# SPDX-License-Identifier: GPL-3.0-or-later from collections import deque from datetime import datetime from functools import reduce from pathlib import Path from platform import python_version_tuple from re import sub from tempfile import mkdtemp from typing import Dict # NOTE: remove after python 3.8.x is no longer supported upstream if int(python_version_tuple()[1]) < 9: # pragma: no cover from typing import Iterable else: from collections.abc import Iterable from typing import List from typing import Optional from .types import Fingerprint from .types import PacketKind from .types import Uid from .types import Username from .util import cwd from .util import natural_sort_path from .util import system def keyring_split(working_dir: Path, keyring: Path, preserve_filename: bool = False) -> Iterable[Path]: """Split a file containing a PGP keyring into separate certificate files The original keyring filename is preserved if the split only yields a single certificate. If preserve_filename is True, all keyrings are placed into separate directories while preserving the filename. The file is split using sq. Parameters ---------- working_dir: The path of the working directory below which to create the output files keyring: The path of a file containing a PGP keyring preserve_filename: If True, all keyrings are placed into separate directories while preserving the filename Returns ------- An iterable over the naturally sorted list of certificate files derived from a keyring """ keyring_dir = Path(mkdtemp(dir=working_dir, prefix="keyring-")).absolute() with cwd(keyring_dir): system(["sq", "keyring", "split", "--prefix", "", str(keyring)]) keyrings: List[Path] = list(natural_sort_path(keyring_dir.iterdir())) if 1 == len(keyrings) or preserve_filename: for index, key in enumerate(keyrings): keyring_sub_dir = Path(mkdtemp(dir=keyring_dir, prefix=f"{keyring.name}-")).absolute() keyrings[index] = key.rename(keyring_sub_dir / keyring.name) return keyrings def keyring_merge(certificates: List[Path], output: Optional[Path] = None, force: bool = False) -> str: """Merge multiple certificates into a keyring Parameters ---------- certificates: List of paths to certificates to merge into a keyring output: Path to a file which the keyring is written, return the result instead if None force: Whether to force overwriting existing files (defaults to False) Returns ------- The result if no output file has been used """ cmd = ["sq", "keyring", "merge"] if force: cmd.insert(1, "--force") if output: cmd += ["--output", str(output)] cmd += [str(cert) for cert in sorted(certificates)] return system(cmd) def packet_split(working_dir: Path, certificate: Path) -> Iterable[Path]: """Split a file containing a PGP certificate into separate packet files The files are split using sq Parameters ---------- working_dir: The path of the working directory below which to create the output files certificate: The absolute path of a file containing one PGP certificate Returns ------- An iterable over the naturally sorted list of packet files derived from certificate """ packet_dir = Path(mkdtemp(dir=working_dir, prefix="packet-")).absolute() with cwd(packet_dir): system(["sq", "packet", "split", "--prefix", "", str(certificate)]) return natural_sort_path(packet_dir.iterdir()) def packet_join(packets: List[Path], output: Optional[Path] = None, force: bool = False) -> str: """Join PGP packet data in files to a single output file Parameters ---------- packets: A list of paths to files that contain PGP packet data output: Path to a file to which all PGP packet data is written, return the result instead if None force: Whether to force overwriting existing files (defaults to False) Returns ------- The result if no output file has been used """ cmd = ["sq", "packet", "join"] if force: cmd.insert(1, "--force") packets_str = list(map(lambda path: str(path), packets)) cmd.extend(packets_str) cmd.extend(["--output", str(output)]) return system(cmd) def inspect( packet: Path, certifications: bool = True, fingerprints: Optional[Dict[Fingerprint, Username]] = None ) -> str: """Inspect PGP packet data and return the result Parameters ---------- packet: Path to a file that contain PGP data certifications: Whether to print third-party certifications fingerprints: Optional dict of fingerprints to usernames to enrich the output with Returns ------- The result of the inspection """ cmd = ["sq", "inspect"] if certifications: cmd.append("--certifications") cmd.append(str(packet)) result: str = system(cmd) if fingerprints: for fingerprint, username in fingerprints.items(): result = sub(f"{fingerprint}", f"{fingerprint} {username}", result) result = sub(f" {fingerprint[24:]}", f" {fingerprint[24:]} {username}", result) return result def packet_dump(packet: Path) -> str: """Dump a PGP packet to string The `sq packet dump` command is used to retrieve a dump of information from a PGP packet Parameters ---------- packet: The path to the PGP packet to retrieve the value from Returns ------- The contents of the packet dump """ return system(["sq", "packet", "dump", str(packet)]) def packet_dump_field(packet: Path, query: str) -> str: """Retrieve the value of a field from a PGP packet Field queries are possible with the following notation during tree traversal: - Use '.' to separate the parent section - Use '*' as a wildcard for the current section - Use '|' inside the current level as a logical OR Example: - Version - Hashed area|Unhashed area.Issuer - *.Issuer Parameters ---------- packet: The path to the PGP packet to retrieve the value from query: The name of the field as a query notation Raises ------ Exception: If the field is not found in the PGP packet Returns ------- The value of the field found in packet """ dump = packet_dump(packet) queries = deque(query.split(".")) path = [queries.popleft()] depth = 0 # remove leading 4 space indention lines = list(filter(lambda line: line.startswith(" "), dump.splitlines())) lines = [sub(r"^ {4}", "", line, count=1) for line in lines] # filter empty lines lines = list(filter(lambda line: line.strip(), lines)) for line in lines: # determine current line depth by counting whitespace pairs depth_line = int((len(line) - len(line.lstrip(" "))) / 2) line = line.lstrip(" ") # skip nodes that are deeper as our currently matched path if depth < depth_line: continue # unwind the current query path until reaching previous match depth while depth > depth_line: queries.appendleft(path.pop()) depth -= 1 matcher = path[-1].split("|") # check if current field matches the query expression field = line.split(sep=":", maxsplit=1)[0] if field not in matcher and "*" not in matcher: continue # next depth is one level deeper as the current line depth = depth_line + 1 # check if matcher is not the leaf of the query expression if queries: path.append(queries.popleft()) continue # return final match return line.split(sep=": ", maxsplit=1)[1] if ": " in line else line raise Exception(f"Packet '{packet}' did not match the query '{query}'") def packet_signature_creation_time(packet: Path) -> datetime: """Retrieve the signature creation time field as datetime Parameters ---------- packet: The path to the PGP packet to retrieve the value from Returns ------- The signature creation time as datetime """ field = packet_dump_field(packet, "Hashed area.Signature creation time") field = " ".join(field.split(" ", 3)[0:3]) return datetime.strptime(field, "%Y-%m-%d %H:%M:%S %Z") def packet_kinds(packet: Path) -> List[PacketKind]: """Retrieve the PGP packet types of a packet path Parameters ---------- packet: The path to the PGP packet to retrieve the kind of Returns ------- The kind of PGP packet """ dump = packet_dump(packet) lines = [line for line in dump.splitlines()] lines = list( filter(lambda line: not line.startswith(" ") and not line.startswith("WARNING") and line.strip(), lines) ) return [PacketKind(line.split()[0]) for line in lines] def latest_certification(certifications: Iterable[Path]) -> Path: """Returns the latest certification based on the signature creation time from a list of packets. Parameters ---------- certifications: List of certification from which to choose the latest from Returns ------- The latest certification from a list of packets """ return reduce( lambda a, b: a if packet_signature_creation_time(a) > packet_signature_creation_time(b) else b, certifications, ) def key_generate(uids: List[Uid], outfile: Path) -> str: """Generate a PGP key with specific uids Parameters ---------- uids: List of uids that the key should have outfile: Path to the file to which the key should be written to Returns ------- The result of the key generate call """ cmd = ["sq", "key", "generate"] for uid in uids: cmd.extend(["--userid", str(uid)]) cmd.extend(["--export", str(outfile)]) return system(cmd) def key_extract_certificate(key: Path, output: Optional[Path]) -> str: """Extracts the non secret part from a key into a certificate Parameters ---------- key: Path to a file that contain secret key material output: Path to the file to which the key should be written to, stdout if None Returns ------- The result of the extract in case output is None """ cmd = ["sq", "key", "extract-cert", str(key)] if output: cmd.extend(["--output", str(output)]) return system(cmd) def certify(key: Path, certificate: Path, uid: Uid, output: Optional[Path]) -> str: """Inspect PGP packet data and return the result Parameters ---------- key: Path to a file that contain secret key material certificate: Path to a certificate file whose uid should be certified uid: Uid contain in the certificate that should be certified output: Path to the file to which the key should be written to, stdout if None Returns ------- The result of the certification in case output is None """ cmd = ["sq", "certify", str(key), str(certificate), uid] if output: cmd.extend(["--output", str(output)]) return system(cmd)