Files
custom-debian-iso/gpg/keystore.py
2025-07-25 05:32:35 +02:00

205 lines
6.7 KiB
Python

"""Utilities for searching and importing GPG keys locally."""
from subprocess import run, STDOUT, PIPE
from re import compile
_DEBIAN_KEY_SERVER_HOSTNAME = "keyring.debian.org"
_DEBIAN_CD_SIGNING_KEY_ID = "DA87E80D6294BE9B"
_DEBIAN_CD_TESTING_SIGNING_KEY_ID = "42468F4009EA8AC3"
def import_debian_signing_key():
"""Imports the public debian CD signing key using gpg.
The key is imported from keyring.debian.org into the invoking user's
GPG public key store using a shell command.
"""
# execute a gpg key import as a shell command, redirecting stderr to stdout
process_result = run(
[
"gpg", "--keyserver", _DEBIAN_KEY_SERVER_HOSTNAME,
"--recv-key", _DEBIAN_CD_SIGNING_KEY_ID
],
stdout=PIPE,
stderr=STDOUT,
text=True,
)
# check shell return code
if process_result.returncode != 0:
if process_result.stdout:
raise RuntimeError(
f"Failed to import key using gpg:\n{process_result.stdout}"
)
else:
raise RuntimeError("Failed to import key using gpg.")
# check shell output:
# verify that the key was imported successfully by checking for key patterns
stdout_lower = process_result.stdout.lower()
key_id_in_output = _DEBIAN_CD_SIGNING_KEY_ID.lower() in stdout_lower
imported_or_unchanged = any(word in stdout_lower for word in ["imported", "unchanged", "importée", "importées"])
if not (key_id_in_output and imported_or_unchanged):
raise RuntimeError(
f"Unexpected output while importing PGP public key:\n"
f"{process_result.stdout}"
)
def import_debian_testing_signing_key():
"""Imports the public debian testing CD signing key using gpg.
The key is imported from keyring.debian.org into the invoking user's
GPG public key store using a shell command.
"""
# execute a gpg key import as a shell command, redirecting stderr to stdout
process_result = run(
[
"gpg", "--keyserver", _DEBIAN_KEY_SERVER_HOSTNAME,
"--recv-key", _DEBIAN_CD_TESTING_SIGNING_KEY_ID
],
stdout=PIPE,
stderr=STDOUT,
text=True,
)
# check shell return code
if process_result.returncode != 0:
if process_result.stdout:
raise RuntimeError(
f"Failed to import key using gpg:\n{process_result.stdout}"
)
else:
raise RuntimeError("Failed to import key using gpg.")
# check shell output:
# verify that the key was imported successfully by checking for key patterns
stdout_lower = process_result.stdout.lower()
key_id_in_output = _DEBIAN_CD_TESTING_SIGNING_KEY_ID.lower() in stdout_lower
imported_or_unchanged = any(word in stdout_lower for word in ["imported", "unchanged", "importée", "importées"])
if not (key_id_in_output and imported_or_unchanged):
raise RuntimeError(
f"Unexpected output while importing PGP public key:\n"
f"{process_result.stdout}"
)
def debian_signing_key_is_imported():
"""Checks whether the debian PGP signing key exists in the local key store.
The invoking user's GPG key store is checked using a shell command.
Returns
-------
True : bool
If the public PGP debian cd signing key exists in the invoking user's
GPG key store.
False : bool
If the public PGP debian cd signing key does not exist in the invoking
user's GPG key store.
"""
# execute a local gpg key lookup as a shell command, redirecting stderr to
# stdout
# NOTE: this command returns 0 even if the key is not present
process_result = run(
["gpg", "--locate-keys", _DEBIAN_CD_SIGNING_KEY_ID],
stdout=PIPE,
stderr=STDOUT,
text=True,
)
# check shell return code
if process_result.returncode != 0:
raise RuntimeError("Failed to search local keys using gpg.")
# no shell output means that the key does not exist locally
if not process_result.stdout:
return False
# verify existing key shell output using regex:
# it should contain six lines in the following format
expected_output_lines_regexes = [
compile(r"^pub .*$"),
compile(r"^ *[0-9A-F]{40}$"),
compile(r"^uid .*$"),
compile(r"^sub .*$"),
compile(r"^$"),
compile(r"^$"),
]
actual_output_lines = process_result.stdout.split("\n")
if not len(actual_output_lines) == len(expected_output_lines_regexes):
raise RuntimeError(
f"Unexpected line count in shell output while performing local"
f"GPG key lookup:\n"
f"{process_result.stdout}"
)
for i in range(4):
if not expected_output_lines_regexes[i].match(actual_output_lines[i]):
raise RuntimeError(
f"Unexpected shell output format while performing local"
f"GPG key lookup:\n"
f"{process_result.stdout}"
)
return True
def debian_testing_signing_key_is_imported():
"""Checks whether the debian testing PGP signing key exists in the local key store.
The invoking user's GPG key store is checked using a shell command.
Returns True if the key exists, False otherwise.
"""
# execute a gpg key lookup as a shell command, redirecting stderr to stdout
process_result = run(
["gpg", "--locate-keys", _DEBIAN_CD_TESTING_SIGNING_KEY_ID],
stdout=PIPE,
stderr=STDOUT,
text=True,
)
# check shell return code
if process_result.returncode != 0:
raise RuntimeError("Failed to search local keys using gpg.")
# no shell output means that the key does not exist locally
if not process_result.stdout:
return False
# verify existing key shell output using regex:
# it should contain six lines in the following format
expected_output_lines_regexes = [
compile(r"^pub .*$"),
compile(r"^ *[0-9A-F]{40}$"),
compile(r"^uid .*$"),
compile(r"^sub .*$"),
compile(r"^$"),
compile(r"^$"),
]
actual_output_lines = process_result.stdout.split("\n")
if len(actual_output_lines) < 4:
raise RuntimeError(
f"Unexpected shell output format while performing local "
f"GPG key lookup:\n"
f"{process_result.stdout}"
)
for i in range(4):
if not expected_output_lines_regexes[i].match(actual_output_lines[i]):
raise RuntimeError(
f"Unexpected shell output format while performing local"
f"GPG key lookup:\n"
f"{process_result.stdout}"
)
return True