某加密音乐解密

package com.liang.fastservice.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

public class FileDecrypt {
    private static final int[] map = {0x77, 0x48, 0x32, 0x73, 0xDE, 0xF2, 0xC0, 0xC8, 0x95, 0xEC, 0x30, 0xB2, 0x51, 0xC3, 0xE1, 0xA0, 0x9E, 0xE6, 0x9D, 0xCF, 0xFA, 0x7F, 0x14, 0xD1, 0xCE, 0xB8, 0xDC, 0xC3, 0x4A, 0x67, 0x93, 0xD6, 0x28, 0xC2, 0x91, 0x70, 0xCA, 0x8D, 0xA2, 0xA4, 0xF0, 8, 0x61, 0x90, 0x7E, 0x6F, 0xA2, 0xE0, 0xEB, 0xAE, 0x3E, 0xB6, 0x67, 0xC7, 0x92, 0xF4, 0x91, 0xB5, 0xF6, 0x6C, 0x5E, 0x84, 0x40, 0xF7, 0xF3, 0x1B, 2, 0x7F, 0xD5, 0xAB, 0x41, 0x89, 0x28, 0xF4, 0x25, 0xCC, 0x52, 0x11, 0xAD, 0x43, 0x68, 0xA6, 0x41, 0x8B, 0x84, 0xB5, 0xFF, 0x2C, 0x92, 0x4A, 0x26, 0xD8, 0x47, 0x6A, 0x7C, 0x95, 0x61, 0xCC, 0xE6, 0xCB, 0xBB, 0x3F, 0x47, 0x58, 0x89, 0x75, 0xC3, 0x75, 0xA1, 0xD9, 0xAF, 0xCC, 8, 0x73, 0x17, 0xDC, 0xAA, 0x9A, 0xA2, 0x16, 0x41, 0xD8, 0xA2, 6, 0xC6, 0x8B, 0xFC, 0x66, 0x34, 0x9F, 0xCF, 0x18, 0x23, 0xA0, 0xA, 0x74, 0xE7, 0x2B, 0x27, 0x70, 0x92, 0xE9, 0xAF, 0x37, 0xE6, 0x8C, 0xA7, 0xBC, 0x62, 0x65, 0x9C, 0xC2, 8, 0xC9, 0x88, 0xB3, 0xF3, 0x43, 0xAC, 0x74, 0x2C, 0xF, 0xD4, 0xAF, 0xA1, 0xC3, 1, 0x64, 0x95, 0x4E, 0x48, 0x9F, 0xF4, 0x35, 0x78, 0x95, 0x7A, 0x39, 0xD6, 0x6A, 0xA0, 0x6D, 0x40, 0xE8, 0x4F, 0xA8, 0xEF, 0x11, 0x1D, 0xF3, 0x1B, 0x3F, 0x3F, 7, 0xDD, 0x6F, 0x5B, 0x19, 0x30, 0x19, 0xFB, 0xEF, 0xE, 0x37, 0xF0, 0xE, 0xCD, 0x16, 0x49, 0xFE, 0x53, 0x47, 0x13, 0x1A, 0xBD, 0xA4, 0xF1, 0x40, 0x19, 0x60, 0xE, 0xED, 0x68, 9, 6, 0x5F, 0x4D, 0xCF, 0x3D, 0x1A, 0xFE, 0x20, 0x77, 0xE4, 0xD9, 0xDA, 0xF9, 0xA4, 0x2B, 0x76, 0x1C, 0x71, 0xDB, 0, 0xBC, 0xFD, 0xC, 0x6C, 0xA5, 0x47, 0xF7, 0xF6, 0, 0x79, 0x4A, 0x11};

    public static boolean decrypt(String fullPath) {
        try {
            String sign = "";
            if (fullPath.contains(".bkc")) {
                sign = ".bkc";
            } else if (fullPath.contains(".qmc")) {
                sign = ".qmc";
            } else {
                return false;
            }
            String decryptFilePath = fullPath.replace(sign, ".");
            String postFix = decryptFilePath.substring(decryptFilePath.indexOf("."));
            if (postFix.equals(".0") || postFix.equals(".2") || postFix.equals(".3")) {
                decryptFilePath.replace(postFix, ".mp3");
            }
            File file = new File(fullPath);
            FileInputStream is = new FileInputStream(file);
            FileOutputStream fout = new FileOutputStream(decryptFilePath);
            byte[] b = new byte[8192];
            int len = 0;
            long total = 0;
            while ((len = is.read(b)) != -1) {
                for (int i = 0; i < len; i++) {
                    b[i] ^= encMap(total + i);
                }
                fout.write(b, 0, len);
                total += len;
            }
            is.close();
            fout.close();
            return true;
        } catch (Exception e) {
            e.printStackTrace();
        }

        return false;
    }

    private static int encMap(long len) {
        int pos = (int) (len % 0x7fff);
        return map[(pos * pos + 80923) % 256];
    }

    public static void main(String[] args) {
        decrypt("D:\\qqmuisc\\1.qmcflac");
    }
}