diff --git a/lib/pleroma/web/auth/authenticator.ex b/lib/pleroma/web/auth/authenticator.ex
index 89d88af32..b02f595dc 100644
--- a/lib/pleroma/web/auth/authenticator.ex
+++ b/lib/pleroma/web/auth/authenticator.ex
@@ -13,21 +13,21 @@ def implementation do
     )
   end
 
-  @callback get_user(Plug.Conn.t(), Map.t()) :: {:ok, User.t()} | {:error, any()}
-  def get_user(plug, params), do: implementation().get_user(plug, params)
+  @callback get_user(Plug.Conn.t()) :: {:ok, User.t()} | {:error, any()}
+  def get_user(plug), do: implementation().get_user(plug)
 
-  @callback create_from_registration(Plug.Conn.t(), Map.t(), Registration.t()) ::
+  @callback create_from_registration(Plug.Conn.t(), Registration.t()) ::
               {:ok, User.t()} | {:error, any()}
-  def create_from_registration(plug, params, registration),
-    do: implementation().create_from_registration(plug, params, registration)
+  def create_from_registration(plug, registration),
+    do: implementation().create_from_registration(plug, registration)
 
-  @callback get_registration(Plug.Conn.t(), Map.t()) ::
+  @callback get_registration(Plug.Conn.t()) ::
               {:ok, Registration.t()} | {:error, any()}
-  def get_registration(plug, params),
-    do: implementation().get_registration(plug, params)
+  def get_registration(plug), do: implementation().get_registration(plug)
 
   @callback handle_error(Plug.Conn.t(), any()) :: any()
-  def handle_error(plug, error), do: implementation().handle_error(plug, error)
+  def handle_error(plug, error),
+    do: implementation().handle_error(plug, error)
 
   @callback auth_template() :: String.t() | nil
   def auth_template do
diff --git a/lib/pleroma/web/auth/ldap_authenticator.ex b/lib/pleroma/web/auth/ldap_authenticator.ex
index 8b6d5a77f..363c99597 100644
--- a/lib/pleroma/web/auth/ldap_authenticator.ex
+++ b/lib/pleroma/web/auth/ldap_authenticator.ex
@@ -13,14 +13,16 @@ defmodule Pleroma.Web.Auth.LDAPAuthenticator do
   @connection_timeout 10_000
   @search_timeout 10_000
 
-  defdelegate get_registration(conn, params), to: @base
+  defdelegate get_registration(conn), to: @base
+  defdelegate create_from_registration(conn, registration), to: @base
+  defdelegate handle_error(conn, error), to: @base
+  defdelegate auth_template, to: @base
+  defdelegate oauth_consumer_template, to: @base
 
-  defdelegate create_from_registration(conn, params, registration), to: @base
-
-  def get_user(%Plug.Conn{} = conn, params) do
+  def get_user(%Plug.Conn{} = conn) do
     if Pleroma.Config.get([:ldap, :enabled]) do
       {name, password} =
-        case params do
+        case conn.params do
           %{"authorization" => %{"name" => name, "password" => password}} ->
             {name, password}
 
@@ -34,25 +36,17 @@ def get_user(%Plug.Conn{} = conn, params) do
 
         {:error, {:ldap_connection_error, _}} ->
           # When LDAP is unavailable, try default authenticator
-          @base.get_user(conn, params)
+          @base.get_user(conn)
 
         error ->
           error
       end
     else
       # Fall back to default authenticator
-      @base.get_user(conn, params)
+      @base.get_user(conn)
     end
   end
 
-  def handle_error(%Plug.Conn{} = _conn, error) do
-    error
-  end
-
-  def auth_template, do: nil
-
-  def oauth_consumer_template, do: nil
-
   defp ldap_user(name, password) do
     ldap = Pleroma.Config.get(:ldap, [])
     host = Keyword.get(ldap, :host, "localhost")
diff --git a/lib/pleroma/web/auth/pleroma_authenticator.ex b/lib/pleroma/web/auth/pleroma_authenticator.ex
index c826adb4c..d647f1e05 100644
--- a/lib/pleroma/web/auth/pleroma_authenticator.ex
+++ b/lib/pleroma/web/auth/pleroma_authenticator.ex
@@ -10,9 +10,9 @@ defmodule Pleroma.Web.Auth.PleromaAuthenticator do
 
   @behaviour Pleroma.Web.Auth.Authenticator
 
-  def get_user(%Plug.Conn{} = _conn, params) do
+  def get_user(%Plug.Conn{} = conn) do
     {name, password} =
-      case params do
+      case conn.params do
         %{"authorization" => %{"name" => name, "password" => password}} ->
           {name, password}
 
@@ -29,10 +29,9 @@ def get_user(%Plug.Conn{} = _conn, params) do
     end
   end
 
-  def get_registration(
-        %Plug.Conn{assigns: %{ueberauth_auth: %{provider: provider, uid: uid} = auth}},
-        _params
-      ) do
+  def get_registration(%Plug.Conn{
+        assigns: %{ueberauth_auth: %{provider: provider, uid: uid} = auth}
+      }) do
     registration = Registration.get_by_provider_uid(provider, uid)
 
     if registration do
@@ -40,7 +39,8 @@ def get_registration(
     else
       info = auth.info
 
-      Registration.changeset(%Registration{}, %{
+      %Registration{}
+      |> Registration.changeset(%{
         provider: to_string(provider),
         uid: to_string(uid),
         info: %{
@@ -54,13 +54,16 @@ def get_registration(
     end
   end
 
-  def get_registration(%Plug.Conn{} = _conn, _params), do: {:error, :missing_credentials}
+  def get_registration(%Plug.Conn{} = _conn), do: {:error, :missing_credentials}
 
-  def create_from_registration(_conn, params, registration) do
-    nickname = value([params["nickname"], Registration.nickname(registration)])
-    email = value([params["email"], Registration.email(registration)])
-    name = value([params["name"], Registration.name(registration)]) || nickname
-    bio = value([params["bio"], Registration.description(registration)])
+  def create_from_registration(
+        %Plug.Conn{params: %{"authorization" => registration_attrs}},
+        registration
+      ) do
+    nickname = value([registration_attrs["nickname"], Registration.nickname(registration)])
+    email = value([registration_attrs["email"], Registration.email(registration)])
+    name = value([registration_attrs["name"], Registration.name(registration)]) || nickname
+    bio = value([registration_attrs["bio"], Registration.description(registration)])
 
     random_password = :crypto.strong_rand_bytes(64) |> Base.encode64()
 
diff --git a/lib/pleroma/web/oauth/fallback_controller.ex b/lib/pleroma/web/oauth/fallback_controller.ex
index afaa00242..e3984f009 100644
--- a/lib/pleroma/web/oauth/fallback_controller.ex
+++ b/lib/pleroma/web/oauth/fallback_controller.ex
@@ -24,6 +24,6 @@ def call(conn, _error) do
     conn
     |> put_status(:unauthorized)
     |> put_flash(:error, "Invalid Username/Password")
-    |> OAuthController.authorize(conn.params["authorization"])
+    |> OAuthController.authorize(conn.params)
   end
 end
diff --git a/lib/pleroma/web/oauth/oauth_controller.ex b/lib/pleroma/web/oauth/oauth_controller.ex
index bee7084ad..8e5a83466 100644
--- a/lib/pleroma/web/oauth/oauth_controller.ex
+++ b/lib/pleroma/web/oauth/oauth_controller.ex
@@ -44,36 +44,40 @@ def authorize(%{assigns: %{token: %Token{} = token}} = conn, params) do
 
   def authorize(conn, params), do: do_authorize(conn, params)
 
-  defp do_authorize(conn, params) do
-    app = Repo.get_by(App, client_id: params["client_id"])
+  defp do_authorize(conn, %{"authorization" => auth_attrs}) do
+    app = Repo.get_by(App, client_id: auth_attrs["client_id"])
     available_scopes = (app && app.scopes) || []
-    scopes = oauth_scopes(params, nil) || available_scopes
+    scopes = oauth_scopes(auth_attrs, nil) || available_scopes
 
     render(conn, Authenticator.auth_template(), %{
-      response_type: params["response_type"],
-      client_id: params["client_id"],
+      response_type: auth_attrs["response_type"],
+      client_id: auth_attrs["client_id"],
       available_scopes: available_scopes,
       scopes: scopes,
-      redirect_uri: params["redirect_uri"],
-      state: params["state"],
-      params: params
+      redirect_uri: auth_attrs["redirect_uri"],
+      state: auth_attrs["state"],
+      params: auth_attrs
     })
   end
 
+  defp do_authorize(conn, auth_attrs), do: do_authorize(conn, %{"authorization" => auth_attrs})
+
   def create_authorization(
         conn,
-        %{"authorization" => auth_params} = params,
+        %{"authorization" => _} = params,
         opts \\ []
       ) do
     with {:ok, auth} <- do_create_authorization(conn, params, opts[:user]) do
-      after_create_authorization(conn, auth, auth_params)
+      after_create_authorization(conn, auth, params)
     else
       error ->
-        handle_create_authorization_error(conn, error, auth_params)
+        handle_create_authorization_error(conn, error, params)
     end
   end
 
-  def after_create_authorization(conn, auth, %{"redirect_uri" => redirect_uri} = auth_params) do
+  def after_create_authorization(conn, auth, %{
+        "authorization" => %{"redirect_uri" => redirect_uri} = auth_attrs
+      }) do
     redirect_uri = redirect_uri(conn, redirect_uri)
 
     if redirect_uri == "urn:ietf:wg:oauth:2.0:oob" do
@@ -86,8 +90,8 @@ def after_create_authorization(conn, auth, %{"redirect_uri" => redirect_uri} = a
       url_params = %{:code => auth.token}
 
       url_params =
-        if auth_params["state"] do
-          Map.put(url_params, :state, auth_params["state"])
+        if auth_attrs["state"] do
+          Map.put(url_params, :state, auth_attrs["state"])
         else
           url_params
         end
@@ -98,26 +102,34 @@ def after_create_authorization(conn, auth, %{"redirect_uri" => redirect_uri} = a
     end
   end
 
-  defp handle_create_authorization_error(conn, {scopes_issue, _}, auth_params)
+  defp handle_create_authorization_error(
+         conn,
+         {scopes_issue, _},
+         %{"authorization" => _} = params
+       )
        when scopes_issue in [:unsupported_scopes, :missing_scopes] do
     # Per https://github.com/tootsuite/mastodon/blob/
     #   51e154f5e87968d6bb115e053689767ab33e80cd/app/controllers/api/base_controller.rb#L39
     conn
     |> put_flash(:error, "This action is outside the authorized scopes")
     |> put_status(:unauthorized)
-    |> authorize(auth_params)
+    |> authorize(params)
   end
 
-  defp handle_create_authorization_error(conn, {:auth_active, false}, auth_params) do
+  defp handle_create_authorization_error(
+         conn,
+         {:auth_active, false},
+         %{"authorization" => _} = params
+       ) do
     # Per https://github.com/tootsuite/mastodon/blob/
     #   51e154f5e87968d6bb115e053689767ab33e80cd/app/controllers/api/base_controller.rb#L76
     conn
     |> put_flash(:error, "Your login is missing a confirmed e-mail address")
     |> put_status(:forbidden)
-    |> authorize(auth_params)
+    |> authorize(params)
   end
 
-  defp handle_create_authorization_error(conn, error, _auth_params) do
+  defp handle_create_authorization_error(conn, error, %{"authorization" => _}) do
     Authenticator.handle_error(conn, error)
   end
 
@@ -151,7 +163,7 @@ def token_exchange(
         conn,
         %{"grant_type" => "password"} = params
       ) do
-    with {_, {:ok, %User{} = user}} <- {:get_user, Authenticator.get_user(conn, params)},
+    with {_, {:ok, %User{} = user}} <- {:get_user, Authenticator.get_user(conn)},
          %App{} = app <- get_app_from_request(conn, params),
          {:auth_active, true} <- {:auth_active, User.auth_active?(user)},
          {:user_active, true} <- {:user_active, !user.info.deactivated},
@@ -214,19 +226,19 @@ def token_revoke(conn, %{"token" => token} = params) do
   end
 
   @doc "Prepares OAuth request to provider for Ueberauth"
-  def prepare_request(conn, %{"provider" => provider} = params) do
+  def prepare_request(conn, %{"provider" => provider, "authorization" => auth_attrs}) do
     scope =
-      oauth_scopes(params, [])
+      oauth_scopes(auth_attrs, [])
       |> Enum.join(" ")
 
     state =
-      params
+      auth_attrs
       |> Map.delete("scopes")
       |> Map.put("scope", scope)
       |> Poison.encode!()
 
     params =
-      params
+      auth_attrs
       |> Map.drop(~w(scope scopes client_id redirect_uri))
       |> Map.put("state", state)
 
@@ -260,26 +272,26 @@ def callback(%{assigns: %{ueberauth_failure: failure}} = conn, params) do
   def callback(conn, params) do
     params = callback_params(params)
 
-    with {:ok, registration} <- Authenticator.get_registration(conn, params) do
+    with {:ok, registration} <- Authenticator.get_registration(conn) do
       user = Repo.preload(registration, :user).user
-      auth_params = Map.take(params, ~w(client_id redirect_uri scope scopes state))
+      auth_attrs = Map.take(params, ~w(client_id redirect_uri scope scopes state))
 
       if user do
         create_authorization(
           conn,
-          %{"authorization" => auth_params},
+          %{"authorization" => auth_attrs},
           user: user
         )
       else
         registration_params =
-          Map.merge(auth_params, %{
+          Map.merge(auth_attrs, %{
             "nickname" => Registration.nickname(registration),
             "email" => Registration.email(registration)
           })
 
         conn
         |> put_session(:registration_id, registration.id)
-        |> registration_details(registration_params)
+        |> registration_details(%{"authorization" => registration_params})
       end
     else
       _ ->
@@ -293,53 +305,44 @@ defp callback_params(%{"state" => state} = params) do
     Map.merge(params, Poison.decode!(state))
   end
 
-  def registration_details(conn, params) do
+  def registration_details(conn, %{"authorization" => auth_attrs}) do
     render(conn, "register.html", %{
-      client_id: params["client_id"],
-      redirect_uri: params["redirect_uri"],
-      state: params["state"],
-      scopes: oauth_scopes(params, []),
-      nickname: params["nickname"],
-      email: params["email"]
+      client_id: auth_attrs["client_id"],
+      redirect_uri: auth_attrs["redirect_uri"],
+      state: auth_attrs["state"],
+      scopes: oauth_scopes(auth_attrs, []),
+      nickname: auth_attrs["nickname"],
+      email: auth_attrs["email"]
     })
   end
 
-  def register(conn, %{"op" => "connect"} = params) do
-    authorization_params = Map.put(params, "name", params["auth_name"])
-    create_authorization_params = %{"authorization" => authorization_params}
-
+  def register(conn, %{"authorization" => _, "op" => "connect"} = params) do
     with registration_id when not is_nil(registration_id) <- get_session_registration_id(conn),
          %Registration{} = registration <- Repo.get(Registration, registration_id),
          {_, {:ok, auth}} <-
-           {:create_authorization, do_create_authorization(conn, create_authorization_params)},
+           {:create_authorization, do_create_authorization(conn, params)},
          %User{} = user <- Repo.preload(auth, :user).user,
          {:ok, _updated_registration} <- Registration.bind_to_user(registration, user) do
       conn
       |> put_session_registration_id(nil)
-      |> after_create_authorization(auth, authorization_params)
+      |> after_create_authorization(auth, params)
     else
       {:create_authorization, error} ->
-        {:register, handle_create_authorization_error(conn, error, create_authorization_params)}
+        {:register, handle_create_authorization_error(conn, error, params)}
 
       _ ->
         {:register, :generic_error}
     end
   end
 
-  def register(conn, %{"op" => "register"} = params) do
+  def register(conn, %{"authorization" => _, "op" => "register"} = params) do
     with registration_id when not is_nil(registration_id) <- get_session_registration_id(conn),
          %Registration{} = registration <- Repo.get(Registration, registration_id),
-         {:ok, user} <- Authenticator.create_from_registration(conn, params, registration) do
+         {:ok, user} <- Authenticator.create_from_registration(conn, registration) do
       conn
       |> put_session_registration_id(nil)
       |> create_authorization(
-        %{
-          "authorization" => %{
-            "client_id" => params["client_id"],
-            "redirect_uri" => params["redirect_uri"],
-            "scopes" => oauth_scopes(params, nil)
-          }
-        },
+        params,
         user: user
       )
     else
@@ -374,15 +377,15 @@ defp do_create_authorization(
              %{
                "client_id" => client_id,
                "redirect_uri" => redirect_uri
-             } = auth_params
-         } = params,
+             } = auth_attrs
+         },
          user \\ nil
        ) do
     with {_, {:ok, %User{} = user}} <-
-           {:get_user, (user && {:ok, user}) || Authenticator.get_user(conn, params)},
+           {:get_user, (user && {:ok, user}) || Authenticator.get_user(conn)},
          %App{} = app <- Repo.get_by(App, client_id: client_id),
          true <- redirect_uri in String.split(app.redirect_uris),
-         scopes <- oauth_scopes(auth_params, []),
+         scopes <- oauth_scopes(auth_attrs, []),
          {:unsupported_scopes, []} <- {:unsupported_scopes, scopes -- app.scopes},
          # Note: `scope` param is intentionally not optional in this context
          {:missing_scopes, false} <- {:missing_scopes, scopes == []},
diff --git a/lib/pleroma/web/templates/o_auth/o_auth/_scopes.html.eex b/lib/pleroma/web/templates/o_auth/o_auth/_scopes.html.eex
index 4b8fb5dae..e6cfe108b 100644
--- a/lib/pleroma/web/templates/o_auth/o_auth/_scopes.html.eex
+++ b/lib/pleroma/web/templates/o_auth/o_auth/_scopes.html.eex
@@ -5,7 +5,7 @@
     <%= for scope <- @available_scopes do %>
       <%# Note: using hidden input with `unchecked_value` in order to distinguish user's empty selection from `scope` param being omitted %>
       <div class="scope">
-        <%= checkbox @form, :"scope_#{scope}", value: scope in @scopes && scope, checked_value: scope, unchecked_value: "", name: assigns[:scope_param] || "scope[]" %>
+        <%= checkbox @form, :"scope_#{scope}", value: scope in @scopes && scope, checked_value: scope, unchecked_value: "", name: "authorization[scope][]" %>
         <%= label @form, :"scope_#{scope}", String.capitalize(scope) %>
       </div>
     <% end %>
diff --git a/lib/pleroma/web/templates/o_auth/o_auth/consumer.html.eex b/lib/pleroma/web/templates/o_auth/o_auth/consumer.html.eex
index 85f62ca64..4bcda7300 100644
--- a/lib/pleroma/web/templates/o_auth/o_auth/consumer.html.eex
+++ b/lib/pleroma/web/templates/o_auth/o_auth/consumer.html.eex
@@ -1,6 +1,6 @@
 <h2>Sign in with external provider</h2>
 
-<%= form_for @conn, o_auth_path(@conn, :prepare_request), [method: "get"], fn f -> %>
+<%= form_for @conn, o_auth_path(@conn, :prepare_request), [as: "authorization", method: "get"], fn f -> %>
   <%= render @view_module, "_scopes.html", Map.put(assigns, :form, f) %>
 
   <%= hidden_input f, :client_id, value: @client_id %>
diff --git a/lib/pleroma/web/templates/o_auth/o_auth/register.html.eex b/lib/pleroma/web/templates/o_auth/o_auth/register.html.eex
index 126390391..facedc8db 100644
--- a/lib/pleroma/web/templates/o_auth/o_auth/register.html.eex
+++ b/lib/pleroma/web/templates/o_auth/o_auth/register.html.eex
@@ -8,8 +8,7 @@
 <h2>Registration Details</h2>
 
 <p>If you'd like to register a new account, please provide the details below.</p>
-
-<%= form_for @conn, o_auth_path(@conn, :register), [], fn f -> %>
+<%= form_for @conn, o_auth_path(@conn, :register), [as: "authorization"], fn f -> %>
 
 <div class="input">
   <%= label f, :nickname, "Nickname" %>
@@ -25,8 +24,8 @@
 <p>Alternatively, sign in to connect to existing account.</p>
 
 <div class="input">
-  <%= label f, :auth_name, "Name or email" %>
-  <%= text_input f, :auth_name %>
+  <%= label f, :name, "Name or email" %>
+  <%= text_input f, :name %>
 </div>
 <div class="input">
   <%= label f, :password, "Password" %>
diff --git a/lib/pleroma/web/templates/o_auth/o_auth/show.html.eex b/lib/pleroma/web/templates/o_auth/o_auth/show.html.eex
index 87278e636..3e360a52c 100644
--- a/lib/pleroma/web/templates/o_auth/o_auth/show.html.eex
+++ b/lib/pleroma/web/templates/o_auth/o_auth/show.html.eex
@@ -17,7 +17,7 @@
   <%= password_input f, :password %>
 </div>
 
-<%= render @view_module, "_scopes.html", Map.merge(assigns, %{form: f, scope_param: "authorization[scope][]"}) %>
+<%= render @view_module, "_scopes.html", Map.merge(assigns, %{form: f}) %>
 
 <%= hidden_input f, :client_id, value: @client_id %>
 <%= hidden_input f, :response_type, value: @response_type %>
diff --git a/test/web/oauth/oauth_controller_test.exs b/test/web/oauth/oauth_controller_test.exs
index ac7843f9b..fb505fab3 100644
--- a/test/web/oauth/oauth_controller_test.exs
+++ b/test/web/oauth/oauth_controller_test.exs
@@ -68,10 +68,12 @@ test "GET /oauth/prepare_request encodes parameters as `state` and redirects", %
           "/oauth/prepare_request",
           %{
             "provider" => "twitter",
-            "scope" => "read follow",
-            "client_id" => app.client_id,
-            "redirect_uri" => app.redirect_uris,
-            "state" => "a_state"
+            "authorization" => %{
+              "scope" => "read follow",
+              "client_id" => app.client_id,
+              "redirect_uri" => app.redirect_uris,
+              "state" => "a_state"
+            }
           }
         )
 
@@ -104,7 +106,7 @@ test "with user-bound registration, GET /oauth/<provider>/callback redirects to
       }
 
       with_mock Pleroma.Web.Auth.Authenticator,
-        get_registration: fn _, _ -> {:ok, registration} end do
+        get_registration: fn _ -> {:ok, registration} end do
         conn =
           get(
             conn,
@@ -134,7 +136,7 @@ test "with user-unbound registration, GET /oauth/<provider>/callback renders reg
       }
 
       with_mock Pleroma.Web.Auth.Authenticator,
-        get_registration: fn _, _ -> {:ok, registration} end do
+        get_registration: fn _ -> {:ok, registration} end do
         conn =
           get(
             conn,
@@ -193,12 +195,14 @@ test "GET /oauth/registration_details renders registration details form", %{
           conn,
           "/oauth/registration_details",
           %{
-            "scopes" => app.scopes,
-            "client_id" => app.client_id,
-            "redirect_uri" => app.redirect_uris,
-            "state" => "a_state",
-            "nickname" => nil,
-            "email" => "john@doe.com"
+            "authorization" => %{
+              "scopes" => app.scopes,
+              "client_id" => app.client_id,
+              "redirect_uri" => app.redirect_uris,
+              "state" => "a_state",
+              "nickname" => nil,
+              "email" => "john@doe.com"
+            }
           }
         )
 
@@ -221,12 +225,14 @@ test "with valid params, POST /oauth/register?op=register redirects to `redirect
           "/oauth/register",
           %{
             "op" => "register",
-            "scopes" => app.scopes,
-            "client_id" => app.client_id,
-            "redirect_uri" => app.redirect_uris,
-            "state" => "a_state",
-            "nickname" => "availablenick",
-            "email" => "available@email.com"
+            "authorization" => %{
+              "scopes" => app.scopes,
+              "client_id" => app.client_id,
+              "redirect_uri" => app.redirect_uris,
+              "state" => "a_state",
+              "nickname" => "availablenick",
+              "email" => "available@email.com"
+            }
           }
         )
 
@@ -244,17 +250,23 @@ test "with invalid params, POST /oauth/register?op=register renders registration
 
       params = %{
         "op" => "register",
-        "scopes" => app.scopes,
-        "client_id" => app.client_id,
-        "redirect_uri" => app.redirect_uris,
-        "state" => "a_state",
-        "nickname" => "availablenickname",
-        "email" => "available@email.com"
+        "authorization" => %{
+          "scopes" => app.scopes,
+          "client_id" => app.client_id,
+          "redirect_uri" => app.redirect_uris,
+          "state" => "a_state",
+          "nickname" => "availablenickname",
+          "email" => "available@email.com"
+        }
       }
 
       for {bad_param, bad_param_value} <-
             [{"nickname", another_user.nickname}, {"email", another_user.email}] do
-        bad_params = Map.put(params, bad_param, bad_param_value)
+        bad_registration_attrs = %{
+          "authorization" => Map.put(params["authorization"], bad_param, bad_param_value)
+        }
+
+        bad_params = Map.merge(params, bad_registration_attrs)
 
         conn =
           conn
@@ -281,12 +293,14 @@ test "with valid params, POST /oauth/register?op=connect redirects to `redirect_
           "/oauth/register",
           %{
             "op" => "connect",
-            "scopes" => app.scopes,
-            "client_id" => app.client_id,
-            "redirect_uri" => app.redirect_uris,
-            "state" => "a_state",
-            "auth_name" => user.nickname,
-            "password" => "testpassword"
+            "authorization" => %{
+              "scopes" => app.scopes,
+              "client_id" => app.client_id,
+              "redirect_uri" => app.redirect_uris,
+              "state" => "a_state",
+              "name" => user.nickname,
+              "password" => "testpassword"
+            }
           }
         )
 
@@ -304,12 +318,14 @@ test "with invalid params, POST /oauth/register?op=connect renders registration_
 
       params = %{
         "op" => "connect",
-        "scopes" => app.scopes,
-        "client_id" => app.client_id,
-        "redirect_uri" => app.redirect_uris,
-        "state" => "a_state",
-        "auth_name" => user.nickname,
-        "password" => "wrong password"
+        "authorization" => %{
+          "scopes" => app.scopes,
+          "client_id" => app.client_id,
+          "redirect_uri" => app.redirect_uris,
+          "state" => "a_state",
+          "name" => user.nickname,
+          "password" => "wrong password"
+        }
       }
 
       conn =