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regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
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    http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.commons.crypto.cipher;

import java.nio.ByteBuffer;
import java.security.GeneralSecurityException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.spec.AlgorithmParameterSpec;
import java.util.Properties;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.ShortBufferException;

import org.apache.commons.crypto.utils.Utils;

Implements the CryptoCipher using JCE provider. /**
 * Implements the {@link CryptoCipher} using JCE provider.
 */
class JceCipher implements CryptoCipher {
    private final Cipher cipher;

    
Constructs a CryptoCipher based on JCE Cipher Cipher. 
Params:
props –  properties for JCE cipher (only uses CryptoCipherFactory.JCE_PROVIDER_KEY)
transformation –  transformation for JCE cipher (algorithm/mode/padding)
Throws:
GeneralSecurityException – if JCE cipher initialize failed/**
     * Constructs a {@link CryptoCipher} based on JCE Cipher {@link Cipher}.
     *
     * @param props  properties for JCE cipher (only uses {@link CryptoCipherFactory#JCE_PROVIDER_KEY})
     * @param transformation  transformation for JCE cipher (algorithm/mode/padding)
     * @throws GeneralSecurityException if JCE cipher initialize failed
     */
    // N.B. this class is not public/protected so does not appear in the main Javadoc
    // Please ensure that property use is documented in the enum CryptoRandomFactory.RandomProvider
    public JceCipher(Properties props, String transformation)
            throws GeneralSecurityException {
        final String provider = props.getProperty(CryptoCipherFactory.JCE_PROVIDER_KEY);
        if (provider == null || provider.isEmpty()) {
            cipher = Cipher.getInstance(transformation);
        } else {
            cipher = Cipher.getInstance(transformation, provider);
        }
    }

    
Returns the block size (in bytes).
Returns:
the block size (in bytes), or 0 if the underlying algorithm is
not a block cipher/**
     * Returns the block size (in bytes).
     *
     * @return the block size (in bytes), or 0 if the underlying algorithm is
     * not a block cipher
     */
    @Override
    public final int getBlockSize() {
        return cipher.getBlockSize();
    }

    
Returns the algorithm name of this CryptoCipher object. 
This is the same name that was specified in one of the CryptoCipherFactory#getInstance calls that created this CryptoCipher object.. 
Returns:
the algorithm name of this CryptoCipher object./**
     * Returns the algorithm name of this {@code CryptoCipher} object.
     *
     * <p>This is the same name that was specified in one of the
     * {@code CryptoCipherFactory#getInstance} calls that created this
     * {@code CryptoCipher} object..
     *
     * @return the algorithm name of this {@code CryptoCipher} object.
     */
    @Override
    public String getAlgorithm() {
        return cipher.getAlgorithm();
    }

    
Initializes the cipher with mode, key and iv.
Params:
mode – Cipher.ENCRYPT_MODE or Cipher.DECRYPT_MODE
key – crypto key for the cipher
params – the algorithm parameters
Throws:
InvalidAlgorithmParameterException – if the given algorithm
        parameters are inappropriate for this cipher, or this cipher
        requires algorithm parameters and params is null, or
        the given algorithm parameters imply a cryptographic strength
        that would exceed the legal limits (as determined from the
        configured jurisdiction policy files)./**
     * Initializes the cipher with mode, key and iv.
     *
     * @param mode {@link Cipher#ENCRYPT_MODE} or {@link Cipher#DECRYPT_MODE}
     * @param key crypto key for the cipher
     * @param params the algorithm parameters
     * @throws InvalidAlgorithmParameterException if the given algorithm
     *         parameters are inappropriate for this cipher, or this cipher
     *         requires algorithm parameters and <code>params</code> is null, or
     *         the given algorithm parameters imply a cryptographic strength
     *         that would exceed the legal limits (as determined from the
     *         configured jurisdiction policy files).
     */
    @Override
    public void init(int mode, Key key, AlgorithmParameterSpec params)
            throws InvalidKeyException, InvalidAlgorithmParameterException {
        Utils.checkNotNull(key);
        Utils.checkNotNull(params);

        // Jce uses the javax.crypto.Cipher modes; no need to convert the input
        cipher.init(mode, key, params);
    }

    
Continues a multiple-part encryption/decryption operation. The data is
encrypted or decrypted, depending on how this cipher was initialized.
Params:
inBuffer – the input ByteBuffer
outBuffer – the output ByteBuffer
Throws:
ShortBufferException – if there is insufficient space in the output
        buffer
Returns:
int number of bytes stored in output/**
     * Continues a multiple-part encryption/decryption operation. The data is
     * encrypted or decrypted, depending on how this cipher was initialized.
     *
     * @param inBuffer the input ByteBuffer
     * @param outBuffer the output ByteBuffer
     * @return int number of bytes stored in <code>output</code>
     * @throws ShortBufferException if there is insufficient space in the output
     *         buffer
     */
    @Override
    public int update(ByteBuffer inBuffer, ByteBuffer outBuffer)
            throws ShortBufferException {
        return cipher.update(inBuffer, outBuffer);
    }

    
Continues a multiple-part encryption/decryption operation. The data is
encrypted or decrypted, depending on how this cipher was initialized.
Params:
input – the input byte array
inputOffset – the offset in input where the input starts
inputLen – the input length
output – the byte array for the result
outputOffset – the offset in output where the result is stored
Throws:
ShortBufferException – if there is insufficient space in the output
        byte array
Returns:
the number of bytes stored in output/**
     * Continues a multiple-part encryption/decryption operation. The data is
     * encrypted or decrypted, depending on how this cipher was initialized.
     *
     * @param input the input byte array
     * @param inputOffset the offset in input where the input starts
     * @param inputLen the input length
     * @param output the byte array for the result
     * @param outputOffset the offset in output where the result is stored
     * @return the number of bytes stored in output
     * @throws ShortBufferException if there is insufficient space in the output
     *         byte array
     */
    @Override
    public int update(byte[] input, int inputOffset, int inputLen,
            byte[] output, int outputOffset) throws ShortBufferException {
        return cipher
                .update(input, inputOffset, inputLen, output, outputOffset);
    }

    
Encrypts or decrypts data in a single-part operation, or finishes a
multiple-part operation. The data is encrypted or decrypted, depending on
how this cipher was initialized.
Params:
inBuffer – the input ByteBuffer
outBuffer – the output ByteBuffer
Throws:
BadPaddingException – if this cipher is in decryption mode, and
        (un)padding has been requested, but the decrypted data is not
        bounded by the appropriate padding bytes
IllegalBlockSizeException – if this cipher is a block cipher, no
        padding has been requested (only in encryption mode), and the
        total input length of the data processed by this cipher is not a
        multiple of block size; or if this encryption algorithm is unable
        to process the input data provided.
ShortBufferException – if the given output buffer is too small to
        hold the result
Returns:
int number of bytes stored in output/**
     * Encrypts or decrypts data in a single-part operation, or finishes a
     * multiple-part operation. The data is encrypted or decrypted, depending on
     * how this cipher was initialized.
     *
     * @param inBuffer the input ByteBuffer
     * @param outBuffer the output ByteBuffer
     * @return int number of bytes stored in <code>output</code>
     * @throws BadPaddingException if this cipher is in decryption mode, and
     *         (un)padding has been requested, but the decrypted data is not
     *         bounded by the appropriate padding bytes
     * @throws IllegalBlockSizeException if this cipher is a block cipher, no
     *         padding has been requested (only in encryption mode), and the
     *         total input length of the data processed by this cipher is not a
     *         multiple of block size; or if this encryption algorithm is unable
     *         to process the input data provided.
     * @throws ShortBufferException if the given output buffer is too small to
     *         hold the result
     */
    @Override
    public int doFinal(ByteBuffer inBuffer, ByteBuffer outBuffer)
            throws ShortBufferException, IllegalBlockSizeException,
            BadPaddingException {
        return cipher.doFinal(inBuffer, outBuffer);
    }

    
Encrypts or decrypts data in a single-part operation, or finishes a
multiple-part operation.
Params:
input – the input byte array
inputOffset – the offset in input where the input starts
inputLen – the input length
output – the byte array for the result
outputOffset – the offset in output where the result is stored
Throws:
ShortBufferException – if the given output byte array is too small
        to hold the result
BadPaddingException – if this cipher is in decryption mode, and
        (un)padding has been requested, but the decrypted data is not
        bounded by the appropriate padding bytes
IllegalBlockSizeException – if this cipher is a block cipher, no
        padding has been requested (only in encryption mode), and the
        total input length of the data processed by this cipher is not a
        multiple of block size; or if this encryption algorithm is unable
        to process the input data provided.
Returns:
the number of bytes stored in output/**
     * Encrypts or decrypts data in a single-part operation, or finishes a
     * multiple-part operation.
     *
     * @param input the input byte array
     * @param inputOffset the offset in input where the input starts
     * @param inputLen the input length
     * @param output the byte array for the result
     * @param outputOffset the offset in output where the result is stored
     * @return the number of bytes stored in output
     * @throws ShortBufferException if the given output byte array is too small
     *         to hold the result
     * @throws BadPaddingException if this cipher is in decryption mode, and
     *         (un)padding has been requested, but the decrypted data is not
     *         bounded by the appropriate padding bytes
     * @throws IllegalBlockSizeException if this cipher is a block cipher, no
     *         padding has been requested (only in encryption mode), and the
     *         total input length of the data processed by this cipher is not a
     *         multiple of block size; or if this encryption algorithm is unable
     *         to process the input data provided.
     */
    @Override
    public int doFinal(byte[] input, int inputOffset, int inputLen,
            byte[] output, int outputOffset) throws ShortBufferException,
            IllegalBlockSizeException, BadPaddingException {
        return cipher.doFinal(input, inputOffset, inputLen, output,
                outputOffset);
    }

    
Closes Jce cipher.
/**
     * Closes Jce cipher.
     */
    @Override
    public void close() {
        // Do nothing
    }
}