1 files changed, 79 insertions, 0 deletions
diff --git a/api/registry.h b/api/registry.h
new file mode 100644
index 0000000..6beed2f
--- /dev/null
+++ b/api/registry.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2018-2021 WireGuard LLC. All Rights Reserved.
+ */
+
+#pragma once
+
+#include "wintun.h"
+#include <Windows.h>
+
+#define MAX_REG_PATH \
+    256 /* Maximum registry path length \
+           https://support.microsoft.com/en-us/help/256986/windows-registry-information-for-advanced-users */
+
+/**
+ * Validates and/or sanitizes string value read from registry.
+ *
+ * @param Buf           On input, it contains a pointer to pointer where the data is stored. The data must be allocated
+ *                      using HeapAlloc(ModuleHeap, 0). On output, it contains a pointer to pointer where the sanitized
+ *                      data is stored. It must be released with HeapFree(ModuleHeap, 0, *Buf) after use.
+ *
+ * @param Len           Length of data string in wide characters.
+ *
+ * @param ValueType     Type of data. Must be either REG_SZ or REG_EXPAND_SZ. REG_MULTI_SZ is treated like REG_SZ; only
+ *                      the first string of a multi-string is to be used.
+ *
+ * @return If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To
+ *         get extended error information, call GetLastError.
+ */
+_Must_inspect_result_
+_Return_type_success_(return != FALSE)
+BOOL
+RegistryGetString(_Inout_ LPWSTR *Buf, _In_ DWORD Len, _In_ DWORD ValueType);
+
+/**
+ * Reads string value from registry key.
+ *
+ * @param Key           Handle of the registry key to read from. Must be opened with read access.
+ *
+ * @param Name          Name of the value to read.
+ *
+ * @param Value         Pointer to string to retrieve registry value. If the value type is REG_EXPAND_SZ the value is
+ *                      expanded using ExpandEnvironmentStrings(). If the value type is REG_MULTI_SZ, only the first
+ *                      string from the multi-string is returned. The string must be released with
+ *                      HeapFree(ModuleHeap, 0, Value) after use.
+ *
+ * @Log                 Set to TRUE to log all failures; FALSE to skip logging the innermost errors. Skipping innermost
+ *                      errors reduces log clutter when we are using RegistryQueryString() from
+ *                      RegistryQueryStringWait() and some errors are expected to occur.
+ *
+ * @return String with registry value on success; If the function fails, the return value is zero. To get extended error
+ *         information, call GetLastError.
+ */
+_Must_inspect_result_
+_Return_type_success_(return != NULL)
+_Post_maybenull_
+LPWSTR
+RegistryQueryString(_In_ HKEY Key, _In_opt_z_ LPCWSTR Name, _In_ BOOL Log);
+
+/**
+ * Reads a 32-bit DWORD value from registry key.
+ *
+ * @param Key           Handle of the registry key to read from. Must be opened with read access.
+ *
+ * @param Name          Name of the value to read.
+ *
+ * @param Value         Pointer to DWORD to retrieve registry value.
+ *
+ * @Log                 Set to TRUE to log all failures; FALSE to skip logging the innermost errors. Skipping innermost
+ *                      errors reduces log clutter when we are using RegistryQueryDWORD() from
+ *                      RegistryQueryDWORDWait() and some errors are expected to occur.
+ *
+ * @return If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To
+ *         get extended error information, call GetLastError.
+ */
+_Must_inspect_result_
+_Return_type_success_(return != FALSE)
+BOOL
+RegistryQueryDWORD(_In_ HKEY Key, _In_opt_z_ LPCWSTR Name, _Out_ DWORD *Value, _In_ BOOL Log);