Java实现AES加密与解密（秘钥）

Love The Way You Lie 2023-06-04 10:55 17阅读 0赞

package com.company.example;
     
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import sun.misc.BASE64Decoder;
    import sun.misc.BASE64Encoder;
     
    import javax.crypto.Cipher;
    import javax.crypto.KeyGenerator;
    import javax.crypto.SecretKey;
    import javax.crypto.spec.SecretKeySpec;
    import java.io.IOException;
    import java.security.SecureRandom;
     
    /**
     * AES加密解密
     */
    public class SecurityUtil {
     
    	private static final Logger logger = LoggerFactory.getLogger(SecurityUtil.class);
    	private static final String ENCODING = "UTF-8";
    	private static final String PASSWORD = "46EBA22EF5204DD5B110A1F730513965"; // 加密秘钥
     
    	/**
    	 * AES加密
    	 * @param content 明文
    	 * @return 密文
    	 */
    	public static String encryptAES(String content) {
    		if (StringUtil.isEmpty(content)) {
    			throw new ParamException("明文不能为空！");
    		}
    		byte[] encryptResult = encrypt(content, PASSWORD);
    		String encryptResultStr = parseByte2HexStr(encryptResult);
    		// BASE64位加密
    		encryptResultStr = ebotongEncrypto(encryptResultStr);
    		return encryptResultStr;
    	}
     
    	/**
    	 * AES解密
    	 * @param encryptResultStr 密文
    	 * @return 明文
    	 */
    	public static String decryptAES(String encryptResultStr) {
    		if (StringUtil.isEmpty(encryptResultStr)) {
    			throw new ParamException("密文不能为空");
    		}
    		// BASE64位解密
    		try {
    			String decrpt = ebotongDecrypto(encryptResultStr);
    			byte[] decryptFrom = parseHexStr2Byte(decrpt);
    			byte[] decryptResult = decrypt(decryptFrom, PASSWORD);
    			return new String(decryptResult);
    		} catch (Exception e) { // 当密文不规范时会报错，可忽略，但调用的地方需要考虑
    			return null;
    		}
    	}
     
    	/**
    	 * 加密字符串
    	 */
    	private static String ebotongEncrypto(String str) {
    		BASE64Encoder base64encoder = new BASE64Encoder();
    		String result = str;
    		if (str != null && str.length() > 0) {
    			try {
    				byte[] encodeByte = str.getBytes(ENCODING);
    				result = base64encoder.encode(encodeByte);
    			} catch (Exception e) {
    				e.printStackTrace();
    			}
    		}
    		// base64加密超过一定长度会自动换行 需要去除换行符
    		return result.replaceAll("\r\n", "").replaceAll("\r", "").replaceAll("\n", "");
    	}
     
    	/**
    	 * 解密字符串
    	 */
    	private static String ebotongDecrypto(String str) {
    		BASE64Decoder base64decoder = new BASE64Decoder();
    		try {
    			byte[] encodeByte = base64decoder.decodeBuffer(str);
    			return new String(encodeByte);
    		} catch (IOException e) {
    			logger.error("IO 异常",e);
    			return str;
    		}
    	}
     
    	/**
    	 * 加密
    	 * @param content 需要加密的内容
    	 * @param password 加密密码
    	 * @return
    	 */
    	private static byte[] encrypt(String content, String password) {
    		try {
    			KeyGenerator kgen = KeyGenerator.getInstance("AES");
    			// 注意这句是关键，防止linux下 随机生成key。用其他方式在Windows上正常，但Linux上会有问题
    			SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
    			secureRandom.setSeed(password.getBytes());
    			kgen.init(128, secureRandom);
    			// kgen.init(128, new SecureRandom(password.getBytes()));
    			SecretKey secretKey = kgen.generateKey();
    			byte[] enCodeFormat = secretKey.getEncoded();
    			SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
    			Cipher cipher = Cipher.getInstance("AES");// 创建密码器
    			byte[] byteContent = content.getBytes("utf-8");
    			cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
    			byte[] result = cipher.doFinal(byteContent);
    			return result; // 加密
    		} catch (Exception e) {
    			logger.error("加密异常", e);
    		}
    		return null;
    	}
     
    	/**
    	 * 解密
    	 * @param content 待解密内容
    	 * @param password 解密密钥
    	 * @return
    	 */
    	private static byte[] decrypt(byte[] content, String password) {
    		try {
    			KeyGenerator kgen = KeyGenerator.getInstance("AES");
    			// 防止linux下 随机生成key
    			SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
    			secureRandom.setSeed(password.getBytes());
    			kgen.init(128, secureRandom);
    			// kgen.init(128, new SecureRandom(password.getBytes()));
    			SecretKey secretKey = kgen.generateKey();
    			byte[] enCodeFormat = secretKey.getEncoded();
    			SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
    			Cipher cipher = Cipher.getInstance("AES");// 创建密码器
    			cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
    			byte[] result = cipher.doFinal(content);
    			return result; // 加密
    		} catch (Exception e) {
    			logger.error("解密异常", e);
    		}
    		return null;
    	}
     
    	/**
    	 * 将二进制转换成16进制
    	 * @param buf
    	 * @return
    	 */
    	private static 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
    	 */
    	private static 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;
    	}
     
    	public static void main(String[] args) {
    		test();
    	}
     
    	/**
    	 * 测试
    	 */
    	private static void test() {
    		System.out.println("加密解密试试：");
    		String content = "EXPRESS";
    		System.out.println("原内容为：" + content);
    		String encryContent = encryptAES(content);
    		System.out.println("加密后的内容为：" + encryContent);
    		String decryContent = decryptAES(encryContent);
    		System.out.println("解密后的内容为：" + decryContent);
    	}
     
    }