@s4r, just read your awesome write up! It does a great job of explaining things, especially your game 2 summary. Also, I was really surprised how you dealt with the encrypt_string; that was a really clever observation. Thanks for the solution! |
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@s4r: I'm glad you're enjoying it! There is at least one printable password, but I can't guarantee there aren't other solutions (printable or otherwise). If you find something that works, it counts as a solution, printable or not. If you do come across a non-printable solution, I'd love to know about it! Also, I did try to put enough checks in the code to avoid things like segfaults, but if you hit an error, please let me know what input caused that, too. I downloaded your bitflip machine a couple of days ago, and I hope I have time to start looking at it soon. Looks like another interesting crackme.... I love this site. |
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@ttlhacker I'll definitely write up a solution at some point, but this one was complicated enough that it'll take some thinking about the best way to do that. I don't want to say too much in a comment because I don't want to spoil it for anyone else. I ended up writing a program to just "compile" (if that's even the right word) the whole thing at once, then statically analyzed the result. Of course, this meant I had to learn how to compile it in the first place, which was by far the most challenging part for me. And naturally I outsmarted myself: I had my compiler simply ignore all the blocks that weren't valid code, which meant that one kind of really super important block was totally missing without my realizing it. It took me a long time to figure that one out. Thanks again for this! I've never written a crackme before, but there have been a few on this site that have made me want to try to write one; this is one of them. |
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This was incredible! Each time I thought I was on the last layer of things I needed to figure out, there was another layer waiting for me. You are a mad scientist ttlhacker!
sha256(flag) = 638da17366d6d99d7a60568a8eba64a71217743f602d9ca2cb961f063bb093b6 |
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Thanks, ttlhacker! This has been one of my favorites so far! |
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