diff options
Diffstat (limited to 'onlineupdate/source/service/certificatecheck.cxx')
| -rw-r--r-- | onlineupdate/source/service/certificatecheck.cxx | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/onlineupdate/source/service/certificatecheck.cxx b/onlineupdate/source/service/certificatecheck.cxx new file mode 100644 index 000000000..58d70162f --- /dev/null +++ b/onlineupdate/source/service/certificatecheck.cxx @@ -0,0 +1,292 @@ +/* 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.hxx" +#include "servicebase.hxx" + +#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, + 0, &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, + 0, 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; +} |