AES 加密与解密

短命女 2022-06-04 09:49 295阅读 0赞

java AES 加密与解密  
近些年DES使用越来越少，原因就在于其使用56位密钥，比较容易被破解，近些年来逐渐被AES替代，AES已经变成目前对称加密中最流行算法之一；AES可以使用128、192、和256位密钥，并且用128位分组加密和解密数据。本文就简单介绍如何通过JAVA实现AES加密。

package com.ss.util.secret;
    
    import java.io.UnsupportedEncodingException;
    import java.security.InvalidKeyException;
    import java.security.NoSuchAlgorithmException;
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.KeyGenerator;
    import javax.crypto.NoSuchPaddingException;
    import javax.crypto.SecretKey;
    import javax.crypto.spec.SecretKeySpec;
    
    /** ** * AES128 算法，加密模式为ECB，填充模式为 pkcs7（实际就是pkcs5） * * */
    public class AESUtils { 
    
        /** * 加密 * * @param content 需要加密的内容 * @param key 加密密码 * @return */
        public static byte[] encrypt(String content, String key) {
            try {
                KeyGenerator kgen = KeyGenerator.getInstance("AES");
                kgen.init(128, new java.security.SecureRandom(key.getBytes()));
                SecretKey secretKey = kgen.generateKey();
                byte[] enCodeFormat = secretKey.getEncoded();
                SecretKeySpec secretKeySpec = 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, secretKeySpec);// 初始化
                byte[] result = cipher.doFinal(byteContent);
                return result; // 加密
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            } catch (NoSuchPaddingException e) {
                e.printStackTrace();
            } catch (InvalidKeyException e) {
                e.printStackTrace();
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (IllegalBlockSizeException e) {
                e.printStackTrace();
            } catch (BadPaddingException e) {
                e.printStackTrace();
            }
            return null;
        }
    
        /**解密 * @param content 待解密内容 * @param key 解密密钥 * @return */
        public static byte[] decrypt(byte[] content, String key) {
            try {
                KeyGenerator kgen = KeyGenerator.getInstance("AES");
                kgen.init(128, new java.security.SecureRandom(key.getBytes()));
                SecretKey secretKey = kgen.generateKey();
                byte[] enCodeFormat = secretKey.getEncoded();
                SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
                Cipher cipher = Cipher.getInstance("AES");// 创建密码器
                cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);// 初始化
                byte[] result = cipher.doFinal(content);
                return result; // 加密
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            } catch (NoSuchPaddingException e) {
                e.printStackTrace();
            } catch (InvalidKeyException e) {
                e.printStackTrace();
            } catch (IllegalBlockSizeException e) {
                e.printStackTrace();
            } catch (BadPaddingException e) {
                e.printStackTrace();
            }
            return null;
        }
    
        /** * 字符串加密 * @param content 要加密的字符串 * @param key 加密的AES Key * @return */
        public static String encryptString(String content, String key) {
            return parseByte2HexStr( encrypt(content, key));
        }
    
        /** * 字符串解密 * @param content 要解密的字符串 * @param key 解密的AES Key * @return */
        public static String decryptString(String content, String key){
            byte[] decryptFrom = parseHexStr2Byte(content);
            byte[] decryptResult = decrypt(decryptFrom,key);
            return new String(decryptResult);
        }
    
    
        /**将16进制转换为二进制 * @param hexStr * @return */
        public 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;
        }
    
    
        /**将二进制转换成16进制 * @param buf * @return */
        public 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();
        }
    
        public static void  main(String aregs[]){
            String content = "协议加密Test&123";
            String key = "25d55ad283aa400af464c76d713c07ad";
            try {
                //加密
                System.out.println("加密前：" + content);
                String encrypt = AESUtils.encryptString(content, key);
                System.out.println("加密后：" + encrypt);
                //解密
                String decrypt = AESUtils.decryptString(encrypt, key);
                System.out.println("解密后：" + decrypt);
            } catch (Exception e) {
                e.printStackTrace();
            }
    
        }
    }

运行结果：

加密前：协议加密Test&123  
加密后：7D07155438880C51E50433C17D9AFF8DCB2A9596AF46B2ABA33C18918053E3E0  
解密后：协议加密Test&123