mirror of
https://github.com/mastodon/mastodon.git
synced 2024-12-30 19:49:18 +01:00
d770b61a74
* Add hardening monkey-patch to prevent IP spoofing on misconfigured installations * Remove rack-attack safelist
72 lines
3.1 KiB
Ruby
72 lines
3.1 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
# Mastodon is not made to be directly accessed without a reverse proxy.
|
|
# This monkey-patch prevents remote IP address spoofing when being accessed
|
|
# directly.
|
|
#
|
|
# See PR: https://github.com/rails/rails/pull/51610
|
|
|
|
# In addition to the PR above, it also raises an error if a request with
|
|
# `X-Forwarded-For` or `Client-Ip` comes directly from a client without
|
|
# going through a trusted proxy.
|
|
|
|
# rubocop:disable all -- This is a mostly vendored file
|
|
|
|
module ActionDispatch
|
|
class RemoteIp
|
|
module GetIpExtensions
|
|
def calculate_ip
|
|
# Set by the Rack web server, this is a single value.
|
|
remote_addr = ips_from(@req.remote_addr).last
|
|
|
|
# Could be a CSV list and/or repeated headers that were concatenated.
|
|
client_ips = ips_from(@req.client_ip).reverse!
|
|
forwarded_ips = ips_from(@req.x_forwarded_for).reverse!
|
|
|
|
# `Client-Ip` and `X-Forwarded-For` should not, generally, both be set. If they
|
|
# are both set, it means that either:
|
|
#
|
|
# 1) This request passed through two proxies with incompatible IP header
|
|
# conventions.
|
|
#
|
|
# 2) The client passed one of `Client-Ip` or `X-Forwarded-For`
|
|
# (whichever the proxy servers weren't using) themselves.
|
|
#
|
|
# Either way, there is no way for us to determine which header is the right one
|
|
# after the fact. Since we have no idea, if we are concerned about IP spoofing
|
|
# we need to give up and explode. (If you're not concerned about IP spoofing you
|
|
# can turn the `ip_spoofing_check` option off.)
|
|
should_check_ip = @check_ip && client_ips.last && forwarded_ips.last
|
|
if should_check_ip && !forwarded_ips.include?(client_ips.last)
|
|
# We don't know which came from the proxy, and which from the user
|
|
raise IpSpoofAttackError, "IP spoofing attack?! " \
|
|
"HTTP_CLIENT_IP=#{@req.client_ip.inspect} " \
|
|
"HTTP_X_FORWARDED_FOR=#{@req.x_forwarded_for.inspect}"
|
|
end
|
|
|
|
# NOTE: Mastodon addition to make sure we don't get requests from a non-trusted client
|
|
if @check_ip && (forwarded_ips.last || client_ips.last) && !@proxies.any? { |proxy| proxy === remote_addr }
|
|
raise IpSpoofAttackError, "IP spoofing attack?! client #{remote_addr} is not a trusted proxy " \
|
|
"HTTP_CLIENT_IP=#{@req.client_ip.inspect} " \
|
|
"HTTP_X_FORWARDED_FOR=#{@req.x_forwarded_for.inspect}"
|
|
end
|
|
|
|
# We assume these things about the IP headers:
|
|
#
|
|
# - X-Forwarded-For will be a list of IPs, one per proxy, or blank
|
|
# - Client-Ip is propagated from the outermost proxy, or is blank
|
|
# - REMOTE_ADDR will be the IP that made the request to Rack
|
|
ips = forwarded_ips + client_ips
|
|
ips.compact!
|
|
|
|
# If every single IP option is in the trusted list, return the IP that's
|
|
# furthest away
|
|
filter_proxies([remote_addr] + ips).first || ips.last || remote_addr
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
ActionDispatch::RemoteIp::GetIp.prepend(ActionDispatch::RemoteIp::GetIpExtensions)
|
|
|
|
# rubocop:enable all
|