[Python-checkins] bpo-18407: win32_urandom() uses PY_DWORD_MAX (GH-10656)

Thu Nov 22 08:43:14 EST 2018

https://github.com/python/cpython/commit/c48ff73dd60bec5dcbe64bedeff91e6db26d98bc
commit: c48ff73dd60bec5dcbe64bedeff91e6db26d98bc
branch: master
author: Victor Stinner <vstinner at redhat.com>
committer: GitHub <noreply at github.com>
date: 2018年11月22日T14:43:07+01:00
summary:
bpo-18407: win32_urandom() uses PY_DWORD_MAX (GH-10656)
CryptGenRandom() maximum size is PY_DWORD_MAX, not INT_MAX.
Use DWORD type for the 'chunk' variable
Co-Authored-By: Jeremy Kloth <jeremy.kloth at gmail.com>
files:
M Python/bootstrap_hash.c

diff --git a/Python/bootstrap_hash.c b/Python/bootstrap_hash.c
index 793c646f12ba..eb848c8ff6e3 100644
--- a/Python/bootstrap_hash.c
+++ b/Python/bootstrap_hash.c
@@ -55,8 +55,6 @@ win32_urandom_init(int raise)
 static int
 win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
 {
- Py_ssize_t chunk;
-
 if (hCryptProv == 0)
 {
 if (win32_urandom_init(raise) == -1) {
@@ -66,8 +64,8 @@ win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
 
 while (size > 0)
 {
- chunk = size > INT_MAX ? INT_MAX : size;
- if (!CryptGenRandom(hCryptProv, (DWORD)chunk, buffer))
+ DWORD chunk = (DWORD)Py_MIN(size, PY_DWORD_MAX);
+ if (!CryptGenRandom(hCryptProv, chunk, buffer))
 {
 /* CryptGenRandom() failed */
 if (raise) {
