RSA 加密解密

小灰灰 2023-06-19 09:42 0阅读 0赞

RSA 加密解密实现代码如下：

package com.barcodecheck;
    
    import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.serializer.SerializerFeature;
    
    import javax.crypto.Cipher;
    import java.security.*;
    import java.security.interfaces.RSAPrivateKey;
    import java.security.interfaces.RSAPublicKey;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    import java.util.Arrays;
    import java.util.Base64;
    import java.util.HashMap;
    import java.util.Map;
    
    /**
     * @author :zoboy
     * @Description:
     * @ Date: Created in 2019-12-05 09:28
     */
    public class RSADemo {
        static String publicKey = "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAM/bj9+o9pQobuHKRCIuFm2fky8cAvmE1aiAsG/fGLm0zqVGt7M9DAHEVcLd3WVPPVSFLGvp9ysRm565vGrU4HkCAwEAAQ==";
        static String privateKey = "MIIBVQIBADANBgkqhkiG9w0BAQEFAASCAT8wggE7AgEAAkEAz9uP36j2lChu4cpEIi4WbZ+TLxwC+YTVqICwb98YubTOpUa3sz0MAcRVwt3dZU89VIUsa+n3KxGbnrm8atTgeQIDAQABAkEAm62pw21sSSlDaw8wGp2EJNTYyvbi73ljARJpk1B311XPlsrfJJzDEGpHmqoenXnKTtrFK+OOLGWEEwPsJWY+gQIhAO6WrONtzxmc9CF3TgpD8c05XpKdQKHlvHNXcnCzn5bRAiEA3wbFJiQFFOXzeelDOVw+xwdKO4o4eyPx67AX4ElKaSkCIBdw+GWT+WAT2qybEzDRAiXeuBsBlkMR1lUix1ypWUmxAiEAonSSAxhVw0VFN1Zcq1mwONXskrY6Miiave2FVtDMLRECIDWX4aXKHKDpu7HwUYwsa7o/bbG7POMsCoeMkKhUxAN9";
    
        public static void main(String[] args) {
            initKey();
            Map map = new HashMap();
            map.put("requestId", "1231");
            map.put("companyCode", "10");
            map.put("busNum", "陕A07157D");
            map.put("svrReqTime", "1575422395");
            map.put("classesMD5Code", "");
            map.put("lineNum", "123569");
            String result11 = encrypt(map);
            decrypt(result11);
        }
        public static void rsaPrivateKeyInfo(RSAPrivateKey rsaPrivateKey){
            System.out.println("Private Key : " + privateKey);
            System.out.println("Private Key Mod: " + rsaPrivateKey.getModulus());
            System.out.println("Private Key Mod length: " + rsaPrivateKey.getModulus().bitLength());
            System.out.println("Private Key Exp: " + rsaPrivateKey.getPrivateExponent());
            System.out.println("Private format:" + rsaPrivateKey.getFormat());
            System.out.println("Private Key Algorithm: " +  rsaPrivateKey.getAlgorithm());
        }
        public static void rsaPublicKeyInfo(RSAPublicKey rsaPublicKey){
            System.out.println("Public Key : " + publicKey);
            System.out.println("Public Key Mod: " + rsaPublicKey.getModulus());
            System.out.println("Public Key Mod length: " + rsaPublicKey.getModulus().bitLength());
            System.out.println("Public Key Exp: " + rsaPublicKey.getPublicExponent());
            System.out.println("Public Key Algorithm: " +  rsaPublicKey.getAlgorithm());
            System.out.println("Public format:" + rsaPublicKey.getFormat());
        }
    
        public static void initKey() {
            // 1、初始化密钥
            KeyPairGenerator keyPairGenerator;
            try {
                keyPairGenerator = KeyPairGenerator.getInstance("RSA");
                keyPairGenerator.initialize(512);// 64的整倍数
                KeyPair keyPair = keyPairGenerator.generateKeyPair();
                RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
                RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
                publicKey = Base64.getEncoder().encodeToString(rsaPublicKey.getEncoded());
                privateKey = Base64.getEncoder().encodeToString(rsaPrivateKey.getEncoded());
                rsaPublicKeyInfo(rsaPublicKey);
                rsaPrivateKeyInfo(rsaPrivateKey);
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            }
        }
    
        public static String encrypt(Object obj) {
    
            //2 私钥加密，公钥解密   --加密
            try {
                String encryptStr = JSON.toJSONString(obj, SerializerFeature.DisableCircularReferenceDetect);
                byte[] result1 = encryptStr.getBytes("utf-8");
                byte[] buffer = Base64.getDecoder().decode(privateKey);
                PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
                KeyFactory instance = KeyFactory.getInstance("RSA");
                RSAPrivateKey key = (RSAPrivateKey) instance.generatePrivate(keySpec);
                rsaPrivateKeyInfo(key);
                Cipher cipher = Cipher.getInstance("RSA");
                cipher.init(Cipher.ENCRYPT_MODE, key);
                int inputLength = result1.length;
                System.out.println("加密字节数：" + inputLength);
    
                int MAX_ENCRYPT_BLOCK = key.getModulus().bitLength()/8-11;
                // 标识
                int offSet = 0;
                byte[] resultBytes = {};
                byte[] cache = {};
                while (inputLength - offSet > 0) {
                    if (inputLength - offSet > MAX_ENCRYPT_BLOCK) {
                        cache = cipher.doFinal(result1, offSet, MAX_ENCRYPT_BLOCK);
                        offSet += MAX_ENCRYPT_BLOCK;
                    } else {
                        cache = cipher.doFinal(result1, offSet, inputLength - offSet);
                        offSet = inputLength;
                    }
                    resultBytes = Arrays.copyOf(resultBytes, resultBytes.length + cache.length);
                    System.arraycopy(cache, 0, resultBytes, resultBytes.length - cache.length, cache.length);
                }
    
                String result11 = Base64.getEncoder().encodeToString(resultBytes);
                System.out.println("私钥加密，公钥解密   --加密: " + result11);
                return result11;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
    
        public static void decrypt(String ss) {
            //3 私钥加密，公钥解密   --解密
            try {
                byte[] buffer = Base64.getDecoder().decode(publicKey);
                byte[] result1 = Base64.getDecoder().decode(ss);
                X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(buffer);
                KeyFactory keyFactory = KeyFactory.getInstance("RSA");
                RSAPublicKey publicKey = (RSAPublicKey) keyFactory.generatePublic(x509EncodedKeySpec);
                rsaPublicKeyInfo(publicKey);
                Cipher cipher = Cipher.getInstance("RSA");
                cipher.init(Cipher.DECRYPT_MODE, publicKey);
                int inputLength = result1.length;
                int MAX_ENCRYPT_BLOCK =  publicKey.getModulus().bitLength()/8;
                // 标识
                int offSet = 0;
                byte[] resultBytes = {};
                byte[] cache = {};
                while (inputLength - offSet > 0) {
                    if (inputLength - offSet > MAX_ENCRYPT_BLOCK) {
                        cache = cipher.doFinal(result1, offSet, MAX_ENCRYPT_BLOCK);
                        offSet += MAX_ENCRYPT_BLOCK;
                    } else {
                        cache = cipher.doFinal(result1, offSet, inputLength - offSet);
                        offSet = inputLength;
                    }
                    resultBytes = Arrays.copyOf(resultBytes, resultBytes.length + cache.length);
                    System.arraycopy(cache, 0, resultBytes, resultBytes.length - cache.length, cache.length);
                }
    
                System.out.println("私钥加密，公钥解密   --解密: " + javax.xml.bind.DatatypeConverter.printHexBinary(resultBytes));
                System.out.println("私钥加密，公钥解密   --解密: " + new String(resultBytes, "utf-8"));
            } catch (Exception e) {
                e.printStackTrace();
            }
    
        }
    }