initialized a basic htpasswd web interface

* imported http://trac.edgewall.org/export/9825/trunk/contrib/htpasswd.py
 * improved file handling and items management

htpasswd.py

@@ -0,0 +1,100 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+"""
+$Id$
+
+A python module for managing htpasswd files.
+
+The code is based on http://trac.edgewall.org/export/9825/trunk/contrib/htpasswd.py
+Original author: Eli Carter
+
+Copyright 2010 Lars Kruse <devel@sumpfralle.de>
+Copyright before 2010 Eli Carter
+
+This module is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This module is distributed 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with This module. If not, see <http://www.gnu.org/licenses/>.
+"""
+
+import crypt
+import shutil
+import tempfile
+import random
+import os
+
+
+def _get_random_salt():
+    """Returns a string of 2 random letters"""
+    letters = 'abcdefghijklmnopqrstuvwxyz' \
+              'ABCDEFGHIJKLMNOPQRSTUVWXYZ' \
+              '0123456789/.'
+    return random.choice(letters) + random.choice(letters)
+
+
+class HtpasswdFile:
+    """A class for manipulating htpasswd files."""
+
+    def __init__(self, filename, create=False):
+        self.entries = {}
+        self.filename = filename
+        if not create:
+            self.load()
+
+    def load(self):
+        """Read the htpasswd file into memory.
+        This function may raise an IOError exception.
+        """
+        self.entries = {}
+        for line in open(self.filename, 'r').readlines():
+            username, pwhash = line.split(':', 1)
+            self.entries[username] = pwhash
+
+    def save(self):
+        """Write the htpasswd file to disk
+        The file is written in a safe manner: first a temporary file with the
+        resulting content is created in the directory of the original file.
+        Afterwards it is moved to the original filename.
+        This function may raise an IOError exception.
+        """
+        # create a temporary file besides the original file
+        temp_file, temp_filename = tempfile.mkstemp(
+                dir=os.path.dirname(self.filename), text=True)
+        try:
+            if os.path.isfile(self.filename):
+                # copy the original file mode (mod, timestamps)
+                shutil.copystat(self.filename, temp_filename)
+            for name, pwhash in self.entries.items():
+                os.write(temp_file, "%s:%s%s" % (name, pwhash, os.linesep))
+            os.close(temp_file)
+        except IOError:
+            try:
+                os.remove(temp_filename)
+            except IOError:
+                # ignore errors during failure handling
+                pass
+        else:
+            # move the temporary file to the original filename
+            os.rename(temp_filename, self.filename)
+
+    def update(self, username, password):
+        """Replace the entry for the given user, or add it if new."""
+        pwhash = crypt.crypt(password, _get_random_salt())
+        self.entries[username] = pwhash
+
+    def delete(self, username):
+        """Remove the entry for the given user."""
+        if username in self.entries:
+            self.entries.pop(username)
+
+    def get_usernames(self):
+        return self.entries.keys()
+