Merge branch 'chore/extricate-http-signatures' into 'develop'

switch to pleroma/http_signatures library

See merge request pleroma/pleroma!1155

4 files changed, 42 insertions, 93 deletions

diff --git a/lib/pleroma/plugs/http_signature.ex b/lib/pleroma/plugs/http_signature.ex
index 21c195713..e2874c469 100644
--- a/lib/pleroma/plugs/http_signature.ex
+++ b/lib/pleroma/plugs/http_signature.ex
@@ -4,7 +4,6 @@
 
 defmodule Pleroma.Web.Plugs.HTTPSignaturePlug do
   alias Pleroma.Web.ActivityPub.Utils
-  alias Pleroma.Web.HTTPSignatures
   import Plug.Conn
   require Logger
 
diff --git a/lib/pleroma/signature.ex b/lib/pleroma/signature.ex
new file mode 100644
index 000000000..b7ecf00a0
--- /dev/null
+++ b/lib/pleroma/signature.ex
@@ -0,0 +1,41 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Signature do
+  @behaviour HTTPSignatures.Adapter
+
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Utils
+  alias Pleroma.Web.Salmon
+  alias Pleroma.Web.WebFinger
+
+  def fetch_public_key(conn) do
+    with actor_id <- Utils.get_ap_id(conn.params["actor"]),
+         {:ok, public_key} <- User.get_public_key_for_ap_id(actor_id) do
+      {:ok, public_key}
+    else
+      e ->
+        {:error, e}
+    end
+  end
+
+  def refetch_public_key(conn) do
+    with actor_id <- Utils.get_ap_id(conn.params["actor"]),
+         {:ok, _user} <- ActivityPub.make_user_from_ap_id(actor_id),
+         {:ok, public_key} <- User.get_public_key_for_ap_id(actor_id) do
+      {:ok, public_key}
+    else
+      e ->
+        {:error, e}
+    end
+  end
+
+  def sign(%User{} = user, headers) do
+    with {:ok, %{info: %{keys: keys}}} <- WebFinger.ensure_keys_present(user),
+         {:ok, private_key, _} <- Salmon.keys_from_pem(keys) do
+      HTTPSignatures.sign(private_key, user.ap_id <> "#main-key", headers)
+    end
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/publisher.ex b/lib/pleroma/web/activity_pub/publisher.ex
index 8e3af0a81..11dba87de 100644
--- a/lib/pleroma/web/activity_pub/publisher.ex
+++ b/lib/pleroma/web/activity_pub/publisher.ex
@@ -54,7 +54,7 @@ defmodule Pleroma.Web.ActivityPub.Publisher do
       |> Timex.format!("{WDshort}, {0D} {Mshort} {YYYY} {h24}:{m}:{s} GMT")
 
     signature =
-      Pleroma.Web.HTTPSignatures.sign(actor, %{
+      Pleroma.Signature.sign(actor, %{
         host: host,
         "content-length": byte_size(json),
         digest: digest,
diff --git a/lib/pleroma/web/http_signatures/http_signatures.ex b/lib/pleroma/web/http_signatures/http_signatures.ex
deleted file mode 100644
index 8e2e2a44b..000000000
--- a/lib/pleroma/web/http_signatures/http_signatures.ex
+++ /dev/null
@@ -1,91 +0,0 @@
-# Pleroma: A lightweight social networking server
-# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
-# SPDX-License-Identifier: AGPL-3.0-only
-
-# https://tools.ietf.org/html/draft-cavage-http-signatures-08
-defmodule Pleroma.Web.HTTPSignatures do
-  alias Pleroma.User
-  alias Pleroma.Web.ActivityPub.ActivityPub
-  alias Pleroma.Web.ActivityPub.Utils
-
-  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("Signature: #{signature["signature"]}")
-    Logger.debug("Sigstring: #{sigstring}")
-    {: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.
-    with actor_id <- Utils.get_ap_id(conn.params["actor"]),
-         {:ok, public_key} <- User.get_public_key_for_ap_id(actor_id) do
-      if validate_conn(conn, public_key) do
-        true
-      else
-        Logger.debug("Could not validate, re-fetching user and trying one more time")
-        # Fetch user anew and try one more time
-        with actor_id <- Utils.get_ap_id(conn.params["actor"]),
-             {:ok, _user} <- ActivityPub.make_user_from_ap_id(actor_id),
-             {:ok, public_key} <- User.get_public_key_for_ap_id(actor_id) do
-          validate_conn(conn, public_key)
-        end
-      end
-    else
-      _e ->
-        Logger.debug("Could not public key!")
-        false
-    end
-  end
-
-  def validate_conn(conn, public_key) do
-    headers = Enum.into(conn.req_headers, %{})
-    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(user, headers) do
-    with {:ok, %{info: %{keys: keys}}} <- Pleroma.Web.WebFinger.ensure_keys_present(user),
-         {:ok, private_key, _} = Pleroma.Web.Salmon.keys_from_pem(keys) do
-      sigstring = build_signing_string(headers, Map.keys(headers))
-
-      signature =
-        :public_key.sign(sigstring, :sha256, private_key)
-        |> Base.encode64()
-
-      [
-        keyId: user.ap_id <> "#main-key",
-        algorithm: "rsa-sha256",
-        headers: Map.keys(headers) |> Enum.join(" "),
-        signature: signature
-      ]
-      |> Enum.map(fn {k, v} -> "#{k}=\"#{v}\"" end)
-      |> Enum.join(",")
-    end
-  end
-end