New submission from Christian Heimes <li...@cheimes.de>: hmac.HMAC's flexibility comes with a cost. To create the MAC of a message, it has to create between three and four hash instances (inner, outer, key for long keys, result), multiple bound method objects and other temporary objects. For short messages, memory allocation, object handling and GIL release/acquire operations dominate the performance.
I propose to provide a fast one-shot HMAC function: hmac.digest(key, msg, digstmod) -> bytes function. A PoC implementation based on OpenSSL's HMAC() function and a pure Python implementation as inlined HMAC showed promising performance improvements. The C implementation is 3 times faster. Standard HMAC: $ ./python -m timeit -n200000 -s "import hmac" -- "hmac.HMAC(b'key', b'message', 'sha256').digest()" 200000 loops, best of 5: 5.38 usec per loop Optimized Python code: $ ./python -m timeit -n 200000 -s "import hmac; hmac._hashopenssl = None" -- "hmac.digest(b'key', b'message', 'sha256')" 200000 loops, best of 5: 3.87 usec per loop OpenSSL HMAC() $ ./python -m timeit -n 200000 -s "import hmac" -- "hmac.digest(b'key', b'message', 'sha256')" 200000 loops, best of 5: 1.82 usec per loop ---------- components: Extension Modules messages: 309097 nosy: christian.heimes, gregory.p.smith priority: normal severity: normal stage: patch review status: open title: Provide optimized HMAC digest type: performance versions: Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue32433> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
