1 files changed, 99 insertions, 18 deletions

diff --git a/lib/pleroma/web/salmon/salmon.ex b/lib/pleroma/web/salmon/salmon.ex
index f26daf824..fe529c4c0 100644
--- a/lib/pleroma/web/salmon/salmon.ex
+++ b/lib/pleroma/web/salmon/salmon.ex
@@ -1,8 +1,12 @@
 defmodule Pleroma.Web.Salmon do
   use Bitwise
+  alias Pleroma.Web.XML
+  alias Pleroma.Web.OStatus.ActivityRepresenter
+  alias Pleroma.User
+  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)
@@ -20,22 +24,12 @@ defmodule Pleroma.Web.Salmon do
   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, %{info: %{"magic_key" => magic_key}}} <- Pleroma.Web.OStatus.find_or_make_user(uri) do
+      {:ok, magic_key}
+    end
   end
 
   def decode_and_validate(magickey, salmon) do
@@ -56,7 +50,7 @@ defmodule Pleroma.Web.Salmon do
     end
   end
 
-  defp decode_key("RSA." <> magickey) do
+  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)
@@ -69,4 +63,91 @@ defmodule Pleroma.Web.Salmon do
 
     {: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
+
+  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
+
+  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 = :public_key.sign(signed_text, :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}}) do
+    to
+    |> Enum.map(fn(id) -> User.get_cached_by_ap_id(id) end)
+    |> Enum.filter(fn(user) -> user && !user.local end)
+  end
+
+  defp send_to_user(%{info: %{"salmon" => salmon}}, feed, poster) do
+    poster.(salmon, feed, [{"Content-Type", "application/magic-envelope+xml"}])
+  end
+
+  defp send_to_user(_,_,_), do: nil
+
+  def publish(user, activity, poster \\ &HTTPoison.post/3)
+  def publish(%{info: %{"keys" => keys}} = user, activity, poster) do
+    feed = ActivityRepresenter.to_simple_form(activity, user, true)
+    |> ActivityRepresenter.wrap_with_entry
+    |> :xmerl.export_simple(:xmerl_xml)
+    |> to_string
+
+    if feed do
+      {:ok, private, _} = keys_from_pem(keys)
+      {:ok, feed} = encode(private, feed)
+
+      remote_users(activity)
+      |> Enum.each(fn(remote_user) ->
+        Logger.debug("sending salmon to #{remote_user.ap_id}")
+        send_to_user(remote_user, feed, poster)
+      end)
+    end
+  end
+
+  def publish(%{id: id}, _, _), do: Logger.debug("Keys missing for user #{id}")
 end