What is LUA Unlocking?

[sinomyth]

im going to snipe the AH at Everlook. ive done it before the old school way, but theres a new method that involves unlocking the LUA. i have the program to unlock it, but im just curious, what does unlocking it exactly do? what else can i do with the lua unlocked?

[l0l1dk]

There are functions in WoW's addon API which are "protected", and can only be called from secure (Blizzard) Lua code. These protected functions do things such as control movement, spell casting, etc.. A Lua Unlock will allow insecure code (regular addons) to call these protected functions. Lua Unlocks are usually used for AH sniping, or for automating your rotation. You can find macros and scripts which use a Lua Unlock for your class here.

[sinomyth]

interesting, thanks =) sounds like you could do some crazy shit with unlocking the lua.

[Zefoxxer]

Sorry for necroposting.
I've been thinking about this whole unlocking thing, got me very curious. Can't really understand how you can "unlock" protected methods while bypassing the interface rules. I mean i always thought this is pretty much impossible without altering the source code.
I'm not familiar with lua and wow api, but if anyone can briefly (if possible at all) explain how this whole thing works, i'd be very thankful.

[Numba1stunna1]

LUA unlocker simply reads the function's value. Using a reverse engineering program such as IDA, a programmer tries to isolate the offset which triggers such value. WoW is one of the more easier games to read, because the offsets usually has a specific string, such as "Obj_TargetGUID". Once you find these offsets, you can use a client-sided program, a bot, to run these functions. Here is a video of what I mean: https://www.youtube.com/watch?v=hABj_mrP-no

Here is an example of using a protected function. The non-protected API is the range check of the spell. The protected API is casting the spell:

if IsSpellInRange(GetSpellInfo(53),"target") -- not protected
 then
CastSpellByID(53,"target") -- protected API
end