The Tor Browser: toolkit/components/maintenanceservice/certificatecheck.cpp@b8a032363ba2 (annotated)

toolkit/components/maintenanceservice/certificatecheck.cpp@b8a032363ba2 (annotated)

toolkit/components/maintenanceservice/certificatecheck.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include <stdio.h>
 #include <stdlib.h>
 #include <windows.h>
 #include <softpub.h>
 #include <wintrust.h>
 #include "certificatecheck.h"
 #include "servicebase.h"
 #pragma comment(lib, "wintrust.lib")
 #pragma comment(lib, "crypt32.lib")
 static const int ENCODING = X509_ASN_ENCODING | PKCS_7_ASN_ENCODING;
 /**
  * Checks to see if a file stored at filePath matches the specified info.
  *
  * @param  filePath    The PE file path to check
  * @param  infoToMatch The acceptable information to match
  * @return ERROR_SUCCESS if successful, ERROR_NOT_FOUND if the info
  *         does not match, or the last error otherwise.
  */
 DWORD
 CheckCertificateForPEFile(LPCWSTR filePath,
                           CertificateCheckInfo &infoToMatch)
 {
   HCERTSTORE certStore = nullptr;
   HCRYPTMSG cryptMsg = nullptr;
   PCCERT_CONTEXT certContext = nullptr;
   PCMSG_SIGNER_INFO signerInfo = nullptr;
   DWORD lastError = ERROR_SUCCESS;
   // Get the HCERTSTORE and HCRYPTMSG from the signed file.
   DWORD encoding, contentType, formatType;
   BOOL result = CryptQueryObject(CERT_QUERY_OBJECT_FILE,
                                   filePath,
                                   CERT_QUERY_CONTENT_FLAG_PKCS7_SIGNED_EMBED,
                                   CERT_QUERY_CONTENT_FLAG_ALL,
 , &encoding, &contentType,
                                   &formatType, &certStore, &cryptMsg, nullptr);
   if (!result) {
     lastError = GetLastError();
     LOG_WARN(("CryptQueryObject failed.  (%d)", lastError));
     goto cleanup;
   }
   // Pass in nullptr to get the needed signer information size.
   DWORD signerInfoSize;
   result = CryptMsgGetParam(cryptMsg, CMSG_SIGNER_INFO_PARAM, 0,
                             nullptr, &signerInfoSize);
   if (!result) {
     lastError = GetLastError();
     LOG_WARN(("CryptMsgGetParam failed.  (%d)", lastError));
     goto cleanup;
   }
   // Allocate the needed size for the signer information.
   signerInfo = (PCMSG_SIGNER_INFO)LocalAlloc(LPTR, signerInfoSize);
   if (!signerInfo) {
     lastError = GetLastError();
     LOG_WARN(("Unable to allocate memory for Signer Info.  (%d)", lastError));
     goto cleanup;
   }
   // Get the signer information (PCMSG_SIGNER_INFO).
   // In particular we want the issuer and serial number.
   result = CryptMsgGetParam(cryptMsg, CMSG_SIGNER_INFO_PARAM, 0,
                             (PVOID)signerInfo, &signerInfoSize);
   if (!result) {
     lastError = GetLastError();
     LOG_WARN(("CryptMsgGetParam failed.  (%d)", lastError));
     goto cleanup;
   }
   // Search for the signer certificate in the certificate store.
   CERT_INFO certInfo;
   certInfo.Issuer = signerInfo->Issuer;
   certInfo.SerialNumber = signerInfo->SerialNumber;
   certContext = CertFindCertificateInStore(certStore, ENCODING, 0,
                                            CERT_FIND_SUBJECT_CERT,
                                            (PVOID)&certInfo, nullptr);
   if (!certContext) {
     lastError = GetLastError();
     LOG_WARN(("CertFindCertificateInStore failed.  (%d)", lastError));
     goto cleanup;
   }
   if (!DoCertificateAttributesMatch(certContext, infoToMatch)) {
     lastError = ERROR_NOT_FOUND;
     LOG_WARN(("Certificate did not match issuer or name.  (%d)", lastError));
     goto cleanup;
   }
 cleanup:
   if (signerInfo) {
     LocalFree(signerInfo);
   }
   if (certContext) {
     CertFreeCertificateContext(certContext);
   }
   if (certStore) {
     CertCloseStore(certStore, 0);
   }
   if (cryptMsg) {
     CryptMsgClose(cryptMsg);
   }
   return lastError;
 }
 /**
  * Checks to see if a file stored at filePath matches the specified info.
  *
  * @param  certContext  The certificate context of the file
  * @param  infoToMatch  The acceptable information to match
  * @return FALSE if the info does not match or if any error occurs in the check
  */
 BOOL
 DoCertificateAttributesMatch(PCCERT_CONTEXT certContext,
                              CertificateCheckInfo &infoToMatch)
 {
   DWORD dwData;
   LPTSTR szName = nullptr;
   if (infoToMatch.issuer) {
     // Pass in nullptr to get the needed size of the issuer buffer.
     dwData = CertGetNameString(certContext,
                                CERT_NAME_SIMPLE_DISPLAY_TYPE,
                                CERT_NAME_ISSUER_FLAG, nullptr,
                                nullptr, 0);
     if (!dwData) {
       LOG_WARN(("CertGetNameString failed.  (%d)", GetLastError()));
       return FALSE;
     }
     // Allocate memory for Issuer name buffer.
     LPTSTR szName = (LPTSTR)LocalAlloc(LPTR, dwData * sizeof(WCHAR));
     if (!szName) {
       LOG_WARN(("Unable to allocate memory for issuer name.  (%d)",
                 GetLastError()));
       return FALSE;
     }
     // Get Issuer name.
     if (!CertGetNameString(certContext, CERT_NAME_SIMPLE_DISPLAY_TYPE,
                            CERT_NAME_ISSUER_FLAG, nullptr, szName, dwData)) {
       LOG_WARN(("CertGetNameString failed.  (%d)", GetLastError()));
       LocalFree(szName);
       return FALSE;
     }
     // If the issuer does not match, return a failure.
     if (!infoToMatch.issuer ||
         wcscmp(szName, infoToMatch.issuer)) {
       LocalFree(szName);
       return FALSE;
     }
     LocalFree(szName);
     szName = nullptr;
   }
   if (infoToMatch.name) {
     // Pass in nullptr to get the needed size of the name buffer.
     dwData = CertGetNameString(certContext, CERT_NAME_SIMPLE_DISPLAY_TYPE,
 , nullptr, nullptr, 0);
     if (!dwData) {
       LOG_WARN(("CertGetNameString failed.  (%d)", GetLastError()));
       return FALSE;
     }
     // Allocate memory for the name buffer.
     szName = (LPTSTR)LocalAlloc(LPTR, dwData * sizeof(WCHAR));
     if (!szName) {
       LOG_WARN(("Unable to allocate memory for subject name.  (%d)",
                 GetLastError()));
       return FALSE;
     }
     // Obtain the name.
     if (!(CertGetNameString(certContext, CERT_NAME_SIMPLE_DISPLAY_TYPE, 0,
                             nullptr, szName, dwData))) {
       LOG_WARN(("CertGetNameString failed.  (%d)", GetLastError()));
       LocalFree(szName);
       return FALSE;
     }
     // If the issuer does not match, return a failure.
     if (!infoToMatch.name ||
         wcscmp(szName, infoToMatch.name)) {
       LocalFree(szName);
       return FALSE;
     }
     // We have a match!
     LocalFree(szName);
   }
   // If there were any errors we would have aborted by now.
   return TRUE;
 }
 /**
  * Duplicates the specified string
  *
  * @param  inputString The string to duplicate
  * @return The duplicated string which should be freed by the caller.
  */
 LPWSTR
 AllocateAndCopyWideString(LPCWSTR inputString)
 {
   LPWSTR outputString =
     (LPWSTR)LocalAlloc(LPTR, (wcslen(inputString) + 1) * sizeof(WCHAR));
   if (outputString) {
     lstrcpyW(outputString, inputString);
   }
   return outputString;
 }
 /**
  * Verifies the trust of the specified file path.
  *
  * @param  filePath  The file path to check.
  * @return ERROR_SUCCESS if successful, or the last error code otherwise.
  */
 DWORD
 VerifyCertificateTrustForFile(LPCWSTR filePath)
 {
   // Setup the file to check.
   WINTRUST_FILE_INFO fileToCheck;
   ZeroMemory(&fileToCheck, sizeof(fileToCheck));
   fileToCheck.cbStruct = sizeof(WINTRUST_FILE_INFO);
   fileToCheck.pcwszFilePath = filePath;
   // Setup what to check, we want to check it is signed and trusted.
   WINTRUST_DATA trustData;
   ZeroMemory(&trustData, sizeof(trustData));
   trustData.cbStruct = sizeof(trustData);
   trustData.pPolicyCallbackData = nullptr;
   trustData.pSIPClientData = nullptr;
   trustData.dwUIChoice = WTD_UI_NONE;
   trustData.fdwRevocationChecks = WTD_REVOKE_NONE;
   trustData.dwUnionChoice = WTD_CHOICE_FILE;
   trustData.dwStateAction = 0;
   trustData.hWVTStateData = nullptr;
   trustData.pwszURLReference = nullptr;
   // no UI
   trustData.dwUIContext = 0;
   trustData.pFile = &fileToCheck;
   GUID policyGUID = WINTRUST_ACTION_GENERIC_VERIFY_V2;
   // Check if the file is signed by something that is trusted.
   LONG ret = WinVerifyTrust(nullptr, &policyGUID, &trustData);
   if (ERROR_SUCCESS == ret) {
     // The hash that represents the subject is trusted and there were no
     // verification errors.  No publisher nor time stamp chain errors.
     LOG(("The file \"%ls\" is signed and the signature was verified.",
          filePath));
       return ERROR_SUCCESS;
   }
   DWORD lastError = GetLastError();
   LOG_WARN(("There was an error validating trust of the certificate for file"
             " \"%ls\". Returned: %d.  (%d)", filePath, ret, lastError));
   return ret;
 }

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toolkit/components/maintenanceservice/certificatecheck.cpp@b8a032363ba2 (annotated)

toolkit/components/maintenanceservice/certificatecheck.cpp