Pleroma.LDAP

This adds a GenServer which will keep an LDAP connection open and auto reconnect on failure with a 5 second wait between retries. Another benefit is this prevents parsing the Root CAs for every login attempt as we only need to do it once per connection.

3 files changed, 236 insertions, 145 deletions

diff --git a/lib/pleroma/application.ex b/lib/pleroma/application.ex
index cb15dc1e9..3f199c002 100644
--- a/lib/pleroma/application.ex
+++ b/lib/pleroma/application.ex
@@ -94,6 +94,7 @@ defmodule Pleroma.Application do
     children =
       [
         Pleroma.PromEx,
+        Pleroma.LDAP,
         Pleroma.Repo,
         Config.TransferTask,
         Pleroma.Emoji,
diff --git a/lib/pleroma/ldap.ex b/lib/pleroma/ldap.ex
new file mode 100644
index 000000000..868932501
--- /dev/null
+++ b/lib/pleroma/ldap.ex
@@ -0,0 +1,233 @@
+defmodule Pleroma.LDAP do
+  use GenServer
+
+  require Logger
+
+  alias Pleroma.Config
+  alias Pleroma.User
+
+  import Pleroma.Web.Auth.Helpers, only: [fetch_user: 1]
+
+  @connection_timeout 10_000
+  @search_timeout 10_000
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+  @impl true
+  def init(state) do
+    case {Config.get(Pleroma.Web.Auth.Authenticator), Config.get([:ldap, :enabled])} do
+      {Pleroma.Web.Auth.LDAPAuthenticator, true} ->
+        {:ok, state, {:continue, :connect}}
+
+      {Pleroma.Web.Auth.LDAPAuthenticator, false} ->
+        Logger.error(
+          "LDAP Authenticator enabled but :pleroma, :ldap is not enabled. Auth will not work."
+        )
+
+        {:ok, state}
+
+      {_, true} ->
+        Logger.warning(
+          ":pleroma, :ldap is enabled but Pleroma.Web.Authenticator is not set to the LDAPAuthenticator. LDAP will not be used."
+        )
+
+        {:ok, state}
+    end
+  end
+
+  @impl true
+  def handle_continue(:connect, _state), do: do_handle_connect()
+
+  @impl true
+  def handle_info(:connect, _state), do: do_handle_connect()
+
+  def handle_info({:bind_after_reconnect, name, password, from}, state) do
+    result = bind_user(state[:connection], name, password)
+
+    GenServer.reply(from, result)
+
+    {:noreply, state}
+  end
+
+  defp do_handle_connect() do
+    state =
+      case connect() do
+        {:ok, connection} ->
+          :eldap.controlling_process(connection, self())
+          [connection: connection]
+
+        _ ->
+          Logger.error("Failed to connect to LDAP. Retrying in 5000ms")
+          Process.send_after(self(), :connect, 5_000)
+          []
+      end
+
+    {:noreply, state}
+  end
+
+  @impl true
+  def handle_call({:bind_user, name, password}, from, state) do
+    case bind_user(state[:connection], name, password) do
+      :needs_reconnect ->
+        Process.send(self(), {:bind_after_reconnect, name, password, from}, [])
+        {:noreply, state, {:continue, :connect}}
+
+      result ->
+        {:reply, result, state, :hibernate}
+    end
+  end
+
+  @impl true
+  def terminate(_, state) do
+    :eldap.close(state[:connection])
+
+    :ok
+  end
+
+  defp connect() do
+    ldap = Config.get(:ldap, [])
+    host = Keyword.get(ldap, :host, "localhost")
+    port = Keyword.get(ldap, :port, 389)
+    ssl = Keyword.get(ldap, :ssl, false)
+    tls = Keyword.get(ldap, :tls, false)
+    cacertfile = Keyword.get(ldap, :cacertfile) || CAStore.file_path()
+
+    default_secure_opts = [
+      verify: :verify_peer,
+      cacerts: decode_certfile(cacertfile),
+      customize_hostname_check: [
+        fqdn_fun: fn _ -> to_charlist(host) end
+      ]
+    ]
+
+    sslopts = Keyword.merge(default_secure_opts, Keyword.get(ldap, :sslopts, []))
+    tlsopts = Keyword.merge(default_secure_opts, Keyword.get(ldap, :tlsopts, []))
+
+    default_options = [{:port, port}, {:ssl, ssl}, {:timeout, @connection_timeout}]
+
+    # :sslopts can only be included in :eldap.open/2 when {ssl: true}
+    # or the connection will fail
+    options =
+      if ssl do
+        default_options ++ [{:sslopts, sslopts}]
+      else
+        default_options
+      end
+
+    case :eldap.open([to_charlist(host)], options) do
+      {:ok, connection} ->
+        try do
+          cond do
+            ssl ->
+              :application.ensure_all_started(:ssl)
+              {:ok, connection}
+
+            tls ->
+              case :eldap.start_tls(
+                     connection,
+                     tlsopts,
+                     @connection_timeout
+                   ) do
+                :ok ->
+                  {:ok, connection}
+
+                error ->
+                  Logger.error("Could not start TLS: #{inspect(error)}")
+                  :eldap.close(connection)
+              end
+
+            true ->
+              {:ok, :connection}
+          end
+        after
+          :ok
+        end
+
+      {:error, error} ->
+        Logger.error("Could not open LDAP connection: #{inspect(error)}")
+        {:error, {:ldap_connection_error, error}}
+    end
+  end
+
+  defp bind_user(connection, name, password) do
+    uid = Config.get([:ldap, :uid], "cn")
+    base = Config.get([:ldap, :base])
+
+    case :eldap.simple_bind(connection, "#{uid}=#{name},#{base}", password) do
+      :ok ->
+        case fetch_user(name) do
+          %User{} = user ->
+            user
+
+          _ ->
+            register_user(connection, base, uid, name)
+        end
+
+      # eldap does not inform us of socket closure
+      # until it is used
+      {:error, {:gen_tcp_error, :closed}} ->
+        :eldap.close(connection)
+        :needs_reconnect
+
+      error ->
+        Logger.error("Could not bind LDAP user #{name}: #{inspect(error)}")
+        {:error, {:ldap_bind_error, error}}
+    end
+  end
+
+  defp register_user(connection, base, uid, name) do
+    case :eldap.search(connection, [
+           {:base, to_charlist(base)},
+           {:filter, :eldap.equalityMatch(to_charlist(uid), to_charlist(name))},
+           {:scope, :eldap.wholeSubtree()},
+           {:timeout, @search_timeout}
+         ]) do
+      # The :eldap_search_result record structure changed in OTP 24.3 and added a controls field
+      # https://github.com/erlang/otp/pull/5538
+      {:ok, {:eldap_search_result, [{:eldap_entry, _object, attributes}], _referrals}} ->
+        try_register(name, attributes)
+
+      {:ok, {:eldap_search_result, [{:eldap_entry, _object, attributes}], _referrals, _controls}} ->
+        try_register(name, attributes)
+
+      error ->
+        Logger.error("Couldn't register user because LDAP search failed: #{inspect(error)}")
+        {:error, {:ldap_search_error, error}}
+    end
+  end
+
+  defp try_register(name, attributes) do
+    params = %{
+      name: name,
+      nickname: name,
+      password: nil
+    }
+
+    params =
+      case List.keyfind(attributes, ~c"mail", 0) do
+        {_, [mail]} -> Map.put_new(params, :email, :erlang.list_to_binary(mail))
+        _ -> params
+      end
+
+    changeset = User.register_changeset_ldap(%User{}, params)
+
+    case User.register(changeset) do
+      {:ok, user} -> user
+      error -> error
+    end
+  end
+
+  defp decode_certfile(file) do
+    with {:ok, data} <- File.read(file) do
+      data
+      |> :public_key.pem_decode()
+      |> Enum.map(fn {_, b, _} -> b end)
+    else
+      _ ->
+        Logger.error("Unable to read certfile: #{file}")
+        []
+    end
+  end
+end
diff --git a/lib/pleroma/web/auth/ldap_authenticator.ex b/lib/pleroma/web/auth/ldap_authenticator.ex
index ad5bc9863..c420c8bc3 100644
--- a/lib/pleroma/web/auth/ldap_authenticator.ex
+++ b/lib/pleroma/web/auth/ldap_authenticator.ex
@@ -5,16 +5,11 @@
 defmodule Pleroma.Web.Auth.LDAPAuthenticator do
   alias Pleroma.User
 
-  require Logger
-
-  import Pleroma.Web.Auth.Helpers, only: [fetch_credentials: 1, fetch_user: 1]
+  import Pleroma.Web.Auth.Helpers, only: [fetch_credentials: 1]
 
   @behaviour Pleroma.Web.Auth.Authenticator
   @base Pleroma.Web.Auth.PleromaAuthenticator
 
-  @connection_timeout 10_000
-  @search_timeout 10_000
-
   defdelegate get_registration(conn), to: @base
   defdelegate create_from_registration(conn, registration), to: @base
   defdelegate handle_error(conn, error), to: @base
@@ -24,7 +19,7 @@ defmodule Pleroma.Web.Auth.LDAPAuthenticator do
   def get_user(%Plug.Conn{} = conn) do
     with {:ldap, true} <- {:ldap, Pleroma.Config.get([:ldap, :enabled])},
          {:ok, {name, password}} <- fetch_credentials(conn),
-         %User{} = user <- ldap_user(name, password) do
+         %User{} = user <- GenServer.call(Pleroma.LDAP, {:bind_user, name, password}) do
       {:ok, user}
     else
       {:ldap, _} ->
@@ -34,142 +29,4 @@ defmodule Pleroma.Web.Auth.LDAPAuthenticator do
         error
     end
   end
-
-  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)
-    tls = Keyword.get(ldap, :tls, false)
-    cacertfile = Keyword.get(ldap, :cacertfile) || CAStore.file_path()
-
-    default_secure_opts = [
-      verify: :verify_peer,
-      cacerts: decode_certfile(cacertfile),
-      customize_hostname_check: [
-        fqdn_fun: fn _ -> to_charlist(host) end
-      ]
-    ]
-
-    sslopts = Keyword.merge(default_secure_opts, Keyword.get(ldap, :sslopts, []))
-    tlsopts = Keyword.merge(default_secure_opts, Keyword.get(ldap, :tlsopts, []))
-
-    # :sslopts can only be included in :eldap.open/2 when {ssl: true}
-    # or the connection will fail
-    options =
-      if ssl do
-        [{:port, port}, {:ssl, ssl}, {:sslopts, sslopts}, {:timeout, @connection_timeout}]
-      else
-        [{:port, port}, {:ssl, ssl}, {:timeout, @connection_timeout}]
-      end
-
-    case :eldap.open([to_charlist(host)], options) do
-      {:ok, connection} ->
-        try do
-          cond do
-            ssl ->
-              :application.ensure_all_started(:ssl)
-
-            tls ->
-              case :eldap.start_tls(
-                     connection,
-                     tlsopts,
-                     @connection_timeout
-                   ) do
-                :ok ->
-                  :ok
-
-                error ->
-                  Logger.error("Could not start TLS: #{inspect(error)}")
-                  :eldap.close(connection)
-              end
-
-            true ->
-              :ok
-          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 fetch_user(name) do
-          %User{} = user ->
-            user
-
-          _ ->
-            register_user(connection, base, uid, name)
-        end
-
-      error ->
-        Logger.error("Could not bind LDAP user #{name}: #{inspect(error)}")
-        {:error, {:ldap_bind_error, error}}
-    end
-  end
-
-  defp register_user(connection, base, uid, name) do
-    case :eldap.search(connection, [
-           {:base, to_charlist(base)},
-           {:filter, :eldap.equalityMatch(to_charlist(uid), to_charlist(name))},
-           {:scope, :eldap.wholeSubtree()},
-           {:timeout, @search_timeout}
-         ]) do
-      # The :eldap_search_result record structure changed in OTP 24.3 and added a controls field
-      # https://github.com/erlang/otp/pull/5538
-      {:ok, {:eldap_search_result, [{:eldap_entry, _object, attributes}], _referrals}} ->
-        try_register(name, attributes)
-
-      {:ok, {:eldap_search_result, [{:eldap_entry, _object, attributes}], _referrals, _controls}} ->
-        try_register(name, attributes)
-
-      error ->
-        Logger.error("Couldn't register user because LDAP search failed: #{inspect(error)}")
-        {:error, {:ldap_search_error, error}}
-    end
-  end
-
-  defp try_register(name, attributes) do
-    params = %{
-      name: name,
-      nickname: name,
-      password: nil
-    }
-
-    params =
-      case List.keyfind(attributes, ~c"mail", 0) do
-        {_, [mail]} -> Map.put_new(params, :email, :erlang.list_to_binary(mail))
-        _ -> params
-      end
-
-    changeset = User.register_changeset_ldap(%User{}, params)
-
-    case User.register(changeset) do
-      {:ok, user} -> user
-      error -> error
-    end
-  end
-
-  defp decode_certfile(file) do
-    with {:ok, data} <- File.read(file) do
-      data
-      |> :public_key.pem_decode()
-      |> Enum.map(fn {_, b, _} -> b end)
-    else
-      _ ->
-        Logger.error("Unable to read certfile: #{file}")
-        []
-    end
-  end
 end