背景

在對(duì)接三方接口或?qū)崿F(xiàn)開放平臺(tái)操作時(shí)需要對(duì)接口提交參數(shù)通過RSA公鑰進(jìn)行加密，在獲取到請(qǐng)求數(shù)據(jù)后需要使用RSA私鑰對(duì)數(shù)據(jù)進(jìn)行解密操作。

RSA生成工具

支付寶的RSA生成工具

幾種方式

1.自定義RsaUtil工具類

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.codec.binary.Base64;

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

/**
 * RSA加解密工具
 *
 * @author sdevil507
 * created on 2021/5/27
 */
@Slf4j
public class RsaUtil {

    /**
     * 算法
     */
    private static final String KEY_ALGORITHM = "RSA";

    /**
     * 類型
     */
    public static final String RSA_TYPE = "RSA/ECB/PKCS1Padding";

    /**
     * 簽名算法
     */
    public static final String SIGNATURE_ALGORITHM = "SHA256withRSA";

    /**
     * 獲取轉(zhuǎn)換后的公鑰
     *
     * @param publicKey 公鑰字符串
     * @return 轉(zhuǎn)換后的公鑰
     */
    private static PublicKey getPublicKey(String publicKey) {
        try {
            byte[] byteKey = Base64.decodeBase64(publicKey);
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(byteKey);
            KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
            return keyFactory.generatePublic(x509EncodedKeySpec);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 獲取轉(zhuǎn)換后的私鑰
     *
     * @param privateKey 私鑰字符串
     * @return 轉(zhuǎn)換后的私鑰
     */
    private static PrivateKey getPrivateKey(String privateKey) {
        try {
            byte[] byteKey = Base64.decodeBase64(privateKey);
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(byteKey);
            KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
            return keyFactory.generatePrivate(pkcs8EncodedKeySpec);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 私鑰簽名
     *
     * @param privateKey 私鑰
     * @param plainText  明文
     * @return 簽名字符串
     */
    public static String sign(String privateKey, String plainText) {
        String signStr = null;
        byte[] signeBytes;
        try {
            log.info("簽名前明文:{}", plainText);
            PrivateKey key = getPrivateKey(privateKey);
            Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
            signature.initSign(key);
            signature.update(plainText.getBytes());
            signeBytes = signature.sign();
            signStr = Base64.encodeBase64String(signeBytes);
            log.info("簽名后密文:{}", signStr);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return signStr;
    }

    /**
     * 公鑰驗(yàn)簽
     *
     * @param plainText 待驗(yàn)簽明文
     * @param signStr   簽名密文
     * @return true/false
     */
    public static boolean verifySign(String publicKey, String plainText, String signStr) {
        boolean verifySignSuccess = false;
        try {
            PublicKey key = getPublicKey(publicKey);
            Signature verifySign = Signature.getInstance(SIGNATURE_ALGORITHM);
            verifySign.initVerify(key);
            verifySign.update(plainText.getBytes());
            verifySignSuccess = verifySign.verify(Base64.decodeBase64(signStr));
            log.info("公鑰驗(yàn)簽結(jié)果:{}", verifySignSuccess);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return verifySignSuccess;
    }

    /**
     * 明文加密
     *
     * @param publicKey 公鑰
     * @param plainText 明文
     * @return 密文
     */
    public static String encrypt(String publicKey, String plainText) {
        String encryptedBase64 = "";
        try {
            Key key = getPublicKey(publicKey);
            final Cipher cipher = Cipher.getInstance(RSA_TYPE);
            cipher.init(Cipher.ENCRYPT_MODE, key);
            // 轉(zhuǎn)換
            byte[] encryptedBytes = cipher.doFinal(plainText.getBytes(StandardCharsets.UTF_8));
            encryptedBase64 = Base64.encodeBase64String(encryptedBytes);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return encryptedBase64;
    }

    /**
     * 密文解密
     *
     * @param privateKey      秘鑰
     * @param encryptedBase64 密文
     * @return 明文
     */
    public static String decrypt(String privateKey, String encryptedBase64) {
        String decryptedString = "";
        try {
            Key key = getPrivateKey(privateKey);
            final Cipher cipher = Cipher.getInstance(RSA_TYPE);
            cipher.init(Cipher.DECRYPT_MODE, key);
            byte[] encryptedBytes = Base64.decodeBase64(encryptedBase64);
            byte[] decryptedBytes = cipher.doFinal(encryptedBytes);
            decryptedString = new String(decryptedBytes);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return decryptedString;
    }
}

2.使用hutool工具類中的RSA工具類

引入hutool類庫

<dependency>
    <groupId>com.xiaoleilu</groupId>
    <artifactId>hutool-all</artifactId>
    <version>x.x.x</version>
</dependency>

測試代碼

    @Test
    public void hutoolRsa() {
        // 公鑰
        String publicKey = "xxx";
        // 私鑰
        String privateKey = "xxx";
        // 明文內(nèi)容
        String content = "test123456helloWorld";
        // 使用公鑰,私鑰初始化RSA對(duì)象
        RSA rsa = new RSA(privateKey, publicKey);
        // 公鑰加密
        String encryptStr = rsa.encryptBase64(content, KeyType.PublicKey);
        System.out.println(encryptStr);
        // 私鑰解密
        String plainText = rsa.decryptStr(encryptStr, KeyType.PrivateKey);
        System.out.println(plainText);
    }

可以繼續(xù)封裝實(shí)現(xiàn)自己的簽名/驗(yàn)簽方法