Files
LangBot/tests/unit_tests/platform/test_slack_media.py
T
RockChinQandmultica-agent c759da50b1 fix(adapters): stop SSRF and arbitrary local file reads in media handling (#2753)
The platform adapters fetch URLs and open paths that come from inbound
messages, so both are attacker-influenced.

New guard module pkg/utils/outbound_url.py:

- assert_safe_outbound_url: checks the scheme, rejects literal private /
  loopback / link-local / reserved / multicast addresses, and resolves the
  hostname so a public-looking name pointing at an internal address is refused
  too. Optional allowed_domains confines a fetch to a known prefix.
- assert_safe_local_media_path: resolves a caller-supplied path and requires it
  to stay inside the media roots (data dir + temp dir), so symlinks and .. cannot
  escape. Directories are refused.

Wired in:

- DingTalk send_message: session_webhook is taken from the inbound event and was
  POSTed verbatim, so a forged event could redirect reply content (including LLM
  output) to any host. Now restricted to dingtalk.com.
- DingTalk send_attachment: component.url was fetched with no destination check;
  now goes through the SSRF guard, which also covers cloud metadata.
- DingTalk upload_image_media: caller-supplied file_path was opened directly; now
  confined to the media roots.
- Slack attachment_bytes: component.path was opened directly and uploaded to the
  channel (arbitrary file exfiltration); now confined to the media roots.
- Slack download_media: redirects were followed with no destination check. Every
  hop is now validated, the hop count is bounded, and a redirect off the Slack
  domain drops the bearer token.

Tests: 25 new cases for the guard (internal address forms, scheme rejection,
suffix impostor, traversal, symlink escape, directory). The Slack credential test
now stubs DNS because the guard resolves before fetching, and asserts
allow_redirects is False for every case since redirects are handled manually.

Co-authored-by: multica-agent <[email protected]>
2026-10-22 20:46:27 +08:00

214 lines
7.8 KiB
Python

import socket
import base64
from types import SimpleNamespace
from unittest.mock import AsyncMock, patch
import pytest
from slack_sdk.web.async_slack_response import AsyncSlackResponse
from langbot.libs.slack_api.api import SlackClient
from langbot.libs.slack_api.media import attachment_bytes, download_media, send_chain
from langbot.libs.slack_api.slackevent import SlackEvent
from langbot.pkg.platform.adapters.slack.message_converter import SlackMessageConverter
from langbot_plugin.api.entities.builtin.platform import message as pm
def sdk_response(data):
return AsyncSlackResponse(
client=None,
http_verb='POST',
api_url='https://slack.com/api/test',
req_args={},
data=data,
headers={},
status_code=200,
)
@pytest.mark.asyncio
@pytest.mark.parametrize('target_type,target_id', [('person', 'U123'), ('channel', 'C123')])
async def test_real_sdk_responses_for_text_and_attachment(target_type, target_id):
client = SlackClient('test-token', '', SimpleNamespace(error=AsyncMock()), unified_mode=True)
text_data = {'ok': True, 'channel': 'C123', 'message': {'ts': '1.2', 'bot_id': 'B123'}}
file_data = {'ok': True, 'files': [{'id': 'F123'}]}
client.client = SimpleNamespace(
chat_postMessage=AsyncMock(return_value=sdk_response(text_data)),
conversations_open=AsyncMock(return_value=sdk_response({'ok': True, 'channel': {'id': 'D123'}})),
files_upload_v2=AsyncMock(return_value=sdk_response(file_data)),
)
result = await send_chain(
client,
target_type,
target_id,
pm.MessageChain(
[
pm.Plain(text='picture'),
pm.File(name='image.png', base64='dGVzdA=='),
]
),
)
assert result['responses'] == [text_data, file_data]
assert client.client.chat_postMessage.await_count == 1
assert client.client.files_upload_v2.await_count == 1
def bot():
return SimpleNamespace(
bot_token='test-token',
client=SimpleNamespace(
conversations_open=AsyncMock(return_value={'ok': True, 'channel': {'id': 'D123'}}),
files_upload_v2=AsyncMock(return_value={'ok': True, 'files': [{'id': 'F123'}]}),
),
send_message_to_one=AsyncMock(return_value={'ok': True}),
send_message_to_channel=AsyncMock(return_value={'ok': True}),
)
@pytest.mark.asyncio
async def test_svg_base64_is_uploaded_to_dm_not_sent_as_filename():
client = bot()
svg = b'<svg xmlns="http://www.w3.org/2000/svg"/>'
await send_chain(
client,
'person',
'U123',
pm.MessageChain(
[
pm.Plain(text='Here is the picture'),
pm.File(name='moon.svg', base64=base64.b64encode(svg).decode()),
]
),
)
client.send_message_to_one.assert_awaited_once_with('Here is the picture', 'U123')
client.client.conversations_open.assert_awaited_once_with(users=['U123'])
client.client.files_upload_v2.assert_awaited_once_with(
channel='D123', file=svg, filename='moon.svg', title='moon.svg'
)
@pytest.mark.asyncio
async def test_multiple_attachments_to_channel_preserve_bytes_and_text_order(tmp_path):
client = bot()
path = tmp_path / 'notes.txt'
path.write_bytes(b'hello')
await send_chain(
client,
'channel',
'C123',
pm.MessageChain(
[
pm.Image(base64='data:image/png;base64,' + base64.b64encode(b'png bytes').decode()),
pm.File(path=str(path)),
pm.Plain(text='done'),
]
),
)
calls = client.client.files_upload_v2.await_args_list
assert [c.kwargs['file'] for c in calls] == [b'png bytes', b'hello']
assert [c.kwargs['filename'] for c in calls] == ['attachment.png', 'notes.txt']
client.client.conversations_open.assert_not_awaited()
client.send_message_to_channel.assert_awaited_once_with('done', 'C123')
@pytest.mark.asyncio
async def test_upload_failure_is_not_reported_as_success():
client = bot()
client.client.files_upload_v2.return_value = {'ok': False, 'error': 'missing_scope'}
with pytest.raises(RuntimeError, match='missing_scope'):
await send_chain(
client,
'channel',
'C123',
pm.MessageChain(
[
pm.File(name='test.txt', base64='dGVzdA=='),
]
),
)
@pytest.mark.asyncio
async def test_missing_attachment_data_fails_instead_of_faking_delivery():
with pytest.raises(ValueError, match='no base64'):
await attachment_bytes(pm.File(name='missing.txt'))
@pytest.mark.asyncio
async def test_local_bytes_take_priority_over_private_url():
data, name = await attachment_bytes(
pm.File(name='file.txt', url='https://files.slack.com/private', base64='dGVzdA==')
)
assert (data, name) == (b'test', 'file.txt')
@pytest.mark.asyncio
async def test_received_multiple_files_keep_type_and_authenticated_bytes():
event = SlackEvent(
{
'event': {
'channel_type': 'im',
'text': 'attachments',
'files': [
{'id': 'F1', 'name': 'a.png', 'mimetype': 'image/png', 'url_private': 'https://files.slack.com/a'},
{
'id': 'F2',
'name': 'b.pdf',
'mimetype': 'application/pdf',
'url_private': 'https://files.slack.com/b',
},
],
}
}
)
with patch(
'langbot.pkg.platform.adapters.slack.message_converter.download_media',
new=AsyncMock(return_value=(b'data', 'application/octet-stream')),
) as download:
chain = await SlackMessageConverter.target2yiri(event, 'test-token')
assert isinstance(chain[1], pm.Image)
assert chain[1].base64 == 'data:image/png;base64,ZGF0YQ=='
assert isinstance(chain[2], pm.File) and chain[2].name == 'b.pdf'
assert chain[2].base64 == 'ZGF0YQ=='
assert chain[3].text == 'attachments'
assert download.await_count == 2
@pytest.mark.asyncio
@pytest.mark.parametrize(
'url,authenticated',
[
('https://files.slack.com/file', True),
('https://example.com/file', False),
('https://files.slack.com.evil.test/file', False),
],
)
async def test_download_credentials_are_scoped_to_slack(url, authenticated):
response = SimpleNamespace(status=200, headers={'Content-Type': 'image/png'})
context = AsyncMock()
context.__aenter__.return_value = response
with (
patch('langbot.libs.slack_api.media.httpclient.get_session') as session,
patch('langbot.libs.slack_api.media.httpclient.read_limited', new=AsyncMock(return_value=b'png')),
# The SSRF guard resolves the host before fetching; the fake hosts in this
# test have no DNS record, so resolution is stubbed to a public address.
patch(
'langbot.pkg.utils.outbound_url.socket.getaddrinfo',
return_value=[(socket.AF_INET, socket.SOCK_STREAM, 6, '', ('93.184.216.34', 443))],
),
):
session.return_value.get.return_value = context
assert await download_media(url, 'test-token') == (b'png', 'image/png')
kwargs = session.return_value.get.call_args.kwargs
assert bool(kwargs['headers']) == authenticated
assert kwargs['allow_redirects'] is False
@pytest.mark.asyncio
async def test_download_http_failure_is_visible():
context = AsyncMock()
context.__aenter__.return_value = SimpleNamespace(status=403)
with patch('langbot.libs.slack_api.media.httpclient.get_session') as session:
session.return_value.get.return_value = context
with pytest.raises(ValueError, match='HTTP 403'):
await download_media('https://files.slack.com/file', 'test-token')