support htpasswd with Windows and Python 2.3

[sid|at|seegrid.com]

Change password fails on Windows if running Python 2.3:

Traceback (most recent call last):
  File "C:\Python23\Lib\site-packages\trac\web\modpython_frontend.py", line 205, in handler
    dispatch_request(mpr.path_info, mpr, env)
  File "C:\Python23\Lib\site-packages\trac\web\main.py", line 139, in dispatch_request
    dispatcher.dispatch(req)
  File "C:\Python23\Lib\site-packages\trac\web\main.py", line 107, in dispatch
    resp = chosen_handler.process_request(req)
  File "build\bdist.win32\egg\acct_mgr\web_ui.py", line 48, in process_request
  File "build\bdist.win32\egg\acct_mgr\web_ui.py", line 64, in _do_change_password
  File "build\bdist.win32\egg\acct_mgr\htfile.py", line 49, in set_password
  File "build\bdist.win32\egg\acct_mgr\htfile.py", line 102, in userline
  File "build\bdist.win32\egg\acct_mgr\htfile.py", line 75, in salt
  File "build\bdist.win32\egg\acct_mgr\htfile.py", line 30, in urandom
IOError: [Errno 2] No such file or directory: '/dev/urandom'

I saw another site hinted at using windrandom.pyd file for Windows for Python 2.3 (although it is deprecated in 2.4 in favor of os.urandom).

[Matt Good]

Ok, I didn't find a reasonable way to generate cryptographically sound random data on Windows with Python 2.3, but that winrandom module may work. Can you try it with the following patch:

acct_mgr/htfile.py

@@ -26 +26 @@
 try:
     from os import urandom
 except ImportError:
-    def urandom(n):
-        return open('/dev/urandom').read(n)
+    try:
+        from winrandom import winrandom as urandom
+    except ImportError:
+        def urandom(n):
+            return open('/dev/urandom').read(n)
 
 
 class AbstractPasswordFileStore(Component):

Also, note that htdigest does not require random data so it could be used instead of htpasswd.