Add hcaptcha to signup form

This should help prevent automated spam signups.

Implements #628.

resources/config.edn

@@ -40,6 +40,10 @@
                        :client-secret #profile {:production #ssm-parameter "/clojars/production/gitlab_oauth_client_secret"
                                                 :default    "testing"}
                        :callback-uri  "https://clojars.org/oauth/gitlab/callback"}
+ :hcaptcha            #profile {:production {:site-key #ssm-parameter "/clojars/production/hcaptcha_site_key"
+                                             :secret #ssm-parameter "/clojars/production/hcaptcha_secret"}
+                                :default {:site-key "10000000-ffff-ffff-ffff-000000000001"
+                                          :secret "0x0000000000000000000000000000000000000000"}}
  :index-path          "data/index"
  :mail                #profile {:production {:from     "[email protected]"
                                              :hostname "email-smtp.us-east-1.amazonaws.com"

src/clojars/config.clj

@@ -26,6 +26,10 @@
 
 (def ^:dynamic *profile* "development")
 
+(defn test-profile?
+  []
+  (= "test" *profile*))
+
 (defmethod aero/reader 'ssm-parameter
   [_opts _tag value]
   (if (= :production *profile*)

src/clojars/friend/registration.clj

@@ -2,35 +2,39 @@
   (:require
    [cemerick.friend.workflows :as workflow]
    [clojars.db :refer [add-user]]
+   [clojars.hcaptcha :as hcaptcha]
+   [clojars.http-utils :as http-utils]
    [clojars.log :as log]
    [clojars.web.user :refer [register-form new-user-validations normalize-email]]
-   [ring.util.response :refer [response content-type]]
    [valip.core :refer [validate]]))
 
-(defn register [db {:keys [email username password confirm]}]
+(defn register
+  [db hcaptcha {:keys [confirm email h-captcha-response password username]}]
   (let [email (normalize-email email)]
     (log/with-context {:email email
                        :username username
                        :tag :registration}
-      (if-let [errors (apply validate {:email email
-                                       :username username
-                                       :password password}
-                             (new-user-validations db confirm))]
+      (if-let [errors (apply validate {:captcha  h-captcha-response
+                                       :email    email
+                                       :password password
+                                       :username username}
+                             (new-user-validations db hcaptcha confirm))]
         (do
           (log/info {:status :validation-failed})
-          (->
-           (response (register-form {:errors (apply concat (vals errors))
-                                     :email email
-                                     :username username}
-                                    nil))
-           (content-type "text/html")))
+          (http-utils/with-extra-csp-srcs
+            hcaptcha/hcaptcha-csp
+            (register-form hcaptcha
+                           {:errors (apply concat (vals errors))
+                            :email email
+                            :username username}
+                           nil)))
         (do
           (add-user db email username password)
           (log/info {:status :success})
           (workflow/make-auth {:identity username :username username}))))))
 
-(defn workflow [db]
+(defn workflow [db hcaptcha]
   (fn [{:keys [uri request-method params]}]
     (when (and (= "/register" uri)
                (= :post request-method))
-      (register db params))))
+      (register db hcaptcha params))))

src/clojars/hcaptcha.clj

@@ -0,0 +1,63 @@
+(ns clojars.hcaptcha
+  "See https://docs.hcaptcha.com/#verify-the-user-response-server-side"
+  (:require
+   [clojars.log :as log]
+   [clojars.remote-service :as remote-service :refer [defendpoint]]
+   [clojure.set :as set]))
+
+(def hcaptcha-csp
+  (let [hcaptcha-urls ["https://hcaptcha.com" "https://*.hcaptcha.com"]]
+    {:connect-src hcaptcha-urls
+     :frame-src   hcaptcha-urls
+     :script-src  hcaptcha-urls
+     :style-src   hcaptcha-urls}))
+
+(defrecord Hcaptcha [config])
+
+(defn site-key
+  [hcaptcha]
+  (get-in hcaptcha [:config :site-key]))
+
+(defn- secret
+  [hcaptcha]
+  (get-in hcaptcha [:config :secret]))
+
+(defendpoint -validate-hcaptcha-response
+  [_client site-key secret hcaptcha-response]
+  {:method :post
+   :url "https://api.hcaptcha.com/siteverify"
+   :form-params {:response hcaptcha-response
+                 :secret secret
+                 :site-key site-key}})
+
+;; These responses from hcaptcha indicate a misconfiguration or a code bug, so
+;; we will throw and error for them.
+(def ^:private invalid-error-codes
+  #{"bad-request"
+    "invalid-input-secret"
+    "invalid-or-already-seen-response"
+    "missing-input-secret"
+    "sitekey-secret-mismatch"})
+
+(defn- log-and-maybe-thrpw
+  [{:as _response :keys [error-codes success]}]
+  (let [log-data {:tag :hcaptcha-response
+                  :error-codes error-codes
+                  :success? success}]
+    (log/info log-data)
+    (when (seq (set/intersection invalid-error-codes (set error-codes)))
+      (throw (ex-info "Invalid hcaptcha configuration" log-data)))))
+
+(defn valid-response?
+  [hcaptcha hcaptcha-response]
+  (let [response (-validate-hcaptcha-response (:client hcaptcha)
+                                              (site-key hcaptcha)
+                                              (secret hcaptcha)
+                                              hcaptcha-response)]
+    (log-and-maybe-thrpw response)
+    (:success response)))
+
+(defn new-hcaptcha
+  [config]
+  (map->Hcaptcha {:config config
+                  :client (remote-service/new-http-remote-service)}))

src/clojars/log.clj

@@ -32,7 +32,7 @@
 
   java.util.List
   (redact [v]
-    (vec (map redact v)))
+    (mapv redact v))
 
   java.util.Map
   (redact [v]

src/clojars/routes/user.clj

@@ -4,6 +4,7 @@
    [clojars.auth :as auth]
    [clojars.db :as db]
    [clojars.event :as event]
+   [clojars.hcaptcha :as hcaptcha]
    [clojars.http-utils :as http-utils]
    [clojars.log :as log]
    [clojars.routes.common :as common]
@@ -115,7 +116,7 @@
         (assoc (redirect "/mfa")
                :flash "Password incorrect.")))))
 
-(defn routes [db event-emitter mailer]
+(defn routes [db event-emitter hcaptcha mailer]
   (compojure/routes
    (GET "/profile" {:keys [flash]}
         (auth/with-account
@@ -146,7 +147,8 @@
            #(view/update-notifications db % params)))
 
    (GET "/register" {:keys [params flash]}
-        (view/register-form params flash))
+        (http-utils/with-extra-csp-srcs hcaptcha/hcaptcha-csp
+          (view/register-form hcaptcha params flash)))
 
    (GET "/forgot-password" _
         (view/forgot-password-form))

src/clojars/system.clj

@@ -2,6 +2,7 @@
   (:require
    [clojars.email :refer [simple-mailer]]
    [clojars.event :as event]
+   [clojars.hcaptcha :as hcaptcha]
    [clojars.notifications :as notifications]
    ;; for defmethods
    [clojars.notifications.admin]
@@ -81,6 +82,7 @@
                                                      (:callback-uri gitlab-oauth))
           :event-emitter  (event/new-sqs-emitter (:event-queue config))
           :event-receiver (event/new-sqs-receiver (:event-queue config))
+          :hcaptcha       (hcaptcha/new-hcaptcha (:hcaptcha config))
           :http           (jetty-server (assoc (:http config)
                                                :configurator patch/use-status-message-header))
           :http-client    (remote-service/new-http-remote-service)
@@ -91,8 +93,8 @@
           :storage        (storage-component (:repo config) (:cdn-token config) (:cdn-url config))))
         (component/system-using
          {:app            [:clojars-app]
-          :clojars-app    [:db :github :gitlab :error-reporter :event-emitter :http-client
-                           :mailer :stats :search :storage]
+          :clojars-app    [:db :github :gitlab :error-reporter :event-emitter :hcaptcha
+                           :http-client :mailer :stats :search :storage]
           :event-emitter  [:error-reporter]
           :http           [:app]
           :notifications  [:db :mailer]

src/clojars/web.clj

@@ -50,7 +50,7 @@
                :status 400})))))
 
 (defn- main-routes
-  [{:as _system :keys [db event-emitter mailer search stats]}]
+  [{:as _system :keys [db event-emitter hcaptcha mailer search stats]}]
   (let [db (:spec db)]
     (routes
      (GET "/" _
@@ -83,7 +83,7 @@
      (artifact/routes db stats)
      ;; user routes must go after artifact routes
      ;; since they both catch /:identifier
-     (user/routes db event-emitter mailer)
+     (user/routes db event-emitter hcaptcha mailer)
      (verify/routes db event-emitter)
      (token/routes db)
      (api/routes db stats)
@@ -139,6 +139,7 @@
     :keys [db
            error-reporter
            event-emitter
+           hcaptcha
            http-client
            github
            gitlab
@@ -168,7 +169,7 @@
          (friend/authenticate
           {:credential-fn (auth/password-credential-fn db event-emitter)
            :workflows [(auth/interactive-form-with-mfa-workflow)
-                       (registration/workflow db)
+                       (registration/workflow db hcaptcha)
                        (github/workflow github http-client db)
                        (gitlab/workflow gitlab http-client db)]})
          (wrap-reject-invalid-params)

src/clojars/web/user.clj

@@ -2,7 +2,7 @@
   (:require
    [buddy.core.codecs.base64 :as base64]
    [cemerick.friend.credentials :as creds]
-   [clojars.config :refer [config]]
+   [clojars.config :as config]
    [clojars.db :as db :refer [find-group-verification
                               find-groupnames
                               find-user
@@ -13,6 +13,7 @@
                               update-user
                               update-user-notifications]]
    [clojars.event :as event]
+   [clojars.hcaptcha :as hcaptcha]
    [clojars.log :as log]
    [clojars.notifications.common :as notif-common]
    [clojars.web.common :refer [html-doc error-list form-table jar-link
@@ -34,7 +35,8 @@
 
 (set! *warn-on-reflection* true)
 
-(defn register-form [{:keys [errors email username]} message]
+(defn register-form
+  [hcaptcha {:keys [errors email username]} message]
   (html-doc "Register" {}
             [:div.small-section
              [:h1 "Register"]
@@ -59,6 +61,17 @@
                       (password-field {:placeholder "confirm your password"
                                        :required true}
                                       :confirm)
+                      ;; We don't load the captcha js in tests, since we can't interact
+                      ;; with it. Instead, we emit a text area that we can fill with a
+                      ;; response value that is valid or not when using an hcaptcha
+                      ;; test token..
+                      (if (config/test-profile?)
+                        (list
+                         (label :h-captcha-response "TEST Captcha")
+                         (text-field :h-captcha-response))
+                        (list
+                         [:div.h-captcha {:data-sitekey (hcaptcha/site-key hcaptcha)}]
+                         [:script {:src "https://js.hcaptcha.com/1/api.js" :async true :defer true}]))
                       (submit-button "Register"))]))
 
 ;; Validations
@@ -97,15 +110,20 @@
             "letters, numbers, hyphens and underscores.")]
       [:username pred/present? "Username can't be blank"]])))
 
+(defn- captcha-validations
+  [hcaptcha]
+  [[:captcha (partial hcaptcha/valid-response? hcaptcha) "Captcha response is invalid."]])
+
 (defn new-user-validations
-  [db confirm]
+  [db hcaptcha confirm]
   (concat [[:password pred/present? "Password can't be blank"]
            [:username #(not (or (reserved-names %)
                                 (find-user db %)
                                 (seq (group-activenames db %))))
             "Username is already taken"]]
           (user-validations db)
-          (password-validations confirm)))
+          (password-validations confirm)
+          (captcha-validations hcaptcha)))
 
 (defn reset-password-validations [db confirm]
   (concat
@@ -249,7 +267,7 @@
   (log/with-context {:email-or-username email-or-username}
     (if-let [user (find-user-by-user-or-email db email-or-username)]
       (let [reset-code (db/set-password-reset-code! db (:user user))
-            base-url (:base-url (config))
+            base-url (:base-url (config/config))
             reset-password-url (str base-url "/password-resets/" reset-code)]
         (log/info {:tag :password-reset-code-generated})
         (mailer (:email user)

test/clojars/integration/steps.clj

@@ -24,6 +24,13 @@
        (cond-> otp (fill-in "Two-Factor Code" otp))
        (press "Login"))))
 
+(defn fill-in-captcha
+  ([state]
+   ;; From https://docs.hcaptcha.com/#integration-testing-test-keys
+   (fill-in-captcha state "10000000-aaaa-bbbb-cccc-000000000001"))
+  ([state value]
+   (fill-in state "TEST Captcha" value)))
+
 (defn register-as
   ([state user email password]
    (register-as state user email password password))
@@ -35,6 +42,7 @@
        (fill-in "Username" user)
        (fill-in "Password" password)
        (fill-in "Confirm password" confirm)
+       (fill-in-captcha)
        (press "Register"))))
 
 (defn create-deploy-token