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# Copyright (C) 2005 John Arbash-Meinel <john@arbash-meinel.com>
# Modified up by: Todd Whiteman <ToddW@ActiveState.com>
#
# This file is part of paramiko.
#
# Paramiko is free software; you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation; either version 2.1 of the License, or (at your option)
# any later version.
#
# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
"""
Functions for communicating with Pageant, the basic windows ssh agent program.
"""
import os
import struct
import tempfile
import mmap
import array
# if you're on windows, you should have one of these, i guess?
# ctypes is part of standard library since Python 2.5
_has_win32all = False
_has_ctypes = False
try:
# win32gui is preferred over win32ui to avoid MFC dependencies
import win32gui
_has_win32all = True
except ImportError:
try:
import ctypes
_has_ctypes = True
except ImportError:
pass
_AGENT_COPYDATA_ID = 0x804e50ba
_AGENT_MAX_MSGLEN = 8192
# Note: The WM_COPYDATA value is pulled from win32con, as a workaround
# so we do not have to import this huge library just for this one variable.
win32con_WM_COPYDATA = 74
def _get_pageant_window_object():
if _has_win32all:
try:
hwnd = win32gui.FindWindow('Pageant', 'Pageant')
return hwnd
except win32gui.error:
pass
elif _has_ctypes:
# Return 0 if there is no Pageant window.
return ctypes.windll.user32.FindWindowA('Pageant', 'Pageant')
return None
def can_talk_to_agent():
"""
Check to see if there is a "Pageant" agent we can talk to.
This checks both if we have the required libraries (win32all or ctypes)
and if there is a Pageant currently running.
"""
if (_has_win32all or _has_ctypes) and _get_pageant_window_object():
return True
return False
def _query_pageant(msg):
hwnd = _get_pageant_window_object()
if not hwnd:
# Raise a failure to connect exception, pageant isn't running anymore!
return None
# Write our pageant request string into the file (pageant will read this to determine what to do)
filename = tempfile.mktemp('.pag')
map_filename = os.path.basename(filename)
f = open(filename, 'w+b')
f.write(msg )
# Ensure the rest of the file is empty, otherwise pageant will read this
f.write('\0' * (_AGENT_MAX_MSGLEN - len(msg)))
# Create the shared file map that pageant will use to read from
pymap = mmap.mmap(f.fileno(), _AGENT_MAX_MSGLEN, tagname=map_filename, access=mmap.ACCESS_WRITE)
try:
# Create an array buffer containing the mapped filename
char_buffer = array.array("c", map_filename + '\0')
char_buffer_address, char_buffer_size = char_buffer.buffer_info()
# Create a string to use for the SendMessage function call
cds = struct.pack("LLP", _AGENT_COPYDATA_ID, char_buffer_size, char_buffer_address)
if _has_win32all:
# win32gui.SendMessage should also allow the same pattern as
# ctypes, but let's keep it like this for now...
response = win32gui.SendMessage(hwnd, win32con_WM_COPYDATA, len(cds), cds)
elif _has_ctypes:
_buf = array.array('B', cds)
_addr, _size = _buf.buffer_info()
response = ctypes.windll.user32.SendMessageA(hwnd, win32con_WM_COPYDATA, _size, _addr)
else:
response = 0
if response > 0:
datalen = pymap.read(4)
retlen = struct.unpack('>I', datalen)[0]
return datalen + pymap.read(retlen)
return None
finally:
pymap.close()
f.close()
# Remove the file, it was temporary only
os.unlink(filename)
class PageantConnection (object):
"""
Mock "connection" to an agent which roughly approximates the behavior of
a unix local-domain socket (as used by Agent). Requests are sent to the
pageant daemon via special Windows magick, and responses are buffered back
for subsequent reads.
"""
def __init__(self):
self._response = None
def send(self, data):
self._response = _query_pageant(data)
def recv(self, n):
if self._response is None:
return ''
ret = self._response[:n]
self._response = self._response[n:]
if self._response == '':
self._response = None
return ret
def close(self):
pass
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