python2/00169-avoid-implicit-usage-of-md5-in-multiprocessing.patch
David Malcolm 41aa0d34f7 2.7.3-23: use SHA-256 rather than MD5 in multiprocessing.connection (patch 169; rhbz#879695)
* Wed Feb 20 2013 David Malcolm <dmalcolm@redhat.com> - 2.7.3-23
- use SHA-256 rather than implicitly using MD5 within the challenge handling
in multiprocessing.connection (patch 169; rhbz#879695)
2013-02-20 15:25:17 -05:00

42 lines
1.6 KiB
Diff

diff --git a/Lib/multiprocessing/connection.py b/Lib/multiprocessing/connection.py
--- a/Lib/multiprocessing/connection.py
+++ b/Lib/multiprocessing/connection.py
@@ -41,6 +41,10 @@
# A very generous timeout when it comes to local connections...
CONNECTION_TIMEOUT = 20.
+# The hmac module implicitly defaults to using MD5.
+# Support using a stronger algorithm for the challenge/response code:
+HMAC_DIGEST_NAME='sha256'
+
_mmap_counter = itertools.count()
default_family = 'AF_INET'
@@ -700,12 +704,16 @@
WELCOME = b'#WELCOME#'
FAILURE = b'#FAILURE#'
+def get_digestmod_for_hmac():
+ import hashlib
+ return getattr(hashlib, HMAC_DIGEST_NAME)
+
def deliver_challenge(connection, authkey):
import hmac
assert isinstance(authkey, bytes)
message = os.urandom(MESSAGE_LENGTH)
connection.send_bytes(CHALLENGE + message)
- digest = hmac.new(authkey, message).digest()
+ digest = hmac.new(authkey, message, get_digestmod_for_hmac()).digest()
response = connection.recv_bytes(256) # reject large message
if response == digest:
connection.send_bytes(WELCOME)
@@ -719,7 +727,7 @@
message = connection.recv_bytes(256) # reject large message
assert message[:len(CHALLENGE)] == CHALLENGE, 'message = %r' % message
message = message[len(CHALLENGE):]
- digest = hmac.new(authkey, message).digest()
+ digest = hmac.new(authkey, message, get_digestmod_for_hmac()).digest()
connection.send_bytes(digest)
response = connection.recv_bytes(256) # reject large message
if response != WELCOME: