We Chall-Training: Encodings I -Writeup

最新推荐文章于 2019-10-25 01:24:29 发布

转载最新推荐文章于 2019-10-25 01:24:29 发布 · 97 阅读

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原文链接：http://www.cnblogs.com/WangAoBo/p/6368519.html

文章标签：

#php #java

本文解析了WeChall-Training中的EncodingsI挑战。通过对二进制编码的分析及使用JPK工具处理，成功解码出原始消息，并找到了flag为easystarter的线索。

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We Chall-Training: Encodings I -Writeup

题目链接:http://www.wechall.net/challenge/training/encodings1/index.php

原题如下：
We intercepted this message from one challenger to another, maybe you can find out what they were talking about.
To help you on your progress I coded a small java application, called JPK.
Note: The message is most likely in english.

10101001101000110100111100110100
00011101001100101111100011101000
10000011010011110011010000001101
11010110111000101101001111010001
00000110010111011101100011110111
11100100110010111001000100000110
00011110011110001111010011101001
01011100100000101100111011111110
10111100100100000111000011000011
11001111100111110111110111111100
10110010001000001101001111001101
00000110010111000011110011111100
11110011111010011000011110010111
0100110010111100100101110

从01，in English以及提供的JPK等提示推测以上数字的编码方式为二进制；
利用提供的JPK或者自己下载的JPK处理以上的01编码：
将01编码粘贴到Bianry->Bianry To Ascii中，通过Bianry->Bianry Format化为8位一组：
Bianry->Bianry To Ascii，将编码转为ASCII码，发现为乱码，查原因发现8位一组时，多了一位0：
尝试将01编码化为7个一组，刚好分完，
Bianry->Bianry To Ascii，出现了正确的ASCII字符串：This text is 7-bit encoded ascii. Your password is easystarter.