Fixed OAuth restrictions for :api routes. Made auth info dropped for :api routes if OAuth check was neither performed nor explicitly skipped.

This commit is contained in:
Ivan Tashkinov 2020-04-22 18:50:25 +03:00
parent f685cbd309
commit 2958a7d246
14 changed files with 101 additions and 53 deletions

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@ -4,29 +4,19 @@ This document contains notes and guidelines for Pleroma developers.
## OAuth token-based authentication & authorization
* Pleroma supports hierarchical OAuth scopes, just like Mastodon but with added granularity of admin scopes.
For a reference, see [Mastodon OAuth scopes](https://docs.joinmastodon.org/api/oauth-scopes/).
* Pleroma supports hierarchical OAuth scopes, just like Mastodon but with added granularity of admin scopes. For a reference, see [Mastodon OAuth scopes](https://docs.joinmastodon.org/api/oauth-scopes/).
* It is important to either define OAuth scope restrictions or explicitly mark OAuth scope check as skipped, for every
controller action. To define scopes, call `plug(Pleroma.Plugs.OAuthScopesPlug, %{scopes: [...]})`. To explicitly set
OAuth scopes check skipped, call `plug(:skip_plug, Pleroma.Plugs.OAuthScopesPlug <when ...>)`.
* It is important to either define OAuth scope restrictions or explicitly mark OAuth scope check as skipped, for every controller action. To define scopes, call `plug(Pleroma.Plugs.OAuthScopesPlug, %{scopes: [...]})`. To explicitly set OAuth scopes check skipped, call `plug(:skip_plug, Pleroma.Plugs.OAuthScopesPlug <when ...>)`.
* In controllers, `use Pleroma.Web, :controller` will result in `action/2` (see `Pleroma.Web.controller/0` for definition)
be called prior to actual controller action, and it'll perform security / privacy checks before passing control to
actual controller action. For routes with `:authenticated_api` pipeline, authentication & authorization are expected,
thus `OAuthScopesPlug` will be run unless explicitly skipped (also `EnsureAuthenticatedPlug` will be executed
immediately before action even if there was an early run to give an early error, since `OAuthScopesPlug` supports
`:proceed_unauthenticated` option, and other plugs may support similar options as well). For `:api` pipeline routes,
`EnsurePublicOrAuthenticatedPlug` will be called to ensure that the instance is not private or user is authenticated
(unless explicitly skipped). Such automated checks help to prevent human errors and result in higher security / privacy
for users.
* In controllers, `use Pleroma.Web, :controller` will result in `action/2` (see `Pleroma.Web.controller/0` for definition) be called prior to actual controller action, and it'll perform security / privacy checks before passing control to actual controller action.
For routes with `:authenticated_api` pipeline, authentication & authorization are expected, thus `OAuthScopesPlug` will be run unless explicitly skipped (also `EnsureAuthenticatedPlug` will be executed immediately before action even if there was an early run to give an early error, since `OAuthScopesPlug` supports `:proceed_unauthenticated` option, and other plugs may support similar options as well).
For `:api` pipeline routes, it'll be verified whether `OAuthScopesPlug` was called or explicitly skipped, and if it was not then auth information will be dropped for request. Then `EnsurePublicOrAuthenticatedPlug` will be called to ensure that either the instance is not private or user is authenticated (unless explicitly skipped). Such automated checks help to prevent human errors and result in higher security / privacy for users.
## [HTTP Basic Authentication](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Authorization)
* With HTTP Basic Auth, OAuth scopes check is _not_ performed for any action (since password is provided during the auth,
requester is able to obtain a token with full permissions anyways). `Pleroma.Plugs.AuthenticationPlug` and
`Pleroma.Plugs.LegacyAuthenticationPlug` both call `Pleroma.Plugs.OAuthScopesPlug.skip_plug(conn)` when password
is provided.
* With HTTP Basic Auth, OAuth scopes check is _not_ performed for any action (since password is provided during the auth, requester is able to obtain a token with full permissions anyways). `Pleroma.Plugs.AuthenticationPlug` and `Pleroma.Plugs.LegacyAuthenticationPlug` both call `Pleroma.Plugs.OAuthScopesPlug.skip_plug(conn)` when password is provided.
## Auth-related configuration, OAuth consumer mode etc.

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@ -28,9 +28,7 @@ def perform(%Plug.Conn{assigns: assigns} = conn, %{scopes: scopes} = options) do
conn
options[:fallback] == :proceed_unauthenticated ->
conn
|> assign(:user, nil)
|> assign(:token, nil)
drop_auth_info(conn)
true ->
missing_scopes = scopes -- matched_scopes
@ -46,6 +44,15 @@ def perform(%Plug.Conn{assigns: assigns} = conn, %{scopes: scopes} = options) do
end
end
@doc "Drops authentication info from connection"
def drop_auth_info(conn) do
# To simplify debugging, setting a private variable on `conn` if auth info is dropped
conn
|> put_private(:authentication_ignored, true)
|> assign(:user, nil)
|> assign(:token, nil)
end
@doc "Filters descendants of supported scopes"
def filter_descendants(scopes, supported_scopes) do
Enum.filter(

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@ -37,7 +37,7 @@ defmodule Pleroma.Web.MastodonAPI.AccountController do
plug(
OAuthScopesPlug,
%{fallback: :proceed_unauthenticated, scopes: ["read:accounts"]}
when action in [:show, :endorsements]
when action in [:show, :followers, :following, :endorsements]
)
plug(
@ -49,7 +49,7 @@ defmodule Pleroma.Web.MastodonAPI.AccountController do
plug(
OAuthScopesPlug,
%{scopes: ["read:accounts"]}
when action in [:endorsements, :verify_credentials, :followers, :following]
when action in [:endorsements, :verify_credentials]
)
plug(OAuthScopesPlug, %{scopes: ["write:accounts"]} when action == :update_credentials)

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@ -5,6 +5,7 @@
defmodule Pleroma.Web.MastodonAPI.AppController do
use Pleroma.Web, :controller
alias Pleroma.Plugs.EnsurePublicOrAuthenticatedPlug
alias Pleroma.Plugs.OAuthScopesPlug
alias Pleroma.Repo
alias Pleroma.Web.OAuth.App
@ -13,7 +14,14 @@ defmodule Pleroma.Web.MastodonAPI.AppController do
action_fallback(Pleroma.Web.MastodonAPI.FallbackController)
plug(
:skip_plug,
[OAuthScopesPlug, EnsurePublicOrAuthenticatedPlug]
when action == :create
)
plug(OAuthScopesPlug, %{scopes: ["read"]} when action == :verify_credentials)
plug(OpenApiSpex.Plug.CastAndValidate)
@local_mastodon_name "Mastodon-Local"

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@ -7,6 +7,12 @@ defmodule Pleroma.Web.MastodonAPI.CustomEmojiController do
plug(OpenApiSpex.Plug.CastAndValidate)
plug(
:skip_plug,
[Pleroma.Plugs.OAuthScopesPlug, Pleroma.Plugs.EnsurePublicOrAuthenticatedPlug]
when action == :index
)
defdelegate open_api_operation(action), to: Pleroma.Web.ApiSpec.CustomEmojiOperation
def index(conn, _params) do

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@ -5,6 +5,12 @@
defmodule Pleroma.Web.MastodonAPI.InstanceController do
use Pleroma.Web, :controller
plug(
:skip_plug,
[Pleroma.Plugs.OAuthScopesPlug, Pleroma.Plugs.EnsurePublicOrAuthenticatedPlug]
when action in [:show, :peers]
)
@doc "GET /api/v1/instance"
def show(conn, _params) do
render(conn, "show.json")

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@ -15,7 +15,11 @@ defmodule Pleroma.Web.MastodonAPI.MastodonAPIController do
require Logger
plug(:skip_plug, Pleroma.Plugs.OAuthScopesPlug when action in [:empty_array, :empty_object])
plug(
:skip_plug,
[Pleroma.Plugs.OAuthScopesPlug, Pleroma.Plugs.EnsurePublicOrAuthenticatedPlug]
when action in [:empty_array, :empty_object]
)
action_fallback(Pleroma.Web.MastodonAPI.FallbackController)

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@ -21,6 +21,8 @@ defmodule Pleroma.Web.MastodonAPI.SearchController do
# Note: Mastodon doesn't allow unauthenticated access (requires read:accounts / read:search)
plug(OAuthScopesPlug, %{scopes: ["read:search"], fallback: :proceed_unauthenticated})
# Note: on private instances auth is required (EnsurePublicOrAuthenticatedPlug is not skipped)
plug(RateLimiter, [name: :search] when action in [:search, :search2, :account_search])
def account_search(%{assigns: %{user: user}} = conn, %{"q" => query} = params) do

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@ -9,6 +9,7 @@ defmodule Pleroma.Web.MastodonAPI.TimelineController do
only: [add_link_headers: 2, add_link_headers: 3, truthy_param?: 1, skip_relationships?: 1]
alias Pleroma.Pagination
alias Pleroma.Plugs.EnsurePublicOrAuthenticatedPlug
alias Pleroma.Plugs.OAuthScopesPlug
alias Pleroma.Plugs.RateLimiter
alias Pleroma.User
@ -26,7 +27,13 @@ defmodule Pleroma.Web.MastodonAPI.TimelineController do
plug(OAuthScopesPlug, %{scopes: ["read:statuses"]} when action in [:home, :direct])
plug(OAuthScopesPlug, %{scopes: ["read:lists"]} when action == :list)
plug(:skip_plug, Pleroma.Plugs.EnsurePublicOrAuthenticatedPlug when action == :public)
plug(
OAuthScopesPlug,
%{scopes: ["read:statuses"], fallback: :proceed_unauthenticated}
when action in [:public, :hashtag]
)
plug(:skip_plug, EnsurePublicOrAuthenticatedPlug when action in [:public, :hashtag])
plug(:put_view, Pleroma.Web.MastodonAPI.StatusView)
@ -93,7 +100,9 @@ def public(%{assigns: %{user: user}} = conn, params) do
restrict? = Pleroma.Config.get([:restrict_unauthenticated, :timelines, cfg_key])
if not (restrict? and is_nil(user)) do
if restrict? and is_nil(user) do
render_error(conn, :unauthorized, "authorization required for timeline view")
else
activities =
params
|> Map.put("type", ["Create", "Announce"])
@ -110,12 +119,10 @@ def public(%{assigns: %{user: user}} = conn, params) do
as: :activity,
skip_relationships: skip_relationships?(params)
)
else
render_error(conn, :unauthorized, "authorization required for timeline view")
end
end
def hashtag_fetching(params, user, local_only) do
defp hashtag_fetching(params, user, local_only) do
tags =
[params["tag"], params["any"]]
|> List.flatten()

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@ -26,6 +26,12 @@ defmodule Pleroma.Web.PleromaAPI.PleromaAPIController do
when action in [:conversation, :conversation_statuses]
)
plug(
OAuthScopesPlug,
%{scopes: ["read:statuses"], fallback: :proceed_unauthenticated}
when action == :emoji_reactions_by
)
plug(
OAuthScopesPlug,
%{scopes: ["write:statuses"]}

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@ -13,7 +13,11 @@ defmodule Pleroma.Web.PleromaAPI.ScrobbleController do
alias Pleroma.Web.CommonAPI
alias Pleroma.Web.MastodonAPI.StatusView
plug(OAuthScopesPlug, %{scopes: ["read"]} when action == :user_scrobbles)
plug(
OAuthScopesPlug,
%{scopes: ["read"], fallback: :proceed_unauthenticated} when action == :user_scrobbles
)
plug(OAuthScopesPlug, %{scopes: ["write"]} when action != :user_scrobbles)
def new_scrobble(%{assigns: %{user: user}} = conn, %{"title" => _} = params) do

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@ -312,14 +312,10 @@ defmodule Pleroma.Web.Router do
post("/scrobble", ScrobbleController, :new_scrobble)
end
scope [] do
pipe_through(:api)
get("/accounts/:id/favourites", AccountController, :favourites)
end
scope [] do
pipe_through(:authenticated_api)
get("/accounts/:id/favourites", AccountController, :favourites)
post("/accounts/:id/subscribe", AccountController, :subscribe)
post("/accounts/:id/unsubscribe", AccountController, :unsubscribe)
end
@ -353,6 +349,8 @@ defmodule Pleroma.Web.Router do
post("/accounts/:id/mute", AccountController, :mute)
post("/accounts/:id/unmute", AccountController, :unmute)
get("/apps/verify_credentials", AppController, :verify_credentials)
get("/conversations", ConversationController, :index)
post("/conversations/:id/read", ConversationController, :mark_as_read)
@ -431,6 +429,7 @@ defmodule Pleroma.Web.Router do
get("/timelines/home", TimelineController, :home)
get("/timelines/direct", TimelineController, :direct)
get("/timelines/list/:list_id", TimelineController, :list)
end
scope "/api/web", Pleroma.Web do
@ -442,15 +441,24 @@ defmodule Pleroma.Web.Router do
scope "/api/v1", Pleroma.Web.MastodonAPI do
pipe_through(:api)
post("/accounts", AccountController, :create)
get("/accounts/search", SearchController, :account_search)
get("/search", SearchController, :search)
get("/accounts/:id/statuses", AccountController, :statuses)
get("/accounts/:id/followers", AccountController, :followers)
get("/accounts/:id/following", AccountController, :following)
get("/accounts/:id", AccountController, :show)
post("/accounts", AccountController, :create)
get("/instance", InstanceController, :show)
get("/instance/peers", InstanceController, :peers)
post("/apps", AppController, :create)
get("/apps/verify_credentials", AppController, :verify_credentials)
get("/statuses", StatusController, :index)
get("/statuses/:id", StatusController, :show)
get("/statuses/:id/context", StatusController, :context)
get("/statuses/:id/card", StatusController, :card)
get("/statuses/:id/favourited_by", StatusController, :favourited_by)
get("/statuses/:id/reblogged_by", StatusController, :reblogged_by)
@ -461,20 +469,8 @@ defmodule Pleroma.Web.Router do
get("/timelines/public", TimelineController, :public)
get("/timelines/tag/:tag", TimelineController, :hashtag)
get("/timelines/list/:list_id", TimelineController, :list)
get("/statuses", StatusController, :index)
get("/statuses/:id", StatusController, :show)
get("/statuses/:id/context", StatusController, :context)
get("/polls/:id", PollController, :show)
get("/accounts/:id/statuses", AccountController, :statuses)
get("/accounts/:id/followers", AccountController, :followers)
get("/accounts/:id/following", AccountController, :following)
get("/accounts/:id", AccountController, :show)
get("/search", SearchController, :search)
end
scope "/api/v2", Pleroma.Web.MastodonAPI do

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@ -18,7 +18,7 @@ defmodule Pleroma.Web.TwitterAPI.Controller do
%{scopes: ["write:notifications"]} when action == :mark_notifications_as_read
)
plug(:skip_plug, OAuthScopesPlug when action in [:oauth_tokens, :revoke_token])
plug(:skip_plug, OAuthScopesPlug when action in [:confirm_email, :oauth_tokens, :revoke_token])
action_fallback(:errors)
@ -47,13 +47,13 @@ def revoke_token(%{assigns: %{user: user}} = conn, %{"id" => id} = _params) do
json_reply(conn, 201, "")
end
def errors(conn, {:param_cast, _}) do
defp errors(conn, {:param_cast, _}) do
conn
|> put_status(400)
|> json("Invalid parameters")
end
def errors(conn, _) do
defp errors(conn, _) do
conn
|> put_status(500)
|> json("Something went wrong")

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@ -67,13 +67,25 @@ defp skip_plug(conn, plug_modules) do
# Executed just before actual controller action, invokes before-action hooks (callbacks)
defp action(conn, params) do
with %Plug.Conn{halted: false} <- maybe_perform_public_or_authenticated_check(conn),
with %Plug.Conn{halted: false} <- maybe_drop_authentication_if_oauth_check_ignored(conn),
%Plug.Conn{halted: false} <- maybe_perform_public_or_authenticated_check(conn),
%Plug.Conn{halted: false} <- maybe_perform_authenticated_check(conn),
%Plug.Conn{halted: false} <- maybe_halt_on_missing_oauth_scopes_check(conn) do
super(conn, params)
end
end
# For non-authenticated API actions, drops auth info if OAuth scopes check was ignored
# (neither performed nor explicitly skipped)
defp maybe_drop_authentication_if_oauth_check_ignored(conn) do
if PlugHelper.plug_called?(conn, ExpectPublicOrAuthenticatedCheckPlug) and
not PlugHelper.plug_called_or_skipped?(conn, OAuthScopesPlug) do
OAuthScopesPlug.drop_auth_info(conn)
else
conn
end
end
# Ensures instance is public -or- user is authenticated if such check was scheduled
defp maybe_perform_public_or_authenticated_check(conn) do
if PlugHelper.plug_called?(conn, ExpectPublicOrAuthenticatedCheckPlug) do