improvement: allow configuring extra claims for a user

lib/ash_authentication/dsl.ex

@@ -138,6 +138,11 @@ defmodule AshAuthentication.Dsl do
                   "The resource used to store token information, such as in-flight confirmations, revocations, and if `store_all_tokens?` is enabled, authentication tokens themselves.",
                 required: true
               ],
+              extra_claims: [
+                type: {:or, [{:fun, 2}, :map]},
+                doc:
+                  "A function that takes the user and the options provided when generating a token (contains the tenant), and returns a map of extra claims to include in the token."
+              ],
               signing_secret: [
                 type: secret_type,
                 doc: "The secret used to sign tokens.  #{secret_doc}"

lib/ash_authentication/jwt.ex

@@ -110,7 +110,13 @@
     default_claims = Config.default_claims(resource, action_opts)
     signer = Config.token_signer(resource, opts, context)
 
-    with {:ok, token, claims} <- Joken.generate_and_sign(default_claims, extra_claims, signer),
+    with {:ok, more_extra_claims} <- extra_claims_for_user(purpose, user, opts),
+         {:ok, token, claims} <-
+           Joken.generate_and_sign(
+             default_claims,
+             Map.merge(extra_claims, more_extra_claims),
+             signer
+           ),
          :ok <- maybe_store_token(token, resource, user, purpose, action_opts) do
       {:ok, token, claims}
     else
@@ -120,6 +126,22 @@
     end
   end
 
+  defp extra_claims_for_user(:user, user, opts) do
+    case AshAuthentication.Info.authentication_tokens_extra_claims(user) do
+      :error ->
+        %{}
+
+      {:ok, nil} ->
+        %{}
+
+      {:ok, extra_claims} when is_map(extra_claims) ->
+        extra_claims
+
+      {:ok, extra_claims} when is_function(extra_claims) ->
+        extra_claims.(user, opts)
+    end
+  end
+
   @doc """
   Given a resource, generate a signed JWT with a set of claims.
   """

lib/ash_authentication/plug/helpers.ex

@@ -223,6 +223,8 @@ defmodule AshAuthentication.Plug.Helpers do
              ),
            {:ok, subject_name} <- Info.authentication_subject_name(resource),
            current_subject_name <- current_subject_name(subject_name) do
+        user = Ash.Resource.set_metadata(user, %{claims: claims})
+
         conn
         |> Conn.assign(current_subject_name, user)
         |> maybe_assign_token_record(token_record, subject_name)