diff options
Diffstat (limited to 'toolkit/xre/dllservices/mozglue/Authenticode.cpp')
| -rw-r--r-- | toolkit/xre/dllservices/mozglue/Authenticode.cpp | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/toolkit/xre/dllservices/mozglue/Authenticode.cpp b/toolkit/xre/dllservices/mozglue/Authenticode.cpp new file mode 100644 index 0000000000..ee702b2ac6 --- /dev/null +++ b/toolkit/xre/dllservices/mozglue/Authenticode.cpp @@ -0,0 +1,439 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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/. */ + +// We need Windows 8 functions and structures to be able to verify SHA-256. +#if defined(_WIN32_WINNT) +# undef _WIN32_WINNT +# define _WIN32_WINNT _WIN32_WINNT_WIN8 +#endif // defined(_WIN32_WINNT) +#if defined(NTDDI_VERSION) +# undef NTDDI_VERSION +# define NTDDI_VERSION NTDDI_WIN8 +#endif // defined(NTDDI_VERSION) + +#include "Authenticode.h" + +#include "mozilla/ArrayUtils.h" +#include "mozilla/Assertions.h" +#include "mozilla/DynamicallyLinkedFunctionPtr.h" +#include "mozilla/ScopeExit.h" +#include "mozilla/UniquePtr.h" +#include "mozilla/WindowsVersion.h" +#include "nsWindowsHelpers.h" + +#include <windows.h> +#include <softpub.h> +#include <wincrypt.h> +#include <wintrust.h> +#include <mscat.h> + +#include <string.h> + +namespace { + +struct CertStoreDeleter { + typedef HCERTSTORE pointer; + void operator()(pointer aStore) { ::CertCloseStore(aStore, 0); } +}; + +struct CryptMsgDeleter { + typedef HCRYPTMSG pointer; + void operator()(pointer aMsg) { ::CryptMsgClose(aMsg); } +}; + +struct CertContextDeleter { + void operator()(PCCERT_CONTEXT aCertContext) { + ::CertFreeCertificateContext(aCertContext); + } +}; + +struct CATAdminContextDeleter { + typedef HCATADMIN pointer; + void operator()(pointer aCtx) { + static const mozilla::StaticDynamicallyLinkedFunctionPtr< + decltype(&::CryptCATAdminReleaseContext)> + pCryptCATAdminReleaseContext(L"wintrust.dll", + "CryptCATAdminReleaseContext"); + + MOZ_ASSERT(!!pCryptCATAdminReleaseContext); + if (!pCryptCATAdminReleaseContext) { + return; + } + + pCryptCATAdminReleaseContext(aCtx, 0); + } +}; + +typedef mozilla::UniquePtr<HCERTSTORE, CertStoreDeleter> CertStoreUniquePtr; +typedef mozilla::UniquePtr<HCRYPTMSG, CryptMsgDeleter> CryptMsgUniquePtr; +typedef mozilla::UniquePtr<const CERT_CONTEXT, CertContextDeleter> + CertContextUniquePtr; +typedef mozilla::UniquePtr<HCATADMIN, CATAdminContextDeleter> + CATAdminContextUniquePtr; + +static const DWORD kEncodingTypes = X509_ASN_ENCODING | PKCS_7_ASN_ENCODING; + +class SignedBinary final { + public: + SignedBinary(const wchar_t* aFilePath, mozilla::AuthenticodeFlags aFlags); + + explicit operator bool() const { return mCertStore && mCryptMsg && mCertCtx; } + + mozilla::UniquePtr<wchar_t[]> GetOrgName(); + + SignedBinary(const SignedBinary&) = delete; + SignedBinary(SignedBinary&&) = delete; + SignedBinary& operator=(const SignedBinary&) = delete; + SignedBinary& operator=(SignedBinary&&) = delete; + + private: + bool VerifySignature(const wchar_t* aFilePath); + bool QueryObject(const wchar_t* aFilePath); + static bool VerifySignatureInternal(WINTRUST_DATA& aTrustData); + + private: + enum class TrustSource { eNone, eEmbedded, eCatalog }; + + private: + const mozilla::AuthenticodeFlags mFlags; + TrustSource mTrustSource; + CertStoreUniquePtr mCertStore; + CryptMsgUniquePtr mCryptMsg; + CertContextUniquePtr mCertCtx; +}; + +SignedBinary::SignedBinary(const wchar_t* aFilePath, + mozilla::AuthenticodeFlags aFlags) + : mFlags(aFlags), mTrustSource(TrustSource::eNone) { + if (!VerifySignature(aFilePath)) { + return; + } + + DWORD certInfoLen = 0; + BOOL ok = CryptMsgGetParam(mCryptMsg.get(), CMSG_SIGNER_CERT_INFO_PARAM, 0, + nullptr, &certInfoLen); + if (!ok) { + return; + } + + auto certInfoBuf = mozilla::MakeUnique<char[]>(certInfoLen); + + ok = CryptMsgGetParam(mCryptMsg.get(), CMSG_SIGNER_CERT_INFO_PARAM, 0, + certInfoBuf.get(), &certInfoLen); + if (!ok) { + return; + } + + auto certInfo = reinterpret_cast<CERT_INFO*>(certInfoBuf.get()); + + PCCERT_CONTEXT certCtx = + CertFindCertificateInStore(mCertStore.get(), kEncodingTypes, 0, + CERT_FIND_SUBJECT_CERT, certInfo, nullptr); + if (!certCtx) { + return; + } + + mCertCtx.reset(certCtx); +} + +bool SignedBinary::QueryObject(const wchar_t* aFilePath) { + DWORD encodingType, contentType, formatType; + HCERTSTORE rawCertStore; + HCRYPTMSG rawCryptMsg; + BOOL result = ::CryptQueryObject(CERT_QUERY_OBJECT_FILE, aFilePath, + CERT_QUERY_CONTENT_FLAG_PKCS7_SIGNED_EMBED, + CERT_QUERY_FORMAT_FLAG_BINARY, 0, + &encodingType, &contentType, &formatType, + &rawCertStore, &rawCryptMsg, nullptr); + if (!result) { + return false; + } + + mCertStore.reset(rawCertStore); + mCryptMsg.reset(rawCryptMsg); + + return true; +} + +/** + * @param aTrustData must be a WINTRUST_DATA structure that has been zeroed out + * and then populated at least with its |cbStruct|, + * |dwUnionChoice|, and appropriate union field. This function + * will then populate the remaining fields as appropriate. + */ +/* static */ +bool SignedBinary::VerifySignatureInternal(WINTRUST_DATA& aTrustData) { + static const mozilla::StaticDynamicallyLinkedFunctionPtr< + decltype(&::WinVerifyTrust)> + pWinVerifyTrust(L"wintrust.dll", "WinVerifyTrust"); + if (!pWinVerifyTrust) { + return false; + } + + aTrustData.dwUIChoice = WTD_UI_NONE; + aTrustData.fdwRevocationChecks = WTD_REVOKE_NONE; + aTrustData.dwStateAction = WTD_STATEACTION_VERIFY; + aTrustData.dwProvFlags = WTD_CACHE_ONLY_URL_RETRIEVAL; + + const HWND hwnd = (HWND)INVALID_HANDLE_VALUE; + GUID policyGUID = WINTRUST_ACTION_GENERIC_VERIFY_V2; + LONG result = pWinVerifyTrust(hwnd, &policyGUID, &aTrustData); + + aTrustData.dwStateAction = WTD_STATEACTION_CLOSE; + pWinVerifyTrust(hwnd, &policyGUID, &aTrustData); + + return result == ERROR_SUCCESS; +} + +bool SignedBinary::VerifySignature(const wchar_t* aFilePath) { + // First, try the binary itself + if (QueryObject(aFilePath)) { + mTrustSource = TrustSource::eEmbedded; + if (mFlags & mozilla::AuthenticodeFlags::SkipTrustVerification) { + return true; + } + + WINTRUST_FILE_INFO fileInfo = {sizeof(fileInfo)}; + fileInfo.pcwszFilePath = aFilePath; + + WINTRUST_DATA trustData = {sizeof(trustData)}; + trustData.dwUnionChoice = WTD_CHOICE_FILE; + trustData.pFile = &fileInfo; + + return VerifySignatureInternal(trustData); + } + + // We didn't find anything in the binary, so now try a catalog file. + + // First, we open a catalog admin context. + HCATADMIN rawCatAdmin; + + // Windows 7 also exports the CryptCATAdminAcquireContext2 API, but it does + // *not* sign its binaries with SHA-256, so we use the old API in that case. + if (mozilla::IsWin8OrLater()) { + static const mozilla::StaticDynamicallyLinkedFunctionPtr< + decltype(&::CryptCATAdminAcquireContext2)> + pCryptCATAdminAcquireContext2(L"wintrust.dll", + "CryptCATAdminAcquireContext2"); + if (!pCryptCATAdminAcquireContext2) { + return false; + } + + CERT_STRONG_SIGN_PARA policy = {sizeof(policy)}; + policy.dwInfoChoice = CERT_STRONG_SIGN_OID_INFO_CHOICE; + policy.pszOID = const_cast<char*>( + szOID_CERT_STRONG_SIGN_OS_CURRENT); // -Wwritable-strings + + if (!pCryptCATAdminAcquireContext2(&rawCatAdmin, nullptr, + BCRYPT_SHA256_ALGORITHM, &policy, 0)) { + return false; + } + } else { + static const mozilla::StaticDynamicallyLinkedFunctionPtr< + decltype(&::CryptCATAdminAcquireContext)> + pCryptCATAdminAcquireContext(L"wintrust.dll", + "CryptCATAdminAcquireContext"); + + if (!pCryptCATAdminAcquireContext || + !pCryptCATAdminAcquireContext(&rawCatAdmin, nullptr, 0)) { + return false; + } + } + + CATAdminContextUniquePtr catAdmin(rawCatAdmin); + + // Now we need to hash the file at aFilePath. + // Since we're hashing this file, let's open it with a sequential scan hint. + HANDLE rawFile = + ::CreateFileW(aFilePath, GENERIC_READ, + FILE_SHARE_READ | FILE_SHARE_DELETE | FILE_SHARE_WRITE, + nullptr, OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, nullptr); + if (rawFile == INVALID_HANDLE_VALUE) { + return false; + } + + nsAutoHandle file(rawFile); + DWORD hashLen = 0; + mozilla::UniquePtr<BYTE[]> hashBuf; + + static const mozilla::StaticDynamicallyLinkedFunctionPtr< + decltype(&::CryptCATAdminCalcHashFromFileHandle2)> + pCryptCATAdminCalcHashFromFileHandle2( + L"wintrust.dll", "CryptCATAdminCalcHashFromFileHandle2"); + if (pCryptCATAdminCalcHashFromFileHandle2) { + if (!pCryptCATAdminCalcHashFromFileHandle2(rawCatAdmin, rawFile, &hashLen, + nullptr, 0) && + ::GetLastError() != ERROR_INSUFFICIENT_BUFFER) { + return false; + } + + hashBuf = mozilla::MakeUnique<BYTE[]>(hashLen); + + if (!pCryptCATAdminCalcHashFromFileHandle2(rawCatAdmin, rawFile, &hashLen, + hashBuf.get(), 0)) { + return false; + } + } else { + static const mozilla::StaticDynamicallyLinkedFunctionPtr< + decltype(&::CryptCATAdminCalcHashFromFileHandle)> + pCryptCATAdminCalcHashFromFileHandle( + L"wintrust.dll", "CryptCATAdminCalcHashFromFileHandle"); + + if (!pCryptCATAdminCalcHashFromFileHandle) { + return false; + } + + if (!pCryptCATAdminCalcHashFromFileHandle(rawFile, &hashLen, nullptr, 0) && + ::GetLastError() != ERROR_INSUFFICIENT_BUFFER) { + return false; + } + + hashBuf = mozilla::MakeUnique<BYTE[]>(hashLen); + + if (!pCryptCATAdminCalcHashFromFileHandle(rawFile, &hashLen, hashBuf.get(), + 0)) { + return false; + } + } + + // Now that we've hashed the file, query the catalog system to see if any + // catalogs reference a binary with our hash. + + static const mozilla::StaticDynamicallyLinkedFunctionPtr< + decltype(&::CryptCATAdminEnumCatalogFromHash)> + pCryptCATAdminEnumCatalogFromHash(L"wintrust.dll", + "CryptCATAdminEnumCatalogFromHash"); + if (!pCryptCATAdminEnumCatalogFromHash) { + return false; + } + + static const mozilla::StaticDynamicallyLinkedFunctionPtr< + decltype(&::CryptCATAdminReleaseCatalogContext)> + pCryptCATAdminReleaseCatalogContext(L"wintrust.dll", + "CryptCATAdminReleaseCatalogContext"); + if (!pCryptCATAdminReleaseCatalogContext) { + return false; + } + + HCATINFO catInfoHdl = pCryptCATAdminEnumCatalogFromHash( + rawCatAdmin, hashBuf.get(), hashLen, 0, nullptr); + if (!catInfoHdl) { + return false; + } + + // We can't use UniquePtr for this because the deleter function requires two + // parameters. + auto cleanCatInfoHdl = + mozilla::MakeScopeExit([rawCatAdmin, catInfoHdl]() -> void { + pCryptCATAdminReleaseCatalogContext(rawCatAdmin, catInfoHdl, 0); + }); + + // We found a catalog! Now query for the path to the catalog file. + + static const mozilla::StaticDynamicallyLinkedFunctionPtr< + decltype(&::CryptCATCatalogInfoFromContext)> + pCryptCATCatalogInfoFromContext(L"wintrust.dll", + "CryptCATCatalogInfoFromContext"); + if (!pCryptCATCatalogInfoFromContext) { + return false; + } + + CATALOG_INFO_ catInfo = {sizeof(catInfo)}; + if (!pCryptCATCatalogInfoFromContext(catInfoHdl, &catInfo, 0)) { + return false; + } + + if (!QueryObject(catInfo.wszCatalogFile)) { + return false; + } + + mTrustSource = TrustSource::eCatalog; + + if (mFlags & mozilla::AuthenticodeFlags::SkipTrustVerification) { + return true; + } + + // WINTRUST_CATALOG_INFO::pcwszMemberTag is commonly set to the string + // representation of the file hash, so we build that here. + + DWORD strHashBufLen = (hashLen * 2) + 1; + auto strHashBuf = mozilla::MakeUnique<wchar_t[]>(strHashBufLen); + if (!::CryptBinaryToStringW(hashBuf.get(), hashLen, + CRYPT_STRING_HEXRAW | CRYPT_STRING_NOCRLF, + strHashBuf.get(), &strHashBufLen)) { + return false; + } + + // Ensure that the tag is uppercase for WinVerifyTrust + // NB: CryptBinaryToStringW overwrites strHashBufLen with the length excluding + // the null terminator, so we need to add it back for this call. + if (_wcsupr_s(strHashBuf.get(), strHashBufLen + 1)) { + return false; + } + + // Now, given the path to the catalog, and the path to the member (ie, the + // binary whose hash we are validating), we may now validate. If the + // validation is successful, we then QueryObject on the *catalog file* + // instead of the binary. + + WINTRUST_CATALOG_INFO wtCatInfo = {sizeof(wtCatInfo)}; + wtCatInfo.pcwszCatalogFilePath = catInfo.wszCatalogFile; + wtCatInfo.pcwszMemberTag = strHashBuf.get(); + wtCatInfo.pcwszMemberFilePath = aFilePath; + wtCatInfo.hMemberFile = rawFile; + if (mozilla::IsWin8OrLater()) { + wtCatInfo.hCatAdmin = rawCatAdmin; + } + + WINTRUST_DATA trustData = {sizeof(trustData)}; + trustData.dwUnionChoice = WTD_CHOICE_CATALOG; + trustData.pCatalog = &wtCatInfo; + + return VerifySignatureInternal(trustData); +} + +mozilla::UniquePtr<wchar_t[]> SignedBinary::GetOrgName() { + DWORD charCount = CertGetNameStringW( + mCertCtx.get(), CERT_NAME_SIMPLE_DISPLAY_TYPE, 0, nullptr, nullptr, 0); + if (charCount <= 1) { + // Not found + return nullptr; + } + + auto result = mozilla::MakeUnique<wchar_t[]>(charCount); + charCount = CertGetNameStringW(mCertCtx.get(), CERT_NAME_SIMPLE_DISPLAY_TYPE, + 0, nullptr, result.get(), charCount); + MOZ_ASSERT(charCount > 1); + + return result; +} + +} // anonymous namespace + +namespace mozilla { + +class AuthenticodeImpl : public Authenticode { + public: + virtual UniquePtr<wchar_t[]> GetBinaryOrgName( + const wchar_t* aFilePath, + AuthenticodeFlags aFlags = AuthenticodeFlags::Default) override; +}; + +UniquePtr<wchar_t[]> AuthenticodeImpl::GetBinaryOrgName( + const wchar_t* aFilePath, AuthenticodeFlags aFlags) { + SignedBinary bin(aFilePath, aFlags); + if (!bin) { + return nullptr; + } + + return bin.GetOrgName(); +} + +static AuthenticodeImpl sAuthenticodeImpl; + +Authenticode* GetAuthenticode() { return &sAuthenticodeImpl; } + +} // namespace mozilla |