chrome/browser/safe_browsing/signature_util_win.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/safe_browsing/signature_util.h"
   6
   7 #include <windows.h>
   8 #include <softpub.h>
   9 #include <wintrust.h>
  10
  11 #include "base/files/file_path.h"
  12 #include "base/logging.h"
  13 #include "chrome/common/safe_browsing/csd.pb.h"
  14
  15 #pragma comment(lib, "wintrust.lib")
  16
  17 namespace safe_browsing {
  18
  19 SignatureUtil::SignatureUtil() {}
  20
  21 SignatureUtil::~SignatureUtil() {}
  22
  23 void SignatureUtil::CheckSignature(
  24     const base::FilePath& file_path,
  25     ClientDownloadRequest_SignatureInfo* signature_info) {
  26   VLOG(2) << "Checking signature for " << file_path.value();
  27
  28   WINTRUST_FILE_INFO file_info = {0};
  29   file_info.cbStruct = sizeof(file_info);
  30   file_info.pcwszFilePath = file_path.value().c_str();
  31   file_info.hFile = NULL;
  32   file_info.pgKnownSubject = NULL;
  33
  34   WINTRUST_DATA wintrust_data = {0};
  35   wintrust_data.cbStruct = sizeof(wintrust_data);
  36   wintrust_data.pPolicyCallbackData = NULL;
  37   wintrust_data.pSIPClientData = NULL;
  38   wintrust_data.dwUIChoice = WTD_UI_NONE;
  39   wintrust_data.fdwRevocationChecks = WTD_REVOKE_NONE;
  40   wintrust_data.dwUnionChoice = WTD_CHOICE_FILE;
  41   wintrust_data.pFile = &file_info;
  42   wintrust_data.dwStateAction = WTD_STATEACTION_VERIFY;
  43   wintrust_data.hWVTStateData = NULL;
  44   wintrust_data.pwszURLReference = NULL;
  45   // Disallow revocation checks over the network.
  46   wintrust_data.dwProvFlags = WTD_CACHE_ONLY_URL_RETRIEVAL;
  47   wintrust_data.dwUIContext = WTD_UICONTEXT_EXECUTE;
  48
  49   // The WINTRUST_ACTION_GENERIC_VERIFY_V2 policy verifies that the certificate
  50   // chains up to a trusted root CA, and that it has appropriate permission to
  51   // sign code.
  52   GUID policy_guid = WINTRUST_ACTION_GENERIC_VERIFY_V2;
  53
  54   LONG result = WinVerifyTrust(static_cast<HWND>(INVALID_HANDLE_VALUE),
  55                                &policy_guid,
  56                                &wintrust_data);
  57
  58   CRYPT_PROVIDER_DATA* prov_data = WTHelperProvDataFromStateData(
  59       wintrust_data.hWVTStateData);
  60   if (prov_data) {
  61     if (prov_data->csSigners > 0) {
  62       signature_info->set_trusted(result == ERROR_SUCCESS);
  63     }
  64     for (DWORD i = 0; i < prov_data->csSigners; ++i) {
  65       const CERT_CHAIN_CONTEXT* cert_chain_context =
  66           prov_data->pasSigners[i].pChainContext;
  67       if (!cert_chain_context)
  68         break;
  69       for (DWORD j = 0; j < cert_chain_context->cChain; ++j) {
  70         CERT_SIMPLE_CHAIN* simple_chain = cert_chain_context->rgpChain[j];
  71         ClientDownloadRequest_CertificateChain* chain =
  72             signature_info->add_certificate_chain();
  73         if (!simple_chain)
  74           break;
  75         for (DWORD k = 0; k < simple_chain->cElement; ++k) {
  76           CERT_CHAIN_ELEMENT* element = simple_chain->rgpElement[k];
  77           chain->add_element()->set_certificate(
  78               element->pCertContext->pbCertEncoded,
  79               element->pCertContext->cbCertEncoded);
  80         }
  81       }
  82     }
  83
  84     // Free the provider data.
  85     wintrust_data.dwStateAction = WTD_STATEACTION_CLOSE;
  86     WinVerifyTrust(static_cast<HWND>(INVALID_HANDLE_VALUE),
  87                    &policy_guid, &wintrust_data);
  88   }
  89 }
  90
  91 }  // namespace safe_browsing