Add HCaptcha support (#304)

* Add HCaptcha support

* Actually verify password reset requests

* Fix password request when captcha not configured

* Add configuration for prod release

config/config.exs

@@ -184,6 +184,10 @@ config :plausible, :custom_domain_server,
 config :plausible, PlausibleWeb.Firewall,
   blocklist: System.get_env("IP_BLOCKLIST", "") |> String.split(",") |> Enum.map(&String.trim/1)
 
+config :plausible, :hcaptcha,
+  sitekey: System.get_env("HCAPTCHA_SITEKEY"),
+  secret: System.get_env("HCAPTCHA_SECRET")
+
 config :geolix,
   databases: [
     %{

config/releases.exs

@@ -53,6 +53,9 @@ custom_domain_server_user = System.get_env("CUSTOM_DOMAIN_SERVER_USER")
 custom_domain_server_password = System.get_env("CUSTOM_DOMAIN_SERVER_PASSWORD")
 geolite2_country_db = System.get_env("GEOLITE2_COUNTRY_DB")
 disable_auth = String.to_existing_atom(System.get_env("DISABLE_AUTH", "false"))
+hcaptcha_sitekey = System.get_env("HCAPTCHA_SITEKEY")
+hcaptcha_secret = System.get_env("HCAPTCHA_SECRET")
+
 
 config :plausible,
   admin_user: admin_user,
@@ -187,6 +190,10 @@ config :plausible, Oban,
   queues: if(cron_enabled, do: base_queues ++ extra_queues, else: base_queues),
   crontab: if(cron_enabled, do: base_cron ++ extra_cron, else: base_cron)
 
+config :plausible, :hcaptcha,
+  sitekey: hcaptcha_sitekey,
+  secret: hcaptcha_secret
+
 config :ref_inspector,
   init: {Plausible.Release, :configure_ref_inspector}
 

config/test.exs

@@ -54,4 +54,5 @@ config :geolix,
   ]
 
 config :plausible,
-  session_timeout: 0
+  session_timeout: 0,
+  environment: System.get_env("ENVIRONMENT", "test")

lib/plausible_web/captcha.ex

@@ -0,0 +1,27 @@
+defmodule PlausibleWeb.Captcha do
+  @verify_endpoint "https://hcaptcha.com/siteverify"
+
+  def enabled? do
+    !!sitekey()
+  end
+
+  def sitekey() do
+    Application.get_env(:plausible, :hcaptcha, [])
+    |> Keyword.fetch!(:sitekey)
+  end
+
+  def verify(token) do
+    if enabled?() do
+      res = HTTPoison.post!(@verify_endpoint, {:form, [{"response", token}, {"secret", secret()}]})
+      json = Jason.decode!(res.body)
+      json["success"]
+    else
+      true
+    end
+  end
+
+  defp secret() do
+    Application.get_env(:plausible, :hcaptcha, [])
+    |> Keyword.fetch!(:secret)
+  end
+end

lib/plausible_web/controllers/auth_controller.ex

@@ -24,28 +24,36 @@ defmodule PlausibleWeb.AuthController do
     end
   end
 
-  def register(conn, %{"user" => params}) do
-    user = Plausible.Auth.User.changeset(%Plausible.Auth.User{}, params)
+  def register(conn, params) do
+    user = Plausible.Auth.User.changeset(%Plausible.Auth.User{}, params["user"])
 
-    case Ecto.Changeset.apply_action(user, :insert) do
-      {:ok, user} ->
-        token = Auth.Token.sign_activation(user.name, user.email)
-        url = PlausibleWeb.Endpoint.clean_url() <> "/claim-activation?token=#{token}"
-        Logger.info(url)
-        email_template = PlausibleWeb.Email.activation_email(user, url)
-        Plausible.Mailer.send_email(email_template)
+    if PlausibleWeb.Captcha.verify(params["h-captcha-response"]) do
+      case Ecto.Changeset.apply_action(user, :insert) do
+        {:ok, user} ->
+          token = Auth.Token.sign_activation(user.name, user.email)
+          url = PlausibleWeb.Endpoint.clean_url() <> "/claim-activation?token=#{token}"
+          Logger.info(url)
+          email_template = PlausibleWeb.Email.activation_email(user, url)
+          Plausible.Mailer.send_email(email_template)
 
-        conn
-        |> render("register_success.html",
-          email: user.email,
-          layout: {PlausibleWeb.LayoutView, "focus.html"}
-        )
+          conn
+          |> render("register_success.html",
+            email: user.email,
+            layout: {PlausibleWeb.LayoutView, "focus.html"}
+          )
 
-      {:error, changeset} ->
-        render(conn, "register_form.html",
-          changeset: changeset,
-          layout: {PlausibleWeb.LayoutView, "focus.html"}
-        )
+        {:error, changeset} ->
+          render(conn, "register_form.html",
+            changeset: changeset,
+            layout: {PlausibleWeb.LayoutView, "focus.html"}
+          )
+      end
+    else
+      render(conn, "register_form.html",
+        changeset: user,
+        captcha_error: "Please complete the captcha to register",
+        layout: {PlausibleWeb.LayoutView, "focus.html"}
+      )
     end
   end
 
@@ -87,23 +95,30 @@ defmodule PlausibleWeb.AuthController do
     )
   end
 
-  def password_reset_request(conn, %{"email" => email}) do
-    user = Repo.get_by(Plausible.Auth.User, email: email)
+  def password_reset_request(conn, %{"email" => email} = params) do
+    if PlausibleWeb.Captcha.verify(params["h-captcha-response"]) do
+      user = Repo.get_by(Plausible.Auth.User, email: email)
 
-    if user do
-      token = Auth.Token.sign_password_reset(email)
-      url = PlausibleWeb.Endpoint.clean_url() <> "/password/reset?token=#{token}"
-      Logger.debug("PASSWORD RESET LINK: " <> url)
-      email_template = PlausibleWeb.Email.password_reset_email(email, url)
-      Plausible.Mailer.deliver_now(email_template)
+      if user do
+        token = Auth.Token.sign_password_reset(email)
+        url = PlausibleWeb.Endpoint.clean_url() <> "/password/reset?token=#{token}"
+        Logger.debug("PASSWORD RESET LINK: " <> url)
+        email_template = PlausibleWeb.Email.password_reset_email(email, url)
+        Plausible.Mailer.deliver_now(email_template)
 
-      render(conn, "password_reset_request_success.html",
-        email: email,
-        layout: {PlausibleWeb.LayoutView, "focus.html"}
-      )
+        render(conn, "password_reset_request_success.html",
+          email: email,
+          layout: {PlausibleWeb.LayoutView, "focus.html"}
+        )
+      else
+        render(conn, "password_reset_request_success.html",
+          email: email,
+          layout: {PlausibleWeb.LayoutView, "focus.html"}
+        )
+      end
     else
-      render(conn, "password_reset_request_success.html",
-        email: email,
+      render(conn, "password_reset_request_form.html",
+        error: "Please complete the captcha to reset your password",
         layout: {PlausibleWeb.LayoutView, "focus.html"}
       )
     end

lib/plausible_web/templates/auth/password_reset_request_form.html.eex

@@ -7,5 +7,16 @@
   <%= if @conn.assigns[:error] do %>
     <div class="text-red-500 text-xs italic my-2"><%= @conn.assigns[:error] %></div>
   <% end %>
+
+  <%= if PlausibleWeb.Captcha.enabled?() do %>
+    <div class="mt-4">
+      <div class="h-captcha" data-sitekey="<%= PlausibleWeb.Captcha.sitekey() %>"></div>
+      <%= if assigns[:captcha_error] do %>
+        <div class="text-red-500 text-xs italic mt-3"><%= @captcha_error %></div>
+      <% end %>
+      <script src="https://hcaptcha.com/1/api.js" async defer></script>
+    </div>
+  <% end %>
+
   <%= submit "Send reset link →", class: "button mt-4 w-full" %>
 <% end %>

lib/plausible_web/templates/auth/register_form.html.eex

@@ -19,6 +19,16 @@
         <%= error_tag f, :email %>
       </div>
 
+      <%= if PlausibleWeb.Captcha.enabled?() do %>
+        <div class="mt-4">
+          <div class="h-captcha" data-sitekey="<%= PlausibleWeb.Captcha.sitekey() %>"></div>
+          <%= if assigns[:captcha_error] do %>
+            <div class="text-red-500 text-xs italic mt-3"><%= @captcha_error %></div>
+          <% end %>
+          <script src="https://hcaptcha.com/1/api.js" async defer></script>
+        </div>
+      <% end %>
+
       <%= submit "Start my free trial →", class: "button mt-4 w-full" %>
 
       <p class="text-center text-gray-600 text-xs mt-4">