某影视APP算法逆向分析

Posted 2021-09-28 web安全工具库

tags:

篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了某影视APP算法逆向分析相关的知识，希望对你有一定的参考价值。

一、抓取数据包

1、请求头有%加十六进制，说以是url编码，先解密一下

GET  http://m.mapps.m1905.cn/User/sendVer?request=jYgPer7AuEqdM+DYqs/AbNb35UrMvjLwt4+f0p3RHXc=  HTTP/1.1

2、需要找的数值是requests的组成、pid（常量值）、key、did(设备编号)

GET  http://m.mapps.m1905.cn/User/sendVer?request=jYgPer7AuEqdM%2BDYqs%2FAbNb35UrMvjLwt4%2Bf0p3RHXc%3D HTTP/1.1sid:pid: 236key: 69b39cb24632252f7bb891bdb1f0de85did: 010067028741939uid:ver: 100/95/2016020901User-Agent: Dalvik/2.1.0 (Linux; U; android 7.1.2; HD1900 Build/N2G47O)Host: m.mapps.m1905.cnConnection: Keep-AliveAccept-Encoding: gzip

二、搜索链接里关键字"User/sendVer"

1、查看aay.b()函数，DESede算法

key：iufles8787rewjk1qkq9dj76，iv：vs0ld7w3

2、由于DESede是对称加密算法，密文是：jYgPer7AuEqdM+DYqs/AbNb35UrMvjLwt4+f0p3RHXc=，可以反推一下得到加密内容为：mobile=15836353612&templateid=1

三、搜索关键字key

1、查看v0.i()函数

  public String i() {        return abh.a(abb.c() + "m1905_2014");    }

2、查看abb.c()函数，获取设备id

public static String c() {        String v0_2;        try {            TelephonyManager v0_1 =  (TelephonyManager)BaseApplication.a().getSystemService("phone");            v0_2 = v0_1 == null ? "" : v0_1.getDeviceId();        }        catch(Exception v0) {            v0_2 = "";        }        return v0_2;    }

3、查看abh.a()函数，获取md5值

public class abh {    public static final String a(String arg9) {        int v0 = 0;        if(!TextUtils.isEmpty(arg9)) {            char[] v2 = new char[]{'0', '1', '2', '3', '4', '5',  '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};            try {                byte[] v1 = arg9.getBytes();                MessageDigest v3 =  MessageDigest.getInstance("MD5");                v3.update(v1);                byte[] v3_1 = v3.digest();                char[] v5 = new char[(((int)v1)) * 2];                int v1_1 = 0;                while(v0 < v3_1.length) {                    int v6 = v3_1[v0];                    int v7 = v7 + 1;                    char v8 = v2[v8 >>> 4 & 15];                    v5[v1_1] = v8;                    ++v1_1;                    v5[v7] = v2[v6 & 15];                    ++v0;                }                arg9 = new String(v5);            }            catch(Exception v0_1) {                arg9 = null;            }        }        return arg9;    }}