From 4b73d18eaad4ec6a69e7ed2b17fc4b5649746ab5 Mon Sep 17 00:00:00 2001 From: JosJuice Date: Sun, 14 Jul 2019 15:01:07 +0200 Subject: [PATCH] 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. --- Source/Core/Core/IOS/ES/Formats.cpp | 10 ++- Source/Core/Core/IOS/ES/Formats.h | 3 +- Source/Core/Core/WiiUtils.cpp | 3 +- Source/Core/DiscIO/Volume.h | 6 ++ Source/Core/DiscIO/VolumeVerifier.cpp | 64 +++++++----------- Source/Core/DiscIO/VolumeVerifier.h | 9 +-- Source/Core/DiscIO/VolumeWad.cpp | 94 +++++++++++++++++++++++++++ Source/Core/DiscIO/VolumeWad.h | 6 ++ 8 files changed, 137 insertions(+), 58 deletions(-) diff --git a/Source/Core/Core/IOS/ES/Formats.cpp b/Source/Core/Core/IOS/ES/Formats.cpp index 0b3431aec8..f264d5e494 100644 --- a/Source/Core/Core/IOS/ES/Formats.cpp +++ b/Source/Core/Core/IOS/ES/Formats.cpp @@ -455,8 +455,8 @@ std::array TicketReader::GetTitleKey(const HLE::IOSC& iosc) const u8 index = m_bytes.at(offsetof(Ticket, common_key_index)); if (index >= HLE::IOSC::COMMON_KEY_HANDLES.size()) { - WARN_LOG(IOS_ES, "Bad common key index for title %016" PRIx64 ": %u -- using common key 0", - GetTitleId(), index); + PanicAlert("Bad common key index for title %016" PRIx64 ": %u -- using common key 0", + GetTitleId(), index); index = 0; } auto common_key_handle = HLE::IOSC::COMMON_KEY_HANDLES[index]; @@ -533,11 +533,9 @@ HLE::ReturnCode TicketReader::Unpersonalise(HLE::IOSC& iosc) return ret; } -void TicketReader::FixCommonKeyIndex() +void TicketReader::OverwriteCommonKeyIndex(u8 index) { - u8& index = m_bytes[offsetof(Ticket, common_key_index)]; - // Assume the ticket is using the normal common key if it's an invalid value. - index = index < HLE::IOSC::COMMON_KEY_HANDLES.size() ? index : 0; + m_bytes[offsetof(Ticket, common_key_index)] = index; } struct SharedContentMap::Entry diff --git a/Source/Core/Core/IOS/ES/Formats.h b/Source/Core/Core/IOS/ES/Formats.h index c9ad6a142e..82b689df32 100644 --- a/Source/Core/Core/IOS/ES/Formats.h +++ b/Source/Core/Core/IOS/ES/Formats.h @@ -257,9 +257,8 @@ public: // and has a title key that must be decrypted first. HLE::ReturnCode Unpersonalise(HLE::IOSC& iosc); - // Reset the common key field back to 0 if it's an incorrect value. // Intended for use before importing fakesigned tickets, which tend to have a high bogus index. - void FixCommonKeyIndex(); + void OverwriteCommonKeyIndex(u8 index); }; class SharedContentMap final diff --git a/Source/Core/Core/WiiUtils.cpp b/Source/Core/Core/WiiUtils.cpp index c8e8bf9b20..007d6ee202 100644 --- a/Source/Core/Core/WiiUtils.cpp +++ b/Source/Core/Core/WiiUtils.cpp @@ -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 || diff --git a/Source/Core/DiscIO/Volume.h b/Source/Core/DiscIO/Volume.h index ede7a2fc23..a26db94370 100644 --- a/Source/Core/DiscIO/Volume.h +++ b/Source/Core/DiscIO/Volume.h @@ -76,6 +76,12 @@ public: } virtual std::vector GetContent(u16 index) const { return {}; } virtual std::vector GetContentOffsets() const { return {}; } + virtual bool CheckContentIntegrity(const IOS::ES::Content& content, u64 content_offset, + const IOS::ES::TicketReader& ticket) const + { + return false; + } + virtual IOS::ES::TicketReader GetTicketWithFixedCommonKey() const { return {}; } // Returns a non-owning pointer. Returns nullptr if the file system couldn't be read. virtual const FileSystem* GetFileSystem(const Partition& partition) const = 0; virtual u64 PartitionOffsetToRawOffset(u64 offset, const Partition& partition) const diff --git a/Source/Core/DiscIO/VolumeVerifier.cpp b/Source/Core/DiscIO/VolumeVerifier.cpp index 22a732a8ab..06d669ce61 100644 --- a/Source/Core/DiscIO/VolumeVerifier.cpp +++ b/Source/Core/DiscIO/VolumeVerifier.cpp @@ -11,7 +11,6 @@ #include #include -#include #include #include #include @@ -604,29 +603,33 @@ void VolumeVerifier::CheckMisc() } } - const IOS::ES::TicketReader& ticket = m_volume.GetTicket(m_volume.GetGamePartition()); - if (ticket.IsValid()) + m_ticket = m_volume.GetTicket(m_volume.GetGamePartition()); + if (m_ticket.IsValid()) { - const u8 common_key = ticket.GetCommonKeyIndex(); + const u8 specified_common_key_index = m_ticket.GetCommonKeyIndex(); - if (common_key > IOS::HLE::IOSC::COMMON_KEY_HANDLES.size()) + // Wii discs only use common key 0 (regular) and common key 1 (Korean), not common key 2 (vWii). + if (m_volume.GetVolumeType() == Platform::WiiDisc && specified_common_key_index > 1) { - // Many fakesigned WADs have the common key index set to a (random?) bogus value. - // For WADs, Dolphin will detect this and use common key 0 instead, making this low severity. - const Severity severity = - m_volume.GetVolumeType() == Platform::WiiWAD ? Severity::Low : Severity::High; - // i18n: This is "common" as in "shared", not the opposite of "uncommon" - AddProblem(severity, Common::GetStringT("This title is set to use an invalid common key.")); - } - - if (common_key == 1 && region != Region::NTSC_K) - { - // Apparently a certain pirate WAD of Chronos Twins DX unluckily got an index of 1, - // which Dolphin does not change to 0 because 1 is valid on Korean Wiis. - // https://forums.dolphin-emu.org/Thread-wiiware-chronos-twins-dx AddProblem(Severity::High, // i18n: This is "common" as in "shared", not the opposite of "uncommon" - Common::GetStringT("This non-Korean title is set to use the Korean common key.")); + Common::GetStringT("This title is set to use an invalid common key.")); + } + + if (m_volume.GetVolumeType() == Platform::WiiWAD) + { + m_ticket = m_volume.GetTicketWithFixedCommonKey(); + const u8 fixed_common_key_index = m_ticket.GetCommonKeyIndex(); + if (specified_common_key_index != fixed_common_key_index) + { + // Many fakesigned WADs have the common key index set to a (random?) bogus value. + // For WADs, Dolphin will detect this and use the correct key, making this low severity. + std::string text = StringFromFormat( + // i18n: This is "common" as in "shared", not the opposite of "uncommon" + Common::GetStringT("The specified common key index is %u but should be %u.").c_str(), + specified_common_key_index, fixed_common_key_index); + AddProblem(Severity::Low, std::move(text)); + } } } @@ -737,7 +740,7 @@ void VolumeVerifier::Process() if (content_read) { - if (!CheckContentIntegrity(content)) + if (!m_volume.CheckContentIntegrity(content, m_content_offsets[m_content_index], m_ticket)) { AddProblem( Severity::High, @@ -768,27 +771,6 @@ void VolumeVerifier::Process() } } -bool VolumeVerifier::CheckContentIntegrity(const IOS::ES::Content& content) -{ - std::vector encrypted_data = m_volume.GetContent(content.index); - - mbedtls_aes_context context; - const std::array key = m_volume.GetTicket(PARTITION_NONE).GetTitleKey(); - mbedtls_aes_setkey_dec(&context, key.data(), 128); - - std::array iv{}; - iv[0] = static_cast(content.index >> 8); - iv[1] = static_cast(content.index & 0xFF); - - std::vector decrypted_data(Common::AlignUp(content.size, 0x40)); - mbedtls_aes_crypt_cbc(&context, MBEDTLS_AES_DECRYPT, decrypted_data.size(), iv.data(), - encrypted_data.data(), decrypted_data.data()); - - std::array sha1; - mbedtls_sha1_ret(decrypted_data.data(), content.size, sha1.data()); - return sha1 == content.sha1; -} - u64 VolumeVerifier::GetBytesProcessed() const { return m_progress; diff --git a/Source/Core/DiscIO/VolumeVerifier.h b/Source/Core/DiscIO/VolumeVerifier.h index 31a4e591d9..9bcf2fa8c2 100644 --- a/Source/Core/DiscIO/VolumeVerifier.h +++ b/Source/Core/DiscIO/VolumeVerifier.h @@ -13,6 +13,7 @@ #include #include "Common/CommonTypes.h" +#include "Core/IOS/ES/Formats.h" #include "DiscIO/DiscScrubber.h" #include "DiscIO/Volume.h" @@ -29,12 +30,6 @@ // // GetResult() can be called before the processing is finished, but the result will be incomplete. -namespace IOS::ES -{ -struct Content; -class SignedBlobReader; -} // namespace IOS::ES - namespace DiscIO { class FileInfo; @@ -103,7 +98,6 @@ private: u64 GetBiggestUsedOffset(const FileInfo& file_info) const; void CheckMisc(); void SetUpHashing(); - bool CheckContentIntegrity(const IOS::ES::Content& content); void AddProblem(Severity severity, std::string text); @@ -120,6 +114,7 @@ private: mbedtls_sha1_context m_sha1_context; DiscScrubber m_scrubber; + IOS::ES::TicketReader m_ticket; std::vector m_content_offsets; u16 m_content_index = 0; std::vector m_blocks; diff --git a/Source/Core/DiscIO/VolumeWad.cpp b/Source/Core/DiscIO/VolumeWad.cpp index e0dda7ebc4..cc83f59081 100644 --- a/Source/Core/DiscIO/VolumeWad.cpp +++ b/Source/Core/DiscIO/VolumeWad.cpp @@ -2,6 +2,7 @@ // Licensed under GPLv2+ // Refer to the license.txt file included. +#include #include #include #include @@ -12,12 +13,16 @@ #include #include +#include +#include + #include "Common/Align.h" #include "Common/Assert.h" #include "Common/CommonTypes.h" #include "Common/Logging/Log.h" #include "Common/MsgHandler.h" #include "Common/StringUtil.h" +#include "Core/IOS/IOSC.h" #include "DiscIO/Blob.h" #include "DiscIO/Enums.h" #include "DiscIO/Volume.h" @@ -147,6 +152,95 @@ std::vector VolumeWAD::GetContentOffsets() const return content_offsets; } +bool VolumeWAD::CheckContentIntegrity(const IOS::ES::Content& content, + const std::vector& encrypted_data, + const IOS::ES::TicketReader& ticket) const +{ + mbedtls_aes_context context; + const std::array key = ticket.GetTitleKey(); + mbedtls_aes_setkey_dec(&context, key.data(), 128); + + std::array iv{}; + iv[0] = static_cast(content.index >> 8); + iv[1] = static_cast(content.index & 0xFF); + + std::vector decrypted_data(encrypted_data.size()); + mbedtls_aes_crypt_cbc(&context, MBEDTLS_AES_DECRYPT, decrypted_data.size(), iv.data(), + encrypted_data.data(), decrypted_data.data()); + + std::array sha1; + mbedtls_sha1_ret(decrypted_data.data(), content.size, sha1.data()); + return sha1 == content.sha1; +} + +bool VolumeWAD::CheckContentIntegrity(const IOS::ES::Content& content, u64 content_offset, + const IOS::ES::TicketReader& ticket) const +{ + std::vector encrypted_data(Common::AlignUp(content.size, 0x40)); + if (!m_reader->Read(content_offset, encrypted_data.size(), encrypted_data.data())) + return false; + return CheckContentIntegrity(content, encrypted_data, ticket); +} + +IOS::ES::TicketReader VolumeWAD::GetTicketWithFixedCommonKey() const +{ + if (!m_ticket.IsValid() || !m_tmd.IsValid()) + return m_ticket; + + const std::vector sig = m_ticket.GetSignatureData(); + if (!std::all_of(sig.cbegin(), sig.cend(), [](u8 a) { return a == 0; })) + { + // This does not look like a typical "invalid common key index" ticket, so let's assume + // the index is correct. This saves some time when reading properly signed titles. + return m_ticket; + } + + const std::vector contents = m_tmd.GetContents(); + if (contents.empty()) + return m_ticket; + + // Find the smallest content so that we spend as little time as possible in CheckContentIntegrity + IOS::ES::Content smallest_content = contents[0]; + u64 offset_of_smallest_content = m_data_offset; + + u64 offset = m_data_offset; + for (const IOS::ES::Content& content : contents) + { + if (content.size < smallest_content.size) + { + smallest_content = content; + offset_of_smallest_content = offset; + } + offset += Common::AlignUp(content.size, 0x40); + } + + std::vector content_data(Common::AlignUp(smallest_content.size, 0x40)); + if (!m_reader->Read(offset_of_smallest_content, content_data.size(), content_data.data())) + return m_ticket; + + const u8 specified_index = m_ticket.GetCommonKeyIndex(); + if (specified_index < IOS::HLE::IOSC::COMMON_KEY_HANDLES.size() && + CheckContentIntegrity(smallest_content, content_data, m_ticket)) + { + return m_ticket; // The common key index is already correct + } + + // Try every common key index except the one we already tried + IOS::ES::TicketReader new_ticket = m_ticket; + for (u8 i = 0; i < IOS::HLE::IOSC::COMMON_KEY_HANDLES.size(); ++i) + { + if (i != specified_index) + { + new_ticket.OverwriteCommonKeyIndex(i); + if (CheckContentIntegrity(smallest_content, content_data, new_ticket)) + return new_ticket; // We've found the common key index that should be used + } + } + + ERROR_LOG(DISCIO, "Couldn't find valid common key for WAD file (%u specified)", specified_index); + return m_ticket; +} + std::string VolumeWAD::GetGameID(const Partition& partition) const { return m_tmd.GetGameID(); diff --git a/Source/Core/DiscIO/VolumeWad.h b/Source/Core/DiscIO/VolumeWad.h index eb85167a96..02bac94e62 100644 --- a/Source/Core/DiscIO/VolumeWad.h +++ b/Source/Core/DiscIO/VolumeWad.h @@ -39,6 +39,9 @@ public: GetCertificateChain(const Partition& partition = PARTITION_NONE) const override; std::vector GetContent(u16 index) const override; std::vector GetContentOffsets() const override; + bool CheckContentIntegrity(const IOS::ES::Content& content, u64 content_offset, + const IOS::ES::TicketReader& ticket) const override; + IOS::ES::TicketReader GetTicketWithFixedCommonKey() const override; std::string GetGameID(const Partition& partition = PARTITION_NONE) const override; std::string GetGameTDBID(const Partition& partition = PARTITION_NONE) const override; std::string GetMakerID(const Partition& partition = PARTITION_NONE) const override; @@ -63,6 +66,9 @@ public: u64 GetRawSize() const override; private: + bool CheckContentIntegrity(const IOS::ES::Content& content, const std::vector& encrypted_data, + const IOS::ES::TicketReader& ticket) const; + std::unique_ptr m_reader; IOS::ES::TicketReader m_ticket; IOS::ES::TMDReader m_tmd;