使用充气城堡在Java中加密xml文件的示例

java encryption bouncycastle

2022-09-04 00:50:51

任何人都可以向我展示（或提供链接）如何使用充气城堡在Java中加密文件的示例吗？我已经查看了 bouncycastle.org 但找不到他们的API的任何文档。即使只是知道要使用哪些类，对我入门也是一个很大的帮助！

答案 1

您要执行哪种类型的加密？基于密码（PBE）、对称、非对称？这完全取决于您如何配置密码。

您不必使用任何特定于 BouncyCastle 的 API，只需使用它提供的算法即可。下面是一个使用 BouncyCastle PBE 密码来加密字符串的示例：

import java.security.SecureRandom;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

public class PBE {

    private static final String salt = "A long, but constant phrase that will be used each time as the salt.";
    private static final int iterations = 2000;
    private static final int keyLength = 256;
    private static final SecureRandom random = new SecureRandom();

    public static void main(String [] args) throws Exception {
        Security.insertProviderAt(new BouncyCastleProvider(), 1);

        String passphrase = "The quick brown fox jumped over the lazy brown dog";
        String plaintext = "hello world";
        byte [] ciphertext = encrypt(passphrase, plaintext);
        String recoveredPlaintext = decrypt(passphrase, ciphertext);

        System.out.println(recoveredPlaintext);
    }

    private static byte [] encrypt(String passphrase, String plaintext) throws Exception {
        SecretKey key = generateKey(passphrase);

        Cipher cipher = Cipher.getInstance("AES/CTR/NOPADDING");
        cipher.init(Cipher.ENCRYPT_MODE, key, generateIV(cipher), random);
        return cipher.doFinal(plaintext.getBytes());
    }

    private static String decrypt(String passphrase, byte [] ciphertext) throws Exception {
        SecretKey key = generateKey(passphrase);

        Cipher cipher = Cipher.getInstance("AES/CTR/NOPADDING");
        cipher.init(Cipher.DECRYPT_MODE, key, generateIV(cipher), random);
        return new String(cipher.doFinal(ciphertext));
    }

    private static SecretKey generateKey(String passphrase) throws Exception {
        PBEKeySpec keySpec = new PBEKeySpec(passphrase.toCharArray(), salt.getBytes(), iterations, keyLength);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWITHSHA256AND256BITAES-CBC-BC");
        return keyFactory.generateSecret(keySpec);
    }

    private static IvParameterSpec generateIV(Cipher cipher) throws Exception {
        byte [] ivBytes = new byte[cipher.getBlockSize()];
        random.nextBytes(ivBytes);
        return new IvParameterSpec(ivBytes);
    }

}

答案 2

您可以在 http://bouncycastle.org/docs/docs1.6/index.html 查看java文档

您可以从此页面下载示例：http://eu.wiley.com/WileyCDA/WileyTitle/productCd-0764596330,descCd-DOWNLOAD.html