Modify Analytics on desktop to use a verified DLL on Windows (although it is currently still a stub).

analytics/CMakeLists.txt

@@ -74,9 +74,15 @@ set(android_SRCS
 set(ios_SRCS
     src/analytics_ios.mm)
 
-# Source files used by the stub implementation.
-set(stub_SRCS
-    src/analytics_stub.cc)
+# Source files used by the desktop / stub implementation.
+set(desktop_SRCS
+    src/analytics_desktop.cc
+    src/analytics_desktop_dynamic.c)
+
+if(WIN32)
+  # Add Windows-specific sources for desktop builds.
+  list(APPEND desktop_SRCS src/analytics_windows.cc)
+endif()
 
 if(ANDROID)
   set(analytics_platform_SRCS
@@ -86,7 +92,7 @@ elseif(IOS)
       "${ios_SRCS}")
 else()
   set(analytics_platform_SRCS
-      "${stub_SRCS}")
+      "${desktop_SRCS}")
 endif()
 
 add_library(firebase_analytics STATIC

analytics/generate_windows_stubs.py

@@ -16,12 +16,13 @@
 """Generate stubs and function pointers for Windows SDK"""
 
 import argparse
+import hashlib
 import os
 import re
 import sys
 
 HEADER_GUARD_PREFIX = "FIREBASE_ANALYTICS_SRC_WINDOWS_"
-INCLUDE_PATH = "src/windows/"
+INCLUDE_PATH = "src/"
 INCLUDE_PREFIX = "analytics/" + INCLUDE_PATH
 COPYRIGHT_NOTICE = """// Copyright 2025 Google LLC
 //
@@ -39,17 +40,29 @@
 
 """
 
-def generate_function_pointers(header_file_path, output_h_path, output_c_path):
+
+def hash_file(filename):
+    sha256_hash = hashlib.sha256()
+    with open(filename, "rb") as file:
+        while chunk := file.read(4096):
+            sha256_hash.update(chunk)
+    return sha256_hash.digest()
+
+def generate_function_pointers(dll_file_path, header_file_path, output_h_path, output_c_path):
     """
     Parses a C header file to generate a self-contained header with typedefs,
     extern function pointer declarations, and a source file with stub functions,
     initialized pointers, and a dynamic loading function for Windows.
 
     Args:
+        header_file_path (str): The path to the DLL file.
         header_file_path (str): The path to the input C header file.
         output_h_path (str): The path for the generated C header output file.
         output_c_path (str): The path for the generated C source output file.
     """
+    print(f"Reading DLL file: {dll_file_path}")
+    dll_hash = hash_file(dll_file_path)
+
     print(f"Reading header file: {header_file_path}")
     try:
         with open(header_file_path, 'r', encoding='utf-8') as f:
@@ -83,7 +96,7 @@ def generate_function_pointers(header_file_path, output_h_path, output_c_path):
         return_type = match.group(1).strip()
         function_name = match.group(2).strip()
         params_str = match.group(3).strip()
-        
+
         cleaned_params_for_decl = re.sub(r'\s+', ' ', params_str) if params_str else ""
         stub_name = f"Stub_{function_name}"
 
@@ -94,7 +107,7 @@ def generate_function_pointers(header_file_path, output_h_path, output_c_path):
             return_statement = f'    return ({return_type})(&g_stub_memory);'
         else: # bool, int64_t, etc.
             return_statement = "    return 1;"
-            
+
         stub_function = (
             f"// Stub for {function_name}\n"
             f"static {return_type} {stub_name}({params_str}) {{\n"
@@ -111,7 +124,7 @@ def generate_function_pointers(header_file_path, output_h_path, output_c_path):
 
         pointer_init = f"{return_type} (*ptr_{function_name})({cleaned_params_for_decl}) = &{stub_name};"
         pointer_initializations.append(pointer_init)
-        
+
         function_details_for_loader.append((function_name, return_type, cleaned_params_for_decl))
 
     print(f"Found {len(pointer_initializations)} functions. Generating output files...")
@@ -124,12 +137,12 @@ def generate_function_pointers(header_file_path, output_h_path, output_c_path):
         f.write(f"#ifndef {header_guard}\n")
         f.write(f"#define {header_guard}\n\n")
         f.write("#include <stdbool.h>  // needed for bool type in pure C\n\n")
-        
+
         f.write("// --- Copied from original header ---\n")
         f.write("\n".join(includes) + "\n\n")
         f.write("".join(typedefs))
         f.write("// --- End of copied section ---\n\n")
-        
+
         f.write("#ifdef __cplusplus\n")
         f.write('extern "C" {\n')
         f.write("#endif\n\n")
@@ -139,15 +152,20 @@ def generate_function_pointers(header_file_path, output_h_path, output_c_path):
         f.write("\n\n")
         f.write("\n".join(macro_definitions))
         f.write("\n// clang-format on\n")
-        f.write("\n\n// --- Dynamic Loader Declaration for Windows ---\n")
+        f.write("\n// --- Dynamic Loader Declaration for Windows ---\n")
         f.write("#if defined(_WIN32)\n")
-        f.write('#include <windows.h> // For HMODULE\n')
-        f.write('// Load Google Analytics functions from the given DLL handle into function pointers.\n')
-        f.write(f'// Returns the number of functions successfully loaded (out of {len(function_details_for_loader)}).\n')
-        f.write("int FirebaseAnalytics_LoadAnalyticsFunctions(HMODULE dll_handle);\n\n")
+        f.write('#include <windows.h>\n')
+        f.write(f'\n// Google Analytics Windows DLL SHA256 hash, to be verified on load.')
+        f.write(f'\nextern const unsigned char FirebaseAnalytics_WindowsDllHash[{len(dll_hash)}];\n');
+
+        f.write(f'\n// Number of Google Analytics functions expected to be loaded from the DLL.')
+        f.write(f'\n#define FIREBASE_ANALYTICS_DYNAMIC_FUNCTION_COUNT {len(function_details_for_loader)}\n\n')
+        f.write('// Load Analytics functions from the given DLL handle into function pointers.\n')
+        f.write(f'// Returns the number of functions successfully loaded (out of\n// FIREBASE_ANALYTICS_DYNAMIC_FUNCTION_COUNT).\n')
+        f.write("int FirebaseAnalytics_LoadDynamicFunctions(HMODULE dll_handle);\n\n")
         f.write('// Reset all function pointers back to stubs.\n')
-        f.write("void FirebaseAnalytics_UnloadAnalyticsFunctions(void);\n\n")
-        f.write("#endif // defined(_WIN32)\n")
+        f.write("void FirebaseAnalytics_UnloadDynamicFunctions(void);\n\n")
+        f.write("#endif  // defined(_WIN32)\n")
         f.write("\n#ifdef __cplusplus\n")
         f.write("}\n")
         f.write("#endif\n\n")
@@ -159,18 +177,22 @@ def generate_function_pointers(header_file_path, output_h_path, output_c_path):
     with open(output_c_path, 'w', encoding='utf-8') as f:
         f.write(f"{COPYRIGHT_NOTICE}")
         f.write(f"// Generated from {os.path.basename(header_file_path)} by {os.path.basename(sys.argv[0])}\n\n")
-        f.write(f'#include "{INCLUDE_PREFIX}{os.path.basename(output_h_path)}"\n')
+        f.write(f'#include "{INCLUDE_PREFIX}{os.path.basename(output_h_path)}"\n\n')
         f.write('#include <stddef.h>\n\n')
-        f.write("// clang-format off\n\n")
         f.write("static void* g_stub_memory = NULL;\n\n")
+        f.write("// clang-format off\n\n")
+        f.write('// Google Analytics Windows DLL SHA256 hash, to be verified on load.\n')
+        f.write('const unsigned char FirebaseAnalytics_WindowsDllHash[] = {\n    ')
+        f.write(', '.join(["0x%02x" % s for s in dll_hash]))
+        f.write('\n};\n\n')
         f.write("// --- Stub Function Definitions ---\n")
         f.write("\n\n".join(stub_functions))
         f.write("\n\n\n// --- Function Pointer Initializations ---\n")
         f.write("\n".join(pointer_initializations))
         f.write("\n\n// --- Dynamic Loader Function for Windows ---\n")
         loader_lines = [
             '#if defined(_WIN32)',
-            'int FirebaseAnalytics_LoadAnalyticsFunctions(HMODULE dll_handle) {',
+            'int FirebaseAnalytics_LoadDynamicFunctions(HMODULE dll_handle) {',
             '    int count = 0;\n',
             '    if (!dll_handle) {',
             '        return count;',
@@ -188,7 +210,7 @@ def generate_function_pointers(header_file_path, output_h_path, output_c_path):
             loader_lines.extend(proc_check)
         loader_lines.append('\n    return count;')
         loader_lines.append('}\n')
-        loader_lines.append('void FirebaseAnalytics_UnloadAnalyticsFunctions(void) {')
+        loader_lines.append('void FirebaseAnalytics_UnloadDynamicFunctions(void) {')
         for name, ret_type, params in function_details_for_loader:
             loader_lines.append(f'    ptr_{name} = &Stub_{name};');
         loader_lines.append('}\n')
@@ -203,6 +225,12 @@ def generate_function_pointers(header_file_path, output_h_path, output_c_path):
     parser = argparse.ArgumentParser(
         description="Generate C stubs and function pointers from a header file."
     )
+    parser.add_argument(
+        "--windows_dll",
+        default = os.path.join(os.path.dirname(sys.argv[0]), "windows/analytics_win.dll"),
+        #required=True,
+        help="Path to the DLL file to calculate a hash."
+    )
     parser.add_argument(
         "--windows_header",
         default = os.path.join(os.path.dirname(sys.argv[0]), "windows/include/public/c/analytics.h"),
@@ -211,21 +239,21 @@ def generate_function_pointers(header_file_path, output_h_path, output_c_path):
     )
     parser.add_argument(
         "--output_header",
-        default = os.path.join(os.path.dirname(sys.argv[0]), INCLUDE_PATH, "analytics_dynamic.h"),
+        default = os.path.join(os.path.dirname(sys.argv[0]), INCLUDE_PATH, "analytics_desktop_dynamic.h"),
         #required=True,
         help="Path for the generated output header file."
     )
     parser.add_argument(
         "--output_source",
-        default = os.path.join(os.path.dirname(sys.argv[0]), INCLUDE_PATH, "analytics_dynamic.c"),
+        default = os.path.join(os.path.dirname(sys.argv[0]), INCLUDE_PATH, "analytics_desktop_dynamic.c"),
         #required=True,
         help="Path for the generated output source file."
     )
-
     args = parser.parse_args()
-    
+
     generate_function_pointers(
-        args.windows_header, 
-        args.output_header, 
+        args.windows_dll,
+        args.windows_header,
+        args.output_header,
         args.output_source
     )

analytics/integration_test/CMakeLists.txt

@@ -211,6 +211,18 @@ else()
     )
   elseif(MSVC)
     set(ADDITIONAL_LIBS advapi32 ws2_32 crypt32)
+    set(ANALYTICS_WINDOWS_DLL "${FIREBASE_CPP_SDK_DIR}/analytics/windows/analytics_win.dll")
+
+    # For Windows, check if the Analytics DLL exists, and copy it in if so.
+    if (EXISTS "${ANALYTICS_WINDOWS_DLL}")
+      add_custom_command(
+        TARGET ${integration_test_target_name} POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E copy
+	  "${ANALYTICS_WINDOWS_DLL}"
+          $<TARGET_FILE_DIR:${integration_test_target_name}>)
+    else()
+      message(WARNING "Couldn't find ${ANALYTICS_WINDOWS_DLL}. Analytics will run in stub mode.")
+    endif()
   else()
     set(ADDITIONAL_LIBS pthread)
   endif()