AdvancedEncryptionStandard

import java.security.GeneralSecurityException;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import com.citi.simpliciti.tempest.TempestRuntimeException;

public class AdvancedEncryptionStandard {

  private static final String ALGORITHM = "AES";
  private final SecretKeySpec secretKey;
  private final Cipher encoder;
  private final Cipher decoder;

  public AdvancedEncryptionStandard(byte[] key) {
    try {
      secretKey = new SecretKeySpec(key, ALGORITHM);
      encoder = Cipher.getInstance(ALGORITHM);
      encoder.init(Cipher.ENCRYPT_MODE, secretKey);
      decoder = Cipher.getInstance(ALGORITHM);
      decoder.init(Cipher.DECRYPT_MODE, secretKey);
    } catch (Exception e) {
      throw new TempestRuntimeException(e);
    }
  }

  /**
   * Encrypts the given plain text
   *
   * @param plainText The plain text to encrypt
   * @throws GeneralSecurityException
   */
  public byte[] encrypt(byte[] plainText) throws GeneralSecurityException {
    synchronized (encoder) {
      return encoder.doFinal(plainText);
    }
  }

  /**
   * Decrypts the given byte array
   *
   * @param cipherText The data to decrypt
   * @throws GeneralSecurityException
   */
  public byte[] decrypt(byte[] cipherText) throws GeneralSecurityException {
    synchronized (decoder) {
      return decoder.doFinal(cipherText);
    }
  }
}