Auto-Input Protection (AIP) is an ASP.NET 2.0 web control that provides a visual CATPCHA to prevent automated spam and hacks against your web sites. It is open-source, written in C# 3.0 by Dave Sexton.

AIP works with Visual Studio 2005, 2008, and Visual Web Developer Express. The AIP web control provides design-time support in Visual Studio, including support for editing the layout template. The installer automatically adds the control to the toolbox and merges the AIP documentation into Visual Studio's help.

AIP works with minimal configuration. Only an HTTP request handler must be added to your web.config file and you'll be able to use the control on any of your web pages.

AIP uses a custom validator's server-side event to test user input so that if user validation fails, Page.IsValid will be false automatically.

AIP is fully extensible. You can define a custom layout template for the control and configure built-in text, image and filter providers to produce random CAPTCHAs in various formats. You can also create custom providers that generate randomized text, images and filters.

Examples

The following example uses the AIP web control with its default template and the default text and image providers (basic English and line noise, respectively).

AIP Example: Default template and providers.

The next example uses a custom data-bound template and various built-in providers.

AIP Example: Custom data-bound template.

The final example illustrates a random CAPTCHA that has been generated using built-in text and filter providers, and a custom image provider. (Note that a randomized cross hatch filter provider is now built-in as of 2.0 Beta.)

AIP Example: Image generated by built-in text and filter providers, and a custom image provider.