On Sun, Feb 14, 2016 at 07:41:19PM +0000, Nick Lowe wrote: > Switch from using os_random() to using > os_get_random(...) in wpas_auth_failed(...) The intention is to facilitate > the future removal of os_random(). os_random() uses a low quality PRNG which > we should avoid using outright unless there is a compelling performance > justification to do so. > diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c > void wpas_auth_failed(struct wpa_supplicant *wpa_s, char *reason) > - int dur; > + int dur, r; > - wpa_key_mgmt_wpa_ieee8021x(ssid->key_mgmt)) > - dur += os_random() % (ssid->auth_failures * 10); > + wpa_key_mgmt_wpa_ieee8021x(ssid->key_mgmt) && > + os_get_random((u8 *) &r, sizeof(r)) >= 0) > + dur += r % (ssid->auth_failures * 10); This does not look safe. Shouldn't r be unsigned at minimum? The proposed construction seems to have about 0.5 chance of being negative and reducing the wait duration. Please note that os_random() returns unsigned long. The dur variable could also be changed to be unsigned (not that this construction would be able to go beyond the maximum int value in practice). -- Jouni Malinen PGP id EFC895FA _______________________________________________ Hostap mailing list Hostap@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/hostap
