draww's DA KeygenMe #2
| Download DAKeygenMe2.zip, 5 kb (password: crackmes.de) Browse contents of DAKeygenMe2.zip Make it say "Registered"
Difficulty: 3 - Getting harder | RatingWaiting for at least 3 votes View profile of draww » |
Solutions
Solution by redoC, published 25. aug, 2016; download (110 kb), password: crackmes.de or browse.
redoC has not rated this crackme yet.
Discussion and comments
| Rune_pe 15. Jul, 16:26 | Hey ! Is anyone check if this chalange is solveable ? I mean how can you make keygen, while the program uses sha512 encryption ? I saw that it use only eighth of the key, but it still 16^16 option that need to bruteforce. |
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| draww Author 18. Jul, 01:19 | Hi there. Yes you have to bruteforce some part. But it won't be a big problem. It's ulong in type but I set it to a relatively low number. Otherwise it would be impossible (or take years) to solve ;) |
| draww Author 25. Jul, 06:57 | to anyone willing to bruteforce, the range is between 0-0xFFFFFFFFFF |
| dsrabot 03. Aug, 08:06 | It solveable but first part you need to bruteforce number which some parts of sha512 = const. > But it won't be a big problem It's a real problem because bruteforce software can't brute by hash mask. I wrote my own bruteforce but it is so slow, I brute ~4FFFFFFF combinations and spent more than 12hrs >the range is between 0-0xFFFFFFFFFF Are you kidding ? |
| dsrabot 03. Aug, 08:09 | Oh, sorry, I bruted 0x16CDF8ED2 (6121557714) combinations but still not found ( |
| draww Author 04. Aug, 07:14 | @dsrabot I'm not kidding, it'd be even worse LOL.. but let's make it easier.. start from 0xE000... and brute backwards ;) @redoC well done mate! |
| draww Author 04. Aug, 11:21 | The value of ulong.MaxValue is 18,446,744,073,709,551,615; in hex 0xFFFFFFFFFFFFFFFF so 0-0xFFFFFFFFFF range is quite reasonable ;) |
| draww Author 04. Aug, 20:17 | @dsrabot normally it can be a neat protection with some tweaks and traps :D did u read the bruteforced number in hex? |
| dsrabot 05. Aug, 06:22 | @draww of course I read it ) I mean the optimal range is 0xFFFFFFFFF (2^36) or Dword (2^32) for brute on CPU on home machine. |
| luxdav 06. Sep, 20:29 | I'm not that good like redoC and I don't have any computing power available but I was able to program an theoretical approach and my own keygen. I looked the magic value up in his solution. Thank you. https://github.com/LuxXx/reverse-engineering/tree/master/draww |
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