trezor-agent/sshagent/server.py
2015-08-13 18:03:25 +03:00

103 lines
2.7 KiB
Python

import socket
import os
import subprocess
import tempfile
import contextlib
import threading
from . import protocol
from . import formats
from . import util
import logging
log = logging.getLogger(__name__)
def remove_file(path, remove=os.remove, exists=os.path.exists):
try:
remove(path)
except OSError:
if exists(path):
raise
@contextlib.contextmanager
def unix_domain_socket_server(sock_path):
log.debug('serving on SSH_AUTH_SOCK=%s', sock_path)
remove_file(sock_path)
server = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
server.bind(sock_path)
server.listen(1)
try:
yield server
finally:
remove_file(sock_path)
def handle_connection(conn, handler):
try:
log.debug('welcome agent')
while True:
msg = util.read_frame(conn)
reply = handler.handle(msg=msg)
util.send(conn, reply)
except EOFError:
log.debug('goodbye agent')
except:
log.exception('error')
raise
def server_thread(server, handler):
log.debug('server thread started')
while True:
log.debug('waiting for connection on %s', server.getsockname())
try:
conn, _ = server.accept()
except socket.error as e:
log.debug('server stopped: %s', e)
break
with contextlib.closing(conn):
handle_connection(conn, handler)
log.debug('server thread stopped')
@contextlib.contextmanager
def spawn(func, **kwargs):
t = threading.Thread(target=func, kwargs=kwargs)
t.start()
yield
t.join()
@contextlib.contextmanager
def serve(public_keys, signer, sock_path=None):
if sock_path is None:
sock_path = tempfile.mktemp(prefix='ssh-agent-')
keys = [formats.import_public_key(k) for k in public_keys]
environ = {'SSH_AUTH_SOCK': sock_path, 'SSH_AGENT_PID': str(os.getpid())}
with unix_domain_socket_server(sock_path) as server:
handler = protocol.Handler(keys=keys, signer=signer)
with spawn(server_thread, server=server, handler=handler):
try:
yield environ
finally:
log.debug('closing server')
server.shutdown(socket.SHUT_RD)
def run_process(command, environ, use_shell=False):
log.debug('running %r with %r', command, environ)
env = dict(os.environ)
env.update(environ)
try:
p = subprocess.Popen(args=command, env=env, shell=use_shell)
except OSError as e:
raise OSError('cannot run %r: %s' % (command, e))
log.debug('subprocess %d is running', p.pid)
ret = p.wait()
log.debug('subprocess %d exited: %d', p.pid, ret)
return ret