RSA/ECB/OAEPWithSHA-256AndMGF1Padding 实现加解密

RSA/ECB/OAEPWithSHA-256AndMGF1Padding是一种RSA加密算法，使用OAEP（Optimal Asymmetric Encryption Padding）填充，使用SHA-256哈希函数和MGF1（Mask Generation Function 1）填充。

以下是Java代码示例：

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.spec.MGF1ParameterSpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;
import javax.crypto.spec.OAEPParameterSpec;
import javax.crypto.spec.PSource;

public class RSAEncryption {

    // 生成RSA密钥对
    public static KeyPair generateRSAKeyPair() throws Exception {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(2048, new SecureRandom());
        return keyPairGenerator.generateKeyPair();
    }

    // RSA加密
    public static byte[] encryptRSA(byte[] data, PublicKey publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA/ECB/OAEPWithSHA-256AndMGF1Padding");
        OAEPParameterSpec oaepParameterSpec = new OAEPParameterSpec("SHA-256", "MGF1",
                new MGF1ParameterSpec("SHA-256"), PSource.PSpecified.DEFAULT);
        cipher.init(Cipher.ENCRYPT_MODE, publicKey, oaepParameterSpec);
        return cipher.doFinal(data);
    }

    // RSA解密
    public static byte[] decryptRSA(byte[] data, PrivateKey privateKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA/ECB/OAEPWithSHA-256AndMGF1Padding");
        OAEPParameterSpec oaepParameterSpec = new OAEPParameterSpec("SHA-256", "MGF1",
                new MGF1ParameterSpec("SHA-256"), PSource.PSpecified.DEFAULT);
        cipher.init(Cipher.DECRYPT_MODE, privateKey, oaepParameterSpec);
        return cipher.doFinal(data);
    }

    // 测试
    public static void main(String[] args) throws Exception {
        // 生成RSA密钥对
        KeyPair keyPair = generateRSAKeyPair();
        PublicKey publicKey = keyPair.getPublic();
        PrivateKey privateKey = keyPair.getPrivate();

        // 加密数据
        byte[] data = "Hello, RSA!".getBytes();
        byte[] encryptedData = encryptRSA(data, publicKey);

        // 解密数据
        byte[] decryptedData = decryptRSA(encryptedData, privateKey);

        // 输出结果
        System.out.println("原始数据：" + new String(data));
        System.out.println("加密后的数据：" + new String(encryptedData));
        System.out.println("解密后的数据：" + new String(decryptedData));
    }
}

需要注意的是，RSA加密算法不适合加密大量数据，因为加密后的数据长度会比原始数据长度长很多，而且加密速度较慢，所以一般只用于加密对称加密算法的密钥。