akkoma/lib/pleroma/plugs/http_security_plug.ex
Mark Felder eaa59daa4c Add Captcha endpoint to CSP headers when MediaProxy is enabled.
Our CSP rules are lax when MediaProxy enabled, but lenient otherwise.

This fixes broken captcha on instances not using MediaProxy.
2020-07-03 17:06:20 -05:00

207 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'"
{img_src, media_src} =
if Config.get([:media_proxy, :enabled]) &&
!Config.get([:media_proxy, :proxy_opts, :redirect_on_failure]) do
sources = get_proxy_and_attachment_sources()
{[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 get_proxy_and_attachment_sources do
media_proxy_whitelist =
Enum.reduce(Config.get([:media_proxy, :whitelist]), [], fn host, acc ->
add_source(acc, host)
end)
media_proxy_base_url =
if Config.get([:media_proxy, :base_url]),
do: URI.parse(Config.get([:media_proxy, :base_url])).host
upload_base_url =
if Config.get([Pleroma.Upload, :base_url]),
do: URI.parse(Config.get([Pleroma.Upload, :base_url])).host
s3_endpoint =
if Config.get([Pleroma.Upload, :uploader]) == Pleroma.Uploaders.S3,
do: URI.parse(Config.get([Pleroma.Uploaders.S3, :public_endpoint])).host
captcha_method = Config.get([Pleroma.Captcha, :method])
captcha_endpoint =
if Config.get([Pleroma.Captcha, :enabled]) &&
captcha_method != "Pleroma.Captcha.Native",
do: 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]
def warn_if_disabled do
unless Config.get([:http_security, :enabled]) do
Logger.warn("
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vov ......:ii..c$MBc..,,,,,,,,,,..iI9i
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iIS. ......:ii::..;@MI....,............;Ez.
.I9. ......:i::::...8M1..................C0z.
.z9; ......:i::::,.. .i:...................zWX.
vbv ......,i::::,,. ................. :AQY
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