【国密算法】深入理解国密算法：原理、实践及注意事项

// 使用SM1算法进行对称加密
import org.bouncycastle.crypto.engines.SM1Engine;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.util.encoders.Hex;
public class SM1EncryptionExample {
    public static void main(String[] args) {
        String plaintext = "Hello, world!";
        byte[] keyBytes = Hex.decode("0123456789ABCDEF0123456789ABCDEF");
        byte[] plaintextBytes = plaintext.getBytes();
        
        SM1Engine engine = new SM1Engine();
        engine.init(true, new KeyParameter(keyBytes));
        byte[] ciphertextBytes = new byte[engine.getOutputSize(plaintextBytes.length)];
        int len = engine.processBytes(plaintextBytes, 0, plaintextBytes.length, ciphertextBytes, 0);
        engine.doFinal(ciphertextBytes, len);
        
        String ciphertext = Hex.toHexString(ciphertextBytes);
        System.out.println("Cipher Text: " + ciphertext);
    }
}

// 使用SM2算法进行非对称加密
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.InvalidCipherTextException;
import org.bouncycastle.crypto.engines.SM2Engine;
import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.util.encoders.Hex;
import java.security.SecureRandom;
public class SM2EncryptionExample {
    public static void main(String[] args) throws InvalidCipherTextException {
        // 生成SM2密钥对
        ECKeyPairGenerator generator = new ECKeyPairGenerator();
        SecureRandom random = new SecureRandom();
        ECKeyGenerationParameters keygenParams = new ECKeyGenerationParameters(SM2.getDomainParameters(), random);
        generator.init(keygenParams);
        AsymmetricCipherKeyPair keyPair = generator.generateKeyPair();
        // 加密
        String plaintext = "Hello, world!";
        byte[] plaintextBytes = plaintext.getBytes();
        SM2Engine engine = new SM2Engine();
        engine.init(true, new ParametersWithRandom(keyPair.getPublic(), random));
        byte[] ciphertextBytes = engine.processBlock(plaintextBytes, 0, plaintextBytes.length);
        String ciphertext = Hex.toHexString(ciphertextBytes);
        System.out.println("Cipher Text: " + ciphertext);
    }
}

// 使用SM3算法进行哈希计算
import org.bouncycastle.crypto.digests.SM3Digest;
import org.bouncycastle.util.encoders.Hex;
public class SM3HashExample {
    public static void main(String[] args) {
        String message = "Hello, world!";
        byte[] messageBytes = message.getBytes();
        
        SM3Digest digest = new SM3Digest();
        digest.update(messageBytes, 0, messageBytes.length);
        byte[] hashBytes = new byte[digest.getDigestSize()];
        digest.doFinal(hashBytes, 0);
        
        String hash = Hex.toHexString(hashBytes);
        System.out.println("Hash Value: " + hash);
    }
}