LaptoniC
June 20th, 2002, 13:36
I am working on program which has interesting reg check.
It gets name and removes spaces and make uppercase ie Mister Stop -> MISTERSTOP
Then it takes SHA-1 of it 2014A31489DEB684260C49792266DB575E69E5A4
then it gets what serial you entered and send MakeAscii procincluded in zip
Then it takes SHA-1 of this number (E400AA622758FF3B29D0E14546EA48DE31DB8A4E)
Then it gets first char of SHA-1(Name) divide to 80h and get SHA-1 hash which is in the program.(80h precalculated SHA-1) compare to SHA-1 of mangled serial.
In order to reverse this one should find 16 chars serial whose SHA-1 is in the program.I think bruteforcing takes a lot time.It is compiled with visual C.If they used any C random algo maybe we can attack here.Also I think they didnt calculated 16 chars at once instead they calculated 4 by 4 or 8 by 8.Any tips are appreciated.I attached predefined 80h SHA-1 hashes,MakeAscii proc
It gets name and removes spaces and make uppercase ie Mister Stop -> MISTERSTOP
Then it takes SHA-1 of it 2014A31489DEB684260C49792266DB575E69E5A4
then it gets what serial you entered and send MakeAscii procincluded in zip
Then it takes SHA-1 of this number (E400AA622758FF3B29D0E14546EA48DE31DB8A4E)
Then it gets first char of SHA-1(Name) divide to 80h and get SHA-1 hash which is in the program.(80h precalculated SHA-1) compare to SHA-1 of mangled serial.
In order to reverse this one should find 16 chars serial whose SHA-1 is in the program.I think bruteforcing takes a lot time.It is compiled with visual C.If they used any C random algo maybe we can attack here.Also I think they didnt calculated 16 chars at once instead they calculated 4 by 4 or 8 by 8.Any tips are appreciated.I attached predefined 80h SHA-1 hashes,MakeAscii proc