Changes

[[Category:File formats]]

[[Category:File formats]]

== Overview ==

== Overview ==

CIA stands for '''C'''TR '''I'''mportable '''A'''rchive. This format allows the installation titles to the 3DS. CIA files and titles on [[Title list|Nintendo's CDN]] contain identical data. As a consequence, valid CIA files can be generated from CDN content. This also means CIA files can contain anything that titles on Nintendo's CDN can contain.  

CIA stands for '''C'''TR '''I'''mportable '''A'''rchive. This format allows the installation of titles to the 3DS. CIA files and titles on [[Title list|Nintendo's CDN]] contain identical data. As a consequence, valid CIA files can be generated from CDN content. This also means CIA files can contain anything that titles on Nintendo's CDN can contain.  

Under normal circumstances CIA files are used where downloading a title is impractical or not possible. Such as distributing a [[Download Play]] child, or installing forced Gamecard updates. Those CIA(s) are stored by the titles in question, in an auxiliary [[NCCH#CFA|CFA]] file.

Under normal circumstances CIA files are used where downloading a title is impractical or not possible. Such as distributing a [[Download Play]] child, or installing forced Gamecard updates. Those CIA(s) are stored by the titles in question, in an auxiliary [[NCCH#CFA|CFA]] file.

* Ticket

* Ticket

* TMD file data

* TMD file data

* APP file data

* Content file data

* Meta file data (Not a necessary component)  

* Meta file data (Not a necessary component)  

The APP data (NCCH/SRL) is encrypted, using 128-bit AES-CBC. The encryption uses the decrypted titlekey of the ticket, and the titleid padded with zeros as the IV. To get the decrypted titlekey, the titlekey stored in the ticket must be decrypted using 128-bit AES-CBC with the 3DS common key, and the same IV as mentioned previously.

The contents (NCCH/SRL) are encrypted using 128-bit AES-CBC. The encryption uses the decrypted titlekey from the [[Ticket#Structure|ticket]], and the content index from the TMD padded with zeros as the IV.

=== Certificate Chain ===

=== Certificate Chain ===

* [https://github.com/3dshax/ctr/tree/master/ctrtool ctrtool] - Reading/Extraction of CIA files. This can only decrypt the title-key for development CIAs, since retail CIAs use the [[AES]] hardware key-scrambler for the common-key keyslot.

* [https://github.com/3dshax/ctr/tree/master/ctrtool ctrtool] - Reading/Extraction of CIA files. This can only decrypt the title-key for development CIAs, since retail CIAs use the [[AES]] hardware key-scrambler for the common-key keyslot.

* [https://github.com/ctrdev/ctrsdk/tree/master/tools/make_cia make_cia] - Generating CIA files. Requires CommonKey and ticket/TMD RSA-2048 private exponents. (link broken at the moment)

* [https://github.com/Tiger21820/ctr_toolkit/tree/master/make_cia make_cia] - Generating CIA files. Requires CommonKey and ticket/TMD RSA-2048 private exponents.

* [https://github.com/ctrdev/ctrsdk/tree/master/tools/make_cdn_cia make_cdn_cia] - (CMD)(Windows/Linux) Generates CIA files from CDN Content (link broken at the moment)

* [https://github.com/Tiger21820/ctr_toolkit/tree/master/make_cdn_cia make_cdn_cia] - (CMD)(Windows/Linux) Generates CIA files from CDN Content

 

* [[makerom]] - Tool which can be used to create NCCH, CCI, and CIA files.

If you have updated links or a local copy of either of the broken repositories, please edit this page or contact us. Thanks.

== Title Key Encryption ==

== Title Key Encryption ==