1. Add a Reference to BotDetect
Run the following command in the Package Manager Console:
PM> Install-Package Captcha
After the command execution, the references to the BotDetect.dll, BotDetect.Web.MVC.dll, and
System.Data.SQLite.dll assemblies will be added to your project.
If your project is not going to be using the Simple API, the System.Data.SQLite.dll assembly reference can be safely removed from it.
Download the BotDetect ASP.NET CAPTCHA Generator archive. The root folder of the extracted archive
is referred as the <BDC-DIR>.
The BotDetect binaries are located in:
<BDC-DIR>/v4.4.2/lgcy-on-lgcy/bin/ folder.
Copy the BotDetect.dll and BotDetect.Web.MVC.dll files to the /your-app-backend-folder/bin/ folder --
and then reference them in your project.
2. Show a Captcha Challenge on the Form
In View code: import the BotDetect namespace, include BotDetect styles in page
<head>, create a
MvcCaptcha object and pass it to the Captcha
HtmlHelper:
<%@ Import Namespace="BotDetect.Web.Mvc" %>
[…]
<link href="<%: Url.Content("~/" + BotDetect.Web.CaptchaUrls.LayoutStyleSheetUrl) %>"
rel="stylesheet" type="text/css" />
</head>
[…]
<% MvcCaptcha exampleCaptcha = new MvcCaptcha("ExampleCaptcha");
exampleCaptcha.UserInputID = "CaptchaCode"; %>
<%: Html.Captcha(exampleCaptcha) %>
@Html.TextBox("CaptchaCode")
3. Check User Input During Form Submission
Mark the protected Controller action with the
CaptchaValidationActionFilter attribute to include Captcha validation in
ModelState.IsValid checks:
using BotDetect.Web.Mvc;
[…]
[HttpPost]
[AllowAnonymous]
[CaptchaValidationActionFilter("CaptchaCode", "ExampleCaptcha", "Incorrect CAPTCHA code!")]
public ActionResult ExampleAction(ExampleModel model)
{
if (!ModelState.IsValid)
{
// TODO: Captcha validation failed, show error message
}
else
{
// TODO: Captcha validation passed, proceed with protected action
MvcCaptcha.ResetCaptcha("ExampleCaptcha");
}
Use the built-in Validate method of a MvcCaptcha instance.
In cases when a CaptchaControl instance is not available, use static Validate method of MvcCaptcha class.
using BotDetect.Web.Mvc;
[…]
[HttpPost]
[AllowAnonymous]
public ActionResult ExampleAction(ExampleModel model)
{
// init mvcCaptcha instance with captchaId
MvcCaptcha mvcCaptcha = new MvcCaptcha("ExampleCaptcha");
// get user input value
string userInput = HttpContext.Request.Form["CaptchaCode"];
// get validatingInstanceId from HttpContext.Request.Form
string validatingInstanceId = HttpContext.Request.Form[mvcCaptcha.ValidatingInstanceKey];
// or get validatingInstanceId from above mvcCaptcha instance
//string validatingInstanceId = mvcCaptcha.WebCaptcha.ValidatingInstanceId;
// call the built-in Validate method from above MvcCaptcha instance.
if (mvcCaptcha.Validate(userInput, validatingInstanceId))
{
// or you can use static Validate method of MvcCaptcha class
(i.e. MvcCaptcha.Validate("ExampleCaptcha", userInput, validatingInstanceId); )
MvcCaptcha.ResetCaptcha("ExampleCaptcha");
}
else
{
ModelState.AddModelError("CaptchaCode", "Incorrect!");
}
return View(model);
}
4. Configure Your ASP.NET Application
Exclude BotDetect paths from ASP.NET MVC Routing:
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
// BotDetect requests must not be routed
routes.IgnoreRoute("{*botdetect}",
new { botdetect = @"(.*)BotDetectCaptcha\.ashx" });
Update your application configuration (the
web.config file):
<system.web>
<httpHandlers>
<!-- Register the HttpHandler used for BotDetect Captcha
requests -->
<add verb="GET" path="BotDetectCaptcha.ashx"
type="BotDetect.Web.CaptchaHandler, BotDetect"/>
</httpHandlers>
<!-- make sure Session State is enabled -->
<pages enableSessionState="true">
<namespaces>
<add namespace="System.Web.Mvc" />
<add namespace="System.Web.Mvc.Ajax" />
<add namespace="System.Web.Mvc.Html" />
<add namespace="System.Web.Routing" />
</namespaces>
</pages>
<!-- Register a custom SessionIDManager for BotDetect Captcha
requests -->
<sessionState mode="InProc" cookieless="AutoDetect" timeout="20"
sessionIDManagerType="BotDetect.Web.CustomSessionIdManager, BotDetect"/>
</system.web>
<system.webServer>
<validation validateIntegratedModeConfiguration="false"/>
<handlers>
<!-- Register the HttpHandler used for BotDetect Captcha
requests (IIS 7.0+) -->
<remove name="BotDetectCaptchaHandler"/>
<add name="BotDetectCaptchaHandler" preCondition="integratedMode"
verb="GET" path="BotDetectCaptcha.ashx"
type="BotDetect.Web.CaptchaHandler, BotDetect"/>
</handlers>
</system.webServer>
1. Add a Reference to BotDetect
Both the BotDetect.dll and BotDetect.Web.Mvc.dll assemblies should be referenced. They are included in the BotDetect installation.
2. Show a Captcha Challenge on the Form
In View code: import the BotDetect namespace, include BotDetect styles in page
<head>, create a
MvcCaptcha object and pass it to the Captcha
HtmlHelper:
@using BotDetect.Web.Mvc;
[…]
<link href="@BotDetect.Web.CaptchaUrls.Absolute.LayoutStyleSheetUrl"
rel="stylesheet" type="text/css" />
</head>
[…]
@{ MvcCaptcha exampleCaptcha = new MvcCaptcha("ExampleCaptcha");
exampleCaptcha.UserInputID = "CaptchaCode"; }
@Html.Captcha(exampleCaptcha)
@Html.TextBox("CaptchaCode")
3. Check User Input During Form Submission
Mark the protected Controller action with the
CaptchaValidationActionFilter attribute to include Captcha validation in
ModelState.IsValid checks:
using BotDetect.Web.Mvc;
[…]
[HttpPost]
[AllowAnonymous]
[CaptchaValidationActionFilter("CaptchaCode", "ExampleCaptcha", "Incorrect CAPTCHA code!")]
public ActionResult ExampleAction(ExampleModel model)
{
if (!ModelState.IsValid)
{
// TODO: Captcha validation failed, show error message
}
else
{
// TODO: Captcha validation passed, proceed with protected action
MvcCaptcha.ResetCaptcha("ExampleCaptcha");
}
Use the built-in Validate method of a MvcCaptcha instance.
In cases when a CaptchaControl instance is not available, use static Validate method of MvcCaptcha class.
using BotDetect.Web.Mvc;
[…]
[HttpPost]
[AllowAnonymous]
public ActionResult ExampleAction(ExampleModel model)
{
// init mvcCaptcha instance with captchaId
MvcCaptcha mvcCaptcha = new MvcCaptcha("ExampleCaptcha");
// get user input value
string userInput = HttpContext.Request.Form["CaptchaCode"];
// get validatingInstanceId from HttpContext.Request.Form
string validatingInstanceId = HttpContext.Request.Form[mvcCaptcha.ValidatingInstanceKey];
// or get validatingInstanceId from above mvcCaptcha instance
//string validatingInstanceId = mvcCaptcha.WebCaptcha.ValidatingInstanceId;
// call the built-in Validate method from above MvcCaptcha instance.
if (mvcCaptcha.Validate(userInput, validatingInstanceId))
{
// or you can use static Validate method of MvcCaptcha class
(i.e. MvcCaptcha.Validate("ExampleCaptcha", userInput, validatingInstanceId); )
MvcCaptcha.ResetCaptcha("ExampleCaptcha");
}
else
{
ModelState.AddModelError("CaptchaCode", "Incorrect!");
}
return View(model);
}
4. Configure Your ASP.NET Application
Exclude BotDetect paths from ASP.NET MVC Routing:
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
// BotDetect requests must not be routed
routes.IgnoreRoute("{*botdetect}",
new { botdetect = @"(.*)BotDetectCaptcha\.ashx" });
Update your application configuration (the
web.config file):
<system.web>
<httpHandlers>
<!-- Register the HttpHandler used for BotDetect Captcha
requests -->
<add verb="GET" path="BotDetectCaptcha.ashx"
type="BotDetect.Web.CaptchaHandler, BotDetect"/>
</httpHandlers>
<!-- make sure Session State is enabled -->
<pages enableSessionState="true">
<namespaces>
<add namespace="System.Web.Helpers" />
<add namespace="System.Web.Mvc" />
<add namespace="System.Web.Mvc.Ajax" />
<add namespace="System.Web.Mvc.Html" />
<add namespace="System.Web.Routing" />
<add namespace="System.Web.WebPages" />
</namespaces>
</pages>
<!-- Register a custom SessionIDManager for BotDetect Captcha
requests -->
<sessionState mode="InProc" cookieless="AutoDetect" timeout="20"
sessionIDManagerType="BotDetect.Web.CustomSessionIdManager, BotDetect"/>
</system.web>
<system.webServer>
<validation validateIntegratedModeConfiguration="false"/>
<handlers>
<!-- Register the HttpHandler used for BotDetect Captcha
requests (IIS 7.0+) -->
<remove name="BotDetectCaptchaHandler"/>
<add name="BotDetectCaptchaHandler" preCondition="integratedMode"
verb="GET" path="BotDetectCaptcha.ashx"
type="BotDetect.Web.CaptchaHandler, BotDetect"/>
</handlers>
</system.webServer>
