AES加密

ゞ浴缸里的玫瑰 2022-02-15 00:09 264阅读 0赞

AES技术是一种对称的分组加密技术，使用128位分组加密数据，提供比WEP/TKIPS的RC4算法更高的加密强度。AES的加密码表和解密码表是分开的，并且支持子密钥加密，这种做法优于以前用一个特殊的密钥解密的做法。

public class AESUtils {
    
        public static String generateKey() throws NoSuchAlgorithmException {
            KeyGenerator kg = KeyGenerator.getInstance("AES");
            kg.init(128);
            SecretKey sk = kg.generateKey();
            byte[] b = sk.getEncoded();
            return byteToHexString(b);
        }
    
        public static String byteToHexString(byte[] bytes){
            StringBuffer sb = new StringBuffer();
            for (int i = 0; i < bytes.length; i++) {
                String strHex=Integer.toHexString(bytes[i]);
                if(strHex.length() > 3){
                    sb.append(strHex.substring(6));
                } else {
                    if(strHex.length() < 2){
                        sb.append("0" + strHex);
                    } else {
                        sb.append(strHex);
                    }
                }
            }
            return  sb.toString();
        }
    
        public static String aesEncryptToBytes(String content, String encryptKey) throws Exception {
            if(StringUtils.isNotBlank(content) && StringUtils.isNotBlank(encryptKey)){
                KeyGenerator kgen = KeyGenerator.getInstance("AES");
                kgen.init(128);
                Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
                cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(), "AES"));
    
                byte[] bytes = cipher.doFinal(content.getBytes("utf-8"));
                return Base64.encodeBase64String(bytes);
            }else{
                return null;
            }
        }
    
        public static String aesDecryptByBytes(String encrypt, String decryptKey) throws Exception {
            byte[] encryptBytes = new BASE64Decoder().decodeBuffer(encrypt);
            if(encryptBytes.length>0 && org.apache.commons.lang.StringUtils.isNotBlank(decryptKey)){
                KeyGenerator kgen = KeyGenerator.getInstance("AES");
                kgen.init(128);
                Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
                cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(), "AES"));
                byte[] decryptBytes = cipher.doFinal(encryptBytes);
                return new String(decryptBytes);
            }else{
                return null;
            }
        }
    
        public static void main(String[] args) throws Exception {
            String key = generateKey();
            String encrypt = aesEncryptToBytes("w1DH8vuC", key);
            System.out.println("加密后：" + encrypt);
            String decrypt = aesDecryptByBytes(encrypt,key);
            System.out.println("解密后：" + decrypt);
        }
    
    }