From db3a89a0da2a0329e60093af1f1733cebfca0bd3 Mon Sep 17 00:00:00 2001
From: momo5502 <mauriceheumann@gmail.com>
Date: Tue, 23 Dec 2025 09:31:10 +0100
Subject: [PATCH] Support KeyCachedInformation

---
 src/common/platform/registry.hpp              | 12 ++++++
 src/windows-emulator/registry/hive_parser.hpp | 17 +++++++++
 .../registry/registry_manager.cpp             | 20 ++++++++++
 .../registry/registry_manager.hpp             |  8 ++++
 src/windows-emulator/syscalls/registry.cpp    | 37 ++++++++++++++++++-
 5 files changed, 93 insertions(+), 1 deletion(-)

diff --git a/src/common/platform/registry.hpp b/src/common/platform/registry.hpp
index a44e8b2e..af2d7286 100644
--- a/src/common/platform/registry.hpp
+++ b/src/common/platform/registry.hpp
@@ -67,6 +67,18 @@ typedef struct _KEY_FULL_INFORMATION
     char16_t Class[1];
 } KEY_FULL_INFORMATION, *PKEY_FULL_INFORMATION;
 
+typedef struct _KEY_CACHED_INFORMATION
+{
+    LARGE_INTEGER LastWriteTime;
+    ULONG TitleIndex;
+    ULONG SubKeys;
+    ULONG MaxNameLen;
+    ULONG Values;
+    ULONG MaxValueNameLen;
+    ULONG MaxValueDataLen;
+    ULONG NameLength;
+} KEY_CACHED_INFORMATION, *PKEY_CACHED_INFORMATION;
+
 struct KEY_HANDLE_TAGS_INFORMATION
 {
     ULONG HandleTags;
diff --git a/src/windows-emulator/registry/hive_parser.hpp b/src/windows-emulator/registry/hive_parser.hpp
index 0db9979b..6fa98440 100644
--- a/src/windows-emulator/registry/hive_parser.hpp
+++ b/src/windows-emulator/registry/hive_parser.hpp
@@ -62,6 +62,18 @@ class hive_key
     const hive_value* get_value(std::ifstream& file, std::string_view name);
     const hive_value* get_value(std::ifstream& file, size_t index);
 
+    size_t get_sub_key_count(std::ifstream& file)
+    {
+        this->parse(file);
+        return this->sub_keys_.size();
+    }
+
+    size_t get_value_count(std::ifstream& file)
+    {
+        this->parse(file);
+        return this->values_.size();
+    }
+
   private:
     struct raw_hive_value : hive_value
     {
@@ -138,6 +150,11 @@ class hive_parser
         return sub_key->get_value(this->file_, index);
     }
 
+    std::ifstream& get_file()
+    {
+        return this->file_;
+    }
+
   private:
     std::ifstream file_{};
     hive_key root_key_;
diff --git a/src/windows-emulator/registry/registry_manager.cpp b/src/windows-emulator/registry/registry_manager.cpp
index 9979e7d4..0845af99 100644
--- a/src/windows-emulator/registry/registry_manager.cpp
+++ b/src/windows-emulator/registry/registry_manager.cpp
@@ -209,6 +209,26 @@ registry_manager::hive_map::iterator registry_manager::find_hive(const utils::pa
     return this->hives_.end();
 }
 
+std::optional<exposed_hive_key> registry_manager::get_hive_key(const registry_key& key)
+{
+    const auto iterator = this->hives_.find(key.hive);
+    if (iterator == this->hives_.end())
+    {
+        return std::nullopt;
+    }
+
+    auto* hive_key = iterator->second->get_sub_key(key.path.get());
+    if (!hive_key)
+    {
+        return std::nullopt;
+    }
+
+    return exposed_hive_key{
+        .key = *hive_key,
+        .file = iterator->second->get_file(),
+    };
+}
+
 std::optional<std::string_view> registry_manager::get_sub_key_name(const registry_key& key, const size_t index)
 {
     const auto iterator = this->hives_.find(key.hive);
diff --git a/src/windows-emulator/registry/registry_manager.hpp b/src/windows-emulator/registry/registry_manager.hpp
index 81e0cb79..d0c48fc9 100644
--- a/src/windows-emulator/registry/registry_manager.hpp
+++ b/src/windows-emulator/registry/registry_manager.hpp
@@ -54,6 +54,12 @@ struct registry_value
     std::span<const std::byte> data;
 };
 
+struct exposed_hive_key
+{
+    hive_key& key;
+    std::ifstream& file;
+};
+
 class registry_manager
 {
   public:
@@ -76,6 +82,8 @@ class registry_manager
 
     std::optional<std::string_view> get_sub_key_name(const registry_key& key, size_t index);
 
+    std::optional<exposed_hive_key> get_hive_key(const registry_key& key);
+
   private:
     std::filesystem::path hive_path_{};
     hive_map hives_{};
diff --git a/src/windows-emulator/syscalls/registry.cpp b/src/windows-emulator/syscalls/registry.cpp
index d511b224..baf880dd 100644
--- a/src/windows-emulator/syscalls/registry.cpp
+++ b/src/windows-emulator/syscalls/registry.cpp
@@ -82,11 +82,46 @@ namespace syscalls
             return STATUS_SUCCESS;
         }
 
-        if (key_information_class == KeyFullInformation || key_information_class == KeyCachedInformation)
+        if (key_information_class == KeyFullInformation)
         {
+            c.win_emu.log.warn("Unsupported registry class: %X\n", key_information_class);
             return STATUS_NOT_SUPPORTED;
         }
 
+        if (key_information_class == KeyCachedInformation)
+        {
+            auto key_name = (key->hive.get() / key->path.get()).u16string();
+            while (key_name.ends_with(u'/') || key_name.ends_with(u'\\'))
+            {
+                key_name.pop_back();
+            }
+
+            const auto hive_key = c.win_emu.registry.get_hive_key(*key);
+            if (!hive_key.has_value())
+            {
+                return STATUS_OBJECT_NAME_NOT_FOUND;
+            }
+
+            constexpr auto required_size = sizeof(KEY_CACHED_INFORMATION);
+            result_length.write(required_size);
+
+            if (required_size > length)
+            {
+                return STATUS_BUFFER_TOO_SMALL;
+            }
+
+            KEY_CACHED_INFORMATION info{};
+            info.SubKeys = static_cast<ULONG>(hive_key->key.get_sub_key_count(hive_key->file));
+            info.Values = static_cast<ULONG>(hive_key->key.get_value_count(hive_key->file));
+            info.NameLength = static_cast<ULONG>(key_name.size() * 2);
+            info.MaxValueDataLen = 0x1000;
+            info.MaxValueNameLen = 0x1000;
+            info.MaxNameLen = 0x1000;
+
+            c.emu.write_memory(key_information, info);
+            return STATUS_SUCCESS;
+        }
+
         if (key_information_class == KeyHandleTagsInformation)
         {
             constexpr auto required_size = sizeof(KEY_HANDLE_TAGS_INFORMATION);