ROM Hack MH4U DLC and savefile encryption

[didix16]

Hey guys. I just start working on MH4U. Take a look and make you opinion . LIQUIDxSNAKE gracias por esos offsets. No los tenía!!
https://gbatemp.net/threads/monster-hunter-4-save-editor.394163/

 

[pitsyi]

Hey there everything seems to be ok but then when I try to download the quest I get a message "An error has occurred Please wait a bit and try again" try everything but it took me awhile to get till this step so...
Also the first time it worked I could download the quest but when I went to the event quest ingame it crashes to homesceen and sais something about an error any help?
BTW sorry my bad english

 

[kae5738]

Can anyone give a basic step by step process to decrypting the user files and encrypting it afterwards? Already have python 2.7 and the pycrypto module installed and the mhef files, but never used python before.

EDIT: Nvm, after testing it out myself, I managed to decrypt it

 

[SaagiBols]

Can anyone give a basic step by step process to decrypting the user files and encrypting it afterwards? Already have python 2.7 and the pycrypto module installed and the mhef files, but never used python before.

EDIT: Nvm, after testing it out myself, I managed to decrypt it

first put ur save in the same folder where the .py editor is and rename the save to filename.crypted
and run this command
c =SavedataCipher(MH4G_EU)

then run this to decrypt it!
c.decrypt_file('filename.crypted','filename.decrypted')

now u will have a file named filename.decrypted
edit it!!!
save it!!!

and encrypt it with this command!
c.encrypt_file('filename.decrypted', 'filename.crypted')

now rename filename.crypted back to userX....

 

[Sonansune]

anyway to download the dlc quest from the server for now?
those mib packs I find out there are out of date.....

 

[v18281]

anyone who has more knowledge about the save file strcture can add to this page https://github.com/svanheulen/mhff/wiki/Monster-Hunter-4-Ultimate-Save

 

[cooroxd]

I have a gateway 3ds, emunand 9.9. How would I go about creating a custom DLC quest and injecting it into my 3ds?

 

[Krude]

I can't get python to run, so i'm trying to recreate the decryption via QuickBMS script, and i'm currently looking at the code trying to figure out what it does (i don't know python).

So, if i get this right, decryption is:
1. byteswap entire file
2. decrypt via blowfish
3. byteswap again
4. get seed from start of the file and XOR rest of the file with it
5. get checksum from start of file and check against the rest of it.

So here's my problems, what's the array's byte size? Kinda hard to swap if i don't know how long the entry is. Same problem with the size of the seed and the csum - are they 2 or 4 bytes long?

Maybe i'm just blind and missing the obvious.

 

[ketal]

Cannot install this, says Visual c++ is not installed
Running Python 2.7, PyCrypto installed

 

[suloku]

This thread has remembered me that I "ported" mh4u save decription code to C and made a tool for it.
I need to upload it later.

 

[ketal]

I found a workaround using bms, no need to use this Python tool