1 // Copyright 2017 Google Inc. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 //////////////////////////////////////////////////////////////////////////////// 16 17 package com.google.crypto.tink.subtle; 18 19 import java.nio.ByteBuffer; 20 import java.security.GeneralSecurityException; 21 22 /** 23 * StreamSegmentDecrypter is a helper class that decrypts individual segments of a stream. 24 * 25 * <p>Instances of this interfaces are passed to {@link StreamingAeadDecryptingChannel}. Each 26 * instance must be initialized with the header of the ciphertext. 27 * 28 * @since 1.1.0 29 */ 30 public interface StreamSegmentDecrypter { init(ByteBuffer header, byte[] aad)31 void init(ByteBuffer header, byte[] aad) throws GeneralSecurityException; 32 33 /** 34 * Decrypts a ciphetext segment. 35 * 36 * @param segmentNr the number of the segment 37 * @param isLastSegment true if this segment is the last segment of the ciphertext stream. The 38 * last segment is encrypted (or authenticated) differently to detect truncated ciphertext. 39 * @param plaintext the decrypted plaintext. 40 * @throws GeneralSecurityException if ciphertext was not a valid ciphertext for the given 41 * segment. 42 */ decryptSegment( ByteBuffer ciphertext, int segmentNr, boolean isLastSegment, ByteBuffer plaintext)43 void decryptSegment( 44 ByteBuffer ciphertext, int segmentNr, boolean isLastSegment, ByteBuffer plaintext) 45 throws GeneralSecurityException; 46 } 47