Java实现SM2算法（国密算法）

快来打我* 2022-11-20 09:47 254阅读 0赞

## Java实现SM2算法（国密算法） ##

**国密即国家密码局认定的国产密码算法。主要有SM1，SM2，SM3，SM4。密钥长度和分组长度均为128位**  
**一、SM1 为对称加密。其加密强度与AES相当。该算法不公开，调用该算法时，需要通过加密芯片的接口进行调用。**  
**二、SM2为非对称加密，基于ECC。该算法已公开。由于该算法基于ECC，故其签名速度与秘钥生成速度都快于RSA。ECC 256位（SM2采用的就是ECC 256位的一种）安全强度比RSA 2048位高，但运算速度快于RSA。**  
**三、SM3 消息摘要。可以用MD5作为对比理解。该算法已公开。校验结果为256位。**  
**四、SM4 无线局域网标准的分组数据算法。对称加密，密钥长度和分组长度均为128位。**

**POM依赖：**

<dependency>
 <groupId>org.bouncycastle</groupId>
 <artifactId>bcprov-jdk15on</artifactId>
 <version>1.56</version>
 </dependency>

**SM2加解密代码：**

/** * @author SongWei * @version 1.0.0 * @ClassName spring-cloud.com.boot.cloud.encryption.sm.Sm2Utils.java * @Description SM2加解密工具类 * @createTime 2018年10月28日 13:57:00 */
 public class Sm2Utils{ 
 /** * 生成随机秘钥对 * * @Version: 1.0.0 * @return: Map<String, String> * @author: SongWei * @date: 2018/10/28 13:57 */
 public static Map<String, String> generateKeyPair() { 
 SM2 sm2 = SM2.Instance();
 AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair();
 ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();
 ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
 //解密密钥
 BigInteger privateKey = ecpriv.getD(); 
 //加密密钥
 ECPoint publicKey = ecpub.getQ(); 
 Map<String, String> resutlMap = new HashMap<String, String>();
 resutlMap.put("privateKey", SecurityUtils.byteToHex(privateKey.toByteArray()));
 resutlMap.put("publicKey", SecurityUtils.byteToHex(publicKey.getEncoded()));
 return resutlMap;
 }
 
 /** * SM2加密 * * @param publicKey 公钥 * @param data 需要加密的数据 * @Version: 1.0.0 * @return: String * @author: SongWei * @date: 2018/10/28 13:57 */
 public static String encrypt(byte[] publicKey, byte[] data) throws IOException { 
 if (publicKey == null || publicKey.length == 0) { 
 return null;
 }
 if (data == null || data.length == 0) { 
 return null;
 }
 byte[] source = new byte[data.length];
 System.arraycopy(data, 0, source, 0, data.length);
 Cipher cipher = new Cipher();
 SM2 sm2 = SM2.Instance();
 ECPoint userKey = sm2.ecc_curve.decodePoint(publicKey);
 ECPoint c1 = cipher.Init_enc(sm2, userKey);
 cipher.Encrypt(source);
 byte[] c3 = new byte[32];
 cipher.Dofinal(c3);
 //C1 C2 C3拼装成加密字串
 return SecurityUtils.byteToHex(c1.getEncoded()) + SecurityUtils.byteToHex(source) + SecurityUtils.byteToHex(c3);
 
 }
 
 /** * 数据解密 * * @param privateKey 私钥 * @param encryptedData 需要解密的内容 * @Version: 1.0.0 * @return: byte * @author: SongWei * @date: 2018/10/18 13:59 */
 public static byte[] decrypt(byte[] privateKey, byte[] encryptedData) throws IOException { 
 if (privateKey == null || privateKey.length == 0) { 
 return null;
 }
 if (encryptedData == null || encryptedData.length == 0) { 
 return null;
 }
 //加密字节数组转换为十六进制的字符串 长度变为encryptedData.length * 2
 String data = SecurityUtils.byteToHex(encryptedData);
 /** * 分解加密字串 * （C1 = C1标志位2位 + C1实体部分128位 = 130） * （C3 = C3实体部分64位 = 64） * （C2 = encryptedData.length * 2 - C1长度 - C2长度） */
 byte[] c1Bytes = SecurityUtils.hexToByte(data.substring(0, 130));
 int c2Len = encryptedData.length - 97;
 byte[] c2 = SecurityUtils.hexToByte(data.substring(130, 130 + 2 * c2Len));
 byte[] c3 = SecurityUtils.hexToByte(data.substring(130 + 2 * c2Len, 194 + 2 * c2Len));
 SM2 sm2 = SM2.Instance();
 BigInteger userD = new BigInteger(1, privateKey);
 //通过C1实体字节来生成ECPoint
 ECPoint c1 = sm2.ecc_curve.decodePoint(c1Bytes);
 Cipher cipher = new Cipher();
 cipher.Init_dec(userD, c1);
 cipher.Decrypt(c2);
 cipher.Dofinal(c3);
 //返回解密结果
 return c2;
 }
 
 public static void main(String[] args) throws Exception { 
 for (int i = 0; i < 200; i++) { 
 //生成密钥对
 Map<String, String> keyMap = generateKeyPair();
 String plainText = "{"id":"123","name":"张三"}";
 加密密钥
 String publicKey = keyMap.get("publicKey");
 //解密蜜月
 String privateKey = keyMap.get("privateKey");
 String encString = SM2Utils.encrypt(SecurityUtils.hexStringToBytes(publicKey), plainText.getBytes());
 System.out.println("密文：" + encString);
 byte[] plainString = SM2Utils.decrypt(SecurityUtils.hexStringToBytes(privateKey), SecurityUtils.hexStringToBytes(encString));
 System.out.println(new String(plainString));
 }
 }
 }

/** * @author SongWei * @version 1.0.0 * @ClassName spring-cloud.com.boot.cloud.sm.Sm2Tool.java * @Description TODO * @createTime 2018年10月28日 14:29:00 */
    public class Sm2Tool { 
    
        /** * 正式参数 * * @Version: 1.0.0 * @date: 2018年10月28日 14:29:00 */
        public static String[] ecc_param = { 
                "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF",
                "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC",
                "28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93",
                "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123",
                "32C4AE2C1F1981195F9904466A39C9948FE30BBFF2660BE1715A4589334C74C7",
                "BC3736A2F4F6779C59BDCEE36B692153D0A9877CC62A474002DF32E52139F0A0"
        };
    
        public static Sm2Tool Instance() { 
            return new Sm2Tool();
        }
    
        public final BigInteger ecc_p;
        public final BigInteger ecc_a;
        public final BigInteger ecc_b;
        public final BigInteger ecc_n;
        public final BigInteger ecc_gx;
        public final BigInteger ecc_gy;
        public final ECCurve ecc_curve;
        public final ECPoint ecc_point_g;
        public final ECDomainParameters ecc_bc_spec;
        public final ECKeyPairGenerator ecc_key_pair_generator;
        public final ECFieldElement ecc_gx_fieldsmen;
        public final ECFieldElement ecc_gy_fieldsmen;
    
    
        public Sm2Tool() { 
            this.ecc_p = new BigInteger(ecc_param[0], 16);
            this.ecc_a = new BigInteger(ecc_param[1], 16);
            this.ecc_b = new BigInteger(ecc_param[2], 16);
            this.ecc_n = new BigInteger(ecc_param[3], 16);
            this.ecc_gx = new BigInteger(ecc_param[4], 16);
            this.ecc_gy = new BigInteger(ecc_param[5], 16);
            this.ecc_gx_fieldsmen = new Fp(this.ecc_p, this.ecc_gx);
            this.ecc_gy_fieldsmen = new Fp(this.ecc_p, this.ecc_gy);
            this.ecc_curve = new ECCurve.Fp(this.ecc_p, this.ecc_a, this.ecc_b);
            this.ecc_point_g = new ECPoint.Fp(this.ecc_curve, this.ecc_gx_fieldsmen, this.ecc_gy_fieldsmen);
            this.ecc_bc_spec = new ECDomainParameters(this.ecc_curve, this.ecc_point_g, this.ecc_n);
            ECKeyGenerationParameters ecc_engender;
            ecc_engender = new ECKeyGenerationParameters(this.ecc_bc_spec, new SecureRandom());
            this.ecc_key_pair_generator = new ECKeyPairGenerator();
            this.ecc_key_pair_generator.init(ecc_engender);
        }
    }

## 此文章是SM2加解密代码，后续更新SM3和其他工具类 ##