Encrypto's Keygenme.8.DCrypt
| Download Keygenme.8.DCrypt.by.FOFF.zip, 284 kb (password: crackmes.de) Browse contents of Keygenme.8.DCrypt.by.FOFF.zip This is my new crypto Crackme. This time i thought instead of modifying existing crackmes why not create a own crypto ?
Difficulty: 3 - Getting harder | RatingWaiting for at least 3 votes View profile of Encrypto » |
Solutions
Solution by freesoul, published 11. mar, 2009; download (82 kb), password: crackmes.de or browse.
freesoul has not rated this crackme yet.
Discussion and comments
| Encrypto Author 10. Feb 2008 | What do you think ? |
|---|---|
| yaaara 10. Feb 2008 | I easily found name/ serial combination. Can I turn crackme's exe file into keygen? |
| Encrypto Author 10. Feb 2008 | that is against the rules remember ;) serialphising is too easy to be honest with you lol |
| vsealv 11. Feb 2008 | Nice tutorial. Thank you. I was able to get Good Cracker msg :-) |
| Encrypto Author 11. Feb 2008 | erm .. tutorial ? what tutorial ? |
| Knight 14. Feb 2008 | "serialphising is too easy to be honest with you" That is the sign of trivial serial check, so it is protection that is easy, not it's cracking method. |
| Encrypto Author 14. Feb 2008 | ehem if you didnt notice.. its a keygenme. |
| Encrypto Author 14. Feb 2008 | And HMX0101 has solved it the proper way :D. damn hes good |
| freesoul 20. Feb 2009 | hello encrypto, I only took a look over the keygenme before analyzing it... so it's a self made algo? isn't a modified of existing one? because it looks so long... :O |
| andrewl.us Moderator 04. Mar 2009 | encrypto did you modify this routine or is delphi crazy? or maybe someone can answer why I'm crazy :) __fastcall Sysstem::__linkproc__ _llushr(void) 0040508C: cmp cl,20h 0040508F: jl loc_004050A2 ; should be JB!!! 00405091: cmp cl,40h 00405094: jl loc_0040509B ; should be JB!!! 00405096: xor edx,edx ; shamt > 64 00405098: xor eax,eax ; so return 0 0040509A: ret 0040509B: mov eax,edx ; 64 > shamt > 32 0040509D: xor edx,edx ; so return shift dword 0040509F: shr eax,cl 004050A1: ret 004050A2: shrd eax,edx,cl ; shamt < 32 004050A5: shr edx,cl ; so do normal shift on 004050A7: ret ; each dword imagine shifting by 0xAD this should shift by 45 bits (0xAD & 0x3F) (as c compiler does with _aullshr()) eg: 0x0000000060099006 -> 0x0000000000000000 instead this delphi routine considers 0xAD as -53, so it jumps down to where it thinks shamt < 32 then shrd considers low 5 bits of 0xAD as 13 eg: 0x0000000060099006 -> 0x000000000003004C |
| simonzack Moderator 05. Mar 2009 | Are you sure it's not 0x3004C80300000? i think this should be the right result, since a<<-b=a>>b |
| simonzack Moderator 05. Mar 2009 | oops sorry my mistake i misunderstood you i'll check the routine again |
| freesoul 09. Mar 2009 | Sent a solution :) I've just ripped it... but at least it's a solution! :D |
| simonzack Moderator 10. Mar 2009 | ripped it? I'm sure it got rejected sorry :p look at what the author said more closely |
| freesoul 10. Mar 2009 | I think it won't, the author authorized me... :D |
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