1. 3ds Simple Cia Converter Exheader Decryption Failed Version
2. 3ds Simple Cia Converter Exheader Decryption Failed Download
3. 3ds Simple Cia Converter Exheader Decryption Failed Windows 10

3ds Simple Cia Converter Exheader Decryption Failed Version

The following text tries to document the structure of the NCCH (Nintendo Content Container Header) container format. This format is used to store the content of any installed title.

Tool to convert decrypted 3ds files to cia. Addeddate 2019-03-05 15:42:56 Identifier Decrypted3DSRomToCIA Scanner Internet Archive HTML5 Uploader 1.6.4. I made a 3DS-Rom with 3DS Builder and a Decrypted ExHeader. The Rom has a decrypted ExHeader already and because of that, your tool gives me an error: 'ExHeader decryption failed. The Problem: I cannot use the Encrypted ExHeader on 3DS Builder so I can't build a Rom which is working with your Converter. There are two types of games format which are compatible with Nintendo 3DS which is the 3ds format and the cia format.You need to have a flashcart such as Sk. The native format for packaging NCCH files for install is CIA, which is also a NCCH container format. CIA files are limited to containing 65535 NCCH files and can be used to contain NCCH files for any title type. CIA files also contain signed data used by the 3DS for general title management and DRM. Installing custom CIA files on a 3DS. Proceed to rebuilding the game it goes all ok (apparently) until finnaly on 3ds simple cia, comes with the following message: 'ExHeader decryption failed. I'm new at this, but i guess that's a problem with the DecryptedExHeader.bin file.

• 1Overview
• 2Container File Format
  • 2.4NCCH Flags

Overview[edit]

There are two known NCCH container specializations used on the 3DS, 'executable' and 'non-executable', officially known as CXI and CFA, respectively.

CXI[edit]

The CXI (CTR Executable Image) specialization of the NCCH container contains executable code, which runs on a single ARM11 core.

The CXI format is structured in the following order:

• first a NCCH header,
• followed by an extended header,
• followed by an access descriptor,
• followed by an optional plain binary region,
• followed by an optional executable filesystem (ExeFS) - (contains ARM11 code, Home menu icn/bnr and logo),
• and finally followed by an optional read-only filesystem (RomFS) - (Used for external file storage).

The extended header contains additional information regarding access control. The plain binary region is an area specifically stored in plaintext, mostly containing SDK library strings for identification.

CFA[edit]

The CFA (CTR File Archive) specialization of the NCCH container is not executable, but is used in conjunction with CXI files, e.g. the DLP Child Container and the Electronic Manual. (There is a system update NCCH which follows this format, but is used by the 3DS rather than the Application NCCH, and only works when embedded in the CCI format because the nVer is kept in the header of retail CCI files instead of the application NCCH). There are CFA files which exist alone in a title, but these are just System Data Archive titles and are found only in the NAND.

CFA files are structured in the following order:

• first a NCCH header,
• followed by an optional executable filesystem (ExeFS) (same as in CXI, except no ARM11 code)
• followed by an optional read-only filesystem (RomFS)

Container File Format[edit]

Encryption[edit]

The extended header, the ExeFS, and the RomFS are encrypted using 128-bit AES CTR unless the NoCrypto flag is set in ncchflag[7]. There are different sets of encryption parameters in use, as over the time new system updates introduced more sophisticated means of encryption.

All encrypted regions are grouped into two categories, each of which uses one kind of encryption scheme:

• The 'menu info' group, including the extended header, the ExeFS header, and the files 'icon' and 'banner' in ExeFS, which are needed to display the game on the menu regardless whether system version supports the game, or whether the pre-downloaded eshop game is officially released.

• The 'content' group, including the rest files ('.code' and '.firm') in ExeFS, and the entire RomFS, which is needed for actually running the game, and which can be only decrypted on the supported system (and when the seed is officially released for eshop games).

The decryption key is generated using the AES Engine. The keyX and keyY for each group are set as follows:

• The 'menu info' group uses the primary key, always generated by keyX in the slot 0x2C (set by bootrom) and keyY from the first 0x10 bytes of the NCCH signature.

• The 'content' group uses the secondary key. The slot selection for keyX depends on ncchflag[3], as listed in the table below.

Besides all rules above, if ncchflag[7] bitmask 0x1 is set, and a fixed AES key instead is used for both groups. There are two fixed keys, one for titles which have the system category bit set (SystemFixedKey), and one for the rest ('zeros' key). These are debug keys, as they aren't nomally supported on retail systems.

The initial CTR for decryption each region is generated from the partition ID, as described below:

• if the version field (NCCH header + 0x112) is 0 or 2, the 16-byte CTR is [partition_id[7], partition_id[6], .., partition_id[0], M, 0, .., 0], where
  • The 8-byte partition ID starts from the beginning in the reverse order. If the partition ID is viewed as a little-endian u64, and the CTR is viewed as big-endian u128, then this is to put the partition ID to the most significant bits of the CTR
  • CTR[8] is set to a magic number M. For extended header, M = 1. For ExeFS, M = 2. For RomFS, M = 3.
  • The rest 7 bytes (the least significant bits of big-endian CTR) are set to zero

• if the version field is 1, the 16-byte CTR is [partition_id[0], partition_id[1], ..,partition_id[7], 0, 0, 0, 0, T[0], T[1], T[2], T[3]], where
  • The 8-byte partition ID starts from the beginning in the same order.
  • Then four zeros follow.
  • Then a number T in big-endian follows. This number is the offset of each encrypted region to the NCCH beginning. So for extended header, T = 0x200. For ExeFS/RomFS. T = 0x200 * ExeFS/RomFS offset in media units

Note that due to the key generation schemes described above, ExeFS can contain regions using different keys. Regardless of this, both regions shared the same initial CTR at the beginning of ExeFS. If one region doesn't start at the beginning of ExeFS, its actual CTR at its own beginning = ExeFS CTR + (region offset / AESBlockSize=16)

Format[edit]

Currently, only ExeFS:/.code can be compressed (with a LZ77 variant). A flag in the exheader determines if this is the case.

On retail for SD applications, exheader_systeminfoflags.flag bit1 must be set.

Retail CFAs use the default NCCH product code 'CTR-P-CTAP', while retail title/gamecard CXIs use NCCH product code 'CTR-X-XXXX'. This product code is the NCCH serial code. The region-locking info checked by home menu is stored in the icon.

All of the hashes stored in this NCCH header are over the cleartext data. The ExeFS/RomFS superblock starts at offset 0x0 in the ExeFS/RomFS, and the size is specified by the hash region fields. Nintendo's NCCH validation code seems to have the size of this region fixed to 0x200 bytes (for ExeFS at least). Wh cs go mac os.

As of 5.0.0-11 the application ExeFS:/logo can be loaded from the plaintext region between the access descriptor and the plain region, all applications built since 5.0.0-11 store the logo here. The size of this logo is always 0x2000-bytes.

The plain region mainly contains tags for each SDK library used when building the CXI. The version used for the 'FIRMWARE' tag is the kernel/FIRM version, this version can also be stored in the exheader 'kernel release version' ARM11 kernel descriptor field. As of 2.2.0-X the NATIVE_FIRM kernels check the CXI exheader 'kernel release version' field, if it is stored in the CXI exheader. If the kernel/FIRM version specified by this field is higher than the version of the running NATIVE_FIRM, the kernel will return error-code 0xD9001413.

NCCH Header[edit]

Given offsets are based on the start of the file.

NCCH Flags[edit]

CXIs NCCH header signature is verified using the RSA public key stored in the accessdesc,(which follows the exheader) while CFAs NCCH header is verified with a fixed RSA public key.

NCCH header example for Lego Starwars III[edit]

Plain region example for Lego Starwars III[edit]

Example dependency list from the extended header[edit]

Tools[edit]

3ds Simple Cia Converter Exheader Decryption Failed Download

ctrtool - (CMD)(Windows/Linux) Parsing and decrypting (debug only) NCCH files

3ds Simple Cia Converter Exheader Decryption Failed Windows 10