Spring Security Crypto支持SM2/3/4加密吗？如果支持，请给出代码示例

是的，Spring Security Crypto支持SM2/3/4加密，使用Bouncy Castle实现。下面是一个简单的示例代码：

import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.codec.Hex;

import java.nio.charset.StandardCharsets;
import java.security.Security;

public class SMExample {

    public static void main(String[] args) {
        // 添加Bouncy Castle算法提供者
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

        // SM4加密/解密示例
        byte[] keyBytes = Hex.decode("0123456789abcdeffedcba9876543210");
        SM4Engine sm4 = new SM4Engine();
        sm4.init(true, new KeyParameter(keyBytes));
        byte[] input = "Hello, SM4!".getBytes(StandardCharsets.UTF_8);
        byte[] output = new byte[sm4.getOutputSize(input.length)];
        int len = sm4.processBytes(input, 0, input.length, output, 0);
        sm4.doFinal(output, len);
        System.out.println("SM4 encrypt result: " + Hex.encode(output));

        sm4.init(false, new KeyParameter(keyBytes));
        byte[] plaintext = new byte[sm4.getOutputSize(output.length)];
        len = sm4.processBytes(output, 0, output.length, plaintext, 0);
        sm4.doFinal(plaintext, len);
        System.out.println("SM4 decrypt result: " + new String(plaintext, StandardCharsets.UTF_8));

        // SM2加密/解密示例
        SM2Engine sm2 = new SM2Engine();
        ECPrivateKeyParameters privateKey = new ECPrivateKeyParameters(new BigInteger("123456"), sm2.getParameters());
        ECPublicKeyParameters publicKey = new ECPublicKeyParameters(sm2.getParameters().getG().multiply(new BigInteger("123456")), sm2.getParameters());
        sm2.init(true, new ParametersWithRandom(publicKey, new SecureRandom()));
        byte[] data = "Hello, SM2!".getBytes(StandardCharsets.UTF_8);
        byte[] encryptedData = sm2.processBlock(data, 0, data.length);
        System.out.println("SM2 encrypt result: " + Hex.encode(encryptedData));
        sm2.init(false, privateKey);
        byte[] decryptedData = sm2.processBlock(encryptedData, 0, encryptedData.length);
        System.out.println("SM2 decrypt result: " + new String(decryptedData, StandardCharsets.UTF_8));
    }
}

需要注意的是，SM4和SM3算法不需要密钥对，而SM2算法需要密钥对。在示例代码中，我们使用Bouncy Castle提供的SM2算法实现了密钥对的生成，并使用SM2Engine进行加密和解密。