Continuing the discussion from Issue 3552 (http://bugs.python.org/issue3552). r65676 makes changes to Modules/md5module.c and Modules/sha1module.c, to allow them to read mutable buffers. There's a segfault in sha1module if given 0 arguments. eg: >>> import _sha1 >>> _sha1.sha1() Segmentation fault Docs here suggest this should be OK: http://docs.python.org/dev/3.0/library/hashlib.html This crashes on the Lib/test/test_hmac.py test case, but apparently (according to Margin on issue 3552) none of the build bots see it because they use libopenssl and completely bypass the _md5 and _sha1 modules. Also there are no direct test cases for either of these modules. This is because new code in r65676 doesn't initialise a pointer to NULL. Fixed in patch (as well as replaced tab with spaces for consistency, in both modules). I strongly recommend that a) A "build bot" be made to use _md5 and _sha1 instead of OpenSSL (or they aren't running that code at all), AND/OR b) Direct test cases be written for _md5 and _sha1. Commit log: Fixed crash on _sha1.sha1(), with no arguments, due to not initialising pointer. Normalised indentation in md5module.c and sha1module.c.

Thanks for the report. Fixed in r65690.