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Idea: Playing with .GBX files

Posted: 20 May 2018, 12:00
by Frankthetankmp
Hello there,
yesterday I was very boored. So I thought of what I could do. Instead of doing usefull things I took the next map.gbx file I could find and played arround withit . Next to the hieroglyphs in the code of an map.gbx I found some normal letters defining the author times, the environment and the size of the map. There were many possibilitys for a boored Frank to spend his time with.
Things I tried: Cheat author times better
put 64x64 on a valley map
add random letters and watch what happens
The problem is: No matter what I do (even if I change the settings, save them, then open the file again, reset the settings and save again) after the map is changed in the code it is no longer openable in Maniaplanet.
Not even If I changed an author time in a gbx file maniaplanet allowed me to open the map. (First it was 22000 and I changed it to 21000) but there was no reason why it should not work.

Well, in result I completely failed to do sth with it. But other people who might understand that could do many things with it.
So If you are boored one day (and you are not such a gbx-noob like I am) - do the same like me :3 . Maybe sth cool happens - or maybe
not... most propably not....

Re: Idea: Playing with .GBX files

Posted: 20 May 2018, 12:09
by Florenzius
Maybe the type how you saved the HEX-edited file is not supported or you always changed a value that is important and shouldn't changed. Maybe Dommy can help you. He was experimenting with GBX files and Hex-editing a lot lately and made impossible things possible :P
I guess you will see later what I mean^^

Re: Idea: Playing with .GBX files

Posted: 20 May 2018, 12:25
by TMarc
Ever heard of checksums? ;)
They are there to detect undesired manipulations.

If it was too easy to manipulate times, the whole ranking and also the dedimania system would be useless :|

Re: Idea: Playing with .GBX files

Posted: 20 May 2018, 15:27
by Xymph
Frankthetankmp wrote: 20 May 2018, 12:00 yesterday I was very boored. So I thought of what I could do. Instead of doing usefull things I took the next map.gbx file I could find and played arround withit . Next to the hieroglyphs in the code of an map.gbx I found some normal letters defining the author times, the environment and the size of the map.
Those are in the plain text XML chunk, and not used by the engine when a binary challenge chunk already defines them. See https://wiki.xaseco.org/wiki/GBX
Also, if saving the file changed null (0x00) bytes into spaces (0x20) then the .gbx won't load indeed. This is an occasional problem with maps uploaded to TMX.

TMarc wrote: 20 May 2018, 12:25 Ever heard of checksums?
There are few checksums in GBX chunks, that is unlikely to be a factor.
TMarc wrote: 20 May 2018, 12:25 If it was too easy to manipulate times, the whole ranking and also the dedimania system would be useless
Those systems are separate from and not directly related to GBX chunks.

Re: Idea: Playing with .GBX files

Posted: 20 May 2018, 16:11
by Miss
Xymph wrote: 20 May 2018, 15:27 Also, if saving the file changed null (0x00) bytes into spaces (0x20) then the .gbx won't load indeed. This is an occasional problem with maps uploaded to TMX.
What. People edit map files in Notepad or some shit? :lol: :lol: