[ 加密 ] AES 加密 目前应用最广泛的加密算法 推荐使用

特殊说明

Java标准库提供的算法实现并不包括所有的工作模式和所有填充模式，但是通常我们只需要挑选常用的使用就可以了

AES算法是目前应用最广泛的加密算法 推荐使用

AES 实现它

ECB模式

import lombok.extern.slf4j.Slf4j;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.GeneralSecurityException;
import java.util.Base64;

/**
 * aes 加密解密demo
 */
@Slf4j
public class AesEncrypt {

    public static void ecb() throws Exception {
        // 原文:
        String message = "Hello, world!";
        System.out.println("Message: " + message);
        // 128位密钥 = 16 bytes Key:
        byte[] key = "1234567890abcdef".getBytes(StandardCharsets.UTF_8);
        // 加密:
        byte[] data = message.getBytes(StandardCharsets.UTF_8);
        byte[] encrypted = encrypt(key, data);
        log.info("Encrypted: {}", Base64.getEncoder().encodeToString(encrypted));
        // 解密:
        byte[] decrypted = decrypt(key, encrypted);
        log.info("Decrypted: {}", new String(decrypted, StandardCharsets.UTF_8));
    }

    // ecb 加密
    public static byte[] encrypt(byte[] key, byte[] input) throws GeneralSecurityException {
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        SecretKey keySpec = new SecretKeySpec(key, "AES");
        cipher.init(Cipher.ENCRYPT_MODE, keySpec);
        return cipher.doFinal(input);
    }

    // ecb 解密
    public static byte[] decrypt(byte[] key, byte[] input) throws GeneralSecurityException {
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        SecretKey keySpec = new SecretKeySpec(key, "AES");
        cipher.init(Cipher.DECRYPT_MODE, keySpec);
        return cipher.doFinal(input);
    }
}

CBC模式

package cn.gd.cz.hong.encrypt.encryption;

import lombok.extern.slf4j.Slf4j;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.GeneralSecurityException;
import java.security.SecureRandom;
import java.util.Base64;

/**
 * aes 加密解密demo
 */
@Slf4j
public class AesEncrypt {


    public static void cbc() throws Exception {
        // 原文:
        String message = "Hello, world!";
        System.out.println("Message: " + message);
        // 256位密钥 = 32 bytes Key:
        byte[] key = "1234567890abcdef1234567890abcdef".getBytes("UTF-8");
        // 加密:
        byte[] data = message.getBytes("UTF-8");
        byte[] encrypted = cbcEncrypt(key, data);
        System.out.println("Encrypted: " + Base64.getEncoder().encodeToString(encrypted));
        // 解密:
        byte[] decrypted = cbcDecrypt(key, encrypted);
        System.out.println("Decrypted: " + new String(decrypted, "UTF-8"));
    }

    // 加密:
    public static byte[] cbcEncrypt(byte[] key, byte[] input) throws GeneralSecurityException {
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
        // CBC模式需要生成一个16 bytes的initialization vector:
        SecureRandom sr = SecureRandom.getInstanceStrong();
        byte[] iv = sr.generateSeed(16);
        IvParameterSpec ivps = new IvParameterSpec(iv);
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivps);
        byte[] data = cipher.doFinal(input);
        // IV不需要保密，把IV和密文一起返回:
        return join(iv, data);
    }

    // 解密:
    public static byte[] cbcDecrypt(byte[] key, byte[] input) throws GeneralSecurityException {
        // 把input分割成IV和密文:
        byte[] iv = new byte[16];
        byte[] data = new byte[input.length - 16];
        System.arraycopy(input, 0, iv, 0, 16);
        System.arraycopy(input, 16, data, 0, data.length);
        // 解密:
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
        IvParameterSpec ivps = new IvParameterSpec(iv);
        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivps);
        return cipher.doFinal(data);
    }

    public static byte[] join(byte[] bs1, byte[] bs2) {
        byte[] r = new byte[bs1.length + bs2.length];
        System.arraycopy(bs1, 0, r, 0, bs1.length);
        System.arraycopy(bs2, 0, r, bs1.length, bs2.length);
        return r;
    }

}