add hmac webhook secret

app/controllers/webhook_hmac_controller.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class WebhookHmacController < ApplicationController
+  load_and_authorize_resource :webhook_url, parent: false
+
+  def show; end
+end

app/models/webhook_url.rb

@@ -6,6 +6,7 @@
 #
 #  id          :bigint           not null, primary key
 #  events      :text             not null
+#  hmac_secret :text             not null
 #  secret      :text             not null
 #  sha1        :string           not null
 #  url         :text             not null
@@ -47,10 +48,15 @@ class WebhookUrl < ApplicationRecord
   serialize :secret, coder: JSON
 
   before_validation :set_sha1
+  before_validation :set_hmac_secret
 
-  encrypts :url, :secret
+  encrypts :url, :secret, :hmac_secret
 
   def set_sha1
     self.sha1 = Digest::SHA1.hexdigest(url)
   end
+
+  def set_hmac_secret
+    self.hmac_secret ||= WebhookUrls::Signatures.generate_secret
+  end
 end

app/views/webhook_hmac/show.html.erb

@@ -0,0 +1,20 @@
+<%= render 'shared/turbo_modal', title: t('webhook_security') do %>
+  <div class="text-center mb-4">
+    <div class="inline-flex justify-center">
+      <%= link_to t('secret'), webhook_secret_path(@webhook_url), class: 'block bg-base-200 md:min-w-[112px] text-sm font-semibold whitespace-nowrap py-1.5 px-4 rounded-l-3xl', data: { turbo_frame: 'modal' } %>
+      <%= link_to t('hmac'), webhook_hmac_path(@webhook_url), class: 'block bg-base-300 md:min-w-[112px] text-sm font-semibold whitespace-nowrap py-1.5 px-4 rounded-r-3xl', data: { turbo_frame: 'modal' } %>
+    </div>
+  </div>
+  <div class="form-control">
+    <label class="label" for="hmac_secret"><%= t('hmac_signing_secret') %></label>
+    <% token = @webhook_url.hmac_secret %>
+    <% obscured = "#{token[0, 10]}#{'*' * [token.length - 10, 0].max}" %>
+    <div class="flex gap-2">
+      <masked-input class="block w-full" data-token="<%= token %>">
+        <input id="hmac_secret" type="text" value="<%= obscured %>" class="base-input font-mono w-full" autocomplete="off" readonly>
+      </masked-input>
+      <%= render 'shared/clipboard_copy', icon: 'copy', text: token, class: 'base-button', icon_class: 'w-6 h-6 text-white', copy_title: t('copy'), copied_title: t('copied') %>
+    </div>
+    <p class="text-sm mt-2 opacity-70"><%= t('hmac_signature_header_hint_html', header: '<code>X-Docuseal-Signature</code>'.html_safe) %></p>
+  </div>
+<% end %>

app/views/webhook_secret/show.erb

@@ -1,4 +1,10 @@
-<%= render 'shared/turbo_modal', title: t('webhook_secret') do %>
+<%= render 'shared/turbo_modal', title: t('webhook_security') do %>
+  <div class="text-center mb-4">
+    <div class="inline-flex justify-center">
+      <%= link_to t('secret'), webhook_secret_path(@webhook_url), class: 'block bg-base-300 md:min-w-[112px] text-sm font-semibold whitespace-nowrap py-1.5 px-4 rounded-l-3xl', data: { turbo_frame: 'modal' } %>
+      <%= link_to t('hmac'), webhook_hmac_path(@webhook_url), class: 'block bg-base-200 md:min-w-[112px] text-sm font-semibold whitespace-nowrap py-1.5 px-4 rounded-r-3xl', data: { turbo_frame: 'modal' } %>
+    </div>
+  </div>
   <%= form_for @webhook_url, url: webhook_secret_path, method: :patch, html: { class: 'space-y-4' }, data: { turbo_frame: :_top } do |f| %>
     <div class="space-y-2">
       <%= f.fields_for :secret, Struct.new(:key, :value).new(*@webhook_url.secret.to_a.first) do |ff| %>

app/views/webhook_settings/show.html.erb

@@ -23,7 +23,7 @@
             <div class="flex items-center space-x-2 md:absolute md:right-0">
               <%= link_to webhook_secret_path(@webhook_url), class: 'btn btn-outline btn-sm bg-white', data: { turbo_frame: 'modal' } do %>
                 <%= svg_icon('lock', class: 'w-4 h-4') %>
-                <span><%= @webhook_url.secret.present? ? t('edit_secret') : t('add_secret') %></span>
+                <span><%= t('security') %></span>
               <% end %>
               <div class="tooltip tooltip-left md:tooltip-top" data-tip="<%= t('delete_webhook') %>">
                 <%= button_to settings_webhook_path(@webhook_url), class: 'btn btn-warning btn-sm', method: :delete, data: { turbo_confirm: t('are_you_sure_') } do %>

config/locales/i18n.yml

@@ -593,6 +593,12 @@ en: &en
   unable_to_resend_webhook_request: Unable to resend webhook request.
   new_webhook: New Webhook
   delete_webhook: Delete webhook
+  security: Security
+  webhook_security: Webhook Security
+  secret: Secret
+  hmac: HMAC
+  hmac_signing_secret: HMAC Signing Secret
+  hmac_signature_header_hint_html: 'Each request is signed with the %{header} header: <timestamp>.<sha256>.'
   count_submissions_have_been_created: '%{count} submissions have been created.'
   sms_length_cant_be_longer_than_120_bytes: SMS length can't be longer than 120 bytes
   connected_successfully: Connected successfully.
@@ -1637,6 +1643,12 @@ es: &es
   unable_to_resend_webhook_request: No se pudo reenviar la solicitud del webhook.
   new_webhook: Nuevo Webhook
   delete_webhook: Eliminar webhook
+  security: Seguridad
+  webhook_security: Seguridad del Webhook
+  secret: Secreto
+  hmac: HMAC
+  hmac_signing_secret: Secreto de firma HMAC
+  hmac_signature_header_hint_html: 'Cada solicitud se firma con el encabezado %{header}: <timestamp>.<sha256>.'
   count_submissions_have_been_created: '%{count} envíos han sido creados.'
   sms_length_cant_be_longer_than_120_bytes: La longitud del SMS no puede ser mayor a 120 bytes.
   connected_successfully: Conectado con éxito.
@@ -2678,6 +2690,12 @@ it: &it
   unable_to_resend_webhook_request: Impossibile reinviare la richiesta del webhook.
   new_webhook: Nuovo Webhook
   delete_webhook: Elimina webhook
+  security: Sicurezza
+  webhook_security: Sicurezza del Webhook
+  secret: Segreto
+  hmac: HMAC
+  hmac_signing_secret: Segreto di firma HMAC
+  hmac_signature_header_hint_html: 'Ogni richiesta viene firmata con l''intestazione %{header}: <timestamp>.<sha256>.'
   count_submissions_have_been_created: '%{count} invii sono stati creati.'
   sms_length_cant_be_longer_than_120_bytes: "La lunghezza dell'SMS non può superare i 120 byte."
   connected_successfully: Collegamento avvenuto con successo.
@@ -3720,6 +3738,12 @@ fr: &fr
   unable_to_resend_webhook_request: Impossible de renvoyer la requête webhook.
   new_webhook: Nouveau webhook
   delete_webhook: Supprimer le webhook
+  security: Sécurité
+  webhook_security: Sécurité du webhook
+  secret: Secret
+  hmac: HMAC
+  hmac_signing_secret: Secret de signature HMAC
+  hmac_signature_header_hint_html: 'Chaque requête est signée avec l''en-tête %{header} : <timestamp>.<sha256>.'
   count_submissions_have_been_created: "%{count} soumissions ont été créées."
   sms_length_cant_be_longer_than_120_bytes: La longueur du SMS ne peut pas dépasser 120 octets
   connected_successfully: Connecté avec succès.
@@ -4758,6 +4782,12 @@ pt: &pt
   unable_to_resend_webhook_request: Não foi possível reenviar a solicitação do webhook.
   new_webhook: Novo Webhook
   delete_webhook: Excluir webhook
+  security: Segurança
+  webhook_security: Segurança do Webhook
+  secret: Segredo
+  hmac: HMAC
+  hmac_signing_secret: Segredo de assinatura HMAC
+  hmac_signature_header_hint_html: 'Cada requisição é assinada com o cabeçalho %{header}: <timestamp>.<sha256>.'
   count_submissions_have_been_created: '%{count} submissões foram criadas.'
   sms_length_cant_be_longer_than_120_bytes: O comprimento do SMS não pode ultrapassar 120 bytes
   connected_successfully: Conectado com sucesso.
@@ -5799,6 +5829,12 @@ de: &de
   unable_to_resend_webhook_request: Webhook-Anfrage konnte nicht erneut gesendet werden.
   new_webhook: Neuer Webhook
   delete_webhook: Webhook löschen
+  security: Sicherheit
+  webhook_security: Webhook-Sicherheit
+  secret: Geheimnis
+  hmac: HMAC
+  hmac_signing_secret: HMAC-Signaturgeheimnis
+  hmac_signature_header_hint_html: 'Jede Anfrage wird mit dem %{header}-Header signiert: <timestamp>.<sha256>.'
   count_submissions_have_been_created: '%{count} Einreichungen wurden erstellt.'
   sms_length_cant_be_longer_than_120_bytes: Die SMS-Länge darf 120 Bytes nicht überschreiten.
   connected_successfully: Erfolgreich verbunden.
@@ -7245,6 +7281,12 @@ nl: &nl
   unable_to_resend_webhook_request: Kan webhook-verzoek niet opnieuw verzenden.
   new_webhook: Nieuwe webhook
   delete_webhook: Webhook verwijderen
+  security: Beveiliging
+  webhook_security: Webhook-beveiliging
+  secret: Geheim
+  hmac: HMAC
+  hmac_signing_secret: HMAC-ondertekeningsgeheim
+  hmac_signature_header_hint_html: 'Elk verzoek wordt ondertekend met de %{header}-header: <timestamp>.<sha256>.'
   count_submissions_have_been_created: "%{count} inzendingen zijn aangemaakt."
   sms_length_cant_be_longer_than_120_bytes: SMS-lengte mag niet langer zijn dan 120 bytes
   connected_successfully: Succesvol verbonden.

config/routes.rb

@@ -83,6 +83,7 @@ Rails.application.routes.draw do
   resources :submitters_resubmit, only: %i[update]
   resources :template_folders_autocomplete, only: %i[index]
   resources :webhook_secret, only: %i[show update]
+  resources :webhook_hmac, only: %i[show]
   resources :webhook_preferences, only: %i[update]
   resource :templates_upload, only: %i[create]
   authenticated do

db/migrate/20260506120000_add_hmac_to_webhook_urls.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+class AddHmacToWebhookUrls < ActiveRecord::Migration[8.1]
+  class MigrationWebhookUrl < ApplicationRecord
+    self.table_name = 'webhook_urls'
+
+    encrypts :hmac_secret
+  end
+
+  def up
+    add_column :webhook_urls, :hmac_secret, :text
+
+    MigrationWebhookUrl.find_each do |webhook_url|
+      webhook_url.update_columns(hmac_secret: WebhookUrls::Signatures.generate_secret)
+    end
+
+    change_column_null :webhook_urls, :hmac_secret, false
+  end
+
+  def down
+    remove_column :webhook_urls, :hmac_secret
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.1].define(version: 2026_04_16_100000) do
+ActiveRecord::Schema[8.1].define(version: 2026_05_06_120000) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "btree_gin"
   enable_extension "pg_catalog.plpgsql"
@@ -545,6 +545,7 @@ ActiveRecord::Schema[8.1].define(version: 2026_04_16_100000) do
     t.bigint "account_id", null: false
     t.datetime "created_at", null: false
     t.text "events", null: false
+    t.text "hmac_secret", null: false
     t.text "secret", null: false
     t.string "sha1", null: false
     t.datetime "updated_at", null: false

lib/send_webhook_request.rb

@@ -15,11 +15,7 @@ module SendWebhookRequest
 
   # rubocop:disable Metrics/AbcSize
   def call(webhook_url, event_uuid:, event_type:, record:, data:, attempt: 0)
-    uri = begin
+    uri = parse_uri(webhook_url.url)
-      URI(webhook_url.url)
-    rescue URI::Error
-      Addressable::URI.parse(webhook_url.url).normalize
-    end
 
     if Docuseal.multitenant?
       raise HttpsError, 'Only HTTPS is allowed.' if (uri.scheme != 'https' || [443, nil].exclude?(uri.port)) &&
@@ -43,6 +39,8 @@ module SendWebhookRequest
         data: data
       }.to_json
 
+      req.headers['X-Docuseal-Signature'] = WebhookUrls::Signatures.sign(webhook_url.hmac_secret, body: req.body)
+
       req.options.read_timeout = 15
       req.options.open_timeout = 8
     end
@@ -55,6 +53,12 @@ module SendWebhookRequest
   end
   # rubocop:enable Metrics/AbcSize
 
+  def parse_uri(url)
+    URI(url)
+  rescue URI::Error
+    Addressable::URI.parse(url).normalize
+  end
+
   def create_webhook_event(webhook_url, event_uuid:, event_type:, record:)
     return if event_uuid.blank?
 

lib/webhook_urls/signatures.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module WebhookUrls
+  module Signatures
+    SECRET_PREFIX = 'whsec_'
+    SECRET_BYTES = 24
+    TOLERANCE = 5 * 60
+
+    InvalidSignatureError = Class.new(StandardError)
+    TimestampError = Class.new(StandardError)
+
+    module_function
+
+    def generate_secret
+      SECRET_PREFIX + Base64.strict_encode64(SecureRandom.bytes(SECRET_BYTES))
+    end
+
+    def sign(secret, body:, timestamp: Time.current.to_i)
+      "#{timestamp}.#{OpenSSL::HMAC.hexdigest('sha256', secret, "#{timestamp}.#{body}")}"
+    end
+
+    def verify(secret, body:, header:, tolerance: TOLERANCE)
+      ts, sig = header.to_s.split('.', 2)
+      ts = Integer(ts, exception: false)
+
+      raise InvalidSignatureError unless ts && sig
+
+      now = Time.current.to_i
+
+      raise TimestampError, 'Too old' if ts < now - tolerance
+      raise TimestampError, 'In future' if ts > now + tolerance
+
+      expected = OpenSSL::HMAC.hexdigest('sha256', secret, "#{ts}.#{body}")
+
+      raise InvalidSignatureError unless ActiveSupport::SecurityUtils.secure_compare(expected, sig)
+
+      true
+    end
+  end
+end

spec/jobs/send_submission_created_webhook_request_job_spec.rb

@@ -57,6 +57,23 @@ RSpec.describe SendSubmissionCreatedWebhookRequestJob do
       ).once
     end
 
+    it 'signs the request with the HMAC secret' do
+      captured_body = nil
+      captured_signature = nil
+      stub_request(:post, webhook_url.url).with do |req|
+        captured_body = req.body
+        captured_signature = req.headers['X-Docuseal-Signature']
+      end.to_return(status: 200)
+
+      described_class.new.perform('submission_id' => submission.id, 'webhook_url_id' => webhook_url.id,
+                                  'event_uuid' => SecureRandom.uuid)
+
+      expect(captured_signature).to be_present
+      expect(WebhookUrls::Signatures.verify(webhook_url.hmac_secret,
+                                            body: captured_body,
+                                            header: captured_signature)).to be(true)
+    end
+
     it "doesn't send a webhook request if the event is not in the webhook's events" do
       webhook_url.update!(events: ['submission.completed'])
 

spec/system/webhook_settings_spec.rb

@@ -49,7 +49,7 @@ RSpec.describe 'Webhook Settings' do
     expect(page).to have_field('webhook_url[url]', type: 'url', with: webhook_url.url)
     expect(page).to have_button('Save')
     expect(page).to have_button('Delete')
-    expect(page).to have_link('Add Secret')
+    expect(page).to have_link('Security')
 
     WebhookUrl::EVENTS.each do |event|
       expect(page).to have_field(event, type: 'checkbox', checked: webhook_url.events.include?(event))
@@ -123,7 +123,7 @@ RSpec.describe 'Webhook Settings' do
 
     expect(webhook_url.secret).to eq({})
 
-    click_link 'Add Secret'
+    click_link 'Security'
 
     within '#modal' do
       fill_in 'Key', with: 'X-Signature'
@@ -136,7 +136,7 @@ RSpec.describe 'Webhook Settings' do
       expect(webhook_url.secret).to eq({ 'X-Signature' => 'secret-value' })
     end
 
-    expect(page).to have_link('Edit Secret')
+    expect(page).to have_link('Security')
     expect(page).to have_content('Webhook Secret has been saved.')
   end
 
@@ -145,7 +145,7 @@ RSpec.describe 'Webhook Settings' do
 
     visit settings_webhooks_path
 
-    click_link 'Edit Secret'
+    click_link 'Security'
 
     within '#modal' do
       fill_in 'Key', with: ''
@@ -158,10 +158,26 @@ RSpec.describe 'Webhook Settings' do
       expect(webhook_url.secret).to eq({})
     end
 
-    expect(page).to have_link('Add Secret')
+    expect(page).to have_link('Security')
     expect(page).to have_content('Webhook Secret has been saved.')
   end
 
+  it 'shows the HMAC signing secret on the HMAC tab' do
+    webhook_url = create(:webhook_url, account:)
+
+    visit settings_webhooks_path
+
+    click_link 'Security'
+
+    within '#modal' do
+      click_link 'HMAC'
+
+      expect(page).to have_field('hmac_secret')
+    end
+
+    expect(webhook_url.reload.hmac_secret).to start_with('whsec_')
+  end
+
   context 'when testing the webhook' do
     let!(:webhook_url) { create(:webhook_url, account:) }
     let!(:template) { create(:template, account:, author: user) }