Merge remote-tracking branch 'upstream/develop' into patch-image-description

[akkoma] / lib / pleroma / web / http_signatures / http_signatures.ex

diff --git a/lib/pleroma/web/http_signatures/http_signatures.ex b/lib/pleroma/web/http_signatures/http_signatures.ex
index 8603cb6712ed0d74a747c7732c83d2912108649a..8e2e2a44b8ca71bf8208a05f89e3824dec401dfb 100644 (file)
--- a/lib/pleroma/web/http_signatures/http_signatures.ex
+++ b/lib/pleroma/web/http_signatures/http_signatures.ex
@@ -1,24 +1,60 @@
+# 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)
+    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"])
-    verify = :public_key.verify(sigstring, :sha256, sig, public_key)
+    :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
@@ -29,7 +65,27 @@ defmodule Pleroma.Web.HTTPSignatures do
 
   def build_signing_string(headers, used_headers) do
     used_headers
-    |> Enum.map(fn (header) -> "#{header}: #{headers[header]}" end)
+    |> 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