RE
Authenticator
Solved by chronocruz.exe
- Disassembling the binary using IDA we get the first code block
- Here we can clearly see the “Alien ID: “ that is supposed to be the first input
- To find the pin, we proceed down the code flow
- We can see there’s a function named “checkpin” being called so we look at what its doing
- It may get slightly difficult to understand what this code really means..
- We can use decompilers like Ghidra to try to convert this into something we can understand better.
- Looking at the decompiled “checkpin” function, we can clearly see a XOR operation on a string.
- It’s safe to say that our pin must be the XOR of each character in this string with 9.
- With the help of this simple Python script we print the flag
Passphrase
Solved by chronocruz.exe
Disassembling the binary in IDA we reach the first code block where a certain portion of the code caught my eye
- So I wrote down the string given here
3xtr4t3rR3stR14L5_VS_hum4n5
- Tried using this string in the program and voila!