| // Copyright 2017 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| package com.google.crypto.tink.subtle; |
| |
| import com.google.crypto.tink.StreamingAead; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.nio.channels.ReadableByteChannel; |
| import java.nio.channels.SeekableByteChannel; |
| import java.nio.channels.WritableByteChannel; |
| import java.security.GeneralSecurityException; |
| |
| /** |
| * An abstract class for StreamingAead using the nonce based online encryption scheme proposed in <a |
| * href="https://eprint.iacr.org/2015/189.pdf">Online Authenticated-Encryption and its Nonce-Reuse |
| * Misuse-Resistance</a> by Hoang, Reyhanitabar, Rogaway and Vizár. |
| */ |
| abstract class NonceBasedStreamingAead implements StreamingAead { |
| |
| // Abstract methods that the subclass has to implement. |
| public abstract StreamSegmentEncrypter newStreamSegmentEncrypter(byte[] associatedData) |
| throws GeneralSecurityException; |
| // TODO(bleichen): Consider to pass aad here too. |
| public abstract StreamSegmentDecrypter newStreamSegmentDecrypter() |
| throws GeneralSecurityException; |
| |
| public abstract int getPlaintextSegmentSize(); |
| |
| public abstract int getCiphertextSegmentSize(); |
| |
| public abstract int getCiphertextOffset(); |
| |
| public abstract int getCiphertextOverhead(); |
| |
| public abstract int getHeaderLength(); |
| |
| @Override |
| public WritableByteChannel newEncryptingChannel( |
| WritableByteChannel ciphertextChannel, byte[] associatedData) |
| throws GeneralSecurityException, IOException { |
| return new StreamingAeadEncryptingChannel(this, ciphertextChannel, associatedData); |
| } |
| |
| @Override |
| public ReadableByteChannel newDecryptingChannel( |
| ReadableByteChannel ciphertextChannel, byte[] associatedData) |
| throws GeneralSecurityException, IOException { |
| return new StreamingAeadDecryptingChannel(this, ciphertextChannel, associatedData); |
| } |
| |
| @Override |
| public SeekableByteChannel newSeekableDecryptingChannel( |
| SeekableByteChannel ciphertextSource, byte[] associatedData) |
| throws GeneralSecurityException, IOException { |
| return new StreamingAeadSeekableDecryptingChannel(this, ciphertextSource, associatedData); |
| } |
| |
| @Override |
| public OutputStream newEncryptingStream(OutputStream ciphertext, byte[] associatedData) |
| throws GeneralSecurityException, IOException { |
| return new StreamingAeadEncryptingStream(this, ciphertext, associatedData); |
| } |
| |
| @Override |
| public InputStream newDecryptingStream(InputStream ciphertextStream, byte[] associatedData) |
| throws GeneralSecurityException, IOException { |
| return new StreamingAeadDecryptingStream(this, ciphertextStream, associatedData); |
| } |
| } |