Re-implement FixCommonKeyIndex for WAD files

The old implementation of this was not able to distinguish between
a title that had the common key index set to 1 because it actually
was Korean and a title that had the common key index set to 1 due to
fakesigning. This new implementation solves the problem by
decrypting a content with each possible common key and checking
which result matches the provided SHA-1 hash.

The problem that the old implementation causes has only been reported
to affect a certain pirated WAD of Chronos Twins DX (WC6EUP), but it's
possible that the problem would start affecting more WADs if we add
support for the vWii common key (which uses index 2). Adding support
for the vWii common key would also prevent us from using the simpler
solution of always forcing the index to 0 if the title is not Korean.
This commit is contained in:
JosJuice 2019-07-14 15:01:07 +02:00
commit 4b73d18eaa
8 changed files with 137 additions and 58 deletions

View file

@ -61,9 +61,8 @@ static bool ImportWAD(IOS::HLE::Kernel& ios, const DiscIO::VolumeWAD& wad)
IOS::HLE::ReturnCode ret;
const bool checks_enabled = SConfig::GetInstance().m_enable_signature_checks;
IOS::ES::TicketReader ticket = wad.GetTicket();
// Ensure the common key index is correct, as it's checked by IOS.
ticket.FixCommonKeyIndex();
IOS::ES::TicketReader ticket = wad.GetTicketWithFixedCommonKey();
while ((ret = es->ImportTicket(ticket.GetBytes(), wad.GetCertificateChain(),
IOS::HLE::Device::ES::TicketImportType::Unpersonalised)) < 0 ||