Geeky Bob

A few years ago I wrote a blog that was titled "FTP 7.5 Service Extensibility References", in which I discussed the extensibility APIs that we added in FTP 7.5. Over the next couple of years I followed that initial blog with a series of walkthroughs on IIS.net and several related blog posts. Here are just a few examples:

• How to use Managed Code (C#) to create an FTP Home Directory Provider that is based on the Remote Client IP Address
• How to Use Managed Code (C#) to Create an FTP Home Directory Provider for the Days of the Week
• FTP and LDAP - How to Use Managed Code (C#) to Create an FTP Authentication Provider that uses an LDAP Server
• How to Create an Authentication Provider for FTP 7.5 using BlogEngine.NET's XML Membership Files
• Merging FTP Extensibility Walkthroughs - Part 1
• Merging FTP Extensibility Walkthroughs - Part 2
• Automatically Creating Checksum Files for FTP Uploads
• Changing the Identity of the FTP 7 Extensibility Process
• etc.

In today's blog I'd like to discuss some of the extensibility features that we added in FTP 8.0, and show you how you can use those in your FTP providers.

Custom FTP Authorization

In FTP 7.5 we provided interfaces for IFtpAuthenticationProvider and IFtpRoleProvider, which respectively allowed developers to create FTP providers that performed user and role lookups. In FTP 8.0 we added a logical extension to that API set with IFtpAuthorizationProvider interface, which allows developers to create FTP providers that perform authorization tasks.

With that in mind, I wrote the following walkthrough on the IIS.net web site:

• How to Use Managed Code (C#) to Create an FTP Authentication and Authorization Provider using an XML Database

The title pretty much says it all: the provider that I describe in that walkthrough will walk you through the steps that are required to create an FTP provider that provides custom user authentication, verification of role memberships, and authorization lookups on a per-path basis.

Custom FTP Event Handling

In FTP 7.5 if you wanted your provider to respond to specific user activity, the best way to do so was to implement the IFtpLogProvider.Log() interface and use that to provide a form of pseudo-event handling. In FTP 8.0 we add two event handling interfaces, IFtpPreprocessProvider and IFtpPostprocessProvider, which respectively allow developers to write providers that implement functionality before or after events have occurred.

With that in mind, I wrote the following walkthrough on the IIS.net web site:

• How to Use Managed Code (C#) to Create an FTP Provider that Prevents Leeching

Once again, the title says it all: the provider that I describe in that walkthrough will walk you through the steps that are required to create an FTP provider that prevents FTP clients from downloading more files per-session than you have allowed in your configuration settings.

Happy coding!

Note: This blog was originally posted at http://blogs.msdn.com/robert_mcmurray/