From ddb39e799d65748c5ea42c344170befc90af9e64 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Tue, 13 May 2014 22:09:23 -0700 Subject: [PATCH] Issue #21470: Do a better job seeding the random number generator to fully cover its state space. --- Lib/random.py | 4 +++- Misc/NEWS | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/Lib/random.py b/Lib/random.py index 2f2f0915e2..e89fae663a 100644 --- a/Lib/random.py +++ b/Lib/random.py @@ -108,7 +108,9 @@ class Random(_random.Random): if a is None: try: - a = long(_hexlify(_urandom(32)), 16) + # Seed with enough bytes to span the 19937 bit + # state space for the Mersenne Twister + a = long(_hexlify(_urandom(2500)), 16) except NotImplementedError: import time a = long(time.time() * 256) # use fractional seconds diff --git a/Misc/NEWS b/Misc/NEWS index 2bda7260c0..e028419fee 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -52,6 +52,9 @@ Library - Issue #21306: Backport hmac.compare_digest from Python 3. This is part of PEP 466. +- Issue #21470: Do a better job seeding the random number generator by + using enough bytes to span the full state space of the Mersenne Twister. + - Issue #21469: Reduced the risk of false positives in robotparser by checking to make sure that robots.txt has been read or does not exist prior to returning True in can_fetch(). -- 2.50.1