Recommitting: https://codereview.chromium.org/406043003/

(originally reverted because the buildbots weren't pointed 
to verifier_test_dll.dll by unit_tests.isolate)

=========================================================
Adding the VerifyModule function (and helpers) to safe browsing.

This function allows us to compare a module in memory with 
its original on disk, and identify any differences (after 
accounting for relocations).  The state of the module 
(MODULE_UNKNOWN, MODULE_UNMODIFIED or MODULE_MODIFIED) is 
returned along with a list of the possibly modified exported 
functions of the module.


BUG=401854
TBR= noelutz@google.com, robertshield@chromium.org, csharp@chromium.org, asvitkine@chromium.org, grt@chromium.org
NOTRY=True

Review URL: https://codereview.chromium.org/451893003

Cr-Commit-Position: refs/heads/master@{#288417}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288417 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/safe_browsing/module_integrity_verifier_win.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_SAFE_BROWSING_MODULE_INTEGRITY_VERIFIER_WIN_H_
+#define CHROME_BROWSER_SAFE_BROWSING_MODULE_INTEGRITY_VERIFIER_WIN_H_
+
+#include <stdint.h>
+
+#include <set>
+#include <string>
+
+namespace base {
+namespace win {
+class PEImage;
+class PEImageAsData;
+}  // namespace win
+}  // namespace base
+
+namespace safe_browsing {
+
+// This enum defines the possible module states VerifyModule can return.
+enum ModuleState {
+  MODULE_STATE_UNKNOWN,
+  MODULE_STATE_UNMODIFIED,
+  MODULE_STATE_MODIFIED,
+};
+
+// Helper to grab the addresses and size of the code section of a PEImage.
+// Returns two addresses: one for the dll loaded as a library, the other for the
+// dll loaded as data.
+bool GetCodeAddrsAndSize(const base::win::PEImage& mem_peimage,
+                         const base::win::PEImageAsData& disk_peimage,
+                         uint8_t** mem_code_addr,
+                         uint8_t** disk_code_addr,
+                         uint32_t* code_size);
+
+// Examines the code section of the given module in memory and on disk, looking
+// for unexpected differences.  Returns a ModuleState and and a set of the
+// possibly modified exports.
+ModuleState VerifyModule(const wchar_t* module_name,
+                         std::set<std::string>* modified_exports);
+
+}  // namespace safe_browsing
+
+#endif  // CHROME_BROWSER_SAFE_BROWSING_MODULE_INTEGRITY_VERIFIER_WIN_H_

chrome/browser/safe_browsing/module_integrity_verifier_win_unittest.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/safe_browsing/module_integrity_verifier_win.h"
+
+#include "base/files/file_path.h"
+#include "base/files/memory_mapped_file.h"
+#include "base/native_library.h"
+#include "base/path_service.h"
+#include "base/scoped_native_library.h"
+#include "base/win/pe_image.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace safe_browsing {
+
+namespace {
+
+const wchar_t kTestDllName[] = L"verifier_test_dll.dll";
+const char kTestExportName[] = "DummyExport";
+
+}  // namespace
+
+class SafeBrowsingModuleVerifierWinTest : public testing::Test {
+ protected:
+  void SetUpTestDllAndPEImages() {
+    LoadModule();
+    HMODULE mem_handle;
+    GetMemModuleHandle(&mem_handle);
+    mem_peimage_ptr_.reset(new base::win::PEImage(mem_handle));
+    ASSERT_TRUE(mem_peimage_ptr_->VerifyMagic());
+
+    LoadDLLAsFile();
+    HMODULE disk_handle;
+    GetDiskModuleHandle(&disk_handle);
+    disk_peimage_ptr_.reset(new base::win::PEImageAsData(disk_handle));
+    ASSERT_TRUE(disk_peimage_ptr_->VerifyMagic());
+  }
+
+  void LoadModule() {
+    HMODULE mem_dll_handle =
+        LoadNativeLibrary(base::FilePath(kTestDllName), NULL);
+    ASSERT_NE(static_cast<HMODULE>(NULL), mem_dll_handle)
+        << "GLE=" << GetLastError();
+    mem_dll_handle_.Reset(mem_dll_handle);
+    ASSERT_TRUE(mem_dll_handle_.is_valid());
+  }
+
+  void GetMemModuleHandle(HMODULE* mem_handle) {
+    *mem_handle = GetModuleHandle(kTestDllName);
+    ASSERT_NE(static_cast<HMODULE>(NULL), *mem_handle);
+  }
+
+  void LoadDLLAsFile() {
+    // Use the module handle to find the it on disk, then load as a file.
+    HMODULE module_handle;
+    GetMemModuleHandle(&module_handle);
+
+    WCHAR module_path[MAX_PATH] = {};
+    DWORD length =
+        GetModuleFileName(module_handle, module_path, arraysize(module_path));
+    ASSERT_NE(arraysize(module_path), length);
+    ASSERT_TRUE(disk_dll_handle_.Initialize(base::FilePath(module_path)));
+  }
+
+  void GetDiskModuleHandle(HMODULE* disk_handle) {
+    *disk_handle =
+        reinterpret_cast<HMODULE>(const_cast<uint8*>(disk_dll_handle_.data()));
+  }
+
+  // Edits the first byte of the single function exported by the test dll.
+  void EditExport() {
+    HMODULE mem_handle;
+    GetMemModuleHandle(&mem_handle);
+    uint8_t* export_addr =
+        reinterpret_cast<uint8_t*>(GetProcAddress(mem_handle, kTestExportName));
+    EXPECT_NE(reinterpret_cast<uint8_t*>(NULL), export_addr);
+
+    // Edit the first byte of the function.
+    uint8_t new_val = (*export_addr) + 1;
+    SIZE_T bytes_written = 0;
+    WriteProcessMemory(GetCurrentProcess(),
+                       export_addr,
+                       reinterpret_cast<void*>(&new_val),
+                       1,
+                       &bytes_written);
+    EXPECT_EQ(1, bytes_written);
+  }
+
+  base::ScopedNativeLibrary mem_dll_handle_;
+  base::MemoryMappedFile disk_dll_handle_;
+  scoped_ptr<base::win::PEImageAsData> disk_peimage_ptr_;
+  scoped_ptr<base::win::PEImage> mem_peimage_ptr_;
+};
+
+TEST_F(SafeBrowsingModuleVerifierWinTest, VerifyModuleUnmodified) {
+  std::set<std::string> modified_exports;
+  // Call VerifyModule before the module has been loaded, should fail.
+  EXPECT_EQ(MODULE_STATE_UNKNOWN,
+            VerifyModule(kTestDllName, &modified_exports));
+  EXPECT_EQ(0, modified_exports.size());
+
+  // On loading, the module should be identical (up to relocations) in memory as
+  // on disk.
+  SetUpTestDllAndPEImages();
+  EXPECT_EQ(MODULE_STATE_UNMODIFIED,
+            VerifyModule(kTestDllName, &modified_exports));
+  EXPECT_EQ(0, modified_exports.size());
+}
+
+TEST_F(SafeBrowsingModuleVerifierWinTest, VerifyModuleModified) {
+  std::set<std::string> modified_exports;
+  // Confirm the module is identical in memory as on disk before we begin.
+  SetUpTestDllAndPEImages();
+  EXPECT_EQ(MODULE_STATE_UNMODIFIED,
+            VerifyModule(kTestDllName, &modified_exports));
+
+  uint8_t* mem_code_addr = NULL;
+  uint8_t* disk_code_addr = NULL;
+  uint32_t code_size = 0;
+  EXPECT_TRUE(GetCodeAddrsAndSize(*mem_peimage_ptr_,
+                                  *disk_peimage_ptr_,
+                                  &mem_code_addr,
+                                  &disk_code_addr,
+                                  &code_size));
+
+  // Edit the first byte of the code section of the module (this may be before
+  // the address of any export).
+  uint8_t new_val = (*mem_code_addr) + 1;
+  SIZE_T bytes_written = 0;
+  WriteProcessMemory(GetCurrentProcess(),
+                     mem_code_addr,
+                     reinterpret_cast<void*>(&new_val),
+                     1,
+                     &bytes_written);
+  EXPECT_EQ(1, bytes_written);
+
+  // VerifyModule should detect the change.
+  EXPECT_EQ(MODULE_STATE_MODIFIED,
+            VerifyModule(kTestDllName, &modified_exports));
+}
+
+TEST_F(SafeBrowsingModuleVerifierWinTest, VerifyModuleExportModified) {
+  std::set<std::string> modified_exports;
+  // Confirm the module is identical in memory as on disk before we begin.
+  SetUpTestDllAndPEImages();
+  EXPECT_EQ(MODULE_STATE_UNMODIFIED,
+            VerifyModule(kTestDllName, &modified_exports));
+  modified_exports.clear();
+
+  // Edit the exported function, VerifyModule should now return the function
+  // name in modified_exports.
+  EditExport();
+  EXPECT_EQ(MODULE_STATE_MODIFIED,
+            VerifyModule(kTestDllName, &modified_exports));
+  EXPECT_EQ(1, modified_exports.size());
+  EXPECT_EQ(0, std::string(kTestExportName).compare(*modified_exports.begin()));
+}
+
+}  // namespace safe_browsing

chrome/browser/safe_browsing/verifier_test/verifier_test_dll.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <windows.h>
+
+extern "C" {
+// Have a dummy export so that the module gets an export table entry.
+void DummyExport() {
+}
+}
+
+BOOL APIENTRY DllMain(HMODULE module, DWORD reason, LPVOID reserved) {
+  return true;
+}

chrome/browser/safe_browsing/verifier_test/verifier_test_dll.def

+; Copyright 2014 The Chromium Authors. All rights reserved.
+; Use of this source code is governed by a BSD-style license that can be
+; found in the LICENSE file.
+
+LIBRARY "verifier_test_dll.dll"
+
+EXPORTS
+  DummyExport

chrome/browser/safe_browsing/verifier_test/verifier_unittest.gyp

+{
+  'targets': [
+    {
+      'target_name': 'verifier_test_dll',
+      'type': 'loadable_module',
+      'sources': [
+        'verifier_test_dll.cc',
+        'verifier_test_dll.def',
+      ],
+    },
+  ],
+}
\ No newline at end of file

chrome/chrome_browser.gypi

@@ -2672,6 +2672,8 @@
       'browser/safe_browsing/incident_report_uploader_impl.h',
       'browser/safe_browsing/last_download_finder.cc',
       'browser/safe_browsing/last_download_finder.h',
+      'browser/safe_browsing/module_integrity_verifier_win.cc',
+      'browser/safe_browsing/module_integrity_verifier_win.h',
       'browser/safe_browsing/path_sanitizer.cc',
       'browser/safe_browsing/path_sanitizer.h',
       'browser/safe_browsing/pe_image_reader_win.cc',

chrome/chrome_tests_unit.gypi

@@ -1216,6 +1216,7 @@
         'browser/safe_browsing/last_download_finder_unittest.cc',
         'browser/safe_browsing/local_two_phase_testserver.cc',
         'browser/safe_browsing/malware_details_unittest.cc',
+        'browser/safe_browsing/module_integrity_verifier_win_unittest.cc',
         'browser/safe_browsing/path_sanitizer_unittest.cc',
         'browser/safe_browsing/pe_image_reader_win_unittest.cc',
         'browser/safe_browsing/ping_manager_unittest.cc',
@@ -2463,6 +2464,7 @@
         }],
         ['OS=="win"', {
           'dependencies': [
+            'browser/safe_browsing/verifier_test/verifier_unittest.gyp:verifier_test_dll',
             'chrome_version_resources',
             'installer_util_strings',
             '../chrome_elf/chrome_elf.gyp:blacklist_test_dll_1',

chrome/unit_tests.isolate

@@ -106,6 +106,7 @@
           '<(PRODUCT_DIR)/ffmpegsumo.dll',
           '<(PRODUCT_DIR)/libexif.dll',
           '<(PRODUCT_DIR)/osmesa.dll',
+          '<(PRODUCT_DIR)/verifier_test_dll.dll',
         ],
         'isolate_dependency_untracked': [
           '../ppapi/lib/gl/include/KHR/',

tools/metrics/histograms/histograms.xml

@@ -25729,6 +25729,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="SafeBrowsing.ModuleBaseRelocation" units="BaseRelocationType">
+  <owner>csharp@chromium.org</owner>
+  <owner>krstnmnlsn@chromium.org</owner>
+  <summary>
+    A windows only historgram. Records when an unknown base relocation type is
+    encountered while reading the reloc table of a loaded module.
+  </summary>
+</histogram>
+
 <histogram name="SB.BloomFilter" units="milliseconds">
   <obsolete>
     Has not been generated for years (7/8/14).
@@ -36832,6 +36841,20 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="2" label="Failure"/>
 </enum>
 
+<enum name="BaseRelocationType" type="int">
+  <int value="0" label="IMAGE_REL_BASED_ABSOLUTE"/>
+  <int value="1" label="IMAGE_REL_BASED_HIGH"/>
+  <int value="2" label="IMAGE_REL_BASED_LOW"/>
+  <int value="3" label="IMAGE_REL_BASED_HIGHLOW"/>
+  <int value="4" label="IMAGE_REL_BASED_HIGHADJ"/>
+  <int value="5" label="IMAGE_REL_BASED_MACHINE_SPECIFIC_5"/>
+  <int value="6" label="IMAGE_REL_BASED_RESERVED"/>
+  <int value="7" label="IMAGE_REL_BASED_MACHINE_SPECIFIC_7"/>
+  <int value="8" label="IMAGE_REL_BASED_MACHINE_SPECIFIC_8"/>
+  <int value="9" label="IMAGE_REL_BASED_MACHINE_SPECIFIC_9"/>
+  <int value="10" label="IMAGE_REL_BASED_DIR64"/>
+</enum>
+
 <enum name="BatteryInfoSampleResult" type="int">
   <int value="0" label="Read"/>
   <int value="1" label="Good"/>