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Java Security/Cookie Encryption

Java Cookie Encryption example

쿠키를 암호화하는 예 ( Java Cookie Encryption example )


Java Keystore 로부터 키를 로드하는 방법을 참고하려면 이 링크를 클릭하세요

AES 알고리듬을 자바에서 사용하여 암호화/복호화하는 예는 여기를 참조하세요


import java.util.logging.Logger;


import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

import javax.crypto.spec.IvParameterSpec;


/* 원문참조:http://www.java2s.com/Code/Java/Security/EncryptUsername.htm */


public class Encrypt 

{

private static Logger log = Logger.getLogger(Encrypt.class.getName());

public final static String accountSeperator = ":";


private static String key = "1234abcd";

private static String charset = "EUC-KR"; //"UTF-8";

public static void main(String[] args) throws Exception {

String encStr = encrypt("Hello 홍길동");

String decStr = decrypt(encStr);

System.out.println(encStr+":"+decStr);

}



  private static String decrypt(String message) throws Exception {

    byte[] bytesrc = convertHexString(message);

    Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

    DESKeySpec desKeySpec = new DESKeySpec(key.getBytes(charset));

    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");

    SecretKey secretKey = keyFactory.generateSecret(desKeySpec);

    IvParameterSpec iv = new IvParameterSpec(key.getBytes(charset));


    cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);

    byte[] retByte = cipher.doFinal(bytesrc);

    return new String(retByte);

  }


  private static String encrypt(String message) throws Exception {

    Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

    DESKeySpec desKeySpec = new DESKeySpec(key.getBytes(charset));

    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");

    SecretKey secretKey = keyFactory.generateSecret(desKeySpec);

    IvParameterSpec iv = new IvParameterSpec(key.getBytes(charset));

    cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);

    return toHexString(cipher.doFinal(message.getBytes(charset)));

  }


  private static byte[] convertHexString(String ss) {

    byte digest[] = new byte[ss.length() / 2];

    for (int i = 0; i < digest.length; i++) {

      String byteString = ss.substring(2 * i, 2 * i + 2);

      int byteValue = Integer.parseInt(byteString, 16);

      digest[i] = (byte) byteValue;

    }

    return digest;

  }


  private static String toHexString(byte b[]) {

    StringBuffer hexString = new StringBuffer();

    for (int i = 0; i < b.length; i++) {

      String plainText = Integer.toHexString(0xff & b[i]);

      if (plainText.length() < 2)

        plainText = "0" + plainText;

      hexString.append(plainText);

    }

    return hexString.toString();

  }


  public static String[] decodeAccount(String cookieValue) {

    try {

      String origi = Encrypt.decrypt(cookieValue);

      String[] parts = origi.split(Encrypt.accountSeperator);

      if (parts.length == 2 && !parts[0].equals("") && !parts[1].equals("")) {

        return parts;

      }

    } catch (Exception e) {

      e.printStackTrace();

      log.warning(e.getMessage());

    }

    return null;

  }


  public static String encodeAccount(String username, String password) {

    String encryptString = null;

    try {

      encryptString = Encrypt.encrypt(username + Encrypt.accountSeperator + password);

    } catch (Exception e) {

      log.warning(e.getMessage());

    }

    return encryptString;

  }

}