forked from AkkomaGang/akkoma
63 lines
1.7 KiB
Elixir
63 lines
1.7 KiB
Elixir
# Pleroma: A lightweight social networking server
|
|
# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
|
|
# SPDX-License-Identifier: AGPL-3.0-only
|
|
|
|
defmodule Pleroma.Web.MediaProxy do
|
|
@base64_opts [padding: false]
|
|
|
|
def url(nil), do: nil
|
|
|
|
def url(""), do: nil
|
|
|
|
def url("/" <> _ = url), do: url
|
|
|
|
def url(url) do
|
|
config = Application.get_env(:pleroma, :media_proxy, [])
|
|
|
|
if !Keyword.get(config, :enabled, false) or String.starts_with?(url, Pleroma.Web.base_url()) do
|
|
url
|
|
else
|
|
secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
|
|
|
|
# The URL is url-decoded and encoded again to ensure it is correctly encoded and not twice.
|
|
base64 =
|
|
url
|
|
|> URI.decode()
|
|
|> URI.encode()
|
|
|> Base.url_encode64(@base64_opts)
|
|
|
|
sig = :crypto.hmac(:sha, secret, base64)
|
|
sig64 = sig |> Base.url_encode64(@base64_opts)
|
|
|
|
build_url(sig64, base64, filename(url))
|
|
end
|
|
end
|
|
|
|
def decode_url(sig, url) do
|
|
secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
|
|
sig = Base.url_decode64!(sig, @base64_opts)
|
|
local_sig = :crypto.hmac(:sha, secret, url)
|
|
|
|
if local_sig == sig do
|
|
{:ok, Base.url_decode64!(url, @base64_opts)}
|
|
else
|
|
{:error, :invalid_signature}
|
|
end
|
|
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], Pleroma.Web.base_url()),
|
|
"proxy",
|
|
sig_base64,
|
|
url_base64,
|
|
filename
|
|
]
|
|
|> Enum.filter(fn value -> value end)
|
|
|> Path.join()
|
|
end
|
|
end
|