Source Code for Module paramiko.win_pageant

  1  # Copyright (C) 2005 John Arbash-Meinel <john@arbash-meinel.com> 
  2  # Modified up by: Todd Whiteman <ToddW@ActiveState.com> 
  3  # 
  4  # This file is part of paramiko. 
  5  # 
  6  # Paramiko is free software; you can redistribute it and/or modify it under the 
  7  # terms of the GNU Lesser General Public License as published by the Free 
  8  # Software Foundation; either version 2.1 of the License, or (at your option) 
  9  # any later version. 
 10  # 
 11  # Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY 
 12  # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR 
 13  # A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more 
 14  # details. 
 15  # 
 16  # You should have received a copy of the GNU Lesser General Public License 
 17  # along with Paramiko; if not, write to the Free Software Foundation, Inc., 
 18  # 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA. 
 19   
 20  """ 
 21  Functions for communicating with Pageant, the basic windows ssh agent program. 
 22  """ 
 23   
 24  import os 
 25  import struct 
 26  import tempfile 
 27  import mmap 
 28  import array 
 29   
 30  # if you're on windows, you should have one of these, i guess? 
 31  # ctypes is part of standard library since Python 2.5 
 32  _has_win32all = False 
 33  _has_ctypes = False 
 34  try: 
 35      # win32gui is preferred over win32ui to avoid MFC dependencies 
 36      import win32gui 
 37      _has_win32all = True 
 38  except ImportError: 
 39      try: 
 40          import ctypes 
 41          _has_ctypes = True 
 42      except ImportError: 
 43          pass 
 44   
 45   
 46  _AGENT_COPYDATA_ID = 0x804e50ba 
 47  _AGENT_MAX_MSGLEN = 8192 
 48  # Note: The WM_COPYDATA value is pulled from win32con, as a workaround 
 49  # so we do not have to import this huge library just for this one variable. 
 50  win32con_WM_COPYDATA = 74 
 51   
 52   
 53 -def _get_pageant_window_object(): 
 54      if _has_win32all: 
 55          try: 
 56              hwnd = win32gui.FindWindow('Pageant', 'Pageant') 
 57              return hwnd 
 58          except win32gui.error: 
 59              pass 
 60      elif _has_ctypes: 
 61          # Return 0 if there is no Pageant window. 
 62          return ctypes.windll.user32.FindWindowA('Pageant', 'Pageant') 
 63      return None 
 64   
 65   
 66 -def can_talk_to_agent(): 
 67      """ 
 68      Check to see if there is a "Pageant" agent we can talk to. 
 69   
 70      This checks both if we have the required libraries (win32all or ctypes) 
 71      and if there is a Pageant currently running. 
 72      """ 
 73      if (_has_win32all or _has_ctypes) and _get_pageant_window_object(): 
 74          return True 
 75      return False 
 76   
 77   
 78 -def _query_pageant(msg): 
 79      hwnd = _get_pageant_window_object() 
 80      if not hwnd: 
 81          # Raise a failure to connect exception, pageant isn't running anymore! 
 82          return None 
 83   
 84      # Write our pageant request string into the file (pageant will read this to determine what to do) 
 85      filename = tempfile.mktemp('.pag') 
 86      map_filename = os.path.basename(filename) 
 87   
 88      f = open(filename, 'w+b') 
 89      f.write(msg ) 
 90      # Ensure the rest of the file is empty, otherwise pageant will read this 
 91      f.write('\0' * (_AGENT_MAX_MSGLEN - len(msg))) 
 92      # Create the shared file map that pageant will use to read from 
 93      pymap = mmap.mmap(f.fileno(), _AGENT_MAX_MSGLEN, tagname=map_filename, access=mmap.ACCESS_WRITE) 
 94      try: 
 95          # Create an array buffer containing the mapped filename 
 96          char_buffer = array.array("c", map_filename + '\0') 
 97          char_buffer_address, char_buffer_size = char_buffer.buffer_info() 
 98          # Create a string to use for the SendMessage function call 
 99          cds = struct.pack("LLP", _AGENT_COPYDATA_ID, char_buffer_size, char_buffer_address) 
100   
101          if _has_win32all: 
102              # win32gui.SendMessage should also allow the same pattern as 
103              # ctypes, but let's keep it like this for now... 
104              response = win32gui.SendMessage(hwnd, win32con_WM_COPYDATA, len(cds), cds) 
105          elif _has_ctypes: 
106              _buf = array.array('B', cds) 
107              _addr, _size = _buf.buffer_info() 
108              response = ctypes.windll.user32.SendMessageA(hwnd, win32con_WM_COPYDATA, _size, _addr) 
109          else: 
110              response = 0 
111    
112          if response > 0: 
113              datalen = pymap.read(4) 
114              retlen = struct.unpack('>I', datalen)[0] 
115              return datalen + pymap.read(retlen) 
116          return None 
117      finally: 
118          pymap.close() 
119          f.close() 
120          # Remove the file, it was temporary only 
121          os.unlink(filename) 
122   
123   
124 -class PageantConnection (object): 
125      """ 
126      Mock "connection" to an agent which roughly approximates the behavior of 
127      a unix local-domain socket (as used by Agent).  Requests are sent to the 
128      pageant daemon via special Windows magick, and responses are buffered back 
129      for subsequent reads. 
130      """ 
131   
132 -    def __init__(self): 
133          self._response = None 
134       
135 -    def send(self, data): 
136          self._response = _query_pageant(data) 
137       
138 -    def recv(self, n): 
139          if self._response is None: 
140              return '' 
141          ret = self._response[:n] 
142          self._response = self._response[n:] 
143          if self._response == '': 
144              self._response = None 
145          return ret 
146   
147 -    def close(self): 
148          pass 
149