逆向工程文件格式 [英] Reverse Engineer a File Format
问题描述
这是我第一次尝试逆向工程,真的,我不知道该怎么做.我有一种程序化的思维,但对流行的加密方法没有基础知识.
This is my first attempt at reverse engineering, and really, I don't know how to go about it. I have a procedural kind of mind and no foundation of knowledge on popular encryption methods.
但是,在我看来,如果我有正确格式的最少数据,并且知道数据中出现了某个单词或单词,以及该单词在数据中的开始和结束位置- 我可以以某种方式发现解密整个文件的方法.
But, it seems to me, if I have the very minimum data in the correct format, and know that there is an occurrence in the data of a certain word, or words, and where that word begins and ends in the data - that I could somehow discover the method of decrypting the entire file.
----- ENCRYPTED -------------------------------------------
HEX 44 5E 12 47 55 5E 53 17 4C 5C 49 4F 4F
ACII D ^ ? G U ^ S ? L \ I O O
DEC 68 94 63 71 85 94 83 63 76 92 73 79 79
BIN 01000100 01011110 00111111 01000111 01010101 01011110 01010011 00111111 01001100 01011100 01001001 01001111 01001111
----- DECRYPTED -------------------------------------------
HEX 74 6F 20 74 61 6B 65 20 74 65 73 74 73
ASCII t o t a k e t e s t s
DEC 116 111 32 116 97 107 101 32 116 101 115 116 115
BIN 01110100 01101111 00100000 01110100 01100001 01101011 01100101 00100000 01110100 01100101 01110011 01110100 01110011
这只是一个数据样本.我知道标题信息从哪里开始和结束,因为我检查了两个具有不同标题的文件 - 所以我知道这些翻译成正确的词 - 但我从这里开始识别加密过程?
This is just a sample of data. I know where the title information starts and ends because I examined two files with different titles - so I know these translate to the correct words - but where do I go from here to identifying the encryption process?
*我知道人们会问为什么:这是来自 VCE(考试)文件格式,我想将其转换为 XML 或 JSON.这将使我很容易编写一个程序来比较来自多个考试文件的问题和答案,附加,删除重复项,并创建新的.*
推荐答案
尝试将两个字符串异或在一起.你得到的是
Try XORing the two strings together. What you get is
HEX 30 31 32 33 34 35 36 37 38 39 3A 3B 3C
ASCII 0 1 2 3 4 5 6 7 8 9 : ; <
看到图案了吗?
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