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  1. Ghost-chu renamed this gist Sep 27, 2024. 1 changed file with 0 additions and 0 deletions.
    0 gistfile1.txt → gistfile1.java
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  2. Ghost-chu created this gist Sep 27, 2024.
    71 changes: 71 additions & 0 deletions gistfile1.txt
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    package com.ghostchu.peerbanhelper.downloader.impl.bitcomet.crypto;

    import org.bouncycastle.jce.provider.BouncyCastleProvider;

    import javax.crypto.Cipher;
    import javax.crypto.Mac;
    import javax.crypto.SecretKeyFactory;
    import javax.crypto.spec.PBEKeySpec;
    import javax.crypto.spec.SecretKeySpec;
    import java.io.ByteArrayOutputStream;
    import java.nio.charset.StandardCharsets;
    import java.security.SecureRandom;
    import java.security.Security;
    import java.util.Base64;

    public class BCAESTool {
    static {
    Security.addProvider(new BouncyCastleProvider());
    }
    public static String credential(String json, String cid) throws Exception {
    // Ensure Bouncy Castle is added to your project for PBKDF2
    byte[] t = new byte[8];
    byte[] r = new byte[8];
    SecureRandom random = new SecureRandom();
    random.nextBytes(t);
    random.nextBytes(r);

    byte[] n = PBKDF2(cid.getBytes(StandardCharsets.UTF_8), t, 10000, 32, "SHA1");
    byte[] i = PBKDF2(cid.getBytes(StandardCharsets.UTF_8), r, 10000, 32, "SHA1");

    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
    SecretKeySpec keySpec = new SecretKeySpec(n, "AES");
    cipher.init(Cipher.ENCRYPT_MODE, keySpec);
    byte[] s = cipher.doFinal(pad(json.getBytes(StandardCharsets.UTF_8), 16));
    byte[] o = cipher.getIV();

    ByteArrayOutputStream msg = new ByteArrayOutputStream();
    msg.write(3); // m[0]
    msg.write(1); // m[1]
    msg.write(t);
    msg.write(r);
    msg.write(o);
    msg.write(s);

    Mac hmac = Mac.getInstance("HmacSHA256");
    hmac.init(new SecretKeySpec(i, "HmacSHA256"));
    hmac.update(msg.toByteArray());
    byte[] sig = hmac.doFinal();

    msg.write(sig);

    // Use an HTTP client like OkHttp or Apache HttpClient for the POST request
    return Base64.getEncoder().encodeToString(msg.toByteArray());
    }

    private static byte[] PBKDF2(byte[] password, byte[] salt, int iterations, int keyLength, String hashAlgorithm) throws Exception {
    PBEKeySpec spec = new PBEKeySpec(new String(password, StandardCharsets.UTF_8).toCharArray(), salt, iterations, keyLength * 8);
    SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmac" + hashAlgorithm);
    return factory.generateSecret(spec).getEncoded();
    }

    private static byte[] pad(byte[] data, int blockSize) {
    int paddingRequired = blockSize - (data.length % blockSize);
    byte[] padded = new byte[data.length + paddingRequired];
    System.arraycopy(data, 0, padded, 0, data.length);
    for (int i = data.length; i < padded.length; i++) {
    padded[i] = (byte) paddingRequired;
    }
    return padded;
    }
    }