# keycloak-hcaptcha

> I am currently not adding any new features, updates or fixes. Feel free to open a PR!

To safeguard registration against bots, Keycloak has integration with Google reCAPTCHA. This provides similar functionality, but with a more privacy friendly provider named hCaptcha. The code is based on the vanilla implementation of reCAPTCHA in Keycloak.

## Installation

Download the newest release JAR (or compile it yourself - see below) and drop it into `your_keycloak_installation/providers`

There are a few steps you need to perform in the Keycloak Admin Console.

### Registration Flow
Click the Authentication left menu item and go to the Flows tab. Select the Registration flow from the drop down list on this page.

![Step 1](img/step-01.png)
Make copy of the Registration flow, and add the hCaptcha execution to the Registration Form.

![Step 2](img/step-02.png)
Set the 'hCaptcha' requirement to Required by clicking the appropriate radio button. This will enable hCaptcha on the screen. Next, you have to enter in the hCaptcha site key and secret that you generated at the hCaptcha.com Website. Click on the 'Actions' button that is to the right of the hCaptcha flow entry, then "Config" link, and enter in the hCaptcha site key and secret on this config page.

![Step 3](img/step-03.png)

### Authorizing Iframes

Now, change some default HTTP response headers that Keycloak sets. Keycloak will prevent a website from including any login page within an iframe. This is to prevent clickjacking attacks. You need to authorize hCaptcha to use the registration page within an iframe. Go to the Realm Settings left menu item and then go to the Security Defenses tab. You will need to add https://newassets.hcaptcha.com to the value of the Content-Security-Policy headers. In the image they are also in the X-Frame-Options, but this is not needed (you can ignore it).

![Step 4](img/step-04.png)

### Registration Template
To show the hCaptcha you need to modify the registration template. You can find the files in your Keycloak installation under `themes/base/login/`. If you use the user profile preview (you start your Keycloak with the `-Dkeycloak.profile=preview` flag), you need to edit the `register-user-profile.ftl`, else the `register.ftl`. Add the following code beneath the reCaptcha code:

```html
<#if hcaptchaRequired??>
    <div class="form-group">
        <div class="${properties.kcInputWrapperClass!}">
            <div class="h-captcha" data-size="<#if hcaptchaCompact?? && hcaptchaCompact=="true">compact<#else>normal</#if>" data-sitekey="${hcaptchaSiteKey}"></div>
        </div>
    </div>
</#if>
```

![Step 5](img/step-05.png)

### Authentication Bindings

You have to change the registration flow to the newly created one and save it. Once you do this, the hCaptcha shows on the registration page and protects your site from bots!

![Step 6](img/step-06.png)

### hCaptcha Response attribute validator

As the last step, go to *Realm Settings* > *User profile* and create a new attribute `h-captcha-response` and add a validator with type `length`. Set the minimum size to 0 and the maximum size to 4096.

Otherwise Keycloak will reject hcaptcha responses longer than 2048 characters.

## Compiling it yourself

Clone the repository:

```bash
git clone https://github.com/p08dev/keycloak-hcaptcha.git
```

Inside the repository, compile it using Maven with Java 17:

```bash
mvn clean compile package
```

You can instruct Maven to use a specific Java version by prepending the JAVA_HOME environment variable:

```bash
JAVA_HOME=/usr/lib/jvm/java-17-oracle/ mvn clean compile package
```

## © License
[MIT](LICENSE)
