Get ELF build-id w/ pyelftools

elf-build-id.py

#!/usr/bin/python3
# encoding: utf-8
# SPDX-FileCopyrightText: 2024 FC (Fay) Stegerman <flx@obfusk.net>
# SPDX-License-Identifier: GPL-3.0-or-later

from elftools.elf.elffile import ELFFile        # type: ignore[import-untyped]
from elftools.elf.sections import NoteSection   # type: ignore[import-untyped]


class Error(Exception):
    pass


def elf_build_id(elffile: str) -> str:
    with open(elffile, "rb") as fh:
        for section in ELFFile(fh).iter_sections():
            if isinstance(section, NoteSection):
                for note in section.iter_notes():
                    if note["n_type"] == "NT_GNU_BUILD_ID":
                        return note["n_desc"]   # type: ignore[no-any-return]
    raise Error("Could not find build-id")


def main() -> None:
    import argparse
    parser = argparse.ArgumentParser(prog="elf-build-id.py", description="Get ELF build-id.")
    parser.add_argument("elffiles", metavar="ELF", nargs="+")
    args = parser.parse_args()
    for elffile in args.elffiles:
        build_id = elf_build_id(elffile)
        print(f"{elffile!r}:\n  0x{build_id}")


if __name__ == "__main__":
    main()

# vim: set tw=80 sw=4 sts=4 et fdm=marker :