java代码实现sm2加解密

可以使用Bouncy Castle等第三方库来实现SM2算法的加解密操作，以下是Java代码示例：

import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.gm.GMObjectIdentifiers;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.crypto.signers.SM2Signer;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.encoders.Hex;

import javax.crypto.Cipher;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.Security;

public class SM2Utils {

    static {
        Security.addProvider(new BouncyCastleProvider());
    }

    /**
     * 生成SM2公私钥对
     *
     * @return 公私钥对
     * @throws Exception
     */
    public static AsymmetricCipherKeyPair generateKeyPair() throws Exception {
        X9ECParameters ecParams = GMObjectIdentifiers.sm2p256v1;
        ECDomainParameters ecDomainParameters = new ECDomainParameters(ecParams.getCurve(), ecParams.getG(),
                ecParams.getN());
        ECKeyPairGenerator keyPairGenerator = new ECKeyPairGenerator();
        ECKeyGenerationParameters generationParameters = new ECKeyGenerationParameters(ecDomainParameters, null);
        keyPairGenerator.init(generationParameters);
        return keyPairGenerator.generateKeyPair();
    }

    /**
     * SM2加密
     *
     * @param data       要加密的数据
     * @param privateKey 私钥
     * @param publicKey  公钥
     * @return 加密结果，以16进制字符串表示
     * @throws Exception
     */
    public static String encrypt(byte[] data, ECPrivateKeyParameters privateKey, ECPublicKeyParameters publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance("SM2", BouncyCastleProvider.PROVIDER_NAME);
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        byte[] encrypted = cipher.doFinal(data);
        return Hex.toHexString(encrypted);
    }

    /**
     * SM2解密
     *
     * @param encrypted  加密的数据，以16进制字符串表示
     * @param privateKey 私钥
     * @param publicKey  公钥
     * @return 解密结果
     * @throws Exception
     */
    public static byte[] decrypt(String encrypted, ECPrivateKeyParameters privateKey, ECPublicKeyParameters publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance("SM2", BouncyCastleProvider.PROVIDER_NAME);
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        byte[] encryptedBytes = Hex.decode(encrypted);
        return cipher.doFinal(encryptedBytes);
    }

    /**
     * SM2签名
     *
     * @param data       要签名的数据
     * @param privateKey 私钥
     * @return 签名结果，以16进制字符串表示
     * @throws Exception
     */
    public static String sign(byte[] data, ECPrivateKeyParameters privateKey) throws Exception {
        SM2Signer signer = new SM2Signer();
        signer.init(true, privateKey);
        signer.update(data, 0, data.length);
        byte[] signature = signer.generateSignature();
        return Hex.toHexString(signature);
    }

    /**
     * SM2验签
     *
     * @param data      被签名的数据
     * @param signature 签名结果，以16进制字符串表示
     * @param publicKey 公钥
     * @return 验签结果
     * @throws Exception
     */
    public static boolean verify(byte[] data, String signature, ECPublicKeyParameters publicKey) throws Exception {
        SM2Signer signer = new SM2Signer();
        signer.init(false, publicKey);
        signer.update(data, 0, data.length);
        byte[] signatureBytes = Hex.decode(signature);
        return signer.verifySignature(signatureBytes);
    }

    public static void main(String[] args) throws Exception {
        AsymmetricCipherKeyPair keyPair = generateKeyPair();
        ECPrivateKeyParameters privateKey = (ECPrivateKeyParameters) keyPair.getPrivate();
        ECPublicKeyParameters publicKey = (ECPublicKeyParameters) keyPair.getPublic();

        String plaintext = "Hello SM2";
        String encryptedText = encrypt(plaintext.getBytes("UTF-8"), privateKey, publicKey);
        System.out.println("Encrypted Text: " + encryptedText);

        byte[] decryptedBytes = decrypt(encryptedText, privateKey, publicKey);
        String decryptedText = new String(decryptedBytes, "UTF-8");
        System.out.println("Decrypted Text: " + decryptedText);

        String signature = sign(plaintext.getBytes("UTF-8"), privateKey);
        System.out.println("Signature: " + signature);

        boolean verified = verify(plaintext.getBytes("UTF-8"), signature, publicKey);
        System.out.println("Verified: " + verified);
    }
}

如果您有更具体的实现问题可以再提出来，我会尽力解答。