前言

美国国家标准技术研究所在2001年发布了高级加密标准（AES）。AES是一个对称分组密码算法，旨在取代DES成为广泛使用的标准。 根据使用的密码长度，AES最常见的有3种方案，用以适应不同的场景要求，分别是AES-128、AES-192和AES-256。本文主要对AES-128进行介绍，另外两种的思路基本一样，只是轮数会适当增加。

AES加密过程图解

1. 字节替代（SubBytes）
2. 行移位（ShiftRows）
3. 列混淆（MixColumns）
4. 轮密钥加（AddRoundKey）

加密代码示例

java加密代码

/**     * 对字符串加密     *     * @param str     * @return     * @throws InvalidKeyException     * @throws IllegalBlockSizeException     * @throws BadPaddingException     */    public byte[] encrytor(String str, String password) throws InvalidKeyException,            IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException {        KeyGenerator kgen = KeyGenerator.getInstance("AES");        SecureRandom random = SecureRandom.getInstance("SHA1PRNG");        random.setSeed(password.getBytes());        kgen.init(128, random);        SecretKey secretKey = kgen.generateKey();        byte[] enCodeFormat = secretKey.getEncoded();        SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");        Cipher cipher = Cipher.getInstance("AES");        byte[] byteContent = str.getBytes("utf-8");        cipher.init(Cipher.ENCRYPT_MODE, key);        byte[] result = cipher.doFinal(byteContent);        return result;    }    /**     * 对字符串解密     *     * @param buff     * @return     * @throws InvalidKeyException     * @throws IllegalBlockSizeException     * @throws BadPaddingException     */    public byte[] decryptor(byte[] buff, String password) throws InvalidKeyException,            IllegalBlockSizeException, BadPaddingException, NoSuchAlgorithmException, NoSuchPaddingException {        KeyGenerator kgen = KeyGenerator.getInstance("AES");        SecureRandom random = SecureRandom.getInstance("SHA1PRNG");        random.setSeed(password.getBytes());        kgen.init(128, random);        SecretKey secretKey = kgen.generateKey();        byte[] enCodeFormat = secretKey.getEncoded();        SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");        Cipher cipher = Cipher.getInstance("AES");        cipher.init(Cipher.DECRYPT_MODE, key);        byte[] result = cipher.doFinal(buff);        return result; // 加密    }    /**     * 将二进制转换成16进制     *     * @param buf     * @return     */    public String parseByte2HexStr(byte buf[]) {        StringBuffer sb = new StringBuffer();        for (int i = 0; i < buf.length; i++) {            String hex = Integer.toHexString(buf[i] & 0xFF);            if (hex.length() == 1) {                hex = '0' + hex;            }            sb.append(hex.toUpperCase());        }        return sb.toString();    }    /**     * 将16进制转换为二进制     *     * @param hexStr     * @return     */    public byte[] parseHexStr2Byte(String hexStr) {        if (hexStr.length() < 1)            return null;        byte[] result = new byte[hexStr.length() / 2];        for (int i = 0; i < hexStr.length() / 2; i++) {            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);            result[i] = (byte) (high * 16 + low);        }        return result;    }

加密解密示例

String content="www.buglife.cn";        //秘钥        String password = "buglife-secret";        byte[] encryptResult = encrytor(content, password);        //加密结果        String encryptResultStr = parseByte2HexStr(encryptResult);        //解密        byte[] decryptFrom = parseHexStr2Byte(encryptResultStr);        byte[] decryptResult = decryptor(decryptFrom, password);        //解密结果        String res = new String(decryptResult);