1 files changed, 6 insertions, 15 deletions

diff --git a/src/mailman/model/messagestore.py b/src/mailman/model/messagestore.py
index 12b2aef46..05069119c 100644
--- a/src/mailman/model/messagestore.py
+++ b/src/mailman/model/messagestore.py
@@ -17,9 +17,6 @@
 
 """Model for message stores."""
 
-from __future__ import absolute_import, print_function, unicode_literals
-
-__metaclass__ = type
 __all__ = [
     'MessageStore',
     ]
@@ -28,16 +25,15 @@ __all__ = [
 import os
 import errno
 import base64
+import pickle
 import hashlib
-import cPickle as pickle
-
-from zope.interface import implementer
 
 from mailman.config import config
 from mailman.database.transaction import dbconnection
 from mailman.interfaces.messages import IMessageStore
 from mailman.model.message import Message
 from mailman.utilities.filesystem import makedirs
+from zope.interface import implementer
 
 
 # It could be very bad if you have already stored files and you change this
@@ -68,8 +64,8 @@ class MessageStore:
             raise ValueError(
                 'Message ID already exists in message store: {0}'.format(
                     message_id))
-        shaobj = hashlib.sha1(message_id)
-        hash32 = base64.b32encode(shaobj.digest())
+        shaobj = hashlib.sha1(message_id.encode('utf-8'))
+        hash32 = base64.b32encode(shaobj.digest()).decode('utf-8')
         del message['X-Message-ID-Hash']
         message['X-Message-ID-Hash'] = hash32
         # Calculate the path on disk where we're going to store this message
@@ -94,7 +90,7 @@ class MessageStore:
         # them and try again.
         while True:
             try:
-                with open(path, 'w') as fp:
+                with open(path, 'wb') as fp:
                     # -1 says to use the highest protocol available.
                     pickle.dump(message, fp, -1)
                     break
@@ -106,7 +102,7 @@ class MessageStore:
 
     def _get_message(self, row):
         path = os.path.join(config.MESSAGES_DIR, row.path)
-        with open(path) as fp:
+        with open(path, 'rb') as fp:
             return pickle.load(fp)
 
     @dbconnection
@@ -118,11 +114,6 @@ class MessageStore:
 
     @dbconnection
     def get_message_by_hash(self, store, message_id_hash):
-        # It's possible the hash came from a message header, in which case it
-        # will be a Unicode.  However when coming from source code, it may be
-        # bytes object.  Coerce to the latter if necessary; it must be ASCII.
-        if not isinstance(message_id_hash, bytes):
-            message_id_hash = message_id_hash.encode('ascii')
         row = store.query(Message).filter_by(
             message_id_hash=message_id_hash).first()
         if row is None: