document/服务器密码/FinalShellDecodePass.java

import java.io.ByteArrayOutputStream;

import java.io.DataOutputStream;

import java.io.IOException;

import java.math.BigInteger;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.security.SecureRandom;

import java.util.Base64;

import java.util.Random;

import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

public class FinalShellDecodePass {

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

    System.out.println(decodePass(args[0]));

  }

  public static byte[] desDecode(byte[] data, byte[] head) throws Exception {

    SecureRandom sr = new SecureRandom();

    DESKeySpec dks = new DESKeySpec(head);

    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");

    SecretKey securekey = keyFactory.generateSecret(dks);

    Cipher cipher = Cipher.getInstance("DES");

    cipher.init(2, securekey, sr);

    return cipher.doFinal(data);

  }

  public static String decodePass(String data) throws Exception {

    if (data == null) {

      return null;

    } else {

      String rs = "";

      byte[] buf = Base64.getDecoder().decode(data);

      byte[] head = new byte[8];

      System.arraycopy(buf, 0, head, 0, head.length);

      byte[] d = new byte[buf.length - head.length];

      System.arraycopy(buf, head.length, d, 0, d.length);

      byte[] bt = desDecode(d, ranDomKey(head));

      rs = new String(bt);

      return rs;

    }

  }

  static byte[] ranDomKey(byte[] head) {

    long ks = 3680984568597093857L / (long)(new Random((long)head[5])).nextInt(127);

    Random random = new Random(ks);

    int t = head[0];

    for(int i = 0; i < t; ++i) {

      random.nextLong();

    }

    long n = random.nextLong();

    Random r2 = new Random(n);

    long[] ld = new long[]{(long)head[4], r2.nextLong(), (long)head[7], (long)head[3], r2.nextLong(), (long)head[1], random.nextLong(), (long)head[2]};

    ByteArrayOutputStream bos = new ByteArrayOutputStream();

    DataOutputStream dos = new DataOutputStream(bos);

    long[] var15 = ld;

    int var14 = ld.length;

    for(int var13 = 0; var13 < var14; ++var13) {

      long l = var15[var13];

      try {

        dos.writeLong(l);

      } catch (IOException var18) {

        var18.printStackTrace();

      }

    }

    try {

      dos.close();

    } catch (IOException var17) {

      var17.printStackTrace();

    }

    byte[] keyData = bos.toByteArray();

    keyData = md5(keyData);

    return keyData;

  }

  public static byte[] md5(byte[] data) {

    String ret = null;

    byte[] res=null;

    try {

      MessageDigest m;

      m = MessageDigest.getInstance("MD5");

      m.update(data, 0, data.length);

      res=m.digest();

      ret = new BigInteger(1, res).toString(16);

    } catch (NoSuchAlgorithmException e) {

      e.printStackTrace();

    }

    return res;

  }

}