gunicorn/tests/test_asgi_proxy_protocol.py
Benoit Chesneau 112d5353c1 fix: enforce proxy_allow_ips and tighten PROXY parsing in ASGI
Three findings against the ASGI PROXY protocol path:

- High: an untrusted peer could send a PROXY v1/v2 header and have the
  client address surfaced to the app. _setup_callback_parser now passes
  proxy_protocol='off' to the parser when the peer is not in
  proxy_allow_ips. _effective_peername adds a defensive re-check.
- Medium: PROXY v1 TCP4/TCP6 addresses were copied as strings without
  validation. Validate with socket.inet_pton, mirroring the WSGI parser.
- Medium: PROXY v2 quietly mapped non-STREAM (DGRAM) protocols to
  UDP4/UDP6. gunicorn is an HTTP server; reject non-STREAM with
  InvalidProxyHeader, mirroring the WSGI parser.
2026-05-03 22:28:48 +02:00

87 lines
3.2 KiB
Python

#
# This file is part of gunicorn released under the MIT license.
# See the NOTICE for more information.
"""ASGI PROXY protocol parser tests.
Covers the validation gaps that the WSGI parser already enforces:
- v1 TCP4/TCP6 addresses must be valid IP addresses (inet_pton).
- v2 must reject non-STREAM (UDP) protocols when family is INET/INET6.
"""
import struct
import pytest
from gunicorn.asgi.parser import (
PythonProtocol,
PP_V2_SIGNATURE,
InvalidProxyLine,
InvalidProxyHeader,
)
class TestProxyV1AddressValidation:
"""v1 must validate IPv4/IPv6 source/destination addresses."""
def test_v1_invalid_ipv4_source_rejected(self):
parser = PythonProtocol(proxy_protocol='v1')
with pytest.raises(InvalidProxyLine):
parser.feed(b"PROXY TCP4 not-an-ip 192.168.0.1 1 2\r\n")
def test_v1_invalid_ipv4_destination_rejected(self):
parser = PythonProtocol(proxy_protocol='v1')
with pytest.raises(InvalidProxyLine):
parser.feed(b"PROXY TCP4 192.168.0.1 999.999.999.999 1 2\r\n")
def test_v1_invalid_ipv6_source_rejected(self):
parser = PythonProtocol(proxy_protocol='v1')
with pytest.raises(InvalidProxyLine):
parser.feed(b"PROXY TCP6 not::an::ip ::1 1 2\r\n")
def test_v1_valid_ipv4_accepted(self):
parser = PythonProtocol(proxy_protocol='v1')
parser.feed(b"PROXY TCP4 192.168.0.1 192.168.0.11 56324 443\r\n")
assert parser.proxy_protocol_info['client_addr'] == '192.168.0.1'
assert parser.proxy_protocol_info['proxy_protocol'] == 'TCP4'
class TestProxyV2NonStreamRejected:
"""v2 must reject DGRAM (UDP) when family is INET or INET6."""
@staticmethod
def _v2_header(fam_proto, addr_payload):
ver_cmd = 0x21 # version 2, command PROXY
length = len(addr_payload)
header = struct.pack('>BBH', ver_cmd, fam_proto, length)
return PP_V2_SIGNATURE + header + addr_payload
def test_v2_inet_dgram_rejected(self):
# family=0x10 (INET), protocol=0x02 (DGRAM)
fam_proto = 0x12
addr_payload = b'\x01\x02\x03\x04\x05\x06\x07\x08' + b'\x00\x50\x01\xbb'
data = self._v2_header(fam_proto, addr_payload)
parser = PythonProtocol(proxy_protocol='v2')
with pytest.raises(InvalidProxyHeader):
parser.feed(data)
def test_v2_inet6_dgram_rejected(self):
# family=0x20 (INET6), protocol=0x02 (DGRAM)
fam_proto = 0x22
addr_payload = b'\x00' * 32 + b'\x00\x50\x01\xbb'
data = self._v2_header(fam_proto, addr_payload)
parser = PythonProtocol(proxy_protocol='v2')
with pytest.raises(InvalidProxyHeader):
parser.feed(data)
def test_v2_inet_stream_accepted(self):
# family=0x10 (INET), protocol=0x01 (STREAM)
fam_proto = 0x11
addr_payload = b'\x01\x02\x03\x04\x05\x06\x07\x08' + b'\x00\x50\x01\xbb'
data = self._v2_header(fam_proto, addr_payload)
parser = PythonProtocol(proxy_protocol='v2')
# Followed by an HTTP request so the parser can transition out of
# the proxy_protocol state without hanging on more data.
parser.feed(data + b"GET / HTTP/1.1\r\nHost: e\r\n\r\n")
assert parser.proxy_protocol_info['proxy_protocol'] == 'TCP4'