http://github.com/google/tink: Tink is a small cryptographic library that provides a safe, simple, agile and fast way to accomplish some common cryptographic tasks. 
// Copyright 2017 Google Inc.
//
// Licensed 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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////////////////////////////////////////////////////////////////////////////////

package com.google.crypto.tink.subtle;

import com.google.crypto.tink.Aead;
import java.security.GeneralSecurityException;


A helper for DEM (data encapsulation mechanism) of ECIES-AEAD-HKDF.

Since:1.0.0
/**
 * A helper for DEM (data encapsulation mechanism) of ECIES-AEAD-HKDF.
 *
 * @since 1.0.0
 */
public interface EciesAeadHkdfDemHelper {
  
Returns:the size of the DEM-key in bytes.
/** @return the size of the DEM-key in bytes. */
  public int getSymmetricKeySizeInBytes();

  
Creates a new Aead-primitive that uses the key material given in 'symmetric_key', which must be of length dem_key_size_in_bytes(). 
Returns:the newly created Aead-primitive.
/**
   * Creates a new {@code Aead}-primitive that uses the key material given in 'symmetric_key', which
   * must be of length dem_key_size_in_bytes().
   *
   * @return the newly created {@code Aead}-primitive.
   */
  public Aead getAead(final byte[] symmetricKeyValue) throws GeneralSecurityException;
}