OPC Classic Core Components

Build system for the OPC Classic COM proxy/stub DLLs, server enumerator, and MSI installers. These are the core runtime components that OPC Classic (COM/DCOM) clients and servers need to communicate.

What's in this repo

• 8 proxy/stub DLLs — COM marshalling for OPC DA, A&E, HDA, Batch, Commands, Data Exchange, Security, and Common interfaces
• OpcEnum.exe — OPC Server Enumerator service (x86)
• OpcCategoryManager.exe — OPC component category registration (x64)
• Merge modules (.msm) — WiX merge modules for embedding in third-party installers
• SDK merge modules (.msm) — headers, IDLs, and reference DLLs for developers
• MSI installers (.msi) — standalone redistributable installers. The x64 MSI includes all x86 components and is the only installer needed on 64-bit systems.
• Test Applications — OPC DA 2.05a test server and test client (x86 and x64)

The test applications allow you to quickly verify that x86 COM servers can be discovered by an x64 client and vice versa. On a 64-bit system with the test components installed, running either the x86 or x64 version of the test client should show two servers (one for each platform). If only the x86 installer is installed, only one server will appear.

Prerequisites

Visual Studio 2022

Install Visual Studio 2022 17.14+ (Community, Professional, or Enterprise) with the Desktop development with C++ workload.

The build requires MSVC CRT >= 14.44.35211 for Windows 7 SP1 compatibility. Both x86 and x64 builds use static CRT (/MT) and target Windows 7 SP1 (subsystem version 6.01).

CMake

CMake 3.20 or later. Included with Visual Studio (Desktop C++ workload) or install separately from https://cmake.org.

.NET SDK

Required to install WiX and AzureSignTool as .NET global tools. Download from https://dotnet.microsoft.com.

WiX Toolset

Install the WiX v4+ command-line tool:

dotnet tool install --global wix

The build script automatically installs the required WixToolset.UI.wixext extension at the correct version.

NuGet package source mapping: If your NuGet.Config uses <packageSourceMapping>, add patterns for wix, WixToolset.*, and AzureSignTool under the nuget.org source.

AzureSignTool (for code signing)

Required only when code signing is enabled:

dotnet tool install --global AzureSignTool

Build

Run from a Developer Command Prompt for VS (or any shell where vcvarsall.bat has been called):

.\build.ps1                            # both platforms (default)
.\build.ps1 -Platform x86             # x86 only
.\build.ps1 -Platform x64             # x64 only
.\build.ps1 -Clean                    # clean rebuild
. .\signing-key.ps1; .\build.ps1      # with code signing

Parameters / environment variables

Parameter	Env Variable	Default	Description
-Platform		both	Target platform: x86, x64, or both
-BuildRoot	BUILD_ROOT	.\build	CMake build directory
-OutDir	OUT_DIR	.\out	Output directory for DLLs and installers
-WixCmd	WIX_CMD	wix	Path to wix executable

Code signing

Code signing uses Azure Key Vault HSM via AzureSignTool. To enable signing, dot-source signing-key.ps1 before running the build:

. .\signing-key.ps1
.\build.ps1

If SigningClientSecret is empty or not set, signing is skipped automatically. If credentials are set but AzureSignTool is not installed, the build fails immediately with an error message.

Signing order: DLLs/EXEs are signed first, then packaged into merge modules which are signed, then packaged into MSI installers which are also signed.

Spectre mitigation (optional)

To enable /Qspectre, install the Spectre-mitigated libs from VS Installer (Individual Components tab), then add -DOPC_ENABLE_SPECTRE=ON to the cmake -S ... line in build.ps1.

Output

All output goes to the out\ directory:

out\
  x86\bin\          proxy/stub DLLs, OpcEnum.exe, test server/client (32-bit)
  x64\bin\          proxy/stub DLLs, OpcCategoryManager.exe, test server/client (64-bit)
  x86\include\      SDK headers, IDLs, reference DLL copies (32-bit)
  x64\include\      SDK headers, IDLs, reference DLL copies (64-bit)
  wix\              merge modules (.msm) and MSI installers (.msi)

Security hardening

All DLLs and EXEs are built with static CRT (/MT) and these security flags:

Flag	Description
/GS	Buffer security check (stack canaries)
/sdl	SDL checks (pointer overwrite, format strings)
/guard:cf	Control Flow Guard (enforced on Win 8.1+)
/NXCOMPAT	DEP (Data Execution Prevention)
/DYNAMICBASE	ASLR (Address Space Layout Randomization)
/SAFESEH	Safe SEH (x86 only)
/HIGHENTROPYVA	High-Entropy ASLR (x64 only)
/Qspectre	Spectre v1 mitigation (opt-in, see above)