SHA-1

Romcenter 4 support discussion. Please do not post roms requests or illegal links, posts will be deleted. After discussion in this forum, please report any new bugs here.

Moderator: Wanderer

Forum rules
No roms requests or illegal links
BigFred
PacMan
PacMan
Posts: 4
Joined: Fri Apr 06, 2007 6:29 pm

SHA-1

Post by BigFred »

Is it possible to add SHA-1 support in the next update? Some funky group is starting to hack their introed, cracked whatever releases to the same crc as the good dumps and a way to check better hashes is highly needed now. Thanks in advance!

User avatar
RomCenter
Author
Author
Posts: 1519
Joined: Fri Sep 28, 2001 12:34 pm
Location: France
Contact:

Post by RomCenter »

Is it true ?
Can someone confirm ?

Anyway, adding sha-1 could be a good thing.
I keep that in the todo list, but I prefer finish the first release and adding new things later (could be in 3.1 if it's really needed).
Eric - RomCenter developer
Report bugs here.

User avatar
Hakkk
Galaga
Galaga
Posts: 38
Joined: Fri Jun 17, 2005 4:05 am

Post by Hakkk »

Yes. CRC32-fake roms for MAME exist for a long time, and recently some GBA roms too.
News in nointro homepage:

27-mar-2007

Rising Scum altered #2720, but Sir VG redumped it.
Please note that CRC32 does not change. Only MD5 and SHA-1 do.
Freaks in that crew are reading math books, lol!

and

31-mar-2007

Rising Sux altered #2722, but CharlieF redumped it.
Please note that CRC32 does not change. Only MD5 and SHA-1 do.
Main GBA dat release #2723.

User avatar
RomCenter
Author
Author
Posts: 1519
Joined: Fri Sep 28, 2001 12:34 pm
Location: France
Contact:

Post by RomCenter »

Yes, I know that some mame fakes appear some years ago, but not for gba.

The main problem with sha-1 is that it will greatly slow down rom analyse.
crc is fast and with zipped roms, you don't even have to calculate the crc because zip archives store files crc in their structure.
Calculating the sha-1 means extracting the rom and apply the sha-1 algo.

Most of the program is already there. The biggest part is the database structure if I keep at the same time crc and sha-1.

Sha-1 calculation is simply a new plugin. It can be developed by anyone (sha-1 algo is freely available) and it should already work with the current version (with an adapted datafile of course).
Eric - RomCenter developer
Report bugs here.

User avatar
Wanderer
Board master
Board master
Posts: 791
Joined: Wed Oct 03, 2001 10:37 am
Location: Milky way

Post by Wanderer »

RomCenter wrote:The main problem with sha-1 is that it will greatly slow down rom analyse.
Hi Eric.

Well, i don't know if you decide to implement this but if you do, it would be nice if you also add an option to let the user decide which algorithm he wishes to use in each DB.

User avatar
Hakkk
Galaga
Galaga
Posts: 38
Joined: Fri Jun 17, 2005 4:05 am

Post by Hakkk »

Wanderer wrote:Hi Eric.

Well, i don't know if you decide to implement this but if you do, it would be nice if you also add an option to let the user decide which algorithm he wishes to use in each DB.
An option for a DB is a good thing. And I think a command item like "SHA-1 check" in right-click menu will be convenient if users do not want to check every sets in a DB. Users can use this right-click command in single/multiple roms and sets, just like the "fix game" in RC2.x

User avatar
RomCenter
Author
Author
Posts: 1519
Joined: Fri Sep 28, 2001 12:34 pm
Location: France
Contact:

Post by RomCenter »

I identified 5 cases:

If datafile provide:
- crc : check crc (old dat)
- sha-1 : check sha-1 (can be used to force sha-1 check on some roms from the dat)
- crc + sha-1 : check crc + option to individual sha-1 check (normal case with mame)
- no signature : check name and size (samples)
- chd + sha-1 : check name + option to individual sha-1 check (chd)

If I remember well, chd have two ways to check theirs validity: a fast one (only compare stored sha-1 with mame sha-1) and the slow one (calculating the real sha-1 on the 300MB+ chd)
Eric - RomCenter developer
Report bugs here.

BigFred
PacMan
PacMan
Posts: 4
Joined: Fri Apr 06, 2007 6:29 pm

Post by BigFred »

This sounds like a perfect solution. I hope we'll see this soon :)

User avatar
RomCenter
Author
Author
Posts: 1519
Joined: Fri Sep 28, 2001 12:34 pm
Location: France
Contact:

Post by RomCenter »

Maybe not in 3.00. I want to finish that version as it is before adding new feature.
Eric - RomCenter developer
Report bugs here.

Post Reply