change compare function in assembly and .exe stopped working x64dbg

Question

I'm trying to bypass (crack) a very old software that require license in order to unlock all the features

i was digging in the lines with a little bit of knowledge in assembly and i found the line where it compare the hash of the request code with the hash of the license i entered

this is the line ( not %100 sure )

arrow1 where the random request code generated and the entered license saved to a param (not sure)

arrow2 where the compare happen ( same not sure)

The software compare a hash with the hash of the key code you entered, if it's the same, it will work

a random license request code generated everytime you run the .exe

using GenerateRandomNumber

and hashed by using HkdfHashAlgorithm

my question is

when i change je 0x7C1AEF1F to jne 0x7C1AEF1F

the software stopped working and when i execute it i got the command prompt for 1second and disappear

so what i need to change in order to compare the hash of the request code with the same hash or to say if not equal so activated...

Appreciate any help

Answer 1

Algorithm: ((Licence request code) + 0x26946948) ^ (your serial number of C: volume or 0xffffffff if failed).

• This keygen I'm written in golang.

• Or javascript keygen function keygen(code, serial) { code = parseInt(/([0-9-]{12})/.exec(code)[0].replace(/-/g, '')) return ((code + 0x26946948) ^ parseInt(serial.replace(/-/g, ''), 16)) >>> 0 } // example // '9950-7444-3132-b9' is Licence request code // 'A639-6EDE' is Volume Serial Number of C: keygen('9950-7444-3132-b9', 'A639-6EDE')

• Or modify assembly at file.exe+178A je file.exe+17B4 -> jne file.exe+17B4 to bypass.