OpenSslEngine.java

/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you 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 divconq.net.ssl;

import javax.net.ssl.SSLEngine;

/**
 * Implements a {@link SSLEngine} using
 * <a href="https://www.openssl.org/docs/crypto/BIO_s_bio.html#EXAMPLE">OpenSSL BIO abstractions</a>.
 */
public final class OpenSslEngine  {
    private static final int MAX_PLAINTEXT_LENGTH = 16 * 1024; // 2^14
    private static final int MAX_COMPRESSED_LENGTH = MAX_PLAINTEXT_LENGTH + 1024;
    private static final int MAX_CIPHERTEXT_LENGTH = MAX_COMPRESSED_LENGTH + 1024;

    // Header (5) + Data (2^14) + Compression (1024) + Encryption (1024) + MAC (20) + Padding (256)
    static final int MAX_ENCRYPTED_PACKET_LENGTH = MAX_CIPHERTEXT_LENGTH + 5 + 20 + 256;

    static final int MAX_ENCRYPTION_OVERHEAD_LENGTH = MAX_ENCRYPTED_PACKET_LENGTH - MAX_PLAINTEXT_LENGTH;
}