Introduce relay

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
2019-07-30 16:40:59 +02:00
parent 56467301a1
commit c51115bdbe
54 changed files with 3100 additions and 1038 deletions
--- a/lib/service/http_signatures/http_signatures.ex
+++ b/lib/service/http_signatures/http_signatures.ex
@@ -1,123 +0,0 @@
-# Portions of this file are derived from Pleroma:
-# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social>
-# SPDX-License-Identifier: AGPL-3.0-only
-# Upstream: https://git.pleroma.social/pleroma/pleroma/blob/develop/lib/pleroma/web/http_signatures/http_signatures.ex
-
-# https://tools.ietf.org/html/draft-cavage-http-signatures-08
-defmodule Mobilizon.Service.HTTPSignatures do
-  @moduledoc """
-  # HTTP Signatures
-
-  Generates and checks HTTP Signatures
-  """
-
-  alias Mobilizon.Actors.Actor
-  alias Mobilizon.Service.ActivityPub
-  require Logger
-
-  def split_signature(sig) do
-    default = %{"headers" => "date"}
-
-    sig =
-      sig
-      |> String.trim()
-      |> String.split(",")
-      |> Enum.reduce(default, fn part, acc ->
-        [key | rest] = String.split(part, "=")
-        value = Enum.join(rest, "=")
-        Map.put(acc, key, String.trim(value, "\""))
-      end)
-
-    Map.put(sig, "headers", String.split(sig["headers"], ~r/\s/))
-  end
-
-  def validate(headers, signature, public_key) do
-    sigstring = build_signing_string(headers, signature["headers"])
-
-    Logger.debug(fn ->
-      "Signature: #{signature["signature"]}"
-    end)
-
-    Logger.debug(fn ->
-      "Sigstring: #{sigstring}"
-    end)
-
-    {:ok, sig} = Base.decode64(signature["signature"])
-    :public_key.verify(sigstring, :sha256, sig, public_key)
-  end
-
-  def validate_conn(conn) do
-    # TODO: How to get the right key and see if it is actually valid for that request.
-    # For now, fetch the key for the actor.
-    case conn.params["actor"] |> Actor.get_public_key_for_url() do
-      {:ok, public_key} ->
-        if validate_conn(conn, public_key) do
-          true
-          Logger.info("Could not validate request, re-fetching user and trying one more time")
-          # Fetch user anew and try one more time
-          with actor_id <- conn.params["actor"],
-               {:ok, _actor} <- ActivityPub.make_actor_from_url(actor_id),
-               {:ok, public_key} <- actor_id |> Actor.get_public_key_for_url() do
-            validate_conn(conn, public_key)
-          end
-        end
-
-      e ->
-        Logger.debug("Could not found url for actor!")
-        Logger.debug(inspect(e))
-        false
-    end
-  end
-
-  def validate_conn(conn, public_key) do
-    headers = Enum.into(conn.req_headers, %{})
-    host_without_port = String.split(headers["host"], ":") |> hd
-    headers = Map.put(headers, "host", host_without_port)
-    signature = split_signature(headers["signature"])
-    validate(headers, signature, public_key)
-  end
-
-  def build_signing_string(headers, used_headers) do
-    used_headers
-    |> Enum.map(fn header -> "#{header}: #{headers[header]}" end)
-    |> Enum.join("\n")
-  end
-
-  def sign(%Actor{} = actor, headers) do
-    with sigstring <- build_signing_string(headers, Map.keys(headers)),
-         {:ok, key} <- actor.keys |> Actor.prepare_public_key(),
-         signature <- sigstring |> :public_key.sign(:sha256, key) |> Base.encode64() do
-      [
-        keyId: actor.url <> "#main-key",
-        algorithm: "rsa-sha256",
-        headers: headers |> Map.keys() |> Enum.join(" "),
-        signature: signature
-      ]
-      |> Enum.map(fn {k, v} -> "#{k}=\"#{v}\"" end)
-      |> Enum.join(",")
-    else
-      err ->
-        Logger.error("Unable to sign headers")
-        Logger.error(inspect(err))
-        nil
-    end
-  end
-
-  def generate_date_header(date \\ Timex.now("GMT")) do
-    case Timex.format(date, "%a, %d %b %Y %H:%M:%S %Z", :strftime) do
-      {:ok, date} ->
-        date
-
-      {:error, err} ->
-        Logger.error("Unable to generate date header")
-        Logger.error(inspect(err))
-        nil
-    end
-  end
-
-  def generate_request_target(method, path), do: "#{method} #{path}"
-
-  def build_digest(body) do
-    "SHA-256=" <> (:crypto.hash(:sha256, body) |> Base.encode64())
-  end
-end
--- a/lib/service/http_signatures/signature.ex
+++ b/lib/service/http_signatures/signature.ex
@@ -0,0 +1,83 @@
+# Portions of this file are derived from Pleroma:
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social>
+# SPDX-License-Identifier: AGPL-3.0-only
+# Upstream: https://git.pleroma.social/pleroma/pleroma/blob/develop/lib/pleroma/signature.ex
+
+defmodule Mobilizon.Service.HTTPSignatures.Signature do
+  @moduledoc """
+  Adapter for the `HTTPSignatures` lib that handles signing and providing public keys to verify HTTPSignatures
+  """
+  @behaviour HTTPSignatures.Adapter
+
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Service.ActivityPub
+  require Logger
+
+  def key_id_to_actor_url(key_id) do
+    uri =
+      URI.parse(key_id)
+      |> Map.put(:fragment, nil)
+
+    uri =
+      if not is_nil(uri.path) and String.ends_with?(uri.path, "/publickey") do
+        Map.put(uri, :path, String.replace(uri.path, "/publickey", ""))
+      else
+        uri
+      end
+
+    URI.to_string(uri)
+  end
+
+  def fetch_public_key(conn) do
+    with %{"keyId" => kid} <- HTTPSignatures.signature_for_conn(conn),
+         actor_id <- key_id_to_actor_url(kid),
+         :ok <- Logger.debug("Fetching public key for #{actor_id}"),
+         {:ok, public_key} <- Actor.get_public_key_for_url(actor_id) do
+      {:ok, public_key}
+    else
+      e ->
+        {:error, e}
+    end
+  end
+
+  def refetch_public_key(conn) do
+    with %{"keyId" => kid} <- HTTPSignatures.signature_for_conn(conn),
+         actor_id <- key_id_to_actor_url(kid),
+         :ok <- Logger.debug("Refetching public key for #{actor_id}"),
+         {:ok, _actor} <- ActivityPub.make_actor_from_url(actor_id),
+         {:ok, public_key} <- Actor.get_public_key_for_url(actor_id) do
+      {:ok, public_key}
+    else
+      e ->
+        {:error, e}
+    end
+  end
+
+  def sign(%Actor{} = actor, headers) do
+    Logger.debug("Signing on behalf of #{actor.url}")
+    Logger.debug("headers")
+    Logger.debug(inspect(headers))
+
+    with {:ok, key} <- actor.keys |> Actor.prepare_public_key() do
+      HTTPSignatures.sign(key, actor.url <> "#main-key", headers)
+    end
+  end
+
+  def generate_date_header(date \\ Timex.now("GMT")) do
+    case Timex.format(date, "%a, %d %b %Y %H:%M:%S %Z", :strftime) do
+      {:ok, date} ->
+        date
+
+      {:error, err} ->
+        Logger.error("Unable to generate date header")
+        Logger.debug(inspect(err))
+        nil
+    end
+  end
+
+  def generate_request_target(method, path), do: "#{method} #{path}"
+
+  def build_digest(body) do
+    "SHA-256=" <> (:crypto.hash(:sha256, body) |> Base.encode64())
+  end
+end