From e9ee207622f0f78e31b8277ccb9eaa895ea3472d Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Thu, 29 Dec 2016 22:54:25 -0700 Subject: [PATCH] Issue #29061: secrets.randbelow() would hang with a negative input --- Lib/secrets.py | 2 ++ Lib/test/test_secrets.py | 1 + Misc/ACKS | 1 + Misc/NEWS | 3 +++ 4 files changed, 7 insertions(+) diff --git a/Lib/secrets.py b/Lib/secrets.py index 27fa4503d75..130434229e9 100644 --- a/Lib/secrets.py +++ b/Lib/secrets.py @@ -26,6 +26,8 @@ choice = _sysrand.choice def randbelow(exclusive_upper_bound): """Return a random int in the range [0, n).""" + if exclusive_upper_bound <= 0: + raise ValueError("Upper bound must be positive.") return _sysrand._randbelow(exclusive_upper_bound) DEFAULT_ENTROPY = 32 # number of bytes to return by default diff --git a/Lib/test/test_secrets.py b/Lib/test/test_secrets.py index 4c65cf00cd3..d31d07e01f9 100644 --- a/Lib/test/test_secrets.py +++ b/Lib/test/test_secrets.py @@ -70,6 +70,7 @@ class Random_Tests(unittest.TestCase): for i in range(2, 10): self.assertIn(secrets.randbelow(i), range(i)) self.assertRaises(ValueError, secrets.randbelow, 0) + self.assertRaises(ValueError, secrets.randbelow, -1) class Token_Tests(unittest.TestCase): diff --git a/Misc/ACKS b/Misc/ACKS index 5faed18582f..1c3f573d610 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -369,6 +369,7 @@ Daniel Dittmar Josip Djolonga Walter Dörwald Jaromir Dolecek +Brendan Donegan Ismail Donmez Robert Donohue Marcos Donolo diff --git a/Misc/NEWS b/Misc/NEWS index 3436c0a52fb..f3c6e9e04e2 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -43,6 +43,9 @@ Library - Issue #29085: Allow random.Random.seed() to use high quality OS randomness rather than the pid and time. +- Issue #29061: Fixed bug in secrets.randbelow() which would hang when given + a negative input. Patch by Brendan Donegan. + - Issue #29079: Prevent infinite loop in pathlib.resolve() on Windows - Issue #13051: Fixed recursion errors in large or resized