wapiflapi/exrs

Exercises for learning Reverse Engineering and Exploitation.

exrs's Issues

Walkthrough

Some guide for solving reverse exercices could be very helpful.

S3 in sploit section

Is there any solution page available? I'm stuck in s3

Is r8 for reverse really solvable?

Thanks for the collection of the challenges! I have completed all the reversing challenges except for r8. Upon closer inspection I think its not solvable. Details are below:

I have reversed the code and understand its logic. So the problem is the MD5. We know its not satisfiable (or more precisely, virtually impossible to find an input that satisfies the constraint). So I guess its probably related to some integer overflow trick. However, since the program checks to make sure the last but one input cannot be zero, the rounds of the MD5 calculation cannot be 0 (and its positive, too). Which makes overflow impossible.

Please double-check. If I am wrong, please also post a working input so I can see how I missed it.

r4

Hi there,

I don't know if this git is still up, but I've found the reverse exercices, and it's pretty cool.
The fact is that that i've solved r1 to r3 easily, but i'm stuck to r4. Do you have any advices to complete this exercices ? I've found a huge array of strings, but I don't know what to do with it..

Thanks,
Libero

Binaries for OSX or source code?

For the reverse engineering challenges, it would be tremendously helpful if you could upload the source code of the challenges or a mach64 binary that runs on OSX for each entry. Starting from r5, things get quite hairy when all you can do is static analysis using hopper.