akkoma/lib/pleroma/plugs/http_security_plug.ex
2020-07-06 11:28:08 -05:00

209 lines
6.7 KiB
Elixir

# Pleroma: A lightweight social networking server
# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Plugs.HTTPSecurityPlug do
alias Pleroma.Config
import Plug.Conn
require Logger
def init(opts), do: opts
def call(conn, _options) do
if Config.get([:http_security, :enabled]) do
conn
|> merge_resp_headers(headers())
|> maybe_send_sts_header(Config.get([:http_security, :sts]))
else
conn
end
end
defp headers do
referrer_policy = Config.get([:http_security, :referrer_policy])
report_uri = Config.get([:http_security, :report_uri])
headers = [
{"x-xss-protection", "1; mode=block"},
{"x-permitted-cross-domain-policies", "none"},
{"x-frame-options", "DENY"},
{"x-content-type-options", "nosniff"},
{"referrer-policy", referrer_policy},
{"x-download-options", "noopen"},
{"content-security-policy", csp_string()}
]
if report_uri do
report_group = %{
"group" => "csp-endpoint",
"max-age" => 10_886_400,
"endpoints" => [
%{"url" => report_uri}
]
}
[{"reply-to", Jason.encode!(report_group)} | headers]
else
headers
end
end
static_csp_rules = [
"default-src 'none'",
"base-uri 'self'",
"frame-ancestors 'none'",
"style-src 'self' 'unsafe-inline'",
"font-src 'self'",
"manifest-src 'self'"
]
@csp_start [Enum.join(static_csp_rules, ";") <> ";"]
defp csp_string do
scheme = Config.get([Pleroma.Web.Endpoint, :url])[:scheme]
static_url = Pleroma.Web.Endpoint.static_url()
websocket_url = Pleroma.Web.Endpoint.websocket_url()
report_uri = Config.get([:http_security, :report_uri])
img_src = "img-src 'self' data: blob:"
media_src = "media-src 'self'"
# Strict multimedia CSP enforcement only when MediaProxy is enabled
{img_src, media_src} =
if Config.get([:media_proxy, :enabled]) &&
!Config.get([:media_proxy, :proxy_opts, :redirect_on_failure]) do
sources = build_csp_multimedia_source_list()
{[img_src, sources], [media_src, sources]}
else
{[img_src, " https:"], [media_src, " https:"]}
end
connect_src = ["connect-src 'self' blob: ", static_url, ?\s, websocket_url]
connect_src =
if Pleroma.Config.get(:env) == :dev do
[connect_src, " http://localhost:3035/"]
else
connect_src
end
script_src =
if Pleroma.Config.get(:env) == :dev do
"script-src 'self' 'unsafe-eval'"
else
"script-src 'self'"
end
report = if report_uri, do: ["report-uri ", report_uri, ";report-to csp-endpoint"]
insecure = if scheme == "https", do: "upgrade-insecure-requests"
@csp_start
|> add_csp_param(img_src)
|> add_csp_param(media_src)
|> add_csp_param(connect_src)
|> add_csp_param(script_src)
|> add_csp_param(insecure)
|> add_csp_param(report)
|> :erlang.iolist_to_binary()
end
defp build_csp_multimedia_source_list do
media_proxy_whitelist =
Enum.reduce(Config.get([:media_proxy, :whitelist]), [], fn host, acc ->
add_source(acc, host)
end)
media_proxy_base_url = build_csp_param(Config.get([:media_proxy, :base_url]))
upload_base_url = build_csp_param(Config.get([Pleroma.Upload, :base_url]))
s3_endpoint = build_csp_param(Config.get([Pleroma.Uploaders.S3, :public_endpoint]))
captcha_method = Config.get([Pleroma.Captcha, :method])
captcha_endpoint = build_csp_param(Config.get([captcha_method, :endpoint]))
[]
|> add_source(media_proxy_base_url)
|> add_source(upload_base_url)
|> add_source(s3_endpoint)
|> add_source(media_proxy_whitelist)
|> add_source(captcha_endpoint)
end
defp add_source(iodata, nil), do: iodata
defp add_source(iodata, source), do: [[?\s, source] | iodata]
defp add_csp_param(csp_iodata, nil), do: csp_iodata
defp add_csp_param(csp_iodata, param), do: [[param, ?;] | csp_iodata]
defp build_csp_param(nil), do: nil
defp build_csp_param(url) when is_binary(url) do
%{host: host, scheme: scheme} = URI.parse(url)
if scheme do
[scheme, "://", host]
end
end
def warn_if_disabled do
unless Config.get([:http_security, :enabled]) do
Logger.warn("
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c6Y. .,...,::::,,..:t0@@QY. ................ :8bi
:6S. ..,,...,:::,,,..EMMMMMMI. ............... .;bZ,
:6o, .,,,,..:::,,,..i#MMMMMM#v................. YW2.
.n8i ..,,,,,,,::,,,,.. tMMMMM@C:.................. .1Wn
7Uc. .:::,,,,,::,,,,.. i1t;,..................... .UEi
7C...::::::::::::,,,,.. .................... vSi.
;1;...,,::::::,......... .................. Yz:
v97,......... .voC.
izAotX7777777777777777777777777777777777777777Y7n92:
.;CoIIIIIUAA666666699999ZZZZZZZZZZZZZZZZZZZZ6ov.
HTTP Security is disabled. Please re-enable it to prevent users from attacking
your instance and your users via malicious posts:
config :pleroma, :http_security, enabled: true
")
end
end
defp maybe_send_sts_header(conn, true) do
max_age_sts = Config.get([:http_security, :sts_max_age])
max_age_ct = Config.get([:http_security, :ct_max_age])
merge_resp_headers(conn, [
{"strict-transport-security", "max-age=#{max_age_sts}; includeSubDomains"},
{"expect-ct", "enforce, max-age=#{max_age_ct}"}
])
end
defp maybe_send_sts_header(conn, _), do: conn
end