Karen Willcox

82 papers A* 1A 1C 1Misc 5Journal 65Unranked 9
YearRankTypeTitle / Venue / Authors
2026 A conf
LAK
Luwen Huang, Inderjit Dhillon, Karen Willcox
2025 J jnl
CoRR
Nicole Aretz, Karen Willcox
2025 J jnl
CoRR
Nicole Aretz, Thomas Lynn, Karen Willcox, Sven Leyffer
2025 J jnl
CoRR
Graham Pash, Umberto Villa, David A. Hormuth II, Thomas E. Yankeelov, Karen Willcox
2025 J jnl
CoRR
Vignesh Sella, Julie Pham, Karen Willcox, Anirban Chaudhuri
2025 J jnl
npj Digit. Medicine
Kaan Sel, Andrea Hawkins-Daarud, Anirban Chaudhuri, Deen Osman, Ahmad Bahai, David Paydarfar, Karen Willcox, Caroline Chung, Roozbeh Jafari
2025 J jnl
CoRR
Michael G. Kapteyn, Anirban Chaudhuri, Ernesto A. B. F. Lima, Graham Pash, Rafael Bravo, Karen Willcox, Thomas E. Yankeelov, David A. Hormuth II
2025 J jnl
CoRR
Guillermo Lorenzo, David A. Hormuth II, Chengyue Wu, Graham Pash, Anirban Chaudhuri, Ernesto A. B. F. Lima, Lois C. Okereke, Reshmi Patel, Karen Willcox, Thomas E. Yankeelov
2024 J jnl
Nat. Comput. Sci.
Alberto Ferrari, Karen Willcox
2024 conf
CDC
Nicole Aretz, Karen Willcox
2024 J jnl
CoRR
Julie Pham, Omar Ghattas, Noel Clemens, Karen Willcox
2024 J jnl
Nat. Comput. Sci.
Karen Willcox, Brittany Segundo
2023 conf
CDC
Rudy Geelen, Laura Balzano, Karen Willcox
2023 J jnl
CoRR
Rudy Geelen, Laura Balzano, Karen Willcox
2023 J jnl
CoRR
Rudy Geelen, Laura Balzano, Stephen Wright, Karen Willcox
2023 J jnl
CoRR
Parisa Khodabakhshi, Olena Burkovska, Karen Willcox, Max D. Gunzburger
2023 J jnl
CoRR
Anirban Chaudhuri, Graham Pash, David A. Hormuth II, Guillermo Lorenzo, Michael G. Kapteyn, Chengyue Wu, Ernesto A. B. F. Lima, Thomas E. Yankeelov, Karen Willcox
2023 J jnl
Frontiers Artif. Intell.
Anirban Chaudhuri, Graham Pash, David A. Hormuth, Guillermo Lorenzo, Michael G. Kapteyn, Chengyue Wu, Ernesto A. B. F. Lima, Thomas E. Yankeelov, Karen Willcox
2022 conf
DDDAS
Anirban Chaudhuri, Karen Willcox
2022 J jnl
CoRR
Rudy Geelen, Stephen Wright, Karen Willcox
2022 J jnl
SIAM J. Sci. Comput.
Elizabeth Qian, Ionut-Gabriel Farcas, Karen Willcox
2022 J jnl
CoRR
Sean McBane, Youngsoo Choi, Karen Willcox
2021 J jnl
CoRR
Thomas O'Leary-Roseberry, Xiaosong Du, Anirban Chaudhuri, Joaquim R. R. A. Martins, Karen Willcox, Omar Ghattas
2021 J jnl
CoRR
Anirban Chaudhuri, Boris Kramer, Matthew Norton, Johannes O. Royset, Karen Willcox
2021 J jnl
Acta Numer.
Omar Ghattas, Karen Willcox
2021 J jnl
CoRR
Elizabeth Qian, Ionut-Gabriel Farcas, Karen Willcox
2021 J jnl
Nat. Comput. Sci.
Steven A. Niederer, Michael S. Sacks, Mark Girolami, Karen Willcox
2020 J jnl
CoRR
Shane A. McQuarrie, Cheng Huang, Karen Willcox
2020 J jnl
CoRR
Peter Benner, Pawan Goyal, Boris Kramer, Benjamin Peherstorfer, Karen Willcox
2019 J jnl
CoRR
Renee Swischuk, Boris Kramer, Cheng Huang, Karen Willcox
2019 J jnl
CoRR
Elizabeth Qian, Boris Kramer, Benjamin Peherstorfer, Karen Willcox
2019 J jnl
CoRR
Boris Kramer, Alexandre Noll Marques, Benjamin Peherstorfer, Umberto Villa, Karen Willcox
2019 J jnl
J. Comput. Phys.
Boris Kramer, Alexandre Noll Marques, Benjamin Peherstorfer, Umberto Villa, Karen Willcox
2018 J jnl
SIAM/ASA J. Uncertain. Quantification
Matthias Heinkenschloss, Boris Kramer, Timur Takhtaganov, Karen Willcox
2018 A* conf
NeurIPS
Alexandre Noll Marques, Rémi Lam, Karen Willcox
2018 J jnl
Numerische Mathematik
Benjamin Peherstorfer, Max D. Gunzburger, Karen Willcox
2018 J jnl
SIAM J. Matrix Anal. Appl.
Ralf Zimmermann, Benjamin Peherstorfer, Karen Willcox
2018 J jnl
SIAM/ASA J. Uncertain. Quantification
Elizabeth Qian, Benjamin Peherstorfer, Daniel O'Malley, Velimir V. Vesselinov, Karen Willcox
2018 J jnl
SIAM/ASA J. Uncertain. Quantification
Benjamin Peherstorfer, Boris Kramer, Karen Willcox
2018 J jnl
CoRR
Boris Kramer, Karen Willcox
2018 J jnl
SIAM Rev.
Ulrich Rüde, Karen Willcox, Lois Curfman McInnes, Hans De Sterck
2018 J jnl
SIAM Rev.
Benjamin Peherstorfer, Karen Willcox, Max D. Gunzburger
2018 J jnl
CoRR
Benjamin Peherstorfer, Karen Willcox, Max D. Gunzburger
2017 J jnl
SIAM J. Sci. Comput.
Elizabeth Qian, Martin A. Grepl, Karen Veroy, Karen Willcox
2017 J jnl
Artif. Intell. Eng. Des. Anal. Manuf.
Sergio Amaral, Douglas L. Allaire, Elena De La Rosa Blanco, Karen Willcox
2017 J jnl
J. Comput. Phys.
Benjamin Peherstorfer, Boris Kramer, Karen Willcox
2017 J jnl
SIAM J. Sci. Comput.
Benjamin Peherstorfer, Serkan Gugercin, Karen Willcox
2017 J jnl
SIAM J. Appl. Dyn. Syst.
Boris Kramer, Benjamin Peherstorfer, Karen Willcox
2017 J jnl
SIAM J. Sci. Comput.
Alessio Spantini, Tiangang Cui, Karen Willcox, Luis Tenorio, Youssef M. Marzouk
2017 conf
NIPS
Rémi Lam, Karen Willcox
2017 J jnl
Stat. Comput.
Sergio Amaral, Douglas L. Allaire, Karen Willcox
2016 J jnl
SIAM J. Sci. Comput.
Ralf Zimmermann, Karen Willcox
2016 conf
NIPS
Rémi Lam, Karen Willcox, David H. Wolpert
2016 J jnl
Adv. Model. Simul. Eng. Sci.
Benjamin Peherstorfer, Karen Willcox
2016 J jnl
SIAM J. Sci. Comput.
Benjamin Peherstorfer, Karen Willcox, Max D. Gunzburger
2016 J jnl
CoRR
Ulrich Rüde, Karen Willcox, Lois Curfman McInnes, Hans De Sterck, George Biros, Hans-Joachim Bungartz, James Corones, Evin Cramer, James Crowley, Omar Ghattas, Max D. Gunzburger, Michael Hanke, Robert J. Harrison, Michael A. Heroux, Jan S. Hesthaven, Peter K. Jimack, Chris Johnson, Kirk E. Jordan, David E. Keyes, Rolf H. Krause, Vipin Kumar, Stefan Mayer, Juan Meza, Knut Martin Mørken, J. Tinsley Oden, Linda R. Petzold, Padma Raghavan, Suzanne M. Shontz, Anne E. Trefethen, Peter R. Turner, Vladimir V. Voevodin, Barbara I. Wohlmuth, Carol S. Woodward
2016 J jnl
J. Comput. Phys.
Tiangang Cui, Youssef M. Marzouk, Karen Willcox
2015 J jnl
SIAM J. Sci. Comput.
Qifeng Liao, Karen Willcox
2015 J jnl
SIAM Rev.
Peter Benner, Serkan Gugercin, Karen Willcox
2015 Misc conf
ICCS
Benjamin Peherstorfer, Karen Willcox
2015 J jnl
SIAM J. Sci. Comput.
Benjamin Peherstorfer, Karen Willcox
2014 J jnl
SIAM J. Sci. Comput.
Benjamin Peherstorfer, Daniel Butnaru, Karen Willcox, Hans-Joachim Bungartz
2014 Misc conf
ICCS
Douglas L. Allaire, D. Kordonowy, M. Lecerf, Laura Mainini, Karen Willcox
2014 J jnl
SIAM J. Sci. Comput.
Chad Lieberman, Karen Willcox
2014 J jnl
Reliab. Eng. Syst. Saf.
Douglas L. Allaire, George Noel, Karen Willcox, Rebecca Cointin
2013 Misc conf
ICCS
Douglas L. Allaire, J. Chambers, Raghvendra V. Cowlagi, David N. Kordonowy, M. Lecerf, Laura Mainini, F. Ulker, Karen Willcox
2013 J jnl
SIAM Rev.
Chad Lieberman, Karen Willcox
2012 J jnl
Reliab. Eng. Syst. Saf.
Douglas L. Allaire, Karen Willcox
2012 Misc conf
ICCS
Douglas L. Allaire, George Biros, J. Chambers, Omar Ghattas, D. Kordonowy, Karen Willcox
2012 C conf
FUSION
Douglas L. Allaire, Karen Willcox
2012 J jnl
SIAM J. Sci. Comput.
Chad Lieberman, Karen Willcox
2010 J jnl
SIAM J. Sci. Comput.
Chad Lieberman, Karen Willcox, Omar Ghattas
2008 J jnl
Autom.
Serkan Gugercin, Karen Willcox
2008 J jnl
IEEE Trans. Autom. Control.
Patricia Astrid, Siep Weiland, Karen Willcox, Ton Backx
2008 J jnl
SIAM J. Sci. Comput.
Tan Bui-Thanh, Karen Willcox, Omar Ghattas
2007 conf
CDC
Leia A. Stirling, Alessandro Arsie, Emilio Frazzoli, Karen Willcox, Dava J. Newman
2007 J jnl
J. Comput. Phys.
Tan Bui-Thanh, Karen Willcox, Omar Ghattas, Bart G. van Bloemen Waanders
2007 Misc conf
International Conference on Computational Science (1)
Omar Bashir, Omar Ghattas, Judith C. Hill, Bart G. van Bloemen Waanders, Karen Willcox
2006 conf
CDC
Svein Hovland, Karen Willcox, Jan Tommy Gravdahl
2005 conf
CDC/ECC
Karen Willcox, Omar Ghattas, Bart G. van Bloemen Waanders, Brett W. Bader
2005 J jnl
SIAM J. Sci. Comput.
Karen Willcox, Alexandre Megretski
2004 conf
CDC
Patricia Astrid, Siep Weiland, Karen Willcox, Ton Backx
redb/extractors/macho_extractors/macho_signature.py
← Index redb/extractors/macho_extractors/macho_signature.py python
"""
MachO Code Signature Extractor using LIEF + asn1crypto

Parses LC_CODE_SIGNATURE to extract:
- Code Directory (identifier, team_id, flags, hashes)
- Entitlements (XML plist)
- X.509 Certificates from CMS/PKCS#7 signature
- Signature verification status
"""

import hashlib
import inspect
import json
import plistlib
import struct
from datetime import datetime, timezone
from typing import Any, Dict, List, Optional, Tuple

import lief

lief.disable_leak_warning()
from asn1crypto import cms, x509

from redb.extractors.enum import Tag
from redb.extractors.macho_extractor import MachOExtractor
from redb.models.dataclasses import (
    MachOCertificate,
    MachOCodeDirectory,
    MachOCodeSigningInfo,
    MachOEntitlement,
)


# Code Signature Magic Values
CSMAGIC_REQUIREMENT = 0xFADE0C00
CSMAGIC_REQUIREMENTS = 0xFADE0C01
CSMAGIC_CODEDIRECTORY = 0xFADE0C02
CSMAGIC_EMBEDDED_SIGNATURE = 0xFADE0CC0  # SuperBlob
CSMAGIC_DETACHED_SIGNATURE = 0xFADE0CC1
CSMAGIC_BLOBWRAPPER = 0xFADE0B01  # CMS Signature
CSMAGIC_EMBEDDED_ENTITLEMENTS = 0xFADE7171
CSMAGIC_EMBEDDED_ENTITLEMENTS_DER = 0xFADE7172

# Code Directory Flags
CS_FLAGS = {
    0x00000001: "CS_VALID",
    0x00000002: "CS_ADHOC",
    0x00000004: "CS_GET_TASK_ALLOW",
    0x00000008: "CS_INSTALLER",
    0x00000010: "CS_FORCED_LV",
    0x00000020: "CS_INVALID_ALLOWED",
    0x00000100: "CS_HARD",
    0x00000200: "CS_KILL",
    0x00000400: "CS_CHECK_EXPIRATION",
    0x00000800: "CS_RESTRICT",
    0x00001000: "CS_ENFORCEMENT",
    0x00002000: "CS_REQUIRE_LV",
    0x00004000: "CS_ENTITLEMENTS_VALIDATED",
    0x00008000: "CS_NVRAM_UNRESTRICTED",
    0x00010000: "CS_RUNTIME",  # Hardened Runtime
    0x00020000: "CS_LINKER_SIGNED",
}

# Hash Types
HASH_TYPES = {
    0: "NO_HASH",
    1: "SHA1",
    2: "SHA256",
    3: "SHA256_TRUNCATED",
    4: "SHA384",
    5: "SHA512",
}

# Slot Types (used in SuperBlob index)
CSSLOT_CODEDIRECTORY = 0  # Primary Code Directory
CSSLOT_INFOSLOT = 1
CSSLOT_REQUIREMENTS = 2
CSSLOT_RESOURCEDIR = 3
CSSLOT_APPLICATION = 4
CSSLOT_ENTITLEMENTS = 5
CSSLOT_DER_ENTITLEMENTS = 7
CSSLOT_SIGNATURESLOT = 0x10000  # CMS Signature
CSSLOT_ALTERNATE_CODEDIRECTORIES = 0x1000  # First alternate CD (0x1000, 0x1001, ...)


class MachOSignatureExtractor(MachOExtractor):
    """
    Extracts code signature information from Mach-O binaries using LIEF.
    Parses certificates using asn1crypto for full X.509 details.
    """

    def __init__(
        self,
        filepath,
        log,
        exporters=None,
        index_prefix=None,
        elastic_index=None,
        known_benign=False,
        known_malicious=False,
        macho=None,
    ):
        super().__init__(
            filepath,
            log,
            exporters,
            index_prefix,
            elastic_index,
            known_benign,
            known_malicious,
            macho,
        )
        self.elastic_index = self.index_prefix + "-macho_signature"
        self.log.debug(inspect.currentframe().f_code.co_name)
        self._lief_binary = None
        self._lief_fat = None

    def tag(self):
        return [
            Tag.MACHO_SIGNATURE.value,
            Tag.MACHO_CODE_DIRECTORY.value,
            Tag.MACHO_CERTIFICATE.value,
            Tag.MACHO_ENTITLEMENTS.value
        ]

    def _get_lief_binary(self, arch_index: int = 0) -> Optional[lief.MachO.Binary]:
        """Get LIEF binary for a specific architecture index."""
        try:
            if self._lief_fat is None:
                config = lief.MachO.ParserConfig()
                config.parse_dyld_exports = False
                config.parse_dyld_bindings = False
                config.parse_dyld_rebases = False
                self._lief_fat = lief.MachO.parse(self.filepath, config)

            if self._lief_fat is None:
                return None

            if arch_index < self._lief_fat.size:
                return self._lief_fat.at(arch_index)
            return None
        except Exception as e:
            self.log.error(f"Error parsing MachO with LIEF: {e}")
            return None

    def _parse_superblob(self, data: bytes) -> Dict[int, bytes]:
        """
        Parse the SuperBlob structure to extract individual blobs.

        SuperBlob structure:
        - magic: uint32 (0xfade0cc0)
        - length: uint32
        - count: uint32
        - index[count]: (type: uint32, offset: uint32)
        - blobs...

        Returns dict keyed by slot type (not magic), so we can handle
        multiple Code Directories (primary at slot 0, alternates at 0x1000+).
        """
        blobs = {}
        if len(data) < 12:
            return blobs

        magic, length, count = struct.unpack(">III", data[:12])

        if magic != CSMAGIC_EMBEDDED_SIGNATURE:
            self.log.warning(f"Unexpected SuperBlob magic: {hex(magic)}")
            return blobs

        # Parse blob index
        offset = 12
        blob_index = []
        for _ in range(count):
            if offset + 8 > len(data):
                break
            slot_type, blob_offset = struct.unpack(">II", data[offset:offset + 8])
            blob_index.append((slot_type, blob_offset))
            offset += 8

        # Extract each blob, keyed by slot type
        for slot_type, blob_offset in blob_index:
            if blob_offset + 8 > len(data):
                continue
            blob_magic, blob_length = struct.unpack(">II", data[blob_offset:blob_offset + 8])
            if blob_offset + blob_length <= len(data):
                blobs[slot_type] = data[blob_offset:blob_offset + blob_length]

        return blobs

    def _parse_code_directory(self, cd_data: bytes) -> Optional[MachOCodeDirectory]:
        """
        Parse CodeDirectory blob.

        CodeDirectory structure:
        - magic: uint32 (0xfade0c02)
        - length: uint32
        - version: uint32
        - flags: uint32
        - hashOffset: uint32
        - identOffset: uint32
        - nSpecialSlots: uint32
        - nCodeSlots: uint32
        - codeLimit: uint32
        - hashSize: uint8
        - hashType: uint8
        - platform: uint8
        - pageSize: uint8
        - spare2: uint32
        - scatterOffset: uint32 (v >= 0x20100)
        - teamOffset: uint32 (v >= 0x20200)
        ...
        """
        if len(cd_data) < 44:
            return None

        try:
            magic, length, version, flags = struct.unpack(">IIII", cd_data[:16])

            if magic != CSMAGIC_CODEDIRECTORY:
                return None

            hash_offset, ident_offset = struct.unpack(">II", cd_data[16:24])
            n_special_slots, n_code_slots, code_limit = struct.unpack(">III", cd_data[24:36])
            hash_size, hash_type, platform, page_size_log2 = struct.unpack(">BBBB", cd_data[36:40])

            # Extract identifier string
            identifier = None
            if ident_offset > 0 and ident_offset < len(cd_data):
                end = cd_data.find(b'\x00', ident_offset)
                if end > ident_offset:
                    identifier = cd_data[ident_offset:end].decode('utf-8', errors='replace')

            # Extract team ID (version >= 0x20200)
            team_id = None
            if version >= 0x20200 and len(cd_data) >= 52:
                team_offset = struct.unpack(">I", cd_data[48:52])[0]
                if team_offset > 0 and team_offset < len(cd_data):
                    end = cd_data.find(b'\x00', team_offset)
                    if end > team_offset:
                        team_id = cd_data[team_offset:end].decode('utf-8', errors='replace')

            # Parse flags
            flags_str = [name for flag, name in CS_FLAGS.items() if flags & flag]

            # Calculate CD hash
            cd_hash = hashlib.sha256(cd_data).hexdigest()

            return MachOCodeDirectory(
                identifier=identifier,
                team_id=team_id,
                flags=flags,
                cd_hash=cd_hash,
            )
        except Exception as e:
            self.log.error(f"Error parsing CodeDirectory: {e}")
            return None

    def _parse_entitlements(self, ent_data: bytes) -> Optional[Dict]:
        """
        Parse Entitlements blob (XML plist).

        Returns parsed entitlements dict.
        """
        if len(ent_data) < 8:
            return None

        try:
            magic, length = struct.unpack(">II", ent_data[:8])

            # Only accept XML plist magic - DER requires separate parser
            if magic != CSMAGIC_EMBEDDED_ENTITLEMENTS:
                return None

            # Extract plist data (after header)
            plist_data = ent_data[8:]

            # Parse plist
            try:
                entitlements = plistlib.loads(plist_data)
                return entitlements
            except Exception:
                # Try to strip null bytes
                plist_data = plist_data.rstrip(b'\x00')
                entitlements = plistlib.loads(plist_data)
                return entitlements

        except Exception as e:
            self.log.debug(f"Error parsing entitlements: {e}")
            return None

    def _parse_entitlements_der(self, ent_data: bytes) -> Optional[Dict]:
        """Best-effort parse of DER-encoded entitlements.

        DER-only binaries are rare (standard codesign embeds both XML and DER).
        Uses a layered approach: structured ASN.1 first, string extraction fallback.
        """
        if len(ent_data) < 8:
            return None

        try:
            magic, length = struct.unpack(">II", ent_data[:8])
            if magic != CSMAGIC_EMBEDDED_ENTITLEMENTS_DER:
                return None

            der_data = ent_data[8:]

            # Layer 1: Try structured ASN.1 parsing via asn1crypto
            try:
                from asn1crypto import core

                entitlements = {}
                seq = core.Sequence.load(der_data)
                for item in seq:
                    try:
                        if len(item) >= 2:
                            key = str(item[0].native)
                            val_element = item[1]
                            tag = val_element.tag
                            if tag == 0:      # BOOLEAN
                                entitlements[key] = val_element.contents != b'\x00'
                            elif tag == 1:    # UTF8String
                                entitlements[key] = val_element.native
                            elif tag == 2:    # INTEGER
                                entitlements[key] = val_element.native
                            elif tag == 3:    # SET OF (array of strings)
                                entitlements[key] = [str(v.native) for v in val_element]
                            else:
                                entitlements[key] = val_element.native
                    except Exception:
                        continue
                if entitlements:
                    return entitlements
            except Exception as e:
                self.log.debug(f"ASN.1 structured parse failed, trying string extraction: {e}")

            # Layer 2: Regex extraction of known entitlement key strings from raw DER
            # Gets keys but not typed values — still useful for detection/triage
            import re
            text = der_data.decode('utf-8', errors='ignore')
            keys = re.findall(
                r'(com\.apple\.[a-zA-Z0-9._-]+'
                r'|application-identifier'
                r'|get-task-allow'
                r'|platform-application'
                r'|team-identifier'
                r'|keychain-access-groups)',
                text
            )
            if keys:
                # Deduplicate while preserving order
                seen = set()
                entitlements = {}
                for key in keys:
                    if key not in seen:
                        seen.add(key)
                        entitlements[key] = True  # Assume boolean (most common type)
                self.log.info(
                    f"DER entitlements: ASN.1 parse failed, extracted {len(entitlements)} "
                    f"keys via string matching (values defaulted to True)"
                )
                return entitlements

            return None

        except Exception as e:
            self.log.debug(f"Error parsing DER entitlements: {e}")
            return None

    def _parse_cms_signature(self, cms_data: bytes) -> Tuple[List[MachOCertificate], Optional[str], bool]:
        """
        Parse CMS/PKCS#7 signature blob to extract certificates.

        Returns tuple of (certificates_list, signing_time, is_verified).
        """
        certificates = []
        signing_time = None
        has_cms_signature = False

        if len(cms_data) < 8:
            return certificates, signing_time, has_cms_signature

        try:
            magic, length = struct.unpack(">II", cms_data[:8])

            if magic != CSMAGIC_BLOBWRAPPER:
                return certificates, signing_time, has_cms_signature

            # CMS data starts after the blob header
            der_data = cms_data[8:]

            # Parse CMS ContentInfo
            content_info = cms.ContentInfo.load(der_data)

            if content_info['content_type'].native != 'signed_data':
                return certificates, signing_time, is_verified

            signed_data = content_info['content']

            # Extract certificates
            if signed_data['certificates']:
                cert_order = 0
                for cert_choice in signed_data['certificates']:
                    try:
                        if cert_choice.name == 'certificate':
                            cert = cert_choice.chosen
                            macho_cert = self._extract_certificate_info(cert, cert_order)
                            if macho_cert:
                                certificates.append(macho_cert)
                                cert_order += 1
                    except Exception as e:
                        self.log.debug(f"Error parsing certificate: {e}")
                        continue

            # Determine certificate types (leaf, intermediate, root)
            self._classify_certificates(certificates)

            # Extract signing time from signer info
            if signed_data['signer_infos']:
                for signer_info in signed_data['signer_infos']:
                    if signer_info['signed_attrs']:
                        for attr in signer_info['signed_attrs']:
                            if attr['type'].native == 'signing_time':
                                signing_time = attr['values'][0].native
                                if isinstance(signing_time, datetime):
                                    signing_time = signing_time.strftime("%Y-%m-%d %H:%M:%S")
                                break

            # Note: This only indicates presence of CMS signature structure, not
            # cryptographic verification. Full verification would require checking
            # against Apple's CA chain.
            has_cms_signature = len(certificates) > 0

        except Exception as e:
            self.log.error(f"Error parsing CMS signature: {e}")

        return certificates, signing_time, has_cms_signature

    def _extract_certificate_info(self, cert: x509.Certificate, order: int) -> Optional[MachOCertificate]:
        """Extract certificate information from an X.509 certificate."""
        try:
            tbs = cert['tbs_certificate']

            # Serial number
            serial = tbs['serial_number'].native
            serial_hex = format(serial, 'x').upper()

            # Subject and Issuer
            subject = self._format_name(tbs['subject'])
            issuer = self._format_name(tbs['issuer'])

            # Extract common name, organization, and OU from subject
            common_name = None
            organization = None
            organizational_unit = None
            try:
                for rdn in tbs['subject'].chosen:
                    for attr in rdn:
                        oid = attr['type'].native
                        value = attr['value'].native
                        if oid == 'common_name':
                            common_name = value
                        elif oid == 'organization_name':
                            organization = value
                        elif oid == 'organizational_unit_name':
                            organizational_unit = value
            except Exception:
                pass

            # Validity
            validity = tbs['validity']
            valid_from = validity['not_before'].native
            valid_to = validity['not_after'].native

            if isinstance(valid_from, datetime):
                valid_from = valid_from.strftime("%Y-%m-%d %H:%M:%S")
            if isinstance(valid_to, datetime):
                valid_to = valid_to.strftime("%Y-%m-%d %H:%M:%S")

            # Algorithm
            algorithm = tbs['signature']['algorithm'].native

            # Thumbprint (SHA-1 - industry standard for certificate thumbprints)
            cert_der = cert.dump()
            thumbprint = hashlib.sha1(cert_der).hexdigest().upper()

            return MachOCertificate(
                subject=subject,
                issuer=issuer,
                serial_number=serial_hex,
                not_before=valid_from,
                not_after=valid_to,
                thumbprint=thumbprint,
                certificate_type="unknown",  # Will be classified later
                order=order,
                algorithm=algorithm,
                common_name=common_name,
                organization=organization,
                organizational_unit=organizational_unit,
            )
        except Exception as e:
            self.log.error(f"Error extracting certificate info: {e}")
            return None

    def _format_name(self, name) -> str:
        """Format X.509 Name as a readable string."""
        try:
            parts = []
            for rdn in name.chosen:
                for attr in rdn:
                    oid = attr['type'].native
                    value = attr['value'].native
                    # Map common OIDs to abbreviations
                    oid_map = {
                        'common_name': 'CN',
                        'organization_name': 'O',
                        'organizational_unit_name': 'OU',
                        'country_name': 'C',
                        'state_or_province_name': 'ST',
                        'locality_name': 'L',
                        'email_address': 'E',
                        'user_id': 'UID',
                    }
                    abbrev = oid_map.get(oid, oid)
                    parts.append(f"{abbrev}={value}")
            return ", ".join(parts)
        except Exception:
            return str(name.human_friendly) if hasattr(name, 'human_friendly') else str(name)

    def _classify_certificates(self, certificates: List[MachOCertificate]):
        """
        Classify certificates as leaf, intermediate, or root using
        chain relationships:
        1. Root: self-signed (subject == issuer)
        2. Intermediate: issued another cert in the chain
        3. Leaf: everything else (end-entity)
        """
        if not certificates:
            return

        for cert in certificates:
            if cert.subject == cert.issuer:
                cert.certificate_type = "root"
            # Check if this cert issued any other cert in the chain
            elif any(c.issuer == cert.subject and c != cert for c in certificates):
                cert.certificate_type = "intermediate"
            else:
                cert.certificate_type = "leaf"

    def _extract_code_signature(self, arch_index: int = 0, arch_name: str = None) -> Optional[MachOCodeSigningInfo]:
        """Extract code signature information for a specific architecture."""
        self.log.debug(f"Extracting code signature for arch index {arch_index}")

        binary = self._get_lief_binary(arch_index)
        if binary is None:
            return None

        # Check if binary has code signature
        if not binary.has_code_signature:
            return MachOCodeSigningInfo(
                _id=self.sha256,
                signing_type="unsigned",
                has_signature=False,
                number_of_certificates=0,
                arch_identifier=arch_name,
            )

        # Get raw code signature data
        code_sig = binary.code_signature
        if code_sig is None:
            return None

        # LIEF's code_sig.data only returns the load command, not the actual signature
        # We need to read the signature data directly from the file
        # For FAT binaries, data_offset is relative to the slice, not the file
        sig_data = None
        try:
            with open(self.filepath, 'rb') as f:
                # fat_offset is 0 for single-arch binaries, slice offset for FAT
                file_offset = code_sig.data_offset + binary.fat_offset
                f.seek(file_offset)
                sig_data = f.read(code_sig.data_size)
        except Exception as e:
            self.log.error(f"Error reading code signature data from file: {e}")
            return None

        if not sig_data:
            return None

        # Parse SuperBlob to get individual blobs (keyed by slot type)
        blobs = self._parse_superblob(sig_data)

        # Parse all Code Directories (primary + alternates)
        code_directories = []

        # Primary Code Directory at slot 0
        if CSSLOT_CODEDIRECTORY in blobs:
            cd = self._parse_code_directory(blobs[CSSLOT_CODEDIRECTORY])
            if cd:
                cd.slot_type = CSSLOT_CODEDIRECTORY
                code_directories.append(cd)

        # Alternate Code Directories at slots 0x1000, 0x1001, ...
        for slot_type in sorted(blobs.keys()):
            if slot_type >= CSSLOT_ALTERNATE_CODEDIRECTORIES and slot_type < CSSLOT_SIGNATURESLOT:
                cd = self._parse_code_directory(blobs[slot_type])
                if cd:
                    cd.slot_type = slot_type
                    code_directories.append(cd)

        # Use primary CD (or first available) for signing info
        primary_cd = code_directories[0] if code_directories else None

        # Parse Entitlements - prefer XML plist, fall back to DER for edge cases
        entitlements = None
        if CSSLOT_ENTITLEMENTS in blobs:
            entitlements = self._parse_entitlements(blobs[CSSLOT_ENTITLEMENTS])
        if entitlements is None and CSSLOT_DER_ENTITLEMENTS in blobs:
            # DER-only binary (rare — non-standard signing tool like ldid)
            self.log.warning("Only DER entitlements found, no XML plist slot")
            entitlements = self._parse_entitlements_der(blobs[CSSLOT_DER_ENTITLEMENTS])

        # Parse CMS Signature (certificates)
        certificates = []
        signing_time = None
        has_cms_signature = False

        if CSSLOT_SIGNATURESLOT in blobs:
            certificates, signing_time, has_cms_signature = self._parse_cms_signature(blobs[CSSLOT_SIGNATURESLOT])

        # Determine signing type
        signing_type = "unsigned"
        if primary_cd:
            if primary_cd.flags and (primary_cd.flags & 0x00000002):  # CS_ADHOC
                signing_type = "ad-hoc"
            elif len(certificates) > 0:
                signing_type = "certificate"
            elif primary_cd.identifier:
                # Has CodeDirectory but no CMS = ad-hoc
                signing_type = "ad-hoc"

        # Check for hardened runtime and library validation flags
        has_hardened_runtime = False
        has_library_validation = False
        if primary_cd and primary_cd.flags:
            has_hardened_runtime = bool(primary_cd.flags & 0x00010000)  # CS_RUNTIME
            has_library_validation = bool(primary_cd.flags & 0x00002000)  # CS_REQUIRE_LV

        return MachOCodeSigningInfo(
            _id=self.sha256,
            signing_type=signing_type,
            has_signature=has_cms_signature,
            number_of_certificates=len(certificates),
            code_directories=code_directories,
            entitlements=entitlements,
            x509_certificates=certificates,
            date_signed=signing_time,
            arch_identifier=arch_name,
            has_hardened_runtime=has_hardened_runtime,
            has_library_validation=has_library_validation,
        )

    def extract(self) -> Optional[Any]:
        """Extract code signature information from the Mach-O binary."""
        self.log.debug(inspect.currentframe().f_code.co_name)

        try:
            # Get LIEF FAT binary to check architecture count
            config = lief.MachO.ParserConfig()
            config.parse_dyld_exports = False
            config.parse_dyld_bindings = False
            config.parse_dyld_rebases = False
            self._lief_fat = lief.MachO.parse(self.filepath, config)

            if self._lief_fat is None:
                self.log.error("Failed to parse MachO with LIEF")
                return None

            # Get architecture names from machofile for consistency
            arch_names = []
            if self.macho:
                try:
                    arch_names = self.macho.get_architectures()
                except Exception:
                    pass

            # If no arch names from machofile, generate them
            if not arch_names:
                arch_names = [f"arch_{i}" for i in range(self._lief_fat.size)]

            if self._lief_fat.size > 1:
                # FAT/Universal binary - extract for each architecture
                results = []
                for i in range(self._lief_fat.size):
                    arch_name = arch_names[i] if i < len(arch_names) else f"arch_{i}"
                    signature = self._extract_code_signature(i, arch_name)
                    if signature:
                        results.append(signature)
                return results if results else None
            else:
                # Single architecture
                arch_name = arch_names[0] if arch_names else None
                return self._extract_code_signature(0, arch_name)

        except Exception as e:
            self.log.error(f"Error extracting MachO code signature: {e}")
            return None

    def prepare_export_data(self, exporter_type: str) -> Any:
        """Prepare data for export to Elasticsearch or ClickHouse."""
        self.log.debug(inspect.currentframe().f_code.co_name)

        if exporter_type == "ElasticsearchExporter":
            return self.extract()

        elif exporter_type == "ClickHouseExporter":
            result = self.extract()
            if result is None:
                return None

            # Normalize to list
            signatures = result if isinstance(result, list) else [result]

            current_time = datetime.now(timezone.utc)

            # Prepare signature data
            signatures_data = []
            certificates_data = []
            entitlements_data = []

            for sig in signatures:
                if sig is None:
                    continue

                # Get architecture-specific hash if available
                arch_sha256 = self.sha256

                # If FAT binary, try to get arch-specific sha256
                if self.macho and sig.arch_identifier:
                    try:
                        arch_info = self.macho.get_general_info(arch=sig.arch_identifier)
                        if arch_info:
                            arch_sha256 = arch_info.get('SHA256', self.sha256)
                    except Exception as e:
                        self.log.debug(f"Could not get arch-specific info: {e}")

                # Get primary CD fields for signatures table
                primary_cd = sig.code_directories[0] if sig.code_directories else None
                cd_identifier = primary_cd.identifier if primary_cd else None
                cd_team_id = primary_cd.team_id if primary_cd else None
                cd_flags = primary_cd.flags if primary_cd else None
                cd_hash = primary_cd.cd_hash if primary_cd else None

                signatures_data.append([
                    arch_sha256,
                    sig.signing_type,
                    sig.has_signature,
                    sig.number_of_certificates,
                    cd_identifier,
                    cd_team_id,
                    cd_flags,
                    cd_hash,
                    sig.has_hardened_runtime,
                    sig.has_library_validation,
                    sig.date_signed,
                    current_time,
                ])

                # Prepare certificate data
                if sig.x509_certificates:
                    for cert in sig.x509_certificates:
                        certificates_data.append([
                            arch_sha256,
                            cert.certificate_type,
                            cert.algorithm,
                            cert.issuer,
                            cert.subject,
                            cert.serial_number,
                            cert.thumbprint,
                            datetime.strptime(cert.not_before, "%Y-%m-%d %H:%M:%S") if cert.not_before else None,
                            datetime.strptime(cert.not_after, "%Y-%m-%d %H:%M:%S") if cert.not_after else None,
                            current_time,
                        ])

                # Prepare entitlements data
                if sig.entitlements:
                    for ent_key, ent_value in sig.entitlements.items():
                        # Determine type and set appropriate value columns
                        if isinstance(ent_value, bool):
                            ent_type = 'boolean'
                            value_bool = 1 if ent_value else 0
                            value_string = None
                            value_array = []
                        elif isinstance(ent_value, list):
                            ent_type = 'array'
                            value_bool = None
                            value_string = None
                            # Convert all list items to strings
                            value_array = [str(v) for v in ent_value]
                        else:
                            ent_type = 'string'
                            value_bool = None
                            value_string = str(ent_value)
                            value_array = []

                        entitlements_data.append([
                            arch_sha256,
                            ent_key,
                            ent_type,
                            value_bool,
                            value_string,
                            value_array,
                            current_time,
                        ])

            return {
                'multi_table': True,
                'signatures': {
                    'table': 'redb_macho_signatures',
                    'data': signatures_data,
                    'column_names': [
                        'sha256',
                        'signing_type', 'has_signature', 'number_of_certificates',
                        'cd_identifier', 'cd_team_id', 'cd_flags', 'cd_hash',
                        'has_hardened_runtime', 'has_library_validation',
                        'date_signed', 'analysis_date'
                    ],
                    'column_type_names': [
                        'FixedString(64)',
                        "Enum8('unsigned' = 0, 'ad-hoc' = 1, 'certificate' = 2)", 'UInt8', 'UInt32',
                        'Nullable(String)', 'Nullable(String)', 'Nullable(UInt32)', 'Nullable(String)',
                        'UInt8', 'UInt8',
                        'Nullable(DateTime64(3, \'UTC\'))', 'DateTime64(3, \'UTC\')'
                    ]
                },
                'certificates': {
                    'table': 'redb_macho_certificates',
                    'data': certificates_data,
                    'column_names': [
                        'sha256', 'certificate_type', 'certificate_algorithm',
                        'certificate_issuer', 'certificate_subject', 'certificate_serial_number',
                        'certificate_thumbprint', 'certificate_valid_from', 'certificate_valid_to',
                        'analysis_date'
                    ],
                    'column_type_names': [
                        'FixedString(64)',
                        "Enum8('leaf' = 1, 'intermediate' = 2, 'root' = 3)", 'LowCardinality(String)',
                        'String', 'String', 'String', 'FixedString(40)',
                        'DateTime64(3, \'UTC\')', 'DateTime64(3, \'UTC\')', 'DateTime64(3, \'UTC\')'
                    ]
                },
                'entitlements': {
                    'table': 'redb_macho_entitlements',
                    'data': entitlements_data,
                    'column_names': [
                        'sha256', 'entitlement_key', 'entitlement_type',
                        'value_bool', 'value_string', 'value_array',
                        'analysis_date'
                    ],
                    'column_type_names': [
                        'FixedString(64)', 'LowCardinality(String)',
                        "Enum8('boolean' = 1, 'string' = 2, 'array' = 3)",
                        'Nullable(UInt8)', 'Nullable(String)', 'Array(String)',
                        'DateTime64(3, \'UTC\')'
                    ]
                }
            }

        return None

    def get_clickhouse_table(self) -> str:
        """Return primary ClickHouse table name."""
        return "redb_macho_signatures"

    def get_clickhouse_tables(self) -> Dict[str, str]:
        """Return all ClickHouse tables for multi-table export."""
        return {
            'signatures': 'redb_macho_signatures',
            'certificates': 'redb_macho_certificates',
            'entitlements': 'redb_macho_entitlements'
        }