md5、rsa、base64、aes

/**
 * 根据模和指数生成公key
 *
 * @param publicKeyStr
* @return
*/
public static RSAPublicKey getRSAPublicKey(String publicKeyStr) {
    X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(HexUtil.hex2Bytes(publicKeyStr));
RSAPublicKey publicKey = null;
    try {
        publicKey = (RSAPublicKey) KeyFactory.getInstance(AlgorithmConstant.ALGORITHM).generatePublic(x509EncodedKeySpec);
} catch (InvalidKeySpecException e) {
        e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
}
    return publicKey;
}

/**
 * 根据模和指数生成私key
 *
 * @param privateKeyStr
* @return
*/
public static RSAPrivateKey getRSAPrivateKey(String privateKeyStr) {
    PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(HexUtil.hex2Bytes(privateKeyStr));
RSAPrivateKey privateKey = null;
    try {
        privateKey = (RSAPrivateKey) KeyFactory.getInstance(AlgorithmConstant.ALGORITHM).generatePrivate(pkcs8EncodedKeySpec);
} catch (InvalidKeySpecException e) {
        e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
}
    return privateKey;
}

/**
 * 生成公钥和私钥
 * @throws NoSuchAlgorithmException
 *
 */
public static String getKeys(String mapKey) throws NoSuchAlgorithmException {
 HashMap<String, String> map = new HashMap<String, String>();
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
keyPairGen.initialize(1024);
KeyPair keyPair = keyPairGen.generateKeyPair();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
map.put("public", HexUtil.bytes2Hex(publicKey.getEncoded()));
map.put("private", HexUtil.bytes2Hex(privateKey.getEncoded()));
 return map.get(mapKey);
}

// 对content字段做MD5摘要，再对摘要进行rsa私钥加密，对加密后的字符串做base64编码

public String getSing(String msg, RSAPrivateKey privateKey) throws Exception {
// md5
MessageDigest alg = MessageDigest.getInstance("MD5");//生成信息摘要。
byte[] data = alg.digest(msg.getBytes("utf-8"));//将要输入的数据转换成字节数组,并且计算摘要
// rsa

PrivateKey privateKey = RSAKeyUtil.getRSAPrivateKey(RSAKeyUtils.getKeys("private"));
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        byte[] encrypted = cipher.doFinal(data);

// base64
return new BASE64Encoder().encode(encrypted);//此处使用BASE64做转码功能，同时能起到2次加密的作用。
}


AES加密
sSrc：内容
sKey：秘钥

public static String Encrypt(String sSrc, String sKey) throws Exception {
        if (sKey == null) {
            System.out.print("Key为空null");
            return null;
        }
        // 判断Key是否为16位
        if (sKey.length() != 16) {
            System.out.print("Key长度不是16位");
            return null;
        }
        byte[] raw = sKey.getBytes();
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");//"算法/模式/补码方式"
        IvParameterSpec iv = new IvParameterSpec("0102030405060708".getBytes());//使用CBC模式，需要一个向量iv，可增加加密算法的强度
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
        byte[] encrypted = cipher.doFinal(sSrc.getBytes());


        return new BASE64Encoder().encode(encrypted);//此处使用BASE64做转码功能，同时能起到2次加密的作用。
    }