MeshChatX/tests/backend/test_security_exploratory_oracle.py

216 lines
7.4 KiB
Python

# SPDX-License-Identifier: 0BSD
"""Exploratory fuzzing and light oracles for hardened security surfaces.
Oracles are intentional invariants (not full differential testing):
- WebAudioSource never raises on arbitrary PCM and drops oversized frames
- call timeout parse always lands in [1, 120]
- attachment-like field shapes never crash normalize helpers
"""
from __future__ import annotations
import base64
from unittest.mock import MagicMock
import numpy as np
import pytest
from hypothesis import HealthCheck, given, settings
from hypothesis import strategies as st
from meshchatx.src.backend.call_timeout import (
MAX_CALL_TIMEOUT_SECONDS,
MIN_CALL_TIMEOUT_SECONDS,
clamp_call_timeout_seconds,
)
from meshchatx.src.backend.web_audio_bridge import WebAudioSource
class _Sink:
def __init__(self):
self.frames = []
def can_receive(self, from_source=None):
return True
def handle_frame(self, frame, source=None):
self.frames.append(frame)
# ---------------------------------------------------------------------------
# Light oracles: call timeout
# ---------------------------------------------------------------------------
@settings(deadline=None, max_examples=80, suppress_health_check=[HealthCheck.too_slow])
@given(
raw=st.one_of(
st.none(),
st.integers(min_value=-10_000, max_value=10_000),
st.text(max_size=40),
st.sampled_from(
["", "15", "0", "-1", "999999", "1.5", "nan", "0x10", "timeout"]
),
),
)
def test_oracle_call_timeout_always_in_bounds(raw):
"""Oracle: every parseable/unparseable input clamps into the safe window."""
out = clamp_call_timeout_seconds(raw)
assert MIN_CALL_TIMEOUT_SECONDS <= out <= MAX_CALL_TIMEOUT_SECONDS
def test_oracle_call_timeout_known_cases():
assert clamp_call_timeout_seconds(None) == 15
assert clamp_call_timeout_seconds("15") == 15
assert clamp_call_timeout_seconds("1") == 1
assert clamp_call_timeout_seconds("120") == 120
assert clamp_call_timeout_seconds("0") == 1
assert clamp_call_timeout_seconds("-5") == 1
assert clamp_call_timeout_seconds("99999") == 120
assert clamp_call_timeout_seconds("nope") == 15
# ---------------------------------------------------------------------------
# Exploratory + oracle: web audio PCM
# ---------------------------------------------------------------------------
@settings(deadline=None, max_examples=60, suppress_health_check=[HealthCheck.too_slow])
@given(pcm=st.binary(min_size=0, max_size=WebAudioSource.MAX_PCM_BYTES + 4096))
def test_exploratory_web_audio_source_never_raises(pcm):
"""Exploratory: arbitrary PCM must not crash push_pcm."""
sink = _Sink()
src = WebAudioSource(target_frame_ms=60, sink=sink)
try:
src.push_pcm(pcm)
except Exception as exc:
pytest.fail(f"push_pcm raised: {exc}")
@settings(
deadline=None,
max_examples=30,
suppress_health_check=[HealthCheck.too_slow, HealthCheck.large_base_example],
)
@given(extra=st.integers(min_value=1, max_value=4096))
def test_oracle_web_audio_drops_oversized_pcm(extra):
"""Oracle: frames above MAX_PCM_BYTES never reach the sink."""
pcm = b"\x00" * (WebAudioSource.MAX_PCM_BYTES + extra)
sink = _Sink()
src = WebAudioSource(target_frame_ms=60, sink=sink)
src.push_pcm(pcm)
assert sink.frames == []
def test_oracle_web_audio_drops_exact_oversize_boundary():
sink = _Sink()
src = WebAudioSource(target_frame_ms=60, sink=sink)
src.push_pcm(b"\x00" * (WebAudioSource.MAX_PCM_BYTES + 1))
assert sink.frames == []
src.push_pcm(np.zeros(160, dtype=np.int16).tobytes())
assert len(sink.frames) == 1
# ---------------------------------------------------------------------------
# Light oracles: attachment-like field shapes (mirror serve guards)
# ---------------------------------------------------------------------------
def _safe_image_type(raw) -> str:
allowed = {"png", "jpeg", "jpg", "gif", "webp", "bmp"}
image_type = raw if isinstance(raw, str) else "png"
image_type = image_type.lower().replace("image/", "").strip() or "png"
if image_type not in allowed:
image_type = "png"
return image_type
def _resolve_served_image_type(image_data: bytes, declared=None) -> str | None:
"""Mirror meshchat LXMF image serve: Content-Type from magic only."""
from meshchatx.src.backend.sticker_utils import detect_image_format_from_magic
allowed = {"png", "jpeg", "jpg", "gif", "webp", "bmp"}
detected = detect_image_format_from_magic(image_data)
if detected is None or detected not in allowed:
return None
return "jpeg" if detected == "jpeg" else detected
def _try_b64(raw):
if not isinstance(raw, str) or not raw:
return None
try:
return base64.b64decode(raw)
except Exception:
return None
@settings(deadline=None, max_examples=80, suppress_health_check=[HealthCheck.too_slow])
@given(
image_type=st.one_of(
st.none(),
st.integers(),
st.booleans(),
st.lists(st.text(max_size=8), max_size=3),
st.text(max_size=40),
st.sampled_from(
["png", "PNG", "image/jpeg", "svg", "svg+xml", "webm", "", " "]
),
),
)
def test_oracle_image_type_always_allowlisted(image_type):
"""Oracle: served image types collapse to the raster allowlist."""
out = _safe_image_type(image_type)
assert out in {"png", "jpeg", "jpg", "gif", "webp", "bmp"}
@settings(deadline=None, max_examples=60, suppress_health_check=[HealthCheck.too_slow])
@given(
raw=st.one_of(
st.none(),
st.binary(max_size=64).map(lambda b: base64.b64encode(b).decode("ascii")),
st.text(max_size=80),
st.integers(),
st.sampled_from(["", "====", "not-base64!!!", "A", "QQ=="]),
),
)
def test_exploratory_b64_decode_never_raises(raw):
"""Exploratory: attachment base64 decode path must not throw."""
try:
_try_b64(raw)
except Exception as exc:
pytest.fail(f"b64 helper raised: {exc}")
def test_oracle_known_bad_attachment_shapes_rejected():
assert _try_b64(None) is None
assert _try_b64(123) is None
assert _try_b64("") is None
assert _safe_image_type(None) == "png"
assert _safe_image_type(99) == "png"
assert _safe_image_type("svg") == "png"
assert _safe_image_type("image/webp") == "webp"
assert _resolve_served_image_type(b"<html>") is None
assert _resolve_served_image_type(b"\x89PNG\r\n\x1a\n" + b"\x00" * 8) == "png"
# ---------------------------------------------------------------------------
# Exploratory: bridge still never crashes with mocked sink under fuzz PCM
# ---------------------------------------------------------------------------
@settings(deadline=None, max_examples=40, suppress_health_check=[HealthCheck.too_slow])
@given(pcm=st.binary(min_size=0, max_size=WebAudioSource.MAX_PCM_BYTES + 2048))
def test_exploratory_bridge_push_with_real_source(pcm):
from meshchatx.src.backend.web_audio_bridge import WebAudioBridge
tele_mgr = MagicMock()
tele_mgr.is_voicemail_session_active = False
bridge = WebAudioBridge(tele_mgr, MagicMock())
sink = _Sink()
bridge.tx_source = WebAudioSource(target_frame_ms=60, sink=sink)
try:
bridge.push_client_frame(pcm)
except Exception as exc:
pytest.fail(f"push_client_frame raised: {exc}")
if len(pcm) > WebAudioSource.MAX_PCM_BYTES:
assert sink.frames == []