VolumeWiiCrypted: Cache TMDs and tickets

Source/Core/DiscIO/Volume.cpp

@@ -32,6 +32,9 @@ static const unsigned int WII_BANNER_HEIGHT = 64;
 static const unsigned int WII_BANNER_SIZE = WII_BANNER_WIDTH * WII_BANNER_HEIGHT * 2;
 static const unsigned int WII_BANNER_OFFSET = 0xA0;
 
+const IOS::ES::TicketReader IVolume::INVALID_TICKET{};
+const IOS::ES::TMDReader IVolume::INVALID_TMD{};
+
 std::vector<u32> IVolume::GetWiiBanner(int* width, int* height, u64 title_id)
 {
   *width = 0;

Source/Core/DiscIO/Volume.h

@@ -55,8 +55,11 @@ public:
   virtual Partition GetGamePartition() const { return PARTITION_NONE; }
   bool GetTitleID(u64* buffer) const { return GetTitleID(buffer, GetGamePartition()); }
   virtual bool GetTitleID(u64* buffer, const Partition& partition) const { return false; }
-  virtual IOS::ES::TicketReader GetTicket(const Partition& partition) const { return {}; }
+  virtual const IOS::ES::TicketReader& GetTicket(const Partition& partition) const
-  virtual IOS::ES::TMDReader GetTMD(const Partition& partition) const { return {}; }
+  {
+    return INVALID_TICKET;
+  }
+  virtual const IOS::ES::TMDReader& GetTMD(const Partition& partition) const { return INVALID_TMD; }
   std::string GetGameID() const { return GetGameID(GetGamePartition()); }
   virtual std::string GetGameID(const Partition& partition) const = 0;
   std::string GetMakerID() const { return GetMakerID(GetGamePartition()); }
@@ -111,6 +114,9 @@ protected:
   static const size_t NAME_STRING_LENGTH = 42;
   static const size_t NAME_BYTES_LENGTH = NAME_STRING_LENGTH * sizeof(u16);
   static const size_t NAMES_TOTAL_BYTES = NAME_BYTES_LENGTH * NUMBER_OF_LANGUAGES;
+
+  static const IOS::ES::TicketReader INVALID_TICKET;
+  static const IOS::ES::TMDReader INVALID_TMD;
 };
 
 std::unique_ptr<IVolume> CreateVolumeFromFilename(const std::string& filename);

Source/Core/DiscIO/VolumeWad.cpp

@@ -83,7 +83,7 @@ Country CVolumeWAD::GetCountry(const Partition& partition) const
   return CountrySwitch(country_code);
 }
 
-IOS::ES::TMDReader CVolumeWAD::GetTMD(const Partition& partition) const
+const IOS::ES::TMDReader& CVolumeWAD::GetTMD(const Partition& partition) const
 {
   return m_tmd;
 }

Source/Core/DiscIO/VolumeWad.h

@@ -34,7 +34,7 @@ public:
   bool Read(u64 offset, u64 length, u8* buffer,
             const Partition& partition = PARTITION_NONE) const override;
   bool GetTitleID(u64* buffer, const Partition& partition = PARTITION_NONE) const override;
-  IOS::ES::TMDReader GetTMD(const Partition& partition = PARTITION_NONE) const override;
+  const IOS::ES::TMDReader& GetTMD(const Partition& partition = PARTITION_NONE) const override;
   std::string GetGameID(const Partition& partition = PARTITION_NONE) const override;
   std::string GetMakerID(const Partition& partition = PARTITION_NONE) const override;
   u16 GetRevision(const Partition& partition = PARTITION_NONE) const override;

Source/Core/DiscIO/VolumeWiiCrypted.cpp

@@ -35,7 +35,7 @@ CVolumeWiiCrypted::CVolumeWiiCrypted(std::unique_ptr<IBlobReader> reader)
 {
   _assert_(m_pReader);
 
-  // Get decryption keys for all partitions
+  // Get tickets, TMDs, and decryption keys for all partitions
   for (u32 partition_group = 0; partition_group < 4; ++partition_group)
   {
     u32 number_of_partitions;
@@ -49,10 +49,12 @@ CVolumeWiiCrypted::CVolumeWiiCrypted(std::unique_ptr<IBlobReader> reader)
 
     for (u32 i = 0; i < number_of_partitions; i++)
     {
+      // Read the partition offset
       if (!m_pReader->ReadSwapped(partition_table_offset + (i * 8), &read_buffer))
         continue;
       const u64 partition_offset = (u64)read_buffer << 2;
 
+      // Set m_game_partition if this is the game partition
       if (m_game_partition == PARTITION_NONE)
       {
         u32 partition_type;
@@ -63,6 +65,36 @@ CVolumeWiiCrypted::CVolumeWiiCrypted(std::unique_ptr<IBlobReader> reader)
           m_game_partition = Partition(partition_offset);
       }
 
+      // Read ticket
+      std::vector<u8> ticket_buffer(sizeof(IOS::ES::Ticket));
+      if (!m_pReader->Read(partition_offset, ticket_buffer.size(), ticket_buffer.data()))
+        continue;
+      IOS::ES::TicketReader ticket{std::move(ticket_buffer)};
+
+      // Read TMD
+      u32 tmd_size = 0;
+      u32 tmd_address = 0;
+      if (!m_pReader->ReadSwapped(partition_offset + 0x2a4, &tmd_size))
+        continue;
+      if (!m_pReader->ReadSwapped(partition_offset + 0x2a8, &tmd_address))
+        continue;
+      tmd_address <<= 2;
+      if (tmd_size > 1024 * 1024 * 4)
+      {
+        // The size is checked so that a malicious or corrupt ISO
+        // can't force Dolphin to allocate up to 4 GiB of memory.
+        // 4 MiB should be much bigger than the size of TMDs and much smaller
+        // than the amount of RAM in a computer that can run Dolphin.
+        PanicAlert("TMD > 4 MiB");
+        continue;
+      }
+      std::vector<u8> tmd_buffer(tmd_size);
+      if (!m_pReader->Read(partition_offset + tmd_address, tmd_size, tmd_buffer.data()))
+        continue;
+      IOS::ES::TMDReader tmd{std::move(tmd_buffer)};
+
+      // All of the code below is for getting the decryption key
+
       u8 sub_key[16];
       if (!m_pReader->Read(partition_offset + 0x1bf, 16, sub_key))
         continue;
@@ -108,7 +140,13 @@ CVolumeWiiCrypted::CVolumeWiiCrypted(std::unique_ptr<IBlobReader> reader)
       std::unique_ptr<mbedtls_aes_context> partition_AES_context =
           std::make_unique<mbedtls_aes_context>();
       mbedtls_aes_setkey_dec(partition_AES_context.get(), volume_key, 128);
-      m_partitions[Partition(partition_offset)] = std::move(partition_AES_context);
+
+      // We've read everything. Time to store it! (The reason we don't store anything
+      // earlier is because we want to be able to skip adding the partition if an error occurs.)
+      const Partition partition(partition_offset);
+      m_partition_keys[partition] = std::move(partition_AES_context);
+      m_partition_tickets[partition] = std::move(ticket);
+      m_partition_tmds[partition] = std::move(tmd);
     }
   }
 }
@@ -124,8 +162,8 @@ bool CVolumeWiiCrypted::Read(u64 _ReadOffset, u64 _Length, u8* _pBuffer,
     return m_pReader->Read(_ReadOffset, _Length, _pBuffer);
 
   // Get the decryption key for the partition
-  auto it = m_partitions.find(partition);
+  auto it = m_partition_keys.find(partition);
-  if (it == m_partitions.end())
+  if (it == m_partition_keys.end())
     return false;
   mbedtls_aes_context* aes_context = it->second.get();
 
@@ -174,7 +212,7 @@ bool CVolumeWiiCrypted::Read(u64 _ReadOffset, u64 _Length, u8* _pBuffer,
 std::vector<Partition> CVolumeWiiCrypted::GetPartitions() const
 {
   std::vector<Partition> partitions;
-  for (const auto& pair : m_partitions)
+  for (const auto& pair : m_partition_keys)
     partitions.push_back(pair.first);
   return partitions;
 }
@@ -189,39 +227,16 @@ bool CVolumeWiiCrypted::GetTitleID(u64* buffer, const Partition& partition) cons
   return m_pReader->ReadSwapped(partition.offset + 0x1DC, buffer);
 }
 
-IOS::ES::TicketReader CVolumeWiiCrypted::GetTicket(const Partition& partition) const
+const IOS::ES::TicketReader& CVolumeWiiCrypted::GetTicket(const Partition& partition) const
 {
-  std::vector<u8> buffer(0x2a4);
+  auto it = m_partition_tickets.find(partition);
-  m_pReader->Read(partition.offset, buffer.size(), buffer.data());
+  return it != m_partition_tickets.end() ? it->second : INVALID_TICKET;
-  return IOS::ES::TicketReader{std::move(buffer)};
 }
 
-IOS::ES::TMDReader CVolumeWiiCrypted::GetTMD(const Partition& partition) const
+const IOS::ES::TMDReader& CVolumeWiiCrypted::GetTMD(const Partition& partition) const
 {
-  u32 tmd_size = 0;
+  auto it = m_partition_tmds.find(partition);
-  u32 tmd_address = 0;
+  return it != m_partition_tmds.end() ? it->second : INVALID_TMD;
-
-  if (!m_pReader->ReadSwapped(partition.offset + 0x2a4, &tmd_size))
-    return {};
-  if (!m_pReader->ReadSwapped(partition.offset + 0x2a8, &tmd_address))
-    return {};
-  tmd_address <<= 2;
-
-  if (tmd_size > 1024 * 1024 * 4)
-  {
-    // The size is checked so that a malicious or corrupt ISO
-    // can't force Dolphin to allocate up to 4 GiB of memory.
-    // 4 MiB should be much bigger than the size of TMDs and much smaller
-    // than the amount of RAM in a computer that can run Dolphin.
-    PanicAlert("TMD > 4 MiB");
-    tmd_size = 1024 * 1024 * 4;
-  }
-
-  std::vector<u8> buffer(tmd_size);
-  if (!m_pReader->Read(partition.offset + tmd_address, tmd_size, buffer.data()))
-    return {};
-
-  return IOS::ES::TMDReader{std::move(buffer)};
 }
 
 u64 CVolumeWiiCrypted::PartitionOffsetToRawOffset(u64 offset, const Partition& partition)
@@ -368,8 +383,8 @@ u64 CVolumeWiiCrypted::GetRawSize() const
 bool CVolumeWiiCrypted::CheckIntegrity(const Partition& partition) const
 {
   // Get the decryption key for the partition
-  auto it = m_partitions.find(partition);
+  auto it = m_partition_keys.find(partition);
-  if (it == m_partitions.end())
+  if (it == m_partition_keys.end())
     return false;
   mbedtls_aes_context* aes_context = it->second.get();
 

Source/Core/DiscIO/VolumeWiiCrypted.h

@@ -34,8 +34,8 @@ public:
   std::vector<Partition> GetPartitions() const override;
   Partition GetGamePartition() const override;
   bool GetTitleID(u64* buffer, const Partition& partition) const override;
-  IOS::ES::TicketReader GetTicket(const Partition& partition) const override;
+  const IOS::ES::TicketReader& GetTicket(const Partition& partition) const override;
-  IOS::ES::TMDReader GetTMD(const Partition& partition) const override;
+  const IOS::ES::TMDReader& GetTMD(const Partition& partition) const override;
   std::string GetGameID(const Partition& partition) const override;
   std::string GetMakerID(const Partition& partition) const override;
   u16 GetRevision(const Partition& partition) const override;
@@ -64,7 +64,9 @@ public:
 
 private:
   std::unique_ptr<IBlobReader> m_pReader;
-  std::map<Partition, std::unique_ptr<mbedtls_aes_context>> m_partitions;
+  std::map<Partition, std::unique_ptr<mbedtls_aes_context>> m_partition_keys;
+  std::map<Partition, IOS::ES::TicketReader> m_partition_tickets;
+  std::map<Partition, IOS::ES::TMDReader> m_partition_tmds;
   Partition m_game_partition;
 
   mutable u64 m_last_decrypted_block;