Custom Post-Build Events for Compiling FTP Providers

I've written a lot of walkthroughs and blog posts about creating custom FTP providers over the past several years, and I usually include instructions like the following example for adding a custom post-build event that will automatically register your extensibility provider in the Global Assembly Cache (GAC) on your development computer:

• Click Project, and then click the menu item your project's properties.
• Click the Build Events tab.
• Enter the following in the Post-build event command line dialog box:

  net stop ftpsvc
  call "%VS100COMNTOOLS%\vsvars32.bat">nul
  gacutil.exe /if "$(TargetPath)"
  net start ftpsvc

And I usually include instructions like the following example for determining the assembly information for your extensibility provider:

• In Windows Explorer, open your "C:\Windows\assembly" path, where C: is your operating system drive.
• Locate the FtpXmlAuthorization assembly.
• Right-click the assembly, and then click Properties.
• Copy the Culture value; for example: Neutral.
• Copy the Version number; for example: 1.0.0.0.
• Copy the Public Key Token value; for example: 426f62526f636b73.
• Click Cancel.

Over time I have changed the custom post-build event that I use when I am creating custom FTP providers, and my changes make it easier to register custom FTP providers. With that in mind, I thought that my changes would make a good blog subject.

First of all, if you take a look at my How to Use Managed Code (C#) to Create a Simple FTP Authentication Provider walkthrough, you will see that I include instructions like my earlier examples to create a custom post-build event and retrieve the assembly information for your extensibility provider.

That being said, instead of using the custom post-build event in that walkthrough, I have started using the following custom post-build event:

net stop ftpsvc
call "$(DevEnvDir)..\Tools\vsvars32.bat"
gacutil.exe /uf "$(TargetName)"
gacutil.exe /if "$(TargetPath)"
gacutil.exe /l "$(TargetName)"
net start ftpsvc

This script should resemble the following example when entered into Visual Studio:

This updated script performs the following actions:

1. Stops the FTP service (this will allow any copies of your DLL to unload)
2. Loads the Visual Studio environment variables (this will add gacutil.exe to the path)
3. Calls gacutil.exe to forcibly unregister any previous version of your FTP provider
4. Calls gacutil.exe to forcibly register the newly-compiled version of your FTP provider
5. Calls gacutil.exe to list the GAC information for your FTP provider (this will be used to register your DLL with IIS)
6. Starts the FTP service

Let's say that you created a simple FTP authentication provider which contained code like the following example:

using System;
using System.Text;
using Microsoft.Web.FtpServer;

public class FtpTestProvider :
    BaseProvider,
    IFtpAuthenticationProvider
{
    private string _username = "test";
    private string _password = "password";
    
    public bool AuthenticateUser(
        string sessionId,
        string siteName,
        string userName,
        string userPassword,
        out string canonicalUserName)
    {
        canonicalUserName = userName;
        if (((userName.Equals(_username,
            StringComparison.OrdinalIgnoreCase)) == true) &&
            userPassword == _password)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
}

When you compile your provider in Visual Studio, the output window should show the results of the custom post-build event:

When you examine the output information in detail, the highlighted area in the example below should be of particular interest, because it contains the assembly information for your extensibility provider:

------ Rebuild All started: Project: FtpTestProvider, Configuration: Debug Any CPU ------
FtpTestProvider -> c:\users\foobar\documents\visual studio 2012\Projects\FtpTestProvider\bin\Debug\FtpTestProvider.dll
The Microsoft FTP Service service is stopping..
The Microsoft FTP Service service was stopped successfully.

Microsoft (R) .NET Global Assembly Cache Utility. Version 4.0.30319.17929
Copyright (c) Microsoft Corporation. All rights reserved.

Assembly successfully added to the cache
Microsoft (R) .NET Global Assembly Cache Utility. Version 4.0.30319.17929
Copyright (c) Microsoft Corporation. All rights reserved.

The Global Assembly Cache contains the following assemblies:
FtpTestProvider, Version=1.0.0.0, Culture=neutral, PublicKeyToken=eb763c2ec0efff75, processorArchitecture=MSIL

Number of items = 1
The Microsoft FTP Service service is starting.
The Microsoft FTP Service service was started successfully.

========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========

Once you have that information, you simply need to reformat it as "FtpTestProvider, FtpTestProvider, Version=1.0.0.0, Culture=neutral, PublicKeyToken=eb763c2ec0efff75" in order to enter it into the FTP Custom Authentication Providers dialog box in the IIS Manager, or by following the steps in my FTP Walkthroughs or my Adding Custom FTP Providers with the IIS Configuration Editor blogs.

That wraps it up for today's post. As always, let me know if you have any questions. ;-]