ReCaptcha.NET

ReCaptcha.NET provides a .NET wrapper library for Google's reCaptcha.

NuGet Package Status

Aliencube.ReCaptcha.NET	Aliencube.ReCaptcha.NET.MVC

Build Status

master	dev	release

Getting Started - Basic Usage

In order to use ReCaptcha.NET in your apps, you should get the Aliencube.ReCaptcha.NET package as a minimum. The following section shows how this is used in ASP.NET MVC apps.

For your ASP.NET MVC apps, you should get the Aliencube.ReCaptcha.NET.MVC package, on top of the Aliencube.ReCaptcha.NET package.

Then add the following into your Razor view script:

@using (Html.BeginForm(MVC.Home.ActionNames.Basic, MVC.Home.Name, FormMethod.Post))
{
  ...

  @Html.ReCaptcha(Model.SiteKey,
                  new { @class = "class1 class2" })

  ...
}

@section Scripts
{
  @Html.ReCaptchaApiJs(Model.ApiUrl)
}

• @Html.Recaptcha() renders the reCaptcha control.
• @Html.ReCaptchaApiJs() renders JavaScript for the reCaptcha control.
• More details can be found on Basic.cshtml as an example.

Advanced Usage

Using the RenderParameters class gives your more control. Properties in the RenderParameters class can be found at: https://developers.google.com/recaptcha/docs/display#render_param.

@using (Html.BeginForm(MVC.Home.ActionNames.Advanced, MVC.Home.Name, FormMethod.Post))
{
  ...

  @Html.ReCaptcha(new RenderParameters() { SiteKey = Model.SiteKey, Theme = RenderThemeType.Dark },
                  new { @class = "form-group" })

  ...
}

Rendering api.js can be asynchronous. For this, you can add ApiJsRenderingOptions enum like:

@section Scripts
{
  @Html.ReCaptchaApiJs(Model.ApiUrl, ApiJsRenderingOptions.Async | ApiJsRenderingOptions.Defer)
}

• @Html.Recaptcha() renders the reCaptcha control.
• @Html.ReCaptchaApiJs() renders JavaScript for the reCaptcha control.
• More details can be found on Advanced.cshtml as an example.

Callback Usage

Instead of rendering the reCaptcha controls automatically, you can explicitly initialise rendering options by using a callback function.

@section Scripts
{
  var callback = "onLoadCallback";
  var elementId = "recaptcha";

  @Html.ReCaptchaApiJs(Model.ApiUrl,
                       ApiJsRenderingOptions.Async | ApiJsRenderingOptions.Defer,
                       new ResourceParameters()
                       {
                         OnLoad = callback,
                         Render = WidgetRenderType.Explicit,
                         LanguageCode = WidgetLanguageCode.Korean
                       })
  @Html.ReCaptchaCallbackJs(callback,
                            elementId,
                            new RenderParameters()
                            {
                              SiteKey = Model.SiteKey,
                              Theme = RenderThemeType.Dark
                            })
}

For this, the ResourceParameters class in ReCaptchaApiJs() is used. This enables to load callback function and the callback function is loaded by using ReCaptchaCallbackJs() method. As all rendering options are defined here, the actual HTML part look like:

@using (Html.BeginForm(MVC.Home.ActionNames.Advanced, MVC.Home.Name, FormMethod.Post))
{
  ...

  <div class="form-group" id="@elementId"></div>

  ...
}

• @Html.ReCaptchaApiJs() renders JavaScript for the reCaptcha control.
• @Html.RecaptchaCallbackJs() renders JavaScript callback function for the reCaptcha control.
• More details can be found on Callback.cshtml as an example.

Controller

In order to handle the reCaptcha control in your controllers, take a look at the following:

[HttpPost]
public virtual async Task<ActionResult> Index(HomeReCaptchaViewModel form)
{
  var result = await this._reCaptcha.SiteVerifyAsync(this.Request.Form, this.Request.ServerVariables);

  var vm = form;
  vm.Success = result.Success;
  vm.ErrorCodes = result.ErrorCodes;
  return View(vm);
}

• ReCaptchaV2.SiteVerifyAsync() takes parameters of Form and ServerVariables and returns the result.
• More details can be found on HomeController.cs as an example.

Settings

As you can see the above example codes, configuration settings needs to be instantiated first by calling:

var settings = ReCaptchaV2Settings.CreateInstance();

Alternatively, the settings instance can be injected by any IoC container. The following code is, for example, using Autofac

var builder = new ContainerBuilder();

...

builder.Register(p => ReCaptchaV2Settings.CreateInstance()).As<IReCaptchaV2Settings>();
builder.RegisterType<ReCaptchaV2>().As<IReCaptchaV2>();

...

var container = builder.Build();

This settings instance comes from either reCaptchaV2Settings section or appSettings section on App.config or Web.config. It firstly look for the reCaptchaV2Settings section and, if no reCaptchaV2Settings section is found, then look for the appSettings section.

<configuration>
  <configSections>
    <section name="reCaptchaV2Settings" type="Aliencube.ReCaptcha.Wrapper.ReCaptchaV2Settings, Aliencube.ReCaptcha.Wrapper" requirePermission="false" />
  </configSections>

  <reCaptchaV2Settings
    requestUrl="https://www.google.com/recaptcha/api/siteverify"
    apiUrl="https://www.google.com/recaptcha/api.js"
    siteKey="[YOUR_SITE_KEY]"
    secretKey="[YOUR_SECRET_KEY]" />
</configuration>

If you want to simply use the appSettings section, you can do the following instead:

<configuration>
  <appSettings>
    <add key="RequestUrl" value="https://www.google.com/recaptcha/api/siteverify" />
    <add key="ApiUrl" value="https://www.google.com/recaptcha/api.js" />
    <add key="SiteKey" value="[YOUR_SITE_KEY]" />
    <add key="SecretKey" value="[YOUR_SECRET_KEY]" />
  </appSettings>
</configuration>

NOTE: Make sure that:

• Both SiteKey and SecretKey MUST be changed to yours before running this code; otherwise you'll get an error. They can be obtained from https://google.com/recaptcha, once you login.

• More details can be found on DependencyConfig.cs as an example.

Acknowledgements

• ReCaptcha.NET currently support Version 2 only. Find another library for Version 1.

Contribution

Your contributions are always welcome! All your work should be done in your forked repository. Once you finish your work, please send us a pull request onto our dev branch for review.

License

ReCaptcha.NET is released under MIT License

The MIT License (MIT)

Copyright (c) 2015 aliencube.org

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.