| // 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; |
| |
| import java.security.GeneralSecurityException; |
| |
| /** |
| * Interface for Authenticated Encryption with Associated Data (AEAD). |
| * |
| * <h3>Security guarantees</h3> |
| * |
| * <p>Implementations of this interface are secure against adaptive chosen ciphertext attacks. |
| * Encryption with associated data ensures authenticity (who the sender is) and integrity (the data |
| * has not been tampered with) of that data, but not its secrecy. (see <a |
| * href="https://tools.ietf.org/html/rfc5116">RFC 5116</a> for more info) |
| * |
| * @since 1.0.0 |
| */ |
| public interface Aead { |
| /** |
| * Encrypts {@code plaintext} with {@code associatedData} as associated authenticated data. |
| * The resulting ciphertext allows for checking authenticity and integrity of associated data |
| * ({@code associatedData}), but does not guarantee its secrecy. |
| * |
| * @param plaintext the plaintext to be encrypted. It must be non-null, but can also |
| * be an empty (zero-length) byte array |
| * @param associatedData associated data to be authenticated, but not encrypted. Associated data |
| * is optional, so this parameter can be null. In this case the null value |
| * is equivalent to an empty (zero-length) byte array. |
| * For successful decryption the same associatedData must be provided |
| * along with the ciphertext. |
| * @return resulting ciphertext |
| */ |
| byte[] encrypt(final byte[] plaintext, final byte[] associatedData) |
| throws GeneralSecurityException; |
| |
| /** |
| * Decrypts {@code ciphertext} with {@code associatedData} as associated authenticated data. |
| * The decryption verifies the authenticity and integrity of the associated data, but there are |
| * no guarantees wrt. secrecy of that data. |
| * |
| * @param ciphertext the plaintext to be decrypted. It must be non-null. |
| * @param associatedData associated data to be authenticated. For successful decryption |
| * it must be the same as associatedData used during encryption. |
| * Can be null, which is equivalent to an empty (zero-length) byte array. |
| * @return resulting plaintext |
| */ |
| byte[] decrypt(final byte[] ciphertext, final byte[] associatedData) |
| throws GeneralSecurityException; |
| } |