/**
* Key Derivation Function for client.dat: Use the database key as an HMAC key to an HMAC of the
* key plus some constant plus the storeIdentifier.
*
* @return An encryption key, as byte[].
*/
public byte[] getKeyForClientLayer() {
byte[] full = new byte[databaseKey.length + CLIENT_LAYER.length];
int x = 0;
System.arraycopy(databaseKey, 0, full, 0, databaseKey.length);
x += databaseKey.length;
System.arraycopy(CLIENT_LAYER, 0, full, x, CLIENT_LAYER.length);
return HMAC.macWithSHA256(databaseKey, full);
}
/**
* Key Derivation Function for plugin stores: Use the database key as an HMAC key to an HMAC of
* the key plus some constant plus the storeIdentifier.
*
* @param storeIdentifier The classname of the plugin, used as part of a filename.
* @return An encryption key, as byte[].
*/
public byte[] getPluginStoreKey(String storeIdentifier) {
try {
byte[] id = storeIdentifier.getBytes("UTF-8");
byte[] full = new byte[databaseKey.length + PLUGIN.length + id.length];
int x = 0;
System.arraycopy(databaseKey, 0, full, 0, databaseKey.length);
x += databaseKey.length;
System.arraycopy(PLUGIN, 0, full, x, PLUGIN.length);
x += PLUGIN.length;
System.arraycopy(id, 0, full, x, id.length);
return HMAC.macWithSHA256(databaseKey, full);
} catch (UnsupportedEncodingException e) {
throw new Error(e);
}
}