Issue #17276: MD5 as default digestmod for HMAC is deprecated. The HMAC
module supports digestmod names, e.g. hmac.HMAC('sha1').
diff --git a/Lib/hmac.py b/Lib/hmac.py
index d13b205..873327b 100644
--- a/Lib/hmac.py
+++ b/Lib/hmac.py
@@ -5,6 +5,7 @@
import warnings as _warnings
from _operator import _compare_digest as compare_digest
+import hashlib as _hashlib
trans_5C = bytes((x ^ 0x5C) for x in range(256))
trans_36 = bytes((x ^ 0x36) for x in range(256))
@@ -28,8 +29,11 @@
key: key for the keyed hash object.
msg: Initial input for the hash, if provided.
digestmod: A module supporting PEP 247. *OR*
- A hashlib constructor returning a new hash object.
+ A hashlib constructor returning a new hash object. *OR*
+ A hash name suitable for hashlib.new().
Defaults to hashlib.md5.
+ Implicit default to hashlib.md5 is deprecated and will be
+ removed in Python 3.6.
Note: key and msg must be a bytes or bytearray objects.
"""
@@ -38,11 +42,14 @@
raise TypeError("key: expected bytes or bytearray, but got %r" % type(key).__name__)
if digestmod is None:
- import hashlib
- digestmod = hashlib.md5
+ _warnings.warn("HMAC() without an explicit digestmod argument "
+ "is deprecated.", PendingDeprecationWarning, 2)
+ digestmod = _hashlib.md5
if callable(digestmod):
self.digest_cons = digestmod
+ elif isinstance(digestmod, str):
+ self.digest_cons = lambda d=b'': _hashlib.new(digestmod, d)
else:
self.digest_cons = lambda d=b'': digestmod.new(d)