帮我用java写RSA/ECB/OAEPWITHSHA-256ANDMGF1PADDING 加密、解密

好的，我能够帮你用 Java 写 RSA/ECB/OAEPWITHSHA-256ANDMGF1PADDING 加密和解密。以下是示例代码：

加密：

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.OAEPParameterSpec;
import javax.crypto.spec.PSource;
import java.security.*;
import java.security.spec.MGF1ParameterSpec;
import java.security.spec.X509EncodedKeySpec;

public class Encryptor {
    public static byte[] encrypt(byte[] input, PublicKey publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA/ECB/OAEPWITHSHA-256ANDMGF1PADDING");
        MGF1ParameterSpec mgf1ParameterSpec = new MGF1ParameterSpec("SHA-256");
        OAEPParameterSpec oaepParameterSpec = new OAEPParameterSpec("SHA-256", "MGF1", mgf1ParameterSpec, PSource.PSpecified.DEFAULT);
        cipher.init(Cipher.ENCRYPT_MODE, publicKey, oaepParameterSpec);
        return cipher.doFinal(input);
    }
}

解密：

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.OAEPParameterSpec;
import javax.crypto.spec.PSource;
import java.security.*;
import java.security.spec.MGF1ParameterSpec;
import java.security.spec.PKCS8EncodedKeySpec;

public class Decryptor {
    public static byte[] decrypt(byte[] input, PrivateKey privateKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA/ECB/OAEPWITHSHA-256ANDMGF1PADDING");
        MGF1ParameterSpec mgf1ParameterSpec = new MGF1ParameterSpec("SHA-256");
        OAEPParameterSpec oaepParameterSpec = new OAEPParameterSpec("SHA-256", "MGF1", mgf1ParameterSpec, PSource.PSpecified.DEFAULT);
        cipher.init(Cipher.DECRYPT_MODE, privateKey, oaepParameterSpec);
        return cipher.doFinal(input);
    }
}

你需要提供公钥和私钥。下面是使用示例：

import java.security.*;

public class Main {
    public static void main(String[] args) throws Exception {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        PublicKey publicKey = keyPair.getPublic();
        PrivateKey privateKey = keyPair.getPrivate();

        String plainText = "Hello, world!";
        byte[] encrypted = Encryptor.encrypt(plainText.getBytes(), publicKey);
        byte[] decrypted = Decryptor.decrypt(encrypted, privateKey);
        String decryptedText = new String(decrypted);
        System.out.println("Original text: " + plainText);
        System.out.println("Decrypted text: " + decryptedText);
    }
}

在这里，我们首先生成一个 RSA 密钥对，并将公钥和私钥传递给加密和解密函数。然后我们加密字符串 "Hello, world!"，并使用相同的私钥解密它。最后，我们将原始文本和解密后的文本一起打印出来。

提醒：在真实的应用中，你需要将生成的密钥保存到文件或数据库中，以便以后使用。