package com.brazoft.foundation.util;

import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
 * @author Anderson Braz - anderson.braz@brazoft.com.br
 */
public class Crypto {

  public static final String ALGORITHM_AES = "AES";

  public static final String ALGORITHM_BLOWFISH = "Blowfish";

  public static final String ALGORITHM_DES = "DES";

  public static final String ALGORITHM_DESede = "DESede";

  public static final String ALGORITHM_PBE_MD5_DES = "PBEWithMD5AndDES";

  public static final String ALGORITHM_PBE_HMAC_SHA1_DESede = "PBEWithHmacSHA1AndDESede";

  public static final String ALGORITHM_RC2 = "RC2";

  public static final String ALGORITHM_RC4 = "RC4";

  public static final String ALGORITHM_RC5 = "RC5";

  public static final String ALGORITHM_RSA = "RSA";

  public static final String MODE_NONE = "NONE";

  public static final String MODE_CBC = "CBC";

  public static final String MODE_CFB = "CFB";

  public static final String MODE_ECB = "ECB";

  public static final String MODE_OFB = "OFB";

  public static final String MODE_PCBC = "PCBC";

  public static final String PADDING_NONE = "NoPadding";

  public static final String PADDING_OAEP_MD5_MGF1 = "OAEPWithMD5AndMGF1Padding";

  public static final String PADDING_PKCS5 = "PKCS5Padding";

  public static final String PADDING_SSL3 = "SSL3Padding";

  public static final String ENCODING = "UTF-8";

  public static SecretKey generateKey(String algorithm) {
    try {
      return KeyGenerator.getInstance(algorithm).generateKey();
    } catch (NoSuchAlgorithmException e) {
      ExceptionHandler.handleRuntime(e);
      return null;
    }
  }

  public static String encrypt(String message, String algorithm, SecretKey key) {
    Cipher encryptor;

    try {
      encryptor = Cipher.getInstance(algorithm);
      encryptor.init(Cipher.ENCRYPT_MODE, key);

      return new BASE64Encoder().encode(encryptor.doFinal(message.getBytes(Crypto.ENCODING)));
    } catch (Exception e) {
      ExceptionHandler.handleRuntime(e);
      return null;
    }
  }

  public static String decrypt(String message, String algorithm, SecretKey key) {
    Cipher encryptor;

    try {
      encryptor = Cipher.getInstance(algorithm);
      encryptor.init(Cipher.DECRYPT_MODE, key);

      return new String(encryptor.doFinal(new BASE64Decoder().decodeBuffer(message)),
          Crypto.ENCODING);
    } catch (Exception e) {
      ExceptionHandler.handleRuntime(e);
      return null;
    }
  }

  public static boolean compare(String s1, String s2) {
    byte[] stored;
    byte[] typed;
    boolean match;

    try {
      match = true;
      stored = s1.getBytes(Crypto.ENCODING);
      typed = s2.getBytes(Crypto.ENCODING);

      if (stored.length != typed.length) {
        match = false;
      } else {
        for (int i = 0; i < stored.length; i++) {
          if (stored[i] != typed[i]) {
            match = false;
            break;
          }
        }
      }
    } catch (Exception e) {
      e.printStackTrace();
      match = false;
    }

    return match;
  }
}