开放平台核心功能--授权

摘要：系统交互流程授权码生成加密解密算法算法名称算法名称加密模式填充方式编码生成密钥对象密钥字符串密钥对象加密数据待加密数据密钥加密后的数据实例化对象，它用于完成实际的加密操作初始化对象，设置为加密模式执行加密操作。

import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;

/**
 * @author liuzhongxu
 * @date 2019/4/16
 */
public class AESUtil {
    /**
     * 算法名称
     */
    public static final String KEY_ALGORITHM = "AES";
    /**
     *算法名称/加密模式/填充方式
     */
    public static final String CIPHER_ALGORITHM = "AES/CBC/PKCS5Padding";
    /**
     * 编码
     */
    public static final String CHARSET_NAME = "UTF-8";

    /**
     *
     * 生成密钥key对象
     * @param keyStr 密钥字符串
     * @return 密钥对象
     * @throws InvalidKeyException
     * @throws NoSuchAlgorithmException
     * @throws InvalidKeySpecException
     * @throws Exception
     */
    private static SecretKey keyGenerator(String keyStr) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(keyStr.getBytes(CHARSET_NAME), KEY_ALGORITHM);
        return secretKey;
    }
    /**
     * 加密数据
     * @param data 待加密数据
     * @param key 密钥
     * @return 加密后的数据
     */
    public static String encrypt(String data, String key) throws Exception {
        Key secretKey = keyGenerator(key);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes(CHARSET_NAME));
        // 实例化Cipher对象，它用于完成实际的加密操作
        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
        // 初始化Cipher对象，设置为加密模式
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
        byte[] results = cipher.doFinal(data.getBytes(CHARSET_NAME));
        // 执行加密操作。加密后的结果通常都会用Base64编码进行传输
        return Base64.encodeBase64String(results);
    }
    /**
     * 解密数据
     * @param data 待解密数据
     * @param key 密钥
     * @return 解密后的数据
     */
    public static String decrypt(String data, String key) throws Exception {
        Key secretKey = keyGenerator(key);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes(CHARSET_NAME));
        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
        //初始化Cipher对象，设置为解密模式
        cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
        // 执行解密操作
        return new String(cipher.doFinal(Base64.decodeBase64(data)));
    }
    public static void main(String[] args) throws Exception {
        String source = "工作模式-->>ECB：电子密码本模式、CBC：加密分组链接模式、CFB：加密反馈模式、OFB：输出反馈模式";
        System.out.println("原文: " + source);
        String key = "A1B2C3D4A1B2C3D4";
        String encryptData = encrypt(source, key);
        System.out.println("加密后: " + encryptData);
        String decryptData = decrypt(encryptData, key);
        System.out.println("解密后: " + decryptData);
    }
}

    /**
     * 计算签名
     */
    private static String calculateSign(String source, String accessSecret) throws InvalidKeyException {
        try {
            //HmacSHA256加密
            Mac mac = Mac.getInstance("HmacSHA256");
            mac.init(new SecretKeySpec(accessSecret.getBytes("UTF-8"), "HmacSHA256"));
            byte[] signData = mac.doFinal(source.getBytes("UTF-8"));
            //bas64加密
            return Base64.getEncoder().encodeToString(signData);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("HMAC-SHA1 not supported.");
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("UTF-8 not supported.");
        }
 
    }