Kai Wan

16 papers C 1Misc 1Journal 6Unranked 7
YearRankTypeTitle / Venue / Authors
2025 J jnl
CoRR
Min Xu, Xuejiao Han, Kai Wan, Gennian Ge
2025 J jnl
CoRR
Zhenhao Huang, Minquan Cheng, Kai Wan, Qifu Tyler Sun, Youlong Wu
2023 conf
CCIS
Tong Liu, Jianchu Liang, Kai Wan, Jun Liu
2023 conf
ICCT
Rui Jiang, Jin Liu, Kai Wan, Changbo Hou
2021 conf
ComComAP
Leitang Huang, Xiaojun Li, Minquan Cheng, Kai Wan
2021 J jnl
IEEE Wirel. Commun. Lett.
Xiaojun Li, Qiaoling Zhang, Minquan Cheng, Kai Wan
2020 C conf
ICCC
Kai Wan, Zhen Wang, Yuanyuan Wang, Chi Zhang, Jianqing Liu
2019 J jnl
Phys. Commun.
Bin Han, Yang Lu, Kai Wan, Hans D. Schotten
2019 conf
ICC
Yuanyuan Wang, Kai Wan, Chi Zhang, Xia Zhang, Miao Pan
2018
Kai Wan
2018 conf
WCSP
Mengyuan Cheng, Kai Wan, Fan Wei, Fuyong Zheng, Yongpeng Wu
2018 J jnl
CoRR
Mengyuan Cheng, Kai Wan, Fan Wei, Fuyong Zheng, Yongpeng Wu
2016 conf
ISPLC
Hongjian Gao, Weilin Liu, Kai Wan, Jianqi Li
2015 conf
ICC
Jianxiao Yang, Kai Wan, Benoit Geller, Charbel Abdel Nour, Olivier Rioul, Catherine Douillard
2015 J jnl
CoRR
Jianxiao Yang, Kai Wan, Benoit Geller, Charbel Abdel Nour, Olivier Rioul, Catherine Douillard
2014 Misc conf
ICASSP
Kai Wan, Jinghui Liu, Michel Kieffer, Pierre Duhamel
redb/extractors/apk_extractors/apk_features.py
← Index redb/extractors/apk_extractors/apk_features.py python
import inspect
import zipfile
from datetime import datetime, timezone
from typing import Any

from redb.extractors.enum import Tag
from redb.extractors.apk_extractor import APKExtractor
from redb.models.dataclasses import APKFeatures


class APKFeaturesExtractor(APKExtractor):

    def __init__(
        self, filepath, log, exporters=None, index_prefix=None,
        known_benign=False, known_malicious=False,
        apk=None,
    ):
        super().__init__(
            filepath, log, exporters, index_prefix,
            known_benign, known_malicious, apk,
        )
        self.apk_features = None
        self.log.debug(inspect.currentframe().f_code.co_name)

    def tag(self):
        return Tag.APK_FEATURES.value

    def _extract_zip_timestamps(self):
        """Extract earliest and latest content modification from ZIP entries."""
        earliest = None
        latest = None
        try:
            zf = self._get_zip_file()
            if zf:
                with zf:
                    for info in zf.infolist():
                        try:
                            dt = datetime(*info.date_time)
                            if earliest is None or dt < earliest:
                                earliest = dt
                            if latest is None or dt > latest:
                                latest = dt
                        except (ValueError, TypeError):
                            continue
        except Exception as e:
            self.log.warning(f"Error extracting ZIP timestamps: {e}")
        return (
            earliest.isoformat() if earliest else None,
            latest.isoformat() if latest else None,
        )

    def _extract_supported_abis(self):
        """Determine supported ABIs from lib/ directory."""
        abis = set()
        for f in self._list_files():
            if f.startswith("lib/") and f.endswith(".so"):
                parts = f.split("/")
                if len(parts) >= 3:
                    abis.add(parts[1])
        return sorted(abis)

    def _count_dex_files(self):
        """Count DEX files and compute total size."""
        dex_count = 0
        total_size = 0
        try:
            zf = self._get_zip_file()
            if zf:
                with zf:
                    for info in zf.infolist():
                        if info.filename.endswith(".dex"):
                            dex_count += 1
                            total_size += info.file_size
        except Exception as e:
            self.log.warning(f"Error counting DEX files: {e}")
        return dex_count, total_size

    def _check_embedded_apk(self):
        """Check if the archive contains nested APK files."""
        for f in self._list_files():
            if f.lower().endswith(".apk"):
                return True
        return False

    def _safe_extract(self, field_name, func, default=None):
        """Extract a single field, logging and returning default on failure."""
        try:
            return func()
        except Exception as e:
            self.log.warning(
                f"Error extracting APK field '{field_name}' for "
                f"{self.hash.sha256}: {e}"
            )
            return default

    def extract(self):
        if not self._is_valid_apk():
            self.log.error(f"Invalid APK for {self.hash.sha256}")
            return None

        package_name = self._safe_extract(
            "package_name", lambda: self.apk.get_package()
        )
        app_name = self._safe_extract(
            "app_name", lambda: self.apk.get_app_name()
        )

        def _get_version_code():
            try:
                return int(self.apk.get_androidversion_code() or 0)
            except (ValueError, TypeError):
                return 0

        version_code = self._safe_extract("version_code", _get_version_code)
        version_name = self._safe_extract(
            "version_name", lambda: self.apk.get_androidversion_name()
        )

        def _get_sdk(getter):
            val = getter()
            return int(val) if val else None

        min_sdk = self._safe_extract(
            "min_sdk_version", lambda: _get_sdk(self.apk.get_min_sdk_version)
        )
        target_sdk = self._safe_extract(
            "target_sdk_version", lambda: _get_sdk(self.apk.get_target_sdk_version)
        )
        compile_sdk = self._safe_extract(
            "compile_sdk_version",
            lambda: _get_sdk(self.apk.get_effective_target_sdk_version),
        )

        main_activity = self._safe_extract(
            "main_activity", lambda: self.apk.get_main_activity()
        )

        is_debuggable = self._safe_extract(
            "is_debuggable",
            lambda: self.apk.get_attribute_value(
                "application", "debuggable"
            ) == "true",
            False,
        )
        allow_backup = self._safe_extract(
            "allow_backup",
            lambda: self.apk.get_attribute_value(
                "application", "allowBackup"
            ) != "false",
            True,
        )
        uses_cleartext = self._safe_extract(
            "uses_cleartext_traffic",
            lambda: self.apk.get_attribute_value(
                "application", "usesCleartextTraffic"
            ) == "true",
            False,
        )

        supported_abis = self._safe_extract(
            "supported_abis", self._extract_supported_abis, []
        )
        dex_count, total_dex_size = self._safe_extract(
            "dex_files", self._count_dex_files, (0, 0)
        )
        all_files = self._safe_extract("file_list", self._list_files, [])
        total_file_count = len(all_files)
        has_native_code = any(
            f.startswith("lib/") and f.endswith(".so") for f in all_files
        )
        has_assets = any(f.startswith("assets/") for f in all_files)
        contains_embedded_apk = self._safe_extract(
            "contains_embedded_apk", self._check_embedded_apk, False
        )

        uses_libraries = self._safe_extract(
            "uses_libraries",
            lambda: list(self.apk.get_libraries() or []),
            [],
        )

        earliest_mod, latest_mod = self._safe_extract(
            "zip_timestamps", self._extract_zip_timestamps, (None, None)
        )

        self.apk_features = APKFeatures(
            package_name=package_name,
            app_name=app_name,
            version_code=version_code,
            version_name=version_name,
            min_sdk_version=min_sdk,
            target_sdk_version=target_sdk,
            compile_sdk_version=compile_sdk,
            main_activity=main_activity,
            is_debuggable=is_debuggable,
            allow_backup=allow_backup,
            uses_cleartext_traffic=uses_cleartext,
            supported_abis=supported_abis,
            dex_count=dex_count,
            total_dex_size=total_dex_size,
            total_file_count=total_file_count,
            has_native_code=has_native_code,
            has_assets=has_assets,
            uses_libraries=uses_libraries,
            earliest_content_modification=earliest_mod,
            latest_content_modification=latest_mod,
            contains_embedded_apk=contains_embedded_apk,
        )
        return self.apk_features

    def prepare_export_data(self, exporter_type: str) -> Any:
        if exporter_type == "ClickHouseExporter":
            if not self.apk_features:
                return None

            f = self.apk_features
            current_time = datetime.now(timezone.utc)
            data = [[
                self.sha256,
                f.package_name,
                f.app_name,
                f.version_code,
                f.version_name,
                f.min_sdk_version,
                f.target_sdk_version,
                f.compile_sdk_version,
                f.main_activity,
                int(f.is_debuggable),
                int(f.allow_backup),
                int(f.uses_cleartext_traffic),
                f.supported_abis,
                f.dex_count,
                f.total_dex_size,
                f.total_file_count,
                int(f.has_native_code),
                int(f.has_assets),
                f.uses_libraries,
                f.earliest_content_modification,
                f.latest_content_modification,
                int(f.contains_embedded_apk),
                current_time,
            ]]

            column_names = [
                "sha256",
                "package_name", "app_name", "version_code", "version_name",
                "min_sdk_version", "target_sdk_version", "compile_sdk_version",
                "main_activity",
                "is_debuggable", "allow_backup", "uses_cleartext_traffic",
                "supported_abis",
                "dex_count", "total_dex_size", "total_file_count",
                "has_native_code", "has_assets",
                "uses_libraries",
                "earliest_content_modification", "latest_content_modification",
                "contains_embedded_apk",
                "analysis_date",
            ]

            column_type_names = [
                "FixedString(64)",
                "Nullable(String)", "Nullable(String)", "Nullable(UInt32)", "Nullable(String)",
                "Nullable(UInt16)", "Nullable(UInt16)", "Nullable(UInt16)",
                "Nullable(String)",
                "UInt8", "UInt8", "UInt8",
                "Array(String)",
                "UInt16", "UInt64", "UInt32",
                "UInt8", "UInt8",
                "Array(String)",
                "Nullable(String)", "Nullable(String)",
                "UInt8",
                "DateTime64(3, 'UTC')",
            ]

            return (data, column_names, column_type_names)

    def get_clickhouse_table(self) -> str:
        return "redb_apk_features"