com.azure.security.keyvault.keys.cryptography.implementation.AesCbc Maven / Gradle / Ivy

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This module contains client library for Microsoft Azure KeyVault Keys.
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// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

package com.azure.security.keyvault.keys.cryptography.implementation;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.Provider;
import java.util.Arrays;

abstract class AesCbc extends SymmetricEncryptionAlgorithm {
    final int keySizeInBytes;
    final int keySize;

    protected AesCbc(String name, int size) {
        super(name);

        keySize = size;
        keySizeInBytes = size >> 3;
    }

    static class AesCbcEncryptor implements ICryptoTransform {
        private final Cipher cipher;

        AesCbcEncryptor(byte[] key, byte[] iv, Provider provider) throws NoSuchAlgorithmException,
            NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException {

            // Create the cipher using the Provider if specified
            if (provider == null) {
                cipher = Cipher.getInstance("AES/CBC/NoPadding");
            } else {
                cipher = Cipher.getInstance("AES/CBC/NoPadding", provider);
            }

            cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"), new IvParameterSpec(iv));
        }

        @Override
        public byte[] doFinal(byte[] plaintext) throws IllegalBlockSizeException, BadPaddingException {
            return cipher.doFinal(plaintext);
        }
    }

    static class AesCbcDecryptor implements ICryptoTransform {
        private final Cipher cipher;

        AesCbcDecryptor(byte[] key, byte[] iv, Provider provider) throws NoSuchAlgorithmException,
            NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException {

            // Create the cipher using the Provider if specified
            if (provider == null) {
                cipher = Cipher.getInstance("AES/CBC/NoPadding");
            } else {
                cipher = Cipher.getInstance("AES/CBC/NoPadding", provider);
            }

            cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key, "AES"), new IvParameterSpec(iv));
        }

        @Override
        public byte[] doFinal(byte[] plaintext) throws IllegalBlockSizeException, BadPaddingException {
            return cipher.doFinal(plaintext);
        }
    }

    @Override
    public ICryptoTransform createEncryptor(byte[] key, byte[] iv, byte[] additionalAuthenticatedData,
                                            byte[] authenticationTag)
        throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidAlgorithmParameterException {

        return createEncryptor(key, iv, additionalAuthenticatedData, null, null);
    }

    @Override
    public ICryptoTransform createEncryptor(byte[] key, byte[] iv, byte[] additionalAuthenticatedData,
                                            byte[] authenticationTag, Provider provider)
        throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidAlgorithmParameterException {

        if (key == null || key.length < keySizeInBytes) {
            throw new InvalidKeyException("Key must be at least " + keySize + " bits in length.");
        }

        return new AesCbcEncryptor(Arrays.copyOfRange(key, 0, keySizeInBytes), iv, provider);
    }

    @Override
    public ICryptoTransform createDecryptor(byte[] key, byte[] iv, byte[] additionalAuthenticatedData,
                                            byte[] authenticationTag)
        throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidAlgorithmParameterException {

        return createDecryptor(key, iv, additionalAuthenticatedData, authenticationTag, null);
    }

    @Override
    public ICryptoTransform createDecryptor(byte[] key, byte[] iv, byte[] additionalAuthenticatedData,
                                            byte[] authenticationTag, Provider provider)
        throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidAlgorithmParameterException {

        if (key == null || key.length < keySizeInBytes) {
            throw new InvalidKeyException("Key must be at least " + keySize + " bits in length.");
        }

        return new AesCbcDecryptor(Arrays.copyOfRange(key, 0, keySizeInBytes), iv, provider);
    }
}