1 defmodule Pleroma.Web.Salmon do
5 {doc, _rest} = :xmerl_scan.string(to_charlist(salmon))
7 {:xmlObj, :string, data} = :xmerl_xpath.string('string(//me:data[1])', doc)
8 {:xmlObj, :string, sig} = :xmerl_xpath.string('string(//me:sig[1])', doc)
9 {:xmlObj, :string, alg} = :xmerl_xpath.string('string(//me:alg[1])', doc)
10 {:xmlObj, :string, encoding} = :xmerl_xpath.string('string(//me:encoding[1])', doc)
11 {:xmlObj, :string, type} = :xmerl_xpath.string('string(//me:data[1]/@type)', doc)
14 {:ok, data} = Base.url_decode64(to_string(data), ignore: :whitespace)
15 {:ok, sig} = Base.url_decode64(to_string(sig), ignore: :whitespace)
17 encoding = to_string(encoding)
18 type = to_string(type)
20 [data, type, encoding, alg, sig]
23 def fetch_magic_key(salmon) do
24 [data, _, _, _, _] = decode(salmon)
25 {doc, _rest} = :xmerl_scan.string(to_charlist(data))
26 {:xmlObj, :string, uri} = :xmerl_xpath.string('string(//author[1]/uri)', doc)
29 base = URI.parse(uri).host
31 # TODO: Find out if this endpoint is mandated by the standard.
32 {:ok, response} = HTTPoison.get(base <> "/.well-known/webfinger", ["Accept": "application/xrd+xml"], [params: [resource: uri]])
34 {doc, _rest} = :xmerl_scan.string(to_charlist(response.body))
36 {:xmlObj, :string, magickey} = :xmerl_xpath.string('string(//Link[@rel="magic-public-key"]/@href)', doc)
37 "data:application/magic-public-key," <> magickey = to_string(magickey)
42 def decode_and_validate(magickey, salmon) do
43 [data, type, encoding, alg, sig] = decode(salmon)
45 signed_text = [data, type, encoding, alg]
46 |> Enum.map(&Base.url_encode64/1)
49 key = decode_key(magickey)
51 verify = :public_key.verify(signed_text, :sha256, sig, key)
60 defp decode_key("RSA." <> magickey) do
61 make_integer = fn(bin) ->
62 list = :erlang.binary_to_list(bin)
63 Enum.reduce(list, 0, fn (el, acc) -> (acc <<< 8) ||| el end)
66 [modulus, exponent] = magickey
68 |> Enum.map(&Base.url_decode64!/1)
69 |> Enum.map(make_integer)
71 {:RSAPublicKey, modulus, exponent}