Amiga Format Subscriber Disk DMS password

[jasonver2.0]

Does anyone know the passwords required to access the Amiga Format subscriber disks? The DMS files don't have a banner and so I cant bypass the password. I downloaded them a while ago from the Zone and there just sitting there in my collection taunting me. :)

If no one can because of legal/moral reasons, then thats okay - Im just curious whats on them

Edit: Electroblaster perhaps?

[gizmomelb]

Hi Jason, Codetapper sent me a DMS cracker ages ago specifically for those DMS files - but unfortunately I cannot send it on as I had a Windows system crash mid this year and lost all my emails and files. Try asking him.

[Solid Snake]

I too ran a search a while back for the AF sub disk passwords, but came up empty. Someone may have a list of these.....

[Galaxy]

What disk do you want - I have most of them decrypted.

[jasonver2.0]

I dont want to bother anyone :shocked , I downloaded all 30 of the disks uploaded to the Zone :p

Thats alot of disks! I just thought someone may have found a way of cracking them or the password was pretty straightforward

Thanks in advance for any replies

I've attached the list of subdisks I have:

[bippym]

PM/Email codetapper ;) I'm sure he'll send you the program he created!

Also maybe ask poohbear if he can modify xdms to ignore the password or brute hack them like Codetapper did

[jasonver2.0]

Thankyou for the replies :)

I gather from another thread poobear is too busy to fix xdms at the moment, but I'll probably PM Codetapper and see what happens :D

I PM'ed Codetapper and he sent me the program - THANKS Codetapper! :great

[Galaxy]

i have all the subs disks in decrypted form (49-127) except for nos 81-87.

[poohbear]

PM/Email codetapper ;) I'm sure he'll send you the program he created!

Also maybe ask poohbear if he can modify xdms to ignore the password or brute hack them like Codetapper did
Ignoring the password is almost certainly not an option. I can't believe that the DMS authors would have built a system secured by an access check in the unpacker.

I have no idea which crypto algorithm they used. Most likely it wasn't very sophisticated, and was susceptible to cryptanalysis.

If it's not a solved problem, I'll have a play with it in a few months. Since I'm not really familiar with DMS (I never used it on a real Amiga!), it would be helpful if someone could summarize the different packers and unpackers that are available.

[Adderly]

I also have some password protected dms files on hd. It would be nice to have Codetappers source included into xdms or is it an executable? If so, can it be zoned for everyone please?

[Toni Wilen]

I implemented my own transparent brute-force DMS decrypter to WinUAE's DMS-support (+no more aborting the decrunch operation because of possible CRC errors).

DMS "encryption" is really crappy, "key" is only 16-bit... "key" = CRC16 of the password string.

(I thought it had "real" encryption, until I saw this thread..)

[Adderly]

I implemented my own transparent brute-force DMS decrypter to WinUAE's DMS-support (+no more aborting the decrunch operation because of possible CRC errors).

DMS "encryption" is really crappy, "key" is only 16-bit... "key" = CRC16 of the password string.

(I thought it had "real" encryption, until I saw this thread..)LOL, really strong dms "encryption"...
How is Winuae's decrypter used? Just put an "encrypted" DMS-image into df0?

[Toni Wilen]

LOL, really strong dms "encryption"...
How is Winuae's decrypter used? Just put an "encrypted" DMS-image into df0?

Yes, it will decrypt it completely transparently. (minus couple of seconds of extra delay)

btw, check your pm :)

[jasonver2.0]

Ive put Codetappers modified xdms executable in the Zone. If Codetapper doesn't want it there, then he should remove it.

I would ask his permission first but he usually logs on to EAB late in the evening (in Australia).

[Codetapper]

I also have some password protected dms files on hd. It would be nice to have Codetappers source included into xdms or is it an executable? If so, can it be zoned for everyone please?

Actually I sent my source to Heikki Orsila more than 3 weeks ago as he was merging in some other changes to do with skipping errors but I haven't even had a reply yet.

Toni's version sounds very impressive if it only takes a few seconds though! I "cheated" and just call the routine passing a different key until it cracks it. Then generate valid passwords which takes a little time too.

I have no objection to anyone using it but I did compile with an old DJGPP so I was hoping Heikki's version would be more recent. Hopefully he will reply one day!

[Toni Wilen]

There is nothing impressive. (bruteforcing isn't impressive way to do things, imho :))

It is quite fast because it is done in quite tight loop (in pfile.c), "decrypt" with current key, call single track decrunch routine, calculate checksum, increase key if crc error and try again until crc is correct or whole key space was checked without correct crc (=real crc error most likely)

I still have some optimization ideas but I am not sure if it is worth the trouble because encrypted DMS files are very rare.

[Adderly]

I'll try both Codetappers and Tonis build-in dms-decrypters on my encrypted files. If i remember it right i own 4 or 5 encrypted dms files...

Thanks jasonver2.0 for the upload. :great

[Adderly]

Just tried both Winuae 1.4beta with build-in dms decryption support and Codetappers hacked xdms on some encrypted dms files:
Winuae had a 2 seconds decryption delay after i inserted an ecrypted dms file into df0:
I then copied the dms to adf with xcopy, worked 100%. :)

Codetappers hacked xdms is supposed to convert the dms file directly to adf. After 20 secs of brute force cracking i got an error "the password is probably wrong" on all files. :(
@Codetapper: If you want to update your prg i can zone the encrypted dms files that doesn't worked if you want.

[Codetapper]

Yes upload the file, I haven't had any errors on my version and it DOES save as .adf at the end of it.

[Adderly]

in the Zone (RELOFDE2.DMS)

[Codetapper]

OK the problem is those stupid banners that have been put on the front and end of the DMS file. Seems my hacked version of XDMS doesn't like them. If you use Mapus to strip them off, it works as expected:

C:\>xdms u relofde2.dms
Brute force cracking the password protection

000%: ................................
006%: ................................
012%: ................................
018%: ................................
025%: ................................
031%: ................................
037%: ................................
043%: ................................
050%: ................................
056%: ................................
062%: ............................

Correct 16-bit key found! Key is 0xad86

Brute forcing valid passwords...

Valid password 1: wJ4
Valid password 2: 8gX8
Valid password 3: 8sX7
Valid password 4: 93XW
Valid password 5: 9GXp
Valid password 6: 9KXu
Valid password 7: 9cXk
Valid password 8: 9oXn
Valid password 9: 9wXd
Valid password 10: A3zW

File relofde2.dms was correctly unpacked to relofde2.adf

Incidentally the real DMS v2.31 on my Amiga won't even unpack that archive without stripping off the banners first. I would stick with Toni's version (which I couldn't find on the net anyway - where is it?)

[Toni Wilen]

I would stick with Toni's version (which I couldn't find on the net anyway - where is it?)

Nowhere yet but I can upload sources later today (I think only pfile.c was changed)

[Adderly]

OK the problem is those stupid banners that have been put on the front and end of the DMS file. Seems my hacked version of XDMS doesn't like them. If you use Mapus to strip them off, it works as expected:
...
Incidentally the real DMS v2.31 on my Amiga won't even unpack that archive without stripping off the banners first. Ah yes, those stupid BBS adverts on all the scene releases. *sigh*
That would explain why the provided pw didn't work...
Upped by Chr
A pass for DMS file = pegas
This is a adventure game, writen with AMOS PRO
Working on AGA Machines & 2MB RAM
Game is cool!
That's all folks ;-)

[Toni Wilen]

Sources uploaded.

[_ThEcRoW]

So it's actually in-built in winuae?

[Toni Wilen]

Not in any official version yet.