python based ftp server

third_party/pyftpdlib/demo/winnt_ftpd.py

+#!/usr/bin/env python
+# winnt_ftpd.py
+
+"""A ftpd using local Windows NT account database to authenticate users
+(users must already exist).
+
+It also provides a mechanism to (temporarily) impersonate the system
+users every time they are going to perform filesystem operations.
+"""
+
+import os
+import win32security, win32net, pywintypes, win32con
+
+from pyftpdlib import ftpserver
+
+
+def get_profile_dir(username):
+    """Return the user's profile directory."""
+    import _winreg, win32api
+    sid = win32security.ConvertSidToStringSid(
+            win32security.LookupAccountName(None, username)[0])
+    try:
+        key = _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE,
+          r"SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList"+"\\"+sid)
+    except WindowsError:
+        raise ftpserver.AuthorizerError("No profile directory defined for %s "
+                                        "user" %username)
+    value = _winreg.QueryValueEx(key, "ProfileImagePath")[0]
+    return win32api.ExpandEnvironmentStrings(value)
+
+
+class WinNtAuthorizer(ftpserver.DummyAuthorizer):
+
+    def add_user(self, username, homedir=None, **kwargs):
+        """Add a "real" system user to the virtual users table.
+
+        If no homedir argument is specified the user's profile
+        directory will possibly be determined and used.
+
+        The keyword arguments in kwargs are the same expected by the
+        original add_user method: "perm", "msg_login" and "msg_quit".
+        """
+        # get the list of all available users on the system and check
+        # if provided username exists
+        users = [entry['name'] for entry in win32net.NetUserEnum(None, 0)[0]]
+        if not username in users:
+            raise ftpserver.AuthorizerError('No such user "%s".' %username)
+        if not homedir:
+            homedir = get_profile_dir(username)
+        ftpserver.DummyAuthorizer.add_user(self, username, '', homedir,
+                                           **kwargs)
+
+    def add_anonymous(self, homedir=None, realuser="Guest",
+                      password="", **kwargs):
+        """Add an anonymous user to the virtual users table.
+
+        If no homedir argument is specified the realuser's profile
+        directory will possibly be determined and used.
+
+        realuser and password arguments are the credentials to use for
+        managing anonymous sessions.
+        The same behaviour is followed in IIS where the Guest account
+        is used to do so (note: it must be enabled first).
+        """
+        users = [entry['name'] for entry in win32net.NetUserEnum(None, 0)[0]]
+        if not realuser in users:
+            raise ftpserver.AuthorizerError('No such user "%s".' %realuser)
+        if not homedir:
+            homedir = get_profile_dir(realuser)
+        # make sure provided credentials are valid, otherwise an exception
+        # will be thrown; to do so we actually impersonate the user
+        self.impersonate_user(realuser, password)
+        self.terminate_impersonation()
+        ftpserver.DummyAuthorizer.add_anonymous(self, homedir, **kwargs)
+        self.anon_user = realuser
+        self.anon_pwd = password
+
+    def validate_authentication(self, username, password):
+        if (username == "anonymous") and self.has_user('anonymous'):
+            username = self.anon_user
+            password = self.anon_pwd
+        try:
+            win32security.LogonUser(username, None, password,
+                win32con.LOGON32_LOGON_INTERACTIVE,
+                win32con.LOGON32_PROVIDER_DEFAULT)
+            return True
+        except pywintypes.error:
+            return False
+
+    def impersonate_user(self, username, password):
+        if (username == "anonymous") and self.has_user('anonymous'):
+            username = self.anon_user
+            password = self.anon_pwd
+        handler = win32security.LogonUser(username, None, password,
+                      win32con.LOGON32_LOGON_INTERACTIVE,
+                      win32con.LOGON32_PROVIDER_DEFAULT)
+        win32security.ImpersonateLoggedOnUser(handler)
+        handler.Close()
+
+    def terminate_impersonation(self):
+        win32security.RevertToSelf()
+
+
+if __name__ == "__main__":
+    authorizer = WinNtAuthorizer()
+    # add a user (note: user must already exists)
+    authorizer.add_user('user', perm='elradfmw')
+    # add an anonymous user using Guest account to handle the anonymous
+    # sessions (note: Guest must be enabled first)
+    authorizer.add_anonymous(os.getcwd())
+    ftp_handler = ftpserver.FTPHandler
+    ftp_handler.authorizer = authorizer
+    address = ('', 21)
+    ftpd = ftpserver.FTPServer(address, ftp_handler)
+    ftpd.serve_forever()