SM2加解密（JAVA）

Edited on In

SM2 是国家密码管理局于2010年12月17日发布的椭圆曲线公钥密码算法。

加解密JAVA 实现

引入依赖

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<dependencies>
    <dependency>
        <groupId>org.bouncycastle</groupId>
        <artifactId>bcprov-jdk15to18</artifactId>
        <version>1.71</version>
    </dependency>
    <dependency>
        <groupId>commons-codec</groupId>
        <artifactId>commons-codec</artifactId>
        <version>1.15</version>
    </dependency>
</dependencies>

代码

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import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import javax.crypto.Cipher;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.security.spec.EncodedKeySpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;

public class SecretUtil {
    private static final Logger log = LoggerFactory.getLogger(SecretUtil.class);
    private static final Provider BOUNCY_CASTLE_PROVIDER = new BouncyCastleProvider();
    private static final String SM2 = "SM2";
    private static final String SM2_ALGORITHM = "EC";
    private static final int SM2_KEY_SIZE = 256;

    private SecretUtil() {
    }


    /**
     * 生成 sm2 key
     *
     * @return [publicKey, privateKey]
     */
    public static String[] generateSm2Key() {
        return generatePairKey(SM2_ALGORITHM, SM2_KEY_SIZE, BOUNCY_CASTLE_PROVIDER);
    }

    private static String[] generatePairKey(String algorithm, int keySize, Provider provider) {
        KeyPairGenerator keyPairGenerator = null;
        try {
            /*KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象*/
            keyPairGenerator = provider == null
                    ? KeyPairGenerator.getInstance(algorithm)
                    : KeyPairGenerator.getInstance(algorithm, provider);
            /* 初始化密钥对生成器 */
            keyPairGenerator.initialize(keySize, new SecureRandom());
        } catch (NoSuchAlgorithmException e) {
            log.warn("{} 公私钥生成失败", algorithm, e);
        }
        /*判断是否生成成功*/
        if (keyPairGenerator == null) {
            /*反馈空数组*/
            return new String[0];
        }
        /*生成秘钥*/
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        PublicKey publicKey = keyPair.getPublic();
        byte[] publicKeyEncoded = publicKey.getEncoded();
        String publicKeyString = Base64.getEncoder().encodeToString(publicKeyEncoded);
        PrivateKey privateKey = keyPair.getPrivate();
        byte[] privateKeyEncoded = privateKey.getEncoded();
        String privateKeyString = Base64.getEncoder().encodeToString(privateKeyEncoded);
        return new String[]{publicKeyString, privateKeyString};
    }

    /**
     * SM2 加密
     *
     * @param content 待加密内容
     * @param key     公钥
     * @return 加密后结果（Base64编码）
     */
    public static String sm2Encrypt(String content, String key) {
        return encryptPk(content, key, SM2, BOUNCY_CASTLE_PROVIDER);
    }

    public static String encryptPk(String content, String key, String algorithm, Provider provider) {
        try {
            EncodedKeySpec keySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(key));
            KeyFactory keyFactory = KeyFactory.getInstance(SM2.equalsIgnoreCase(algorithm) ? SM2_ALGORITHM : algorithm);
            Cipher cipher = provider == null
                    ? Cipher.getInstance(algorithm)
                    : Cipher.getInstance(algorithm, provider);
            cipher.init(Cipher.ENCRYPT_MODE, keyFactory.generatePublic(keySpec));
            byte[] encryptStr = cipher.doFinal(content.getBytes(StandardCharsets.UTF_8));
            return Base64.getEncoder().encodeToString(encryptStr);
        } catch (Exception e) {
            log.error("{} 数据加密失败：{}", algorithm, e.getMessage(), e);
            return null;
        }
    }

    /**
     * SM2 解密
     *
     * @param content 内容（Base64编码）
     * @param key     私钥
     * @return 解密后数据
     */
    public static String sm2Decrypt(String content, String key) {
        return decryptPk(content, key, SM2, BOUNCY_CASTLE_PROVIDER);
    }

    public static String decryptPk(String content, String key, String algorithm, Provider provider) {
        try {
            EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(key));
            KeyFactory keyFactory = KeyFactory.getInstance(SM2.equalsIgnoreCase(algorithm) ? SM2_ALGORITHM : algorithm);
            Cipher cipher = provider == null
                    ? Cipher.getInstance(algorithm)
                    : Cipher.getInstance(algorithm, provider);
            cipher.init(Cipher.DECRYPT_MODE, keyFactory.generatePrivate(keySpec));
            byte[] decryptBytes = cipher.doFinal(Base64.getDecoder().decode(content));
            return new String(decryptBytes);
        } catch (Exception e) {
            log.error("{} 数据解密失败：{}", algorithm, e.getMessage(), e);
            return null;
        }
    }
}

本文地址： https://github.com/maxzhao-it/blog/post/a97a9b/