[#923] Merge remote-tracking branch 'remotes/upstream/develop' into twitter_oauth

# Conflicts:
#	config/config.exs
#	lib/pleroma/web/auth/pleroma_authenticator.ex

lib/pleroma/web/auth/ldap_authenticator.ex

@@ -0,0 +1,145 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+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(%Plug.Conn{} = conn, params) do
+    if Pleroma.Config.get([:ldap, :enabled]) do
+      {name, password} =
+        case 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, params)
+
+        error ->
+          error
+      end
+    else
+      # Fall back to default authenticator
+      Pleroma.Web.Auth.PleromaAuthenticator.get_user(conn, params)
+    end
+  end
+
+  def get_or_create_user_by_oauth(conn, params), do: get_user(conn, params)
+
+  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)
+    ssl = Keyword.get(ldap, :ssl, false)
+    sslopts = Keyword.get(ldap, :sslopts, [])
+
+    options =
+      [{:port, port}, {:ssl, ssl}, {:timeout, @connection_timeout}] ++
+        if sslopts != [], do: [{:sslopts, sslopts}], else: []
+
+    case :eldap.open([to_charlist(host)], options) do
+      {:ok, connection} ->
+        try do
+          if Keyword.get(ldap, :tls, false) do
+            :application.ensure_all_started(:ssl)
+
+            case :eldap.start_tls(
+                   connection,
+                   Keyword.get(ldap, :tlsopts, []),
+                   @connection_timeout
+                 ) do
+              :ok ->
+                :ok
+
+              error ->
+                Logger.error("Could not start TLS: #{inspect(error)}")
+            end
+          end
+
+          bind_user(connection, ldap, name, password)
+        after
+          :eldap.close(connection)
+        end
+
+      {:error, error} ->
+        Logger.error("Could not open LDAP connection: #{inspect(error)}")
+        {:error, {:ldap_connection_error, error}}
+    end
+  end
+
+  defp bind_user(connection, ldap, name, password) do
+    uid = Keyword.get(ldap, :uid, "cn")
+    base = Keyword.get(ldap, :base)
+
+    case :eldap.simple_bind(connection, "#{uid}=#{name},#{base}", password) do
+      :ok ->
+        case User.get_by_nickname_or_email(name) do
+          %User{} = user ->
+            user
+
+          _ ->
+            register_user(connection, base, uid, name, password)
+        end
+
+      error ->
+        error
+    end
+  end
+
+  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))},
+           {:scope, :eldap.wholeSubtree()},
+           {:attributes, ['mail', 'email']},
+           {:timeout, @search_timeout}
+         ]) do
+      {:ok, {:eldap_search_result, [{:eldap_entry, _, attributes}], _}} ->
+        with {_, [mail]} <- List.keyfind(attributes, 'mail', 0) do
+          params = %{
+            email: :erlang.list_to_binary(mail),
+            name: name,
+            nickname: name,
+            password: password,
+            password_confirmation: password
+          }
+
+          changeset = User.register_changeset(%User{}, params)
+
+          case User.register(changeset) do
+            {:ok, user} -> user
+            error -> error
+          end
+        else
+          _ ->
+            Logger.error("Could not find LDAP attribute mail: #{inspect(attributes)}")
+            {:error, :ldap_registration_missing_attributes}
+        end
+
+      error ->
+        error
+    end
+  end
+end