ROM Hack [Release] 3DS_CTR_Decryptor-VOiD

[kyogre123]

This one's ncchinfo.bin generates a single xorpad, for some weird reason

Weird reason? that's how it's supposed to work.

 

[piratesephiroth]

Weird reason? that's how it's supposed to work.

Something looks wrong ith it.
I tried with the NCCH extracted from a DevMenu.cia and it generated 2 files named DevMenu (second overwrites the first one) and 1MB big, haha

 

[kyogre123]

Something looks worong ith it.
I tried with the NCCH extracted from a DevMenu.cia and it generated 2 files named DevMenu (second overwrites the first one) and 1MB big, haha

The tool behaves awkwardly with stuff encrypted with zero keys, however they can simply be extracted without xorpads with ctrtool.

 

[piratesephiroth]

It's encrypted.

 

[Nic333]

DevMenu will not decrypt on a retail console, different keyslots

 

[piratesephiroth]

Yeah I thought there would be something like that. But I guessed it would simply be wrong xorpads, not entirely glitched results.

 

[kyogre123]

So, summarising, these are the steps to edit dumps of retail games:

1. Create a xorpad of the original 3DS ROM with the modified CTR_Keygen.
2. Decrypt the whole rom, then extract the contents of romfs.
3. Edit whatever you want in the folder that contains the extracted files of romfs.
4. Recompile a whole (temporary) ROM with makerom doing the proper modifications to a rsf file in order to rebuild the romfs folder.
5. Extract romfs of this new temporary ROM.
6. Replace the romfs of the decrypted ROM with the one extracted in step 5.
7. Rexor with original xorpad.

What about that rexoring part? What if the new romfs is bigger than the original?

 

[kyogre123]

It's encrypted.

With zero keys. Also, I don't think this works with cia files, you have to use the actual cci.

 

[piratesephiroth]

I think you could just edit your ncchinfo.bin to reflect the new RomFS size and generate a new xorpad.
Couldn't you then you xor it back after having the hashes fixed and reinsert the encrypted romfs.bin with makerom?
I don't get the purpose of this NCCH ctrkeygen for romfs modding.

 

[kyogre123]

I think you could just edit your ncchinfo.bin to reflect the new RomFS size and generate a new xorpad.
Couldn't you then you xor it back after having the hashes fixed and reinsert the encrypted romfs.bin with makerom?
I don't get the purpose of this NCCH ctrkeygen for romfs modding.

The purpose is to get a single xorpad as I can understand, instead of one for every partition contained in the NCSD

 

[piratesephiroth]

The modded keygen still generates multiple xorpads, only it uses a NCCH container (CXI, CFA, or content extracted from NCSD) instead of a NCSD (CCI, CSU, 3DS rom).

 

[kyogre123]

Well, then I'm legitimately confused about this. Is the xorpad supposed to be obtained from a decrypted and modified NCCH?

 

[hippy dave]

Any hints for recompressing code.bin? Cheers

 

[kyogre123]

Any hints for recompressing code.bin? Cheers

Rebuild the whole ncch: makerom.exe -f ncch -target d -rsf gw.rsf -o "%filename%.cxi" -exheader exh.bin -code code.bin -icon icon.bin -banner banner.bin -alignwr

 

[piratesephiroth]

Any hints for recompressing code.bin? Cheers

it's in the 'Options' of the rsf file

EnableCompress          : true # Compresses exefs code

 

[piratesephiroth]

Well, then I'm legitimately confused about this. Is the xorpad supposed to be obtained from a decrypted and modified NCCH?

yeah according to SciresM he took out the NCCH partition 0 from Pokemon and made a xorpad for the whole thing.

 

[FAST6191]

Has anybody looked at a binary (as in CPU instructions) yet? If so any changes, even included strings or something.

 

[piratesephiroth]

Has anybody looked at a binary (as in CPU instructions) yet? If so any changes, even included strings or something.

I don't even know how to load code.bin in a disassembler, let alone figure out the code... haha

 

[kyogre123]

yeah according to SciresM he took out the NCCH partition 0 from Pokemon and made a xorpad for the whole thing.

OK, then according to you (because I haven't tried myself) the modified CTR_Keygen generates a single xorpad for a NCCH partition or is still divided in romfs, exefs and exheader; or both?

 

[piratesephiroth]

OK, then according to you (because I haven't tried myself) the modified CTR_Keygen generates a single xorpad for a NCCH partition or is still divided in romfs, exefs and exheader; or both?

Still multiple xorpads. Only it was weird for that devmenu content, generated exefs and exheader as 'devmenu' and both were 1MB big. Probably the file used a diferent encryption.