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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.
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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.InvalidAlgorithmParameterException;
import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.BadPaddingException;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.ShortBufferException;
import javax.crypto.spec.IvParameterSpec;

This class do the real work(Encryption/Decryption) for non-authenticated modes, such as CTR, CBC.

It will call the OpenSSL API to implement encryption/decryption
/**
 * This class do the real work(Encryption/Decryption) for non-authenticated modes, such as CTR, CBC.
 * <p>
 * It will call the OpenSSL API to implement encryption/decryption
 */
class OpenSslCommonMode extends OpenSslFeedbackCipher {

    OpenSslCommonMode(final long context, final int algorithmMode, final int padding) {
        super(context, algorithmMode, padding);
    }

    @Override
    public void init(final int mode, final byte[] key, final AlgorithmParameterSpec params)
            throws InvalidAlgorithmParameterException {
        this.cipherMode = mode;
        byte[] iv;
        if (params instanceof IvParameterSpec) {
            iv = ((IvParameterSpec) params).getIV();
        } else {
            // other AlgorithmParameterSpec is not supported now.
            throw new InvalidAlgorithmParameterException("Illegal parameters");
        }
        context = OpenSslNative.init(context, mode, algorithmMode, padding, key, iv);
    }

    @Override
    public int update(final ByteBuffer input, final ByteBuffer output) throws ShortBufferException {
        checkState();

        final int len = OpenSslNative.update(context, input, input.position(),
                input.remaining(), output, output.position(),
                output.remaining());
        input.position(input.limit());
        output.position(output.position() + len);

        return len;
    }

    @Override
    public int update(final byte[] input, final int inputOffset, final int inputLen, final byte[] output, final int outputOffset)
            throws ShortBufferException {
        checkState();

        return OpenSslNative.updateByteArray(context, input, inputOffset,
                inputLen, output, outputOffset, output.length - outputOffset);
    }

    @Override
    public int doFinal(final byte[] input, final int inputOffset, final int inputLen, final byte[] output, final int outputOffset)
            throws ShortBufferException, IllegalBlockSizeException, BadPaddingException {
        checkState();

        int len = OpenSslNative.updateByteArray(context, input, inputOffset,
                inputLen, output, outputOffset, output.length - outputOffset);

        len += OpenSslNative.doFinalByteArray(context, output, outputOffset + len,
                output.length - outputOffset - len);

        return len;
    }

    @Override
    public int doFinal(final ByteBuffer input, final ByteBuffer output)
            throws ShortBufferException, IllegalBlockSizeException, BadPaddingException {
        checkState();

        int totalLen = 0;
        int len = OpenSslNative.update(context, input, input.position(),
                input.remaining(), output, output.position(), output.remaining());
        totalLen += len;

        input.position(input.limit());
        output.position(output.position() + len);

        len = OpenSslNative.doFinal(context, output, output.position(),
                output.remaining());
        totalLen += len;

        output.position(output.position() + len);

        return totalLen;
    }

    @Override
    public void updateAAD(final byte[] aad) {
        throw new UnsupportedOperationException(
                "The underlying Cipher implementation "
                        + "does not support this method");
    }
}