page_type	languages	name	description
sample	cpp	RaspWrap	Extends Microsoft's wrap-existing-credential-provider sample to wrap the RAS Provider

RaspWrap Pre-Logon Provider

The Windows RAS allows establishing dial-up and/or VPN connections in pre-logon via the RAS pre-logon provider (PLAP). It has, however, this annoying limitation, where it assumes the same crednetials used for the network connection should also be used to logon to Windows. So when the credentials differ, if the network credentials are entered, the connection will be established, but the logon will fail and the user does not have the option to enter other credentials to logon with. If, on the other hand, the Windows credentials are entered then either the network connection will fail, or, if the provider doesn't care about the entered credentials (e.g. it has other means to track the usage, as is often the case on 4G mobile networks), then everything will work, except you'd be handing off your Windows/AD credentials to the ISP (which I suspect happens quite often).

The RaspWrap attempts to fix this, by extending Microsoft's credential-provider samplewrapexistingcredentialprovider sample (see link below), in order to wrap the RAS Provider (CLSID_RASProvider) and add a "Use SSO" checkbox to allow using different credentials for network and local logon.

It does that by implementing the IConnectableCredentialProviderCredential interface, that is, adding the Connect/Disconnect methods, and by implementing the ICredentialProviderFilter interface, in order to filter out the real RASProvider, thus avoiding two connect-buttons from being shown.

Links:

• Microsoft's original credential-provider samplewrapexistingcredentialprovider sample:

https://github.com/microsoft/Windows-classic-samples/tree/master/Samples/Win7Samples/security/credentialproviders/samplewrapexistingcredentialprovider

• How to build debug and test (downlowd the mht file and open in IE):

https://github.com/microsoft/Windows-classic-samples/blob/master/Samples/Win7Samples/security/credentialproviders/Credential%20Provider%20Samples%20Overview.mht

• Many useful links and contents, at:

https://github.com/DavidWeiss2/windows-Credential-Provider-library

Operating system requirements

Tested on Windows 10.

Build the sample

1. Start Visual Studio and select File > Open > Project/Solution.
2. Go to the directory named for the sample, and double-click the Visual Studio Solution (.sln) file.
3. Press F7 or use Build > Build Solution to build the sample.