java国密加密方案

Java国密加密方案

在信息安全领域中，加密算法起着至关重要的作用，其作用是保护数据的隐私和完整性。在中国，有一种名为国密的加密算法，也称为SM2、SM3、SM4算法，是由国家密码管理局发布的一种密码学标准。

SM2算法

SM2算法是一种基于椭圆曲线密码学的非对称加密算法，它支持数字签名和密钥交换。下面是一个使用Java实现SM2算法的示例代码：

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.jce.spec.ECNamedCurveParameterSpec;
import org.bouncycastle.jce.interfaces.ECPublicKey;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.jce.spec.ECParameterSpec;
import org.bouncycastle.jce.spec.ECPublicKeySpec;
import org.bouncycastle.util.encoders.Base64;

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.SecureRandom;
import java.security.Security;
import java.security.Signature;
import java.security.interfaces.ECPrivateKey;
import java.security.interfaces.ECPublicKey;

public class SM2Sample {
    public static void main(String[] args) throws Exception {
        Security.addProvider(new BouncyCastleProvider());
        
        // 生成SM2密钥对
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC", "BC");
        ECParameterSpec ecParameterSpec = ECNamedCurveParameterSpec.getByName("sm2p256v1");
        keyPairGenerator.initialize(ecParameterSpec, new SecureRandom());
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        ECPrivateKey privateKey = (ECPrivateKey) keyPair.getPrivate();
        ECPublicKey publicKey = (ECPublicKey) keyPair.getPublic();
        
        // 数字签名
        Signature signature = Signature.getInstance("SM3withSM2", "BC");
        signature.initSign(privateKey);
        byte[] data = "Hello, SM2".getBytes();
        signature.update(data);
        byte[] sign = signature.sign();
        
        // 验证签名
        signature.initVerify(publicKey);
        signature.update(data);
        boolean verified = signature.verify(sign);
        System.out.println("Verified: " + verified);
    }
}

SM3算法

SM3算法是一种杂凑算法，用于计算消息的摘要。下面是一个使用Java实现SM3算法的示例代码：

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.encoders.Hex;

import java.security.MessageDigest;
import java.security.Security;

public class SM3Sample {
    public static void main(String[] args) throws Exception {
        Security.addProvider(new BouncyCastleProvider());
        
        // 计算摘要
        MessageDigest digest = MessageDigest.getInstance("SM3", "BC");
        byte[] data = "Hello, SM3".getBytes();
        byte[] hash = digest.digest(data);
        System.out.println("Hash: " + Hex.toHexString(hash));
    }
}

SM4算法

SM4算法是一种对称加密算法，也称为国密算法，用于加密和解密数据。下面是一个使用Java实现SM4算法的示例代码：

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.encoders.Hex;
import org.bouncycastle.crypto.engines.SM4Engine;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.ParametersWithIV;

import java.security.Security;

public class SM4Sample {
    public static void main(String[] args) throws Exception {
        Security.addProvider(new BouncyCastleProvider());
        
        // 加密和解密
        byte[] key = Hex.decode("0123456789abcdeffedcba9876543210");
        byte[] iv = Hex.decode("0123456789abcdeffedcba9876543210");
        
        SM4Engine engine = new SM4Engine();
        engine.init(true, new ParametersWithIV(new KeyParameter(key), iv));

        byte[] data = "Hello, SM4".getBytes();
        byte[] cipher = new byte[data.length];
        engine.processBytes(data, 0, data.length, cipher, 0);
        engine.doFinal(cipher, 0);
        
        System.out.println("Cipher: " + Hex.toHexString(cipher));
    }
}

序列图

下面是一个示例的序列图，展示了SM2算法中的数字签名过程：

sequenceDiagram
    participant A as Client
    participant B as Server

    A->>B: 请求公钥
    B->>A: 返回公钥
    A->>B: 发