/*  Copyright (c) 2019 AT&T Intellectual Property.                             #
#                                                                              #
#   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.   #
#   See the License for the specific language governing permissions and        #
#   limitations under the License.                                             #
##############################################################################*/


package org.oran.otf.camunda.workflow.utility;

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import javax.crypto.Cipher;
import org.springframework.stereotype.Service;

@Service
public class RsaEncryptDecrypt {

  private KeyPair keyPair;

  public RsaEncryptDecrypt() throws NoSuchAlgorithmException {
    this.keyPair = buildKeyPair();

  }

  private KeyPair buildKeyPair() throws NoSuchAlgorithmException {
    final int keySize = 2048;
    KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
    keyPairGenerator.initialize(keySize);
    return keyPairGenerator.genKeyPair();
  }

  public byte[] encrypt(String message) throws Exception {
    Cipher cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.ENCRYPT_MODE, this.keyPair.getPrivate());

    return cipher.doFinal(message.getBytes());
  }

  public byte[] decrypt(byte[] encrypted) throws Exception {
    Cipher cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.DECRYPT_MODE, this.keyPair.getPublic());

    return cipher.doFinal(encrypted);
  }
}