cipherspi.java

gcc的组建

   * <code>abstract</code>, and the default implementation will throw an
   * {@link java.lang.UnsupportedOperationException}. Concrete
   * subclasses should override this method to return the correct
   * value.</p>
   *
   * @param key The key to get the size for.
   * @return The size of the key, in bits.
   * @throws java.security.InvalidKeyException If the key's length
   *         cannot be determined by this implementation.
   */
  protected int engineGetKeySize(Key key) throws InvalidKeyException
  {
    throw new UnsupportedOperationException();
  }

  /**
   * <p>Returns the size, in bytes, an output buffer must be for a call
   * to {@link #engineUpdate(byte[],int,int,byte[],int)} or {@link
   * #engineDoFinal(byte[],int,int,byte[],int)} to succeed.</p>
   *
   * <p>The actual output length may be smaller than the value returned
   * by this method, as it considers the padding length as well. The
   * length considered is the argument plus the length of any buffered,
   * unprocessed bytes.</p>
   *
   * @param inputLength The input length, in bytes.
   * @return The size an output buffer must be.
   */
  protected abstract int engineGetOutputSize(int inputLength);

  /**
   * Returns the parameters that this cipher is using. This may be the
   * parameters used to initialize this cipher, or it may be parameters
   * that have been initialized with random values.
   *
   * @return This cipher's parameters, or <code>null</code> if this
   *         cipher does not use parameters.
   */
  protected abstract AlgorithmParameters engineGetParameters();

  /**
   * Initializes this cipher with an operation mode, key, and source of
   * randomness. If this cipher requires any other initializing data,
   * for example an initialization vector, then it should generate it
   * from the provided source of randomness.
   *
   * @param opmode The operation mode, one of {@link
   *        Cipher#DECRYPT_MODE}, {@link Cipher#ENCRYPT_MODE}, {@link
   *        Cipher#UNWRAP_MODE}, or {@link Cipher#WRAP_MODE}.
   * @param key    The key to initialize this cipher with.
   * @param random The source of random bytes to use.
   * @throws java.security.InvalidKeyException If the given key is not
   *         acceptable for this implementation.
   */
  protected abstract void engineInit(int opmode, Key key, SecureRandom random)
  throws InvalidKeyException;

  /**
   * Initializes this cipher with an operation mode, key, parameters,
   * and source of randomness. If this cipher requires any other
   * initializing data, for example an initialization vector, then it should
   * generate it from the provided source of randomness.
   *
   * @param opmode The operation mode, one of {@link
   *        Cipher#DECRYPT_MODE}, {@link Cipher#ENCRYPT_MODE}, {@link
   *        Cipher#UNWRAP_MODE}, or {@link Cipher#WRAP_MODE}.
   * @param key    The key to initialize this cipher with.
   * @param params The algorithm parameters to initialize with.
   * @param random The source of random bytes to use.
   * @throws java.security.InvalidAlgorithmParameterException If the
   *         given parameters are not appropriate for this
   *         implementation.
   * @throws java.security.InvalidKeyException If the given key is not
   *         acceptable for this implementation.
   */
  protected abstract void
  engineInit(int opmode, Key key, AlgorithmParameters params,
             SecureRandom random)
  throws InvalidAlgorithmParameterException, InvalidKeyException;

  /**
   * Initializes this cipher with an operation mode, key, parameters,
   * and source of randomness. If this cipher requires any other
   * initializing data, for example an initialization vector, then it should
   * generate it from the provided source of randomness.
   *
   * @param opmode The operation mode, one of {@link
   *        Cipher#DECRYPT_MODE}, {@link Cipher#ENCRYPT_MODE}, {@link
   *        Cipher#UNWRAP_MODE}, or {@link Cipher#WRAP_MODE}.
   * @param key    The key to initialize this cipher with.
   * @param params The algorithm parameters to initialize with.
   * @param random The source of random bytes to use.
   * @throws java.security.InvalidAlgorithmParameterException If the
   *         given parameters are not appropriate for this
   *         implementation.
   * @throws java.security.InvalidKeyException If the given key is not
   *         acceptable for this implementation.
   */
  protected abstract void
  engineInit(int opmode, Key key, AlgorithmParameterSpec params,
             SecureRandom random)
  throws InvalidAlgorithmParameterException, InvalidKeyException;

  /**
   * Set the mode in which this cipher is to run.
   *
   * @param mode The name of the mode to use.
   * @throws java.security.NoSuchAlgorithmException If the mode is
   *         not supported by this cipher's provider.
   */
  protected abstract void engineSetMode(String mode)
  throws NoSuchAlgorithmException;

  /**
   * Set the method with which the input is to be padded.
   *
   * @param padding The name of the padding to use.
   * @throws javax.crypto.NoSuchPaddingException If the padding is not
   *         supported by this cipher's provider.
   */
  protected abstract void engineSetPadding(String padding)
  throws NoSuchPaddingException;

  /**
   * <p>Unwraps a previously-wrapped key.</p>
   *
   * <p>For compatibility this method is not declared
   * <code>abstract</code>, and the default implementation will throw an
   * {@link java.lang.UnsupportedOperationException}.</p>
   *
   * @param wrappedKey          The wrapped key.
   * @param wrappedKeyAlgorithm The name of the algorithm used to wrap
   *                            this key.
   * @param wrappedKeyType      The type of wrapped key; one of
   *                            {@link Cipher#PRIVATE_KEY},
   *                            {@link Cipher#PUBLIC_KEY}, or
   *                            {@link Cipher#SECRET_KEY}.
   * @return The unwrapped key.
   * @throws java.security.InvalidKeyException If the key cannot be
   *         unwrapped, or if <code>wrappedKeyType</code> is an
   *         inappropriate type for the unwrapped key.
   * @throws java.security.NoSuchAlgorithmException If the
   *         <code>wrappedKeyAlgorithm</code> is unknown.
   */
  protected Key engineUnwrap(byte[] wrappedKey, String wrappedKeyAlgorithm,
                             int wrappedKeyType)
  throws InvalidKeyException, NoSuchAlgorithmException
  {
    throw new UnsupportedOperationException();
  }

  /**
   * Continue with a multi-part transformation, returning a new array of
   * the transformed bytes.
   *
   * @param input       The next input bytes.
   * @param inputOffset The index in the input array from which to start.
   * @param inputLength The number of bytes to input.
   * @return The transformed bytes.
   */
  protected abstract byte[]
  engineUpdate(byte[] input, int inputOffset, int inputLength);

  /**
   * Continue with a multi-part transformation, storing the transformed
   * bytes into the specified array.
   *
   * @param input        The next input bytes.
   * @param inputOffset  The index in the input from which to start.
   * @param inputLength  The number of bytes to input.
   * @param output       The output buffer.
   * @param outputOffset The index in the output array from which to start.
   * @return The transformed bytes.
   * @throws javax.crypto.ShortBufferException If there is not enough
   *         space in the output array to store the transformed bytes.
   */
  protected abstract int
  engineUpdate(byte[] input, int inputOffset, int inputLength,
               byte[] output, int outputOffset)
  throws ShortBufferException;

  /**
   * <p>Wrap a key.</p>
   *
   * <p>For compatibility this method is not declared
   * <code>abstract</code>, and the default implementation will throw an
   * {@link java.lang.UnsupportedOperationException}.</p>
   *
   * @param key The key to wrap.
   * @return The wrapped key.
   * @throws java.security.InvalidKeyException If the key cannot be
   *         wrapped.
   */
  protected byte[] engineWrap(Key key) throws InvalidKeyException, IllegalBlockSizeException
  {
    throw new UnsupportedOperationException();
  }
}