.warn(LOG_TAG, "Got exception encrypting while persisting crypto/keys.", e);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   public boolean persistedKeysExist() {
michael@0:     return lastModified() > 0;
michael@0:   }
michael@0: 
michael@0:   public long lastModified() {
michael@0:     return prefs.getLong(CRYPTO5_KEYS_LAST_MODIFIED, -1);
michael@0:   }
michael@0: 
michael@0:   public void persistLastModified(long lastModified) {
michael@0:     if (lastModified <= 0) {
michael@0:       Logger.debug(LOG_TAG, "Clearing persisted crypto/keys last modified timestamp.");
michael@0:       prefs.edit().remove(CRYPTO5_KEYS_LAST_MODIFIED).commit();
michael@0:       return;
michael@0:     }
michael@0:     Logger.debug(LOG_TAG, "Persisting crypto/keys last modified timestamp " + lastModified + ".");
michael@0:     prefs.edit().putLong(CRYPTO5_KEYS_LAST_MODIFIED, lastModified).commit();
michael@0:   }
michael@0: 
michael@0:   public void purge() {
michael@0:     persistLastModified(-1);
michael@0:     persistKeys(null);
michael@0:   }
michael@0: }