如何在C++中实现Windows Credential Provider隐藏（无需修改注册表禁用键）

Great question! Hiding a Credential Provider without touching that registry disable key is totally feasible with C++. The approach you pick depends on whether you have access to the Credential Provider's source code or need to target a third-party provider. Let's break down the options:

Option 1: Modify the Credential Provider's Own Logic (If You Control the Code) #

If you built the Credential Provider yourself, the simplest way to hide it is to tweak its core COM interface implementations to "opt out" of appearing in the logon UI. The Windows logon host calls methods like GetCredentialCount to figure out which providers to display—so we can use that to our advantage.

For example, in your ICredentialProvider::GetCredentialCount method, return 0 credentials when you want the provider hidden. You can base this on a runtime condition (like a config flag, environment variable, or even a custom system state check):

STDMETHODIMP MyCustomCredentialProvider::GetCredentialCount(
    DWORD* pdwCount,
    DWORD* pdwDefault,
    BOOL* pbAutoLogonWithDefault
)
{
    // Add your own logic here to decide if we should hide
    bool shouldHide = CheckIfProviderShouldBeHidden(); // Your custom check

    if (shouldHide)
    {
        *pdwCount = 0; // No credentials = provider doesn't show up
        *pdwDefault = 0;
        *pbAutoLogonWithDefault = FALSE;
        return S_OK;
    }

    // Normal behavior: return our credential count
    *pdwCount = 1; // Adjust based on how many credentials your provider exposes
    *pdwDefault = 0;
    *pbAutoLogonWithDefault = FALSE;
    return S_OK;
}

You can also use ICredentialProvider::SetUsageScenario to disable the provider for specific logon scenarios (e.g., only hide it during lock screen logins). Just return E_NOTIMPL if the scenario doesn't match what you want to support.

Option 2: Dynamically Unregister the Provider (For Third-Party Providers) #

If you need to hide a provider you don't own, you can use Windows' built-in ICredentialProviderRegistrar interface to temporarily unregister it from the active list. This doesn't touch the disable registry key—it just removes the provider from the logon UI's active set.

Note: This requires admin privileges to modify the Credential Provider registration. Here's a code example:

#include <windows.h>
#include <credui.h>
#include <credentialprovider.h>

HRESULT HideThirdPartyCredentialProvider(const GUID& targetProviderGuid)
{
    HRESULT hr = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
    if (SUCCEEDED(hr))
    {
        ICredentialProviderRegistrar* pRegistrar = nullptr;
        hr = CoCreateInstance(
            CLSID_CredentialProviderRegistrar,
            NULL,
            CLSCTX_ALL,
            IID_ICredentialProviderRegistrar,
            (void**)&pRegistrar
        );

        if (SUCCEEDED(hr))
        {
            // Unregister the provider to hide it from logon UI
            hr = pRegistrar->UnregisterCredentialProvider(targetProviderGuid);
            pRegistrar->Release();
        }
        CoUninitialize();
    }
    return hr;
}

If you need to bring the provider back later, just call RegisterCredentialProvider with the same GUID instead.

Option 3: Build a Credential Provider Filter (Advanced) #

For more granular control (like hiding multiple providers or applying conditional rules), you can create a Credential Provider Filter. Filters act as gatekeepers—Windows asks the filter whether each provider should be enabled before displaying it.

To use this, you'll need to implement the ICredentialProviderFilter interface, specifically the IsCredentialProviderEnabled method. Return FALSE for any provider you want to hide:

STDMETHODIMP MyCredentialFilter::IsCredentialProviderEnabled(
    REFGUID guidCredentialProvider,
    BOOL* pbEnabled
)
{
    // Check if this is the provider we want to hide
    if (IsEqualGUID(guidCredentialProvider, PROVIDER_TO_HIDE_GUID))
    {
        *pbEnabled = FALSE; // Hide this provider
        return S_OK;
    }

    // Allow all other providers to show up
    *pbEnabled = TRUE;
    return S_OK;
}

You'll need to register the filter under HKLM\Software\Microsoft\Windows\CurrentVersion\Authentication\Credential Provider Filters\{YourFilterGUID} to make Windows use it.

Key Notes #

• All these methods require elevated (admin) rights, since they interact with Windows' authentication subsystem.
• For third-party providers, dynamic unregistration (Option 2) is the most straightforward if you don't want to build a full filter.
• If you control the provider's code, Option 1 is the cleanest—no external dependencies, just a runtime check.

内容的提问来源于stack exchange，提问作者Girish D Singh