pyzmq/zmq/backend/cffi/utils.py

79 lines
2.0 KiB
Python

"""miscellaneous zmq_utils wrapping"""
# Copyright (C) PyZMQ Developers
# Distributed under the terms of the Modified BSD License.
from zmq.error import InterruptedSystemCall, _check_rc, _check_version
from ._cffi import ffi
from ._cffi import lib as C
def has(capability):
"""Check for zmq capability by name (e.g. 'ipc', 'curve')
.. versionadded:: libzmq-4.1
.. versionadded:: 14.1
"""
_check_version((4, 1), 'zmq.has')
if isinstance(capability, str):
capability = capability.encode('utf8')
return bool(C.zmq_has(capability))
def curve_keypair():
"""generate a Z85 key pair for use with zmq.CURVE security
Requires libzmq (≥ 4.0) to have been built with CURVE support.
Returns
-------
(public, secret) : two bytestrings
The public and private key pair as 40 byte z85-encoded bytestrings.
"""
_check_version((3, 2), "curve_keypair")
public = ffi.new('char[64]')
private = ffi.new('char[64]')
rc = C.zmq_curve_keypair(public, private)
_check_rc(rc)
return ffi.buffer(public)[:40], ffi.buffer(private)[:40]
def curve_public(private):
"""Compute the public key corresponding to a private key for use
with zmq.CURVE security
Requires libzmq (≥ 4.2) to have been built with CURVE support.
Parameters
----------
private
The private key as a 40 byte z85-encoded bytestring
Returns
-------
bytestring
The public key as a 40 byte z85-encoded bytestring.
"""
if isinstance(private, str):
private = private.encode('utf8')
_check_version((4, 2), "curve_public")
public = ffi.new('char[64]')
rc = C.zmq_curve_public(public, private)
_check_rc(rc)
return ffi.buffer(public)[:40]
def _retry_sys_call(f, *args, **kwargs):
"""make a call, retrying if interrupted with EINTR"""
while True:
rc = f(*args)
try:
_check_rc(rc)
except InterruptedSystemCall:
continue
else:
break
__all__ = ['has', 'curve_keypair', 'curve_public']