1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.security.keystore; 18 19 import android.security.KeyStore; 20 import android.security.KeyStoreException; 21 22 /** 23 * Helper for streaming a crypto operation's input and output via {@link KeyStore} service's 24 * {@code update} and {@code finish} operations. 25 * 26 * <p>The helper abstracts away to issues that need to be solved in most code that uses KeyStore's 27 * update and finish operations. Firstly, KeyStore's update operation can consume only a limited 28 * amount of data in one go because the operations are marshalled via Binder. Secondly, the update 29 * operation may consume less data than provided, in which case the caller has to buffer the 30 * remainder for next time. The helper exposes {@link #update(byte[], int, int) update} and 31 * {@link #doFinal(byte[], int, int, byte[], byte[]) doFinal} operations which can be used to 32 * conveniently implement various JCA crypto primitives. 33 * 34 * @hide 35 */ 36 interface KeyStoreCryptoOperationStreamer { 37 byte[] update(byte[] input, int inputOffset, int inputLength) throws KeyStoreException; 38 byte[] doFinal(byte[] input, int inputOffset, int inputLength, byte[] signature, 39 byte[] additionalEntropy) throws KeyStoreException; 40 long getConsumedInputSizeBytes(); 41 long getProducedOutputSizeBytes(); 42 } 43
