【Java】使用 RSA 进行加密和解密

环境

• JDK 8
• Spring Tool Suite 4.6.1
• Maven 3.6.3

概述

使用 Java 进行 RSA 的加密和解密。

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>jiangbo.java.rsa</groupId>
    <artifactId>java-rsa</artifactId>
    <version>1.0.0</version>
    <description>Java 使用 RSA 进行加密和解密示例</description>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

</project>

RSAUtil

package jiangbo.springmvc;

import java.security.GeneralSecurityException;
import java.security.KeyFactory;
import java.security.spec.EncodedKeySpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;

import javax.crypto.Cipher;

public class RSAUtil {

    private static String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCz1zqQHtHvKczHh58ePiRNgOyiHEx6lZDPlvwBTaHmkNlQyyJ06SIlMU1pmGKxILjT7n06nxG7LlFVUN5MkW/jwF39/+drkHM5B0kh+hPQygFjRq81yxvLwolt+Vq7h+CTU0Z1wkFABcTeQQldZkJlTpyx0c3+jq0o47wIFjq5fwIDAQAB";
    private static String privateKey = "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";

    public static void main(String[] args) throws GeneralSecurityException {

        String encryptedString = encrypt("this is a test!", publicKey);
        System.out.println(encryptedString);
        String decryptedString = RSAUtil.decrypt(encryptedString, privateKey);
        System.out.println(decryptedString);

    }

    public static String encrypt(String data, String publicKey) throws GeneralSecurityException {

        EncodedKeySpec keySpec = new X509EncodedKeySpec(base64Decode(publicKey));
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");

        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(Cipher.ENCRYPT_MODE, keyFactory.generatePublic(keySpec));
        return base64Encode(cipher.doFinal(data.getBytes()));
    }

    public static String decrypt(String data, String privateKey) throws GeneralSecurityException {

        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(base64Decode(privateKey));
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");

        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(Cipher.DECRYPT_MODE, keyFactory.generatePrivate(keySpec));
        return new String(cipher.doFinal(base64Decode(data)));
    }

    static String base64Encode(byte[] bytes) {

        return Base64.getEncoder().encodeToString(bytes);
    }

    static byte[] base64Decode(String str) {

        return Base64.getDecoder().decode(str);
    }
}

其中 PublicKey 和 PrivateKey 的生成请参考 【Java】RSA 生成密钥对