/*
 * Copyright 2010-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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.amazonaws.services.s3.internal.crypto;

import java.util.Map;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;

/**
 * Contains information used to encrypt and decrypt objects in S3.
 */
public class EncryptionInstruction {

    private final Map<String, String> materialsDescription;
    private final byte[] encryptedSymmetricKey;
    private final Cipher symmetricCipher;
    private final CipherFactory symmetricCipherFactory;

    /**
     * Construct a new EncryptionInstruction object with the provided fields.
     *
     * @param materialsDescription The description of the encryption materials
     *            that were used to encrypt the envelope symmetric key.
     * @param encryptedSymmetricKey A byte[] array representing an encrypted
     *            envelope symmetric key.
     * @param symmetricKey The symmetric key used to create the cipher that will
     *            encrypt the object data.
     * @param symmetricCipher The symmetric cipher that will encrypt the object
     *            data.
     */
    public EncryptionInstruction(Map<String, String> materialsDescription,
            byte[] encryptedSymmetricKey, SecretKey symmetricKey, Cipher symmetricCipher) {
        this.materialsDescription = materialsDescription;
        this.encryptedSymmetricKey = encryptedSymmetricKey;
        this.symmetricCipher = symmetricCipher;
        this.symmetricCipherFactory = null;
    }

    public EncryptionInstruction(Map<String, String> materialsDescription,
            byte[] encryptedSymmetricKey, SecretKey symmetricKey,
            CipherFactory symmetricCipherFactory) {
        this.materialsDescription = materialsDescription;
        this.encryptedSymmetricKey = encryptedSymmetricKey;
        this.symmetricCipherFactory = symmetricCipherFactory;
        this.symmetricCipher = symmetricCipherFactory.createCipher();
    }

    public CipherFactory getCipherFactory() {
        return symmetricCipherFactory;
    }

    /**
     * Returns the description of the encryption materials that were used to
     * encrypt the envelope symmetric key.
     *
     * @return the description of the encryption materials that were used to
     *         encrypt the envelope symmetric key.
     */
    public Map<String, String> getMaterialsDescription() {
        return this.materialsDescription;
    }

    /**
     * Returns an array of bytes representing the encrypted envelope symmetric
     * key.
     *
     * @return an array of bytes representing the encrypted envelope symmetric
     *         key.
     */
    public byte[] getEncryptedSymmetricKey() {
        return this.encryptedSymmetricKey;
    }

    /**
     * Returns the symmetric cipher created with the envelope symmetric key.
     *
     * @return the symmetric cipher created with the envelope symmetric key.
     */
    public Cipher getSymmetricCipher() {
        return this.symmetricCipher;
    }
}