Merge pull request #8861 from JosJuice/netplay-hash

Make netplay's "same game" check more robust

1 files changed, 41 insertions, 0 deletions

diff --git a/Source/Core/DiscIO/Volume.cpp b/Source/Core/DiscIO/Volume.cpp
index 23df2afc5c..ab4b0e562b 100644
--- a/Source/Core/DiscIO/Volume.cpp
+++ b/Source/Core/DiscIO/Volume.cpp
@@ -9,12 +9,16 @@
 #include <memory>
 #include <optional>
 #include <string>
+#include <type_traits>
 #include <utility>
 #include <vector>
 
+#include <mbedtls/sha1.h>
+
 #include "Common/CommonTypes.h"
 #include "Common/StringUtil.h"
 
+#include "Core/IOS/ES/Formats.h"
 #include "DiscIO/Blob.h"
 #include "DiscIO/Enums.h"
 #include "DiscIO/VolumeDisc.h"
@@ -28,6 +32,43 @@ const IOS::ES::TicketReader Volume::INVALID_TICKET{};
 const IOS::ES::TMDReader Volume::INVALID_TMD{};
 const std::vector<u8> Volume::INVALID_CERT_CHAIN{};
 
+template <typename T>
+static void AddToSyncHash(mbedtls_sha1_context* context, const T& data)
+{
+  static_assert(std::is_trivially_copyable_v<T>);
+  mbedtls_sha1_update_ret(context, reinterpret_cast<const u8*>(&data), sizeof(data));
+}
+
+void Volume::ReadAndAddToSyncHash(mbedtls_sha1_context* context, u64 offset, u64 length,
+                                  const Partition& partition) const
+{
+  std::vector<u8> buffer(length);
+  if (Read(offset, length, buffer.data(), partition))
+    mbedtls_sha1_update_ret(context, buffer.data(), buffer.size());
+}
+
+void Volume::AddTMDToSyncHash(mbedtls_sha1_context* context, const Partition& partition) const
+{
+  // We want to hash some important parts of the TMD, but nothing that changes when fakesigning.
+  // (Fakesigned WADs are very popular, and we don't want people with properly signed WADs to
+  // unnecessarily be at a disadvantage due to most netplay partners having fakesigned WADs.)
+
+  const IOS::ES::TMDReader& tmd = GetTMD(partition);
+  if (!tmd.IsValid())
+    return;
+
+  AddToSyncHash(context, tmd.GetIOSId());
+  AddToSyncHash(context, tmd.GetTitleId());
+  AddToSyncHash(context, tmd.GetTitleFlags());
+  AddToSyncHash(context, tmd.GetGroupId());
+  AddToSyncHash(context, tmd.GetRegion());
+  AddToSyncHash(context, tmd.GetTitleVersion());
+  AddToSyncHash(context, tmd.GetBootIndex());
+
+  for (const IOS::ES::Content& content : tmd.GetContents())
+    AddToSyncHash(context, content);
+}
+
 std::map<Language, std::string> Volume::ReadWiiNames(const std::vector<char16_t>& data)
 {
   std::map<Language, std::string> names;