AES 加密 128位

論述

  AES已經變成目前對稱加密中最流行算法之一；AES可以使用128、192、和256位密鑰，并且用128位分組加密和解密資料。本文就簡單介紹如何通過JAVA實作AES加密。

 java實作

加密

/**
 * 加密
 *
 * @param content
 * @param encryptKey
 */

public static String aesEncrypt(String content, String encryptKey) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
    return base64Encode(aesEncryptToBytes(content, encryptKey));
}
public static byte[] aesEncryptToBytes(String content, String encryptKey) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
    KeyGenerator kgen = KeyGenerator.getInstance("AES");
    kgen.init(128, new SecureRandom(encryptKey.getBytes()));
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
    return cipher.doFinal(content.getBytes("UTF-8"));
}
public static String base64Encode(byte[] bytes) {
    return new BASE64Encoder().encode(bytes);
}      

 解密資料

public static String aesDecrypt(String encryptStr, String decryptKey) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, IOException {
    return isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
}
public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
    KeyGenerator kgen = KeyGenerator.getInstance("AES");
    kgen.init(128, new SecureRandom(decryptKey.getBytes()));
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
    byte[] decryptBytes = cipher.doFinal(encryptBytes);
    return new String(decryptBytes, "UTF-8");
}
public static byte[] base64Decode(String base64Code) throws IOException {
    return isEmpty(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);
}      

這裡少了一段話是判斷為空的方法

/**
 * 判斷是否為空
 *
 * @param str
 * @return
 */
public static boolean isEmpty(String str) {
    if (str == null) {
        return true;
    } else if ("".equals(str.trim())) {
        return true;
    } else {
        return false;
    }
}      

填寫加密資料進行加解密      

String content ="{'amt':'" + "0.01" + "'},{'traceNo':'" + "000415" + "'}";
            System.out.println("原文："+content);
            String encodeContent = aesEncrypt(content,"123456789");
//            System.out.println("密文："+byteToHexString(encodeContent.getBytes()));
            String decodeContent = aesDecrypt(encodeContent,"123456789");
            System.out.println("解密："+decodeContent);      

如果加密資料想看十六進制寫了轉化類

public static String byteToHexString(byte [] byteHex){
    String strHex="";
    if(byteHex==null)
        return "";
    for(int i=0;i<byteHex.length;i++){
        strHex=strHex+String.format("%02X", byteHex[i]);
    }
    return strHex;
}