+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
defmodule Pleroma.Web.Salmon do
+ @httpoison Application.get_env(:pleroma, :httpoison)
+
use Bitwise
+ alias Pleroma.Instances
+ alias Pleroma.User
+ alias Pleroma.Web.XML
+ alias Pleroma.Web.OStatus.ActivityRepresenter
+
+ require Logger
+
def decode(salmon) do
- {doc, _rest} = :xmerl_scan.string(to_charlist(salmon))
+ doc = XML.parse_document(salmon)
{:xmlObj, :string, data} = :xmerl_xpath.string('string(//me:data[1])', doc)
{:xmlObj, :string, sig} = :xmerl_xpath.string('string(//me:sig[1])', doc)
end
def fetch_magic_key(salmon) do
- [data, _, _, _, _] = decode(salmon)
- {doc, _rest} = :xmerl_scan.string(to_charlist(data))
- {:xmlObj, :string, uri} = :xmerl_xpath.string('string(//author[1]/uri)', doc)
-
- uri = to_string(uri)
- base = URI.parse(uri).host
-
- # TODO: Find out if this endpoint is mandated by the standard.
- {:ok, response} = HTTPoison.get(base <> "/.well-known/webfinger", ["Accept": "application/xrd+xml"], [params: [resource: uri]])
-
- {doc, _rest} = :xmerl_scan.string(to_charlist(response.body))
-
- {:xmlObj, :string, magickey} = :xmerl_xpath.string('string(//Link[@rel="magic-public-key"]/@href)', doc)
- "data:application/magic-public-key," <> magickey = to_string(magickey)
-
- magickey
+ with [data, _, _, _, _] <- decode(salmon),
+ doc <- XML.parse_document(data),
+ uri when not is_nil(uri) <- XML.string_from_xpath("/entry/author[1]/uri", doc),
+ {:ok, public_key} <- User.get_public_key_for_ap_id(uri),
+ magic_key <- encode_key(public_key) do
+ {:ok, magic_key}
+ end
end
def decode_and_validate(magickey, salmon) do
[data, type, encoding, alg, sig] = decode(salmon)
- signed_text = [data, type, encoding, alg]
- |> Enum.map(&Base.url_encode64/1)
- |> Enum.join(".")
+ signed_text =
+ [data, type, encoding, alg]
+ |> Enum.map(&Base.url_encode64/1)
+ |> Enum.join(".")
key = decode_key(magickey)
end
end
- defp decode_key("RSA." <> magickey) do
- make_integer = fn(bin) ->
+ def decode_key("RSA." <> magickey) do
+ make_integer = fn bin ->
list = :erlang.binary_to_list(bin)
- Enum.reduce(list, 0, fn (el, acc) -> (acc <<< 8) ||| el end)
+ Enum.reduce(list, 0, fn el, acc -> acc <<< 8 ||| el end)
end
- [modulus, exponent] = magickey
- |> String.split(".")
- |> Enum.map(&Base.url_decode64!/1)
- |> Enum.map(make_integer)
+ [modulus, exponent] =
+ magickey
+ |> String.split(".")
+ |> Enum.map(fn n -> Base.url_decode64!(n, padding: false) end)
+ |> Enum.map(make_integer)
{:RSAPublicKey, modulus, exponent}
end
+
+ def encode_key({:RSAPublicKey, modulus, exponent}) do
+ modulus_enc = :binary.encode_unsigned(modulus) |> Base.url_encode64()
+ exponent_enc = :binary.encode_unsigned(exponent) |> Base.url_encode64()
+
+ "RSA.#{modulus_enc}.#{exponent_enc}"
+ end
+
+ # Native generation of RSA keys is only available since OTP 20+ and in default build conditions
+ # We try at compile time to generate natively an RSA key otherwise we fallback on the old way.
+ try do
+ _ = :public_key.generate_key({:rsa, 2048, 65537})
+
+ def generate_rsa_pem do
+ key = :public_key.generate_key({:rsa, 2048, 65537})
+ entry = :public_key.pem_entry_encode(:RSAPrivateKey, key)
+ pem = :public_key.pem_encode([entry]) |> String.trim_trailing()
+ {:ok, pem}
+ end
+ rescue
+ _ ->
+ def generate_rsa_pem do
+ port = Port.open({:spawn, "openssl genrsa"}, [:binary])
+
+ {:ok, pem} =
+ receive do
+ {^port, {:data, pem}} -> {:ok, pem}
+ end
+
+ Port.close(port)
+
+ if Regex.match?(~r/RSA PRIVATE KEY/, pem) do
+ {:ok, pem}
+ else
+ :error
+ end
+ end
+ end
+
+ def keys_from_pem(pem) do
+ [private_key_code] = :public_key.pem_decode(pem)
+ private_key = :public_key.pem_entry_decode(private_key_code)
+ {:RSAPrivateKey, _, modulus, exponent, _, _, _, _, _, _, _} = private_key
+ public_key = {:RSAPublicKey, modulus, exponent}
+ {:ok, private_key, public_key}
+ end
+
+ def encode(private_key, doc) do
+ type = "application/atom+xml"
+ encoding = "base64url"
+ alg = "RSA-SHA256"
+
+ signed_text =
+ [doc, type, encoding, alg]
+ |> Enum.map(&Base.url_encode64/1)
+ |> Enum.join(".")
+
+ signature =
+ signed_text
+ |> :public_key.sign(:sha256, private_key)
+ |> to_string
+ |> Base.url_encode64()
+
+ doc_base64 =
+ doc
+ |> Base.url_encode64()
+
+ # Don't need proper xml building, these strings are safe to leave unescaped
+ salmon = """
+ <?xml version="1.0" encoding="UTF-8"?>
+ <me:env xmlns:me="http://salmon-protocol.org/ns/magic-env">
+ <me:data type="application/atom+xml">#{doc_base64}</me:data>
+ <me:encoding>#{encoding}</me:encoding>
+ <me:alg>#{alg}</me:alg>
+ <me:sig>#{signature}</me:sig>
+ </me:env>
+ """
+
+ {:ok, salmon}
+ end
+
+ def remote_users(%{data: %{"to" => to} = data}) do
+ to = to ++ (data["cc"] || [])
+
+ to
+ |> Enum.map(fn id -> User.get_cached_by_ap_id(id) end)
+ |> Enum.filter(fn user -> user && !user.local end)
+ end
+
+ @doc "Pushes an activity to remote account."
+ def send_to_user(%{recipient: %{info: %{salmon: salmon}}} = params),
+ do: send_to_user(Map.put(params, :recipient, salmon))
+
+ def send_to_user(%{recipient: url, feed: feed, poster: poster} = params) when is_binary(url) do
+ with {:ok, %{status: code}} when code in 200..299 <-
+ poster.(
+ url,
+ feed,
+ [{"Content-Type", "application/magic-envelope+xml"}]
+ ) do
+ if !Map.has_key?(params, :unreachable_since) || params[:unreachable_since],
+ do: Instances.set_reachable(url)
+
+ Logger.debug(fn -> "Pushed to #{url}, code #{code}" end)
+ :ok
+ else
+ e ->
+ unless params[:unreachable_since], do: Instances.set_reachable(url)
+ Logger.debug(fn -> "Pushing Salmon to #{url} failed, #{inspect(e)}" end)
+ :error
+ end
+ end
+
+ def send_to_user(_), do: :noop
+
+ @supported_activities [
+ "Create",
+ "Follow",
+ "Like",
+ "Announce",
+ "Undo",
+ "Delete"
+ ]
+
+ @doc """
+ Publishes an activity to remote accounts
+ """
+ @spec publish(User.t(), Pleroma.Activity.t(), Pleroma.HTTP.t()) :: none
+ def publish(user, activity, poster \\ &@httpoison.post/3)
+
+ def publish(%{info: %{keys: keys}} = user, %{data: %{"type" => type}} = activity, poster)
+ when type in @supported_activities do
+ feed = ActivityRepresenter.to_simple_form(activity, user, true)
+
+ if feed do
+ feed =
+ ActivityRepresenter.wrap_with_entry(feed)
+ |> :xmerl.export_simple(:xmerl_xml)
+ |> to_string
+
+ {:ok, private, _} = keys_from_pem(keys)
+ {:ok, feed} = encode(private, feed)
+
+ remote_users = remote_users(activity)
+
+ salmon_urls = Enum.map(remote_users, & &1.info.salmon)
+ reachable_urls_metadata = Instances.filter_reachable(salmon_urls)
+ reachable_urls = Map.keys(reachable_urls_metadata)
+
+ remote_users
+ |> Enum.filter(&(&1.info.salmon in reachable_urls))
+ |> Enum.each(fn remote_user ->
+ Logger.debug(fn -> "Sending Salmon to #{remote_user.ap_id}" end)
+
+ Pleroma.Web.Federator.publish_single_salmon(%{
+ recipient: remote_user,
+ feed: feed,
+ poster: poster,
+ unreachable_since: reachable_urls_metadata[remote_user.info.salmon]
+ })
+ end)
+ end
+ end
+
+ def publish(%{id: id}, _, _), do: Logger.debug(fn -> "Keys missing for user #{id}" end)
end
projects / akkoma / blobdiff