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@gmail.com>
This commit is contained in:
Victor Stinner 2018-11-22 14:43:07 +01:00 committed by GitHub
parent 28f468cb19
commit c48ff73dd6
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@ -55,8 +55,6 @@ error:
static int static int
win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise) win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
{ {
Py_ssize_t chunk;
if (hCryptProv == 0) if (hCryptProv == 0)
{ {
if (win32_urandom_init(raise) == -1) { if (win32_urandom_init(raise) == -1) {
@ -66,8 +64,8 @@ win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
while (size > 0) while (size > 0)
{ {
chunk = size > INT_MAX ? INT_MAX : size; DWORD chunk = (DWORD)Py_MIN(size, PY_DWORD_MAX);
if (!CryptGenRandom(hCryptProv, (DWORD)chunk, buffer)) if (!CryptGenRandom(hCryptProv, chunk, buffer))
{ {
/* CryptGenRandom() failed */ /* CryptGenRandom() failed */
if (raise) { if (raise) {