password hacking

[invictius]

I've noticed that someone on http://www.gamefaqs.com/console/snes/code/588803.html (gamefaqs link for the game in question) has found a way to "tell" the game to give you all upgrades, cash, etc at any point in the game, even if they aren't available yet. Does any of that look like hex? I know there has to be parameters for difficulty, number of players, etc, but what part of the code affects what?

[grinvader]

What you linked to is a list of in-game passwords.

1- it's not hex. 'hex' stands for "hexadecimal" and means 'base 16'. You use 16 different 1-character digits to write numbers, which makes it good for computer stuff (since it's a power of 2) and rather efficient (big numbers need less hex digits than decimal digits) while remaining close enough to base 10 not to be daunting (see sexagesimal - go go babylonians !).
Anyway. Hex digits go from 0 to F, but you could pick any 16 characters. These codes use way more than 16 characters. It's not hex.

2- they are in-game codes. which means, you go to a "enter password" screen, type that in, and the game chugs at it and restores a state depending the result, i.e. the password has "fields" of bits at specific offsets that get transformed into your cash, your available power ups, the name of your character and some more.
The transformation can be easy (direct value read) or not (xor'ed with another part of the password, or with whatever is in ram at a specific offset depending another part of the password... as complicated as the coders wanted).
To know exactly what does what, read the code-decrypting routine.

[Rashidi]

this somehow remind me of metroid password...

[h4tred]

but what part of the code affects what?

As grin said, find the ASM for the key decryption/encryption code....The same process for application keygenning can be applied here: all you need to do is RE the code responsible for the keycodes and make a generator based on that research.