pyzmq/zmq/auth/certs.py

141 lines
4.2 KiB
Python

"""0MQ authentication related functions and classes."""
# Copyright (C) PyZMQ Developers
# Distributed under the terms of the Modified BSD License.
import datetime
import glob
import os
from typing import Dict, Optional, Tuple, Union
import zmq
_cert_secret_banner = """# **** Generated on {0} by pyzmq ****
# ZeroMQ CURVE **Secret** Certificate
# DO NOT PROVIDE THIS FILE TO OTHER USERS nor change its permissions.
"""
_cert_public_banner = """# **** Generated on {0} by pyzmq ****
# ZeroMQ CURVE Public Certificate
# Exchange securely, or use a secure mechanism to verify the contents
# of this file after exchange. Store public certificates in your home
# directory, in the .curve subdirectory.
"""
def _write_key_file(
key_filename: Union[str, os.PathLike],
banner: str,
public_key: Union[str, bytes],
secret_key: Optional[Union[str, bytes]] = None,
metadata: Optional[Dict[str, str]] = None,
encoding: str = 'utf-8',
) -> None:
"""Create a certificate file"""
if isinstance(public_key, bytes):
public_key = public_key.decode(encoding)
if isinstance(secret_key, bytes):
secret_key = secret_key.decode(encoding)
with open(key_filename, 'w', encoding='utf8') as f:
f.write(banner.format(datetime.datetime.now()))
f.write('metadata\n')
if metadata:
for k, v in metadata.items():
if isinstance(k, bytes):
k = k.decode(encoding)
if isinstance(v, bytes):
v = v.decode(encoding)
f.write(f" {k} = {v}\n")
f.write('curve\n')
f.write(f" public-key = \"{public_key}\"\n")
if secret_key:
f.write(f" secret-key = \"{secret_key}\"\n")
def create_certificates(
key_dir: Union[str, os.PathLike],
name: str,
metadata: Optional[Dict[str, str]] = None,
) -> Tuple[str, str]:
"""Create zmq certificates.
Returns the file paths to the public and secret certificate files.
"""
public_key, secret_key = zmq.curve_keypair()
base_filename = os.path.join(key_dir, name)
secret_key_file = f"{base_filename}.key_secret"
public_key_file = f"{base_filename}.key"
now = datetime.datetime.now()
_write_key_file(public_key_file, _cert_public_banner.format(now), public_key)
_write_key_file(
secret_key_file,
_cert_secret_banner.format(now),
public_key,
secret_key=secret_key,
metadata=metadata,
)
return public_key_file, secret_key_file
def load_certificate(
filename: Union[str, os.PathLike],
) -> Tuple[bytes, Optional[bytes]]:
"""Load public and secret key from a zmq certificate.
Returns (public_key, secret_key)
If the certificate file only contains the public key,
secret_key will be None.
If there is no public key found in the file, ValueError will be raised.
"""
public_key = None
secret_key = None
if not os.path.exists(filename):
raise OSError(f"Invalid certificate file: {filename}")
with open(filename, 'rb') as f:
for line in f:
line = line.strip()
if line.startswith(b'#'):
continue
if line.startswith(b'public-key'):
public_key = line.split(b"=", 1)[1].strip(b' \t\'"')
if line.startswith(b'secret-key'):
secret_key = line.split(b"=", 1)[1].strip(b' \t\'"')
if public_key and secret_key:
break
if public_key is None:
raise ValueError(f"No public key found in {filename}")
return public_key, secret_key
def load_certificates(directory: Union[str, os.PathLike] = '.') -> Dict[bytes, bool]:
"""Load public keys from all certificates in a directory"""
certs = {}
if not os.path.isdir(directory):
raise OSError(f"Invalid certificate directory: {directory}")
# Follow czmq pattern of public keys stored in *.key files.
glob_string = os.path.join(directory, "*.key")
cert_files = glob.glob(glob_string)
for cert_file in cert_files:
public_key, _ = load_certificate(cert_file)
if public_key:
certs[public_key] = True
return certs
__all__ = ['create_certificates', 'load_certificate', 'load_certificates']