Kai Yen

24 papers B 9C 1Journal 8Unranked 6
YearRankTypeTitle / Venue / Authors
2025 conf
VTC2025-Fall
Kai Yen, Xiaojuan Zhang, Amnart Boonkajay, Hongbo Sun, Francois Chin Po Shin
2020 B conf
GLOBECOM
Beixiong Zheng, Kai Yen, Xiaoming Peng, Rui Zhang
2012 conf
WPMC
Kai Yen, Sumei Sun, Ubolthip Sethakaset, Peng Hui Tan, Zhengguo Li, Jinghong Zheng
2011 conf
VTC Spring
Ernest Kurniawan, Kai Fong Ernest Chong, Sumei Sun, Kai Yen
2011 J jnl
IEEE Trans. Commun.
Ernest Kurniawan, Sumei Sun, Kai Yen, Kai Fong Ernest Chong
2011 B conf
WCNC
Ernest Kurniawan, Kai Fong Ernest Chong, Sumei Sun, Kai Yen
2010 J jnl
CoRR
Kai Fong Ernest Chong, Ernest Kurniawan, Sumei Sun, Kai Yen
2010 C conf
ISITA
Ernest Kurniawan, Sumei Sun, Kai Yen, Kai Fong Ernest Chong
2010 J jnl
CoRR
Ernest Kurniawan, Sumei Sun, Kai Yen, Kai Fong Ernest Chong
2010 B conf
WCNC
Ernest Kurniawan, Sumei Sun, Kai Yen, Kai Fong Ernest Chong
2009 B conf
PIMRC
Ernest Kurniawan, Sumei Sun, Kai Yen
2008 B conf
WCNC
Hongyi Fu, Sumei Sun, Kai Yen, Yuen Sam Kwok
2008 conf
VTC Spring
Hongyi Fu, Kai Yen, Yuen Sam Kwok, Sumei Sun
2007 conf
VTC Spring
Kai Yen, Juha Karjalainen, Tadashi Matsumoto
2007 J jnl
EURASIP J. Wirel. Commun. Netw.
Huahui Wang, Kai Yen, Kay Wee Ang, Yong Huat Chew
2004 J jnl
IEEE Trans. Veh. Technol.
Kai Yen, Lajos Hanzo
2003 J jnl
IEEE Trans. Commun.
Kai Yen, Lajos Hanzo
2003 B conf
WCNC
Soon Xin Ng, Kai Yen, Lajos Hanzo
2003 B conf
PIMRC
Huahui Wang, Kai Yen, Kay Wee Ang, Yong Huat Chew
2002 B conf
PIMRC
Kai Yen
2001 J jnl
IEEE J. Sel. Areas Commun.
Kai Yen, Lajos Hanzo
2001 conf
ICC
Kai Yen, Lajos Hanzo
2000 J jnl
IEEE J. Sel. Areas Commun.
Lie-Liang Yang, Kai Yen, Lajos Hanzo
2000 B conf
PIMRC
Lie-Liang Yang, Kai Yen, Markus Dillinger, Lajos Hanzo
tests/unit/conftest.py
← Index tests/unit/conftest.py python
"""
Unit test configuration.

Replaces the redb.extractors package with a minimal stub so that
``from redb.extractors.database_exporters import ...`` works without
pulling in the heavy __init__.py import chain (pefile, elftools,
signify, magic, etc.).

Also stubs out redb.settings so that Elasticsearch / ClickHouse
clients are never actually created during unit tests.

Additionally installs binaryninja stubs for decompiler unit tests.

Stubs heavy third-party packages (pefile, magic, psutil, etc.) so that
redb.workers, redb.queries, redb.ingestor, and redb.s3_utils can all
be imported and patched in unit tests without requiring the real packages.
"""
import sys
import types
from pathlib import Path
from unittest.mock import MagicMock

# ---------------------------------------------------------------------------
# 0. Install binaryninja stubs FIRST — must happen before any decompiler
#    module is imported (triggered by __init__.py chain).
# ---------------------------------------------------------------------------
from tests.unit.conftest_binja_stubs import install_binja_stubs as _install_binja_stubs
_install_binja_stubs()

# ---------------------------------------------------------------------------
# 1. Stub external packages required by database_exporters.py itself,
#    the decompiler chain, and the workers/ingestor modules.
# ---------------------------------------------------------------------------
_heavy_deps = [
    # Database / networking
    "elasticsearch", "clickhouse_connect", "dotenv",
    # Binary analysis — top-level packages
    "pefile", "magic", "machofile",
    # Archive handling
    "py7zr", "pyzipper",
    # File type detection
    "magika",
    # System monitoring
    "psutil",
    # S3 / MinIO (submodule paths needed for `from minio.error import S3Error`)
    "minio", "minio.error",
    # YARA
    "yara_x",
    # Binary parsing — elftools tree
    "elftools", "elftools.elf", "elftools.elf.elffile",
    "elftools.common", "elftools.common.exceptions",
    # Code signing — signify tree
    "signify", "signify.fingerprinter", "signify.authenticode",
    # LIEF
    "lief",
    # Fuzzy hashing
    "ppdeep",
    # .NET analysis
    "dotnetfile",
    # Crypto / ASN.1
    "asn1crypto", "asn1crypto.cms", "asn1crypto.pem", "asn1crypto.x509", "asn1crypto.core",
    # Hashing
    "xxhash", "blake3", "mmh3", "numpy",
    # APK analysis
    "androguard", "androguard.core", "androguard.core.apk",
    "androguard.core.dex", "androguard.core.api_specific_resources",
    "androguard.misc",
    "permhash",
]
for _mod in _heavy_deps:
    if _mod not in sys.modules:
        try:
            __import__(_mod)
        except (ImportError, ModuleNotFoundError):
            sys.modules[_mod] = MagicMock()

# Stub urllib3 with a real Warning subclass (warnings.filterwarnings needs a class)
if "urllib3" not in sys.modules or isinstance(sys.modules.get("urllib3"), MagicMock):
    try:
        import urllib3  # noqa: F401
    except (ImportError, ModuleNotFoundError):
        _urllib3_mod = types.ModuleType("urllib3")
        _urllib3_exc = types.ModuleType("urllib3.exceptions")

        class _InsecureRequestWarning(UserWarning):
            pass

        _urllib3_exc.InsecureRequestWarning = _InsecureRequestWarning
        _urllib3_mod.exceptions = _urllib3_exc
        sys.modules["urllib3"] = _urllib3_mod
        sys.modules["urllib3.exceptions"] = _urllib3_exc

# Provide a functional ppdeep stub (tests call ppdeep.hash() and expect a string).
# Must overwrite the MagicMock that the loop above may have installed.
_ppdeep_existing = sys.modules.get("ppdeep")
if _ppdeep_existing is None or isinstance(_ppdeep_existing, MagicMock):
    _ppdeep_mod = types.ModuleType("ppdeep")
    _ppdeep_mod.__name__ = "ppdeep"

    def _ppdeep_hash(data):
        """Fake ssdeep hash — returns a deterministic placeholder."""
        if isinstance(data, str):
            data = data.encode("utf-8")
        if len(data) < 50:
            return None
        import hashlib
        h = hashlib.md5(data).hexdigest()
        return f"3:{h[:16]}:{h[16:]}"

    _ppdeep_mod.hash = _ppdeep_hash
    sys.modules["ppdeep"] = _ppdeep_mod

# Stub mmh3 if the C extension is not available
_mmh3_existing = sys.modules.get("mmh3")
if _mmh3_existing is None or isinstance(_mmh3_existing, MagicMock):
    _mmh3_mod = types.ModuleType("mmh3")
    _mmh3_mod.__name__ = "mmh3"

    def _mmh3_hash(data, seed=0):
        """Fake MurmurHash3 — deterministic hash using built-in hashlib."""
        import hashlib
        if isinstance(data, str):
            data = data.encode("utf-8")
        seed_bytes = (seed & 0xFFFFFFFF).to_bytes(8, "little")
        h = hashlib.md5(data + seed_bytes).digest()
        return int.from_bytes(h[:4], "little", signed=True)

    _mmh3_mod.hash = _mmh3_hash
    sys.modules["mmh3"] = _mmh3_mod

# Stub tlsh if the C extension is not available
if "tlsh" not in sys.modules:
    try:
        import tlsh as _real_tlsh  # noqa: F401
    except (ImportError, ModuleNotFoundError):
        _tlsh_mock = types.ModuleType("tlsh")
        _tlsh_mock.__name__ = "tlsh"

        def _tlsh_hash(data):
            """Fake TLSH hash — returns a deterministic placeholder.

            Returns empty string for data < 50 bytes or data with very
            low entropy (e.g. repeating patterns), mimicking the real
            TLSH library's "TNULL" behaviour.
            """
            if isinstance(data, str):
                data = data.encode("utf-8")
            if len(data) < 50:
                return ""
            # Real TLSH returns "" for low-entropy input
            if len(set(data)) < 8:
                return ""
            import hashlib
            return "T1" + hashlib.sha256(data).hexdigest()[:70].upper()

        _tlsh_mock.hash = _tlsh_hash
        sys.modules["tlsh"] = _tlsh_mock

# ---------------------------------------------------------------------------
# 2. Stub redb.settings (package) so module-level code never runs
# ---------------------------------------------------------------------------
_settings_mock = MagicMock()
_settings_mock.__name__ = "redb.settings"
sys.modules["redb.settings"] = _settings_mock
sys.modules["redb.settings.elasticsearch"] = MagicMock()
sys.modules["redb.settings.clickhouse"] = MagicMock()

# ---------------------------------------------------------------------------
# 3. Replace redb.extractors with a minimal package that does NOT eagerly
#    import every extractor (and their heavy deps).  Sub-module imports
#    like ``from redb.extractors.database_exporters import ...`` still work
#    because __path__ points to the real package directory.
# ---------------------------------------------------------------------------
_repo_root = Path(__file__).resolve().parents[2]
_extractors_pkg = types.ModuleType("redb.extractors")
_extractors_pkg.__path__ = [str(_repo_root / "redb" / "extractors")]
_extractors_pkg.__package__ = "redb.extractors"
sys.modules["redb.extractors"] = _extractors_pkg

# ---------------------------------------------------------------------------
# 4. Force-import redb submodules so that @patch('redb.workers.xxx'),
#    @patch('redb.queries.xxx'), etc. can resolve at decoration time.
#    This works because all heavy deps are already stubbed above.
# ---------------------------------------------------------------------------
import redb.logging_utils   # noqa: F401, E402
import redb.s3_utils         # noqa: F401, E402
import redb.queries          # noqa: F401, E402
import redb.workers          # noqa: F401, E402
import redb.ingestor         # noqa: F401, E402