/*
   * 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.
   * <p>
   * It will call the OpenSSL API to implement encryption/decryption
   * </p>
   */
  final class OpenSslCommonMode extends AbstractOpenSslFeedbackCipher {
  
      OpenSslCommonMode(final long context, final int algorithmMode, final int padding) {
          super(context, algorithmMode, padding);
      }
  
      @Override
      public int doFinal(final byte[] input, final int inputOffset, final int inputLen, final byte[] output, final int outputOffset)
              throws ShortBufferException, IllegalBlockSizeException, BadPaddingException {
          checkState();
          final int outputLength = output.length;
  
          int len = OpenSslNative.updateByteArray(context, input, inputOffset, inputLen, output, outputOffset, outputLength - outputOffset);
  
          len += OpenSslNative.doFinalByteArray(context, output, outputOffset + len, outputLength - 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 init(final int mode, final byte[] key, final AlgorithmParameterSpec params) throws InvalidAlgorithmParameterException {
          this.cipherMode = mode;
          final byte[] iv;
          if (!(params instanceof IvParameterSpec)) {
              // other AlgorithmParameterSpec is not supported now.
              throw new InvalidAlgorithmParameterException("Illegal parameters");
          }
          iv = ((IvParameterSpec) params).getIV();
          context = OpenSslNative.init(context, mode, algorithmMode, padding, key, iv);
      }
  
      @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 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 void updateAAD(final byte[] aad) {
         throw new UnsupportedOperationException("The underlying Cipher implementation does not support this method");
     }
 }