1 /* 2 * Copyright (C) 2016 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 package com.android.apksig.internal.util; 17 18 import com.android.apksig.util.DataSink; 19 import java.nio.ByteBuffer; 20 import java.security.MessageDigest; 21 22 /** 23 * Data sink which feeds all received data into the associated {@link MessageDigest} instances. Each 24 * {@code MessageDigest} instance receives the same data. 25 */ 26 public class MessageDigestSink implements DataSink { 27 28 private final MessageDigest[] mMessageDigests; 29 30 public MessageDigestSink(MessageDigest[] digests) { 31 mMessageDigests = digests; 32 } 33 34 @Override 35 public void consume(byte[] buf, int offset, int length) { 36 for (MessageDigest md : mMessageDigests) { 37 md.update(buf, offset, length); 38 } 39 } 40 41 @Override 42 public void consume(ByteBuffer buf) { 43 int originalPosition = buf.position(); 44 for (MessageDigest md : mMessageDigests) { 45 // Reset the position back to the original because the previous iteration's 46 // MessageDigest.update set the buffer's position to the buffer's limit. 47 buf.position(originalPosition); 48 md.update(buf); 49 } 50 } 51 } 52
