Imports/exports don't always use the title key. Exporting a title and
importing it back uses the PRNG key (aka backup key handle or key #5),
not the title key (at all).
To make things even more fun, some versions of IOS have a bug that
causes it to use a zeroed key instead of the PRNG key. When Nintendo
decided to fix it, they added checks to keep using the zeroed key only
in affected titles to avoid making existing exports useless.
(Thanks to tueidj for drawing my attention to this.
I missed this edge case during the initial implementation.)
This commit implements these checks so we are using the correct key
in all of these cases.
We now also use IOSC for decryption/encryption since built-in key
handles are used. And we now reject any invalid common key index,
just like ES.
The region mismatch check that we used can give false positives.
Skipping the check won't lead to any harm - games will ignore
save files that have a non-matching fourth game ID character.
Now fails if any commands fail. I noticed that on the buildbot, the
arguments to this script can be incorrect (somehow?) which can result in
no lint checks happening but the buildbot still passing.
According to http://scanlines16.com/en/blog-3/retro-gaming/game-cube/gamecube-korean-master-list/,
Korean GC releases use the following country codes:
- E or W for games in English
- K for games in Korean
- Unknown value for games in Japanese (my guess is that they might
have made the discs bit-for-bit identical to Japanese releases
because the regions of these games are already set to NTSC-J)
As far as I know, the GC has no Taiwanese releases, which is what
the W country code is used for on the Wii. But I could be wrong.
A small note: The country_byte == 'K' check in the code isn't
actually necessary as long as RegionSwitchGC returns NTSC_J
for 'K', but I thought it would be better to not rely on that.
The county code isn't 100% reliable for detecting the region.
For instance, some games released in Korea have the country
code E even though they're region-locked to NTSC-J consoles.
This commit makes the GC disc region detection match the Wii
disc region detection (apart from the region value being in
a different place on the disc).
Tracking a buffer's size manually and storing it under a name that
does not make it obvious it is related to the buffer is really... meh.
Also gets rid of the need to manually manage its capacity and
new/delete an array.
This commit merges the import and export contexts into a single context
because this is what IOS does, which means we can only reproduce its
behaviour correctly if we use a single context for both operations.
The other reason is that having two separate and very similar structs
is not really a good idea.
While working on this commit, I was notified that our handling of
ImportTmd/ExportTitleInit is not correct. In particular, we always use
the title key for both importing and exporting, which is wrong. To make
this easier to fix in a follow-up PR, the context now also has a title
key field, just like ES. This also lets us avoid computing it every
single time in ImportContentDone.
Allows them to be reused easily. Still a bit too much duplicated code
in my opinion (OpenContent/SeekContent/ReadContent should just call
FS code), but this is a start.
I think I do not need to explain why hardcoding space usage for two
random directories when we can calculate it and when IOS doesn't
actually do that is wrong.
