make HtdigestTokenGenerator work with py3k

Define a textopen function that returns "native strings" (in the sense
of pep3333). Therefore textopen needs to decode using iso-8859-1 iff
running on py3k. Additionally use a with construct to close the file
being read in all circumstances.

2 files changed, 18 insertions, 12 deletions

diff --git a/wsgitools/digest.py b/wsgitools/digest.py
index 532b371..6395d02 100644
--- a/wsgitools/digest.py
+++ b/wsgitools/digest.py
@@ -19,7 +19,7 @@ import hashlib
 import time
 import os
 
-from wsgitools.internal import bytes2str, str2bytes
+from wsgitools.internal import bytes2str, str2bytes, textopen
 from wsgitools.authentication import AuthenticationRequired, \
         ProtocolViolation, AuthenticationMiddleware
 
@@ -239,18 +239,19 @@ class HtdigestTokenGenerator(AbstractTokenGenerator):
         """
         assert isinstance(htdigestfile, str)
         self.users = {}
-        for line in file(htdigestfile):
-            parts = line.rstrip("\n").split(":")
-            if len(parts) != 3:
-                if ignoreparseerrors:
+        with textopen(htdigestfile, "r") as htdigest:
+            for line in htdigest:
+                parts = line.rstrip("\n").split(":")
+                if len(parts) != 3:
+                    if ignoreparseerrors:
+                        continue
+                    raise ValueError("invalid number of colons in htdigest file")
+                user, realm, token = parts
+                if realm != self.realm:
                     continue
-                raise ValueError("invalid number of colons in htdigest file")
-            user, realm, token = parts
-            if realm != self.realm:
-                continue
-            if user in self.users and not ignoreparseerrors:
-                raise ValueError("duplicate user in htdigest file")
-            self.users[user] = token
+                if user in self.users and not ignoreparseerrors:
+                    raise ValueError("duplicate user in htdigest file")
+                self.users[user] = token
 
     def __call__(self, user, algo="md5"):
         assert algo.lower() in ["md5", "md5-sess"]
diff --git a/wsgitools/internal.py b/wsgitools/internal.py
index c392b6a..c4f1da1 100644
--- a/wsgitools/internal.py
+++ b/wsgitools/internal.py
@@ -5,6 +5,8 @@ if bytes is str:
     def str2bytes(sstr):
         assert isinstance(sstr, str)
         return sstr
+    def textopen(filename, mode):
+        return open(filename, mode)
 else:
     def bytes2str(bstr):
         assert isinstance(bstr, bytes)
@@ -12,3 +14,6 @@ else:
     def str2bytes(sstr):
         assert isinstance(sstr, str)
         return sstr.encode("iso-8859-1") # might fail, but spec says it doesn't
+    def textopen(filename, mode):
+        # We use the same encoding as for all wsgi strings here.
+        return open(filename, mode, encoding="iso-8859-1")