1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
# Pleroma: A lightweight social networking server
# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Web.MediaProxy do
alias Pleroma.Config
alias Pleroma.Upload
alias Pleroma.Web
@base64_opts [padding: false]
def url(url) when is_nil(url) or url == "", do: nil
def url("/" <> _ = url), do: url
def url(url) do
if disabled?() or local?(url) or whitelisted?(url) do
url
else
encode_url(url)
end
end
defp disabled?, do: !Config.get([:media_proxy, :enabled], false)
defp local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
defp whitelisted?(url) do
%{host: domain} = URI.parse(url)
mediaproxy_whitelist = Config.get([:media_proxy, :whitelist])
upload_base_url_domain =
if !is_nil(Config.get([Upload, :base_url])) do
[URI.parse(Config.get([Upload, :base_url])).host]
else
[]
end
whitelist = mediaproxy_whitelist ++ upload_base_url_domain
Enum.any?(whitelist, fn pattern ->
String.equivalent?(domain, pattern)
end)
end
def encode_url(url) do
base64 = Base.url_encode64(url, @base64_opts)
sig64 =
base64
|> signed_url
|> Base.url_encode64(@base64_opts)
build_url(sig64, base64, filename(url))
end
def decode_url(sig, url) do
with {:ok, sig} <- Base.url_decode64(sig, @base64_opts),
signature when signature == sig <- signed_url(url) do
{:ok, Base.url_decode64!(url, @base64_opts)}
else
_ -> {:error, :invalid_signature}
end
end
defp signed_url(url) do
:crypto.hmac(:sha, Config.get([Web.Endpoint, :secret_key_base]), url)
end
def filename(url_or_path) do
if path = URI.parse(url_or_path).path, do: Path.basename(path)
end
def build_url(sig_base64, url_base64, filename \\ nil) do
[
Pleroma.Config.get([:media_proxy, :base_url], Web.base_url()),
"proxy",
sig_base64,
url_base64,
filename
]
|> Enum.filter(& &1)
|> Path.join()
end
end
|
