Move LDAP code to LDAPAuthenticator. Use Authenticator for token_exchange with grant_type as well

docs/config.md

@@ -336,3 +336,8 @@ config :auto_linker,
 * `sslopts`: additional SSL options
 * `base`: LDAP base, e.g. "dc=example,dc=com"
 * `uid`: attribute type to authenticate the user, e.g. when "cn", the filter will be "cn=username,base"
+
+## Pleroma.Web.Auth.Authenticator
+
+* `Pleroma.Web.Auth.PleromaAuthenticator`: default database authenticator
+* `Pleroma.Web.Auth.LDAPAuthenticator`: LDAP authentication

lib/pleroma/web/auth/ldap_authenticator.ex

@@ -2,15 +2,51 @@
 # Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
 # SPDX-License-Identifier: AGPL-3.0-only
 
-defmodule Pleroma.LDAP do
+defmodule Pleroma.Web.Auth.LDAPAuthenticator do
   alias Pleroma.User
 
   require Logger
 
+  @behaviour Pleroma.Web.Auth.Authenticator
+
   @connection_timeout 10_000
   @search_timeout 10_000
 
-  def get_user(name, password) do
+  def get_user(%Plug.Conn{} = conn) do
+    if Pleroma.Config.get([:ldap, :enabled]) do
+      {name, password} =
+        case conn.params do
+          %{"authorization" => %{"name" => name, "password" => password}} ->
+            {name, password}
+
+          %{"grant_type" => "password", "username" => name, "password" => password} ->
+            {name, password}
+        end
+
+      case ldap_user(name, password) do
+        %User{} = user ->
+          {:ok, user}
+
+        {:error, {:ldap_connection_error, _}} ->
+          # When LDAP is unavailable, try default authenticator
+          Pleroma.Web.Auth.PleromaAuthenticator.get_user(conn)
+
+        error ->
+          error
+      end
+    else
+      # Fall back to default authenticator
+      Pleroma.Web.Auth.PleromaAuthenticator.get_user(conn)
+    end
+  end
+
+  def handle_error(%Plug.Conn{} = _conn, error) do
+    error
+  end
+
+  def auth_template, do: nil
+
+  defp ldap_user(name, password) do
     ldap = Pleroma.Config.get(:ldap, [])
     host = Keyword.get(ldap, :host, "localhost")
     port = Keyword.get(ldap, :port, 389)
@@ -50,7 +86,7 @@ def get_user(name, password) do
     end
   end
 
-  def register_user(connection, base, uid, name, password) do
+  defp register_user(connection, base, uid, name, password) do
     case :eldap.search(connection, [
            {:base, to_charlist(base)},
            {:filter, :eldap.equalityMatch(to_charlist(uid), to_charlist(name))},

lib/pleroma/web/auth/pleroma_authenticator.ex

@@ -9,7 +9,14 @@ defmodule Pleroma.Web.Auth.PleromaAuthenticator do
   @behaviour Pleroma.Web.Auth.Authenticator
 
   def get_user(%Plug.Conn{} = conn) do
-    %{"authorization" => %{"name" => name, "password" => password}} = conn.params
+    {name, password} =
+      case conn.params do
+        %{"authorization" => %{"name" => name, "password" => password}} ->
+          {name, password}
+
+        %{"grant_type" => "password", "username" => name, "password" => password} ->
+          {name, password}
+      end
 
     with {_, %User{} = user} <- {:user, User.get_by_nickname_or_email(name)},
          {_, true} <- {:checkpw, Pbkdf2.checkpw(password, user.password_hash)} do

lib/pleroma/web/oauth/oauth_controller.ex

@@ -11,7 +11,6 @@ defmodule Pleroma.Web.OAuth.OAuthController do
   alias Pleroma.Web.OAuth.App
   alias Pleroma.Repo
   alias Pleroma.User
-  alias Comeonin.Pbkdf2
 
   import Pleroma.Web.ControllerHelper, only: [oauth_scopes: 2]
 
@@ -126,10 +125,10 @@ def token_exchange(conn, %{"grant_type" => "authorization_code"} = params) do
 
   def token_exchange(
         conn,
-        %{"grant_type" => "password", "username" => name, "password" => password} = params
+        %{"grant_type" => "password"} = params
       ) do
-    with %App{} = app <- get_app_from_request(conn, params),
+    with {_, {:ok, %User{} = user}} <- {:get_user, Authenticator.get_user(conn)},
-         %User{} = user <- get_user(name, password),
+         %App{} = app <- get_app_from_request(conn, params),
          {:auth_active, true} <- {:auth_active, User.auth_active?(user)},
          scopes <- oauth_scopes(params, app.scopes),
          [] <- scopes -- app.scopes,
@@ -213,28 +212,4 @@ defp get_app_from_request(conn, params) do
       nil
     end
   end
-
-  defp get_user(name, password) do
-    if Pleroma.Config.get([:ldap, :enabled]) do
-      case Pleroma.LDAP.get_user(name, password) do
-        %User{} = user ->
-          user
-
-        {:error, {:ldap_connection_error, _}} ->
-          # When LDAP is unavailable, try default login
-          with %User{} = user <- User.get_by_nickname_or_email(name),
-               true <- Pbkdf2.checkpw(password, user.password_hash) do
-            user
-          end
-
-        error ->
-          error
-      end
-    else
-      with %User{} = user <- User.get_by_nickname_or_email(name),
-           true <- Pbkdf2.checkpw(password, user.password_hash) do
-        user
-      end
-    end
-  end
 end