Manifest file

A Visual Prolog project can contain a manifest file. The manifest file is a Microsoft invention to deal with side-by-side installation, a new hell that is supposed to replace the so called DLL hell.

The file is either named <project>.manifest or main.manifest (current standard).

The manifest file is an XML file, and it is linked into EXE/DLL as a resource. Windows automatically look for it there (if not found there it looks for a file called myProgram.exe.manifest in the same directory as myProgram.exe).

Sample manifest file

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
    <assemblyIdentity
        name="MyProgram"
        version="1.0.0.0"
        processorArchitecture="X86"
        type="win32"
    />
    <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
        <security>
            <requestedPrivileges>
                <requestedExecutionLevel level="asInvoker" uiAccess="false"/>
            </requestedPrivileges>
        </security>
    </trustInfo>
    <dependency>
        <dependentAssembly>
            <assemblyIdentity
                name="Microsoft.Windows.Common-Controls"
                version="6.0.0.0"
                processorArchitecture="X86"
                type="win32"
                publicKeyToken="6595b64144ccf1df"
                language="*"
            />
        </dependentAssembly>
    </dependency>
</assembly>

The file contains three major elements:

• The programs own assemblyIdentity
• A trustInfo element
• A dependency, which lists assemblyIdentity's of assemplies that the program depends on.

The assemblyIdentity element

<assemblyIdentity
    name="MyProgram"
    version="1.0.0.0"
    processorArchitecture="X86"
    type="win32"
/>

This element list attributes of the program/DLL itself.

The trustInfo element

<trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
    <security>
        <requestedPrivileges>
            <requestedExecutionLevel level="asInvoker" uiAccess="false"/>
        </requestedPrivileges>
    </security>
</trustInfo>

The level can have one of these values:

asInvoker

The application runs with the same access token as the parent process.

Recommended for standard user applications. Do refractoring with internal elevation points, as per the guidance provided earlier in this document.

highestAvailable

The application runs with the highest privileges the current user can obtain.

Recommended for mixed-mode applications. Plan to refractor the application in a future release.

requireAdministrator

The application runs only for administrators and requires that the application be launched with the full access token of an administrator.

Recommended for administrator only applications. Internal elevation points are not needed. The application is already running elevated.

Notice programs which don't have a manifest with a requestedExecutionLevel element, will run virtualized on Windows Vista and forward. As an example of what this means: A virtualized program cannot write to the HKEY_LOCAL_MACHINE hive of the registry, instead it writes to a virtual overlay of this hive. However only virtualized programs for the same user see this overlay. So other users cannot see this overlay, and non-virtualized programs does not see it either.

The dependency element

<dependency>
    <dependentAssembly>
        <assemblyIdentity
            name="Microsoft.Windows.Common-Controls"
            version="6.0.0.0"
            processorArchitecture="X86"
            type="win32"
            publicKeyToken="6595b64144ccf1df"
            language="*"
        />
    </dependentAssembly>
</dependency>

References

• MSDN: Application Manifests
• wikipedia:Side-by-side assembly
• wikipedia:DLL hell