Cloudflare Turnstile

A Cloudflare Turnstile bot verification library for Go web servers. A CAPTCHA Replacement Solution.

Installation

This library works with the Go Programming Language

$ go get -u github.com/dreams-money/turnstile

Start now

You'll start by creating an account with Cloudflare Turnstile and adding a host to your account. localhost works just fine for testing.

Next, Import the package

package main

import "github.com/dreams-money/turnstile"

Create a new client:

botcheck := turnstile.New(turnstileSecretCode)

Then, collect 1) the "cf-turnstile-response" and 2) the form submitter's IP to send to Turnstile:

err := request.ParseForm()
if err != nil {
    log.Println(err)
    http.Error(resp, "Server Error", http.StatusInternalServerError)
    return
}

botErr, requestErr := botcheck.Verify(request.FormValue("cf-turnstile-response"), request.RemoteAddr)

Error handling

Turnstilre requires that you call their /siteverify api to check the validity of a verification token.

As such, the verification returns two errors types:

1. A bot error - this only returns if Turnstile /siteverify was successfully called.
2. A /siteverify request error - this signifies that there was an HTTP related error with /siteverify

Here's how you may handle these errors:

botErr, requestErr := botcheck.Verify(request.FormValue("cf-turnstile-response"), request.RemoteAddr)
if requestErr != nil {
    log.Println(requestErr)
    http.Error(resp, "Server error", http.StatusInternalServerError)
    return
}

if botErr == turnstile.ErrTimeoutOrDuplicate {
    http.Error(resp, "Refresh form before resubmitting it", http.StatusBadRequest)
    return
} else if botErr != nil { // Turnstile found a bot
    log.Println("Bot match: ", err)
    http.Error(resp, "Are you a bot?", http.StatusUnauthorized)
    return
}

turnstile.ErrTimeoutOrDuplicate is a common error if the user uses the back button.

For a complete example please navigate through the _examples directory.

License

This software is licensed under the MIT License.