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WPS: Added support for wildcard PINs that work with any UUID-E

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Since the Registrar may not yet know the UUID-E when a new PIN is
entered, use of a wildcard PIN that works with any UUID-E can be useful.
Such a PIN will be bound to the first Enrollee trying to use it and it
will be invalidated after the first use.
This commit is contained in:
Jouni Malinen 2008-11-30 20:32:03 +02:00
parent 79d7d8efe7
commit 08bec36178
3 changed files with 58 additions and 20 deletions
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6
hostapd/README-WPS
View file

@ -154,6 +154,12 @@ Example command to add a PIN (12345670) for an Enrollee:
hostapd_cli wps_pin 53b63a98-d29e-4457-a2ed-094d7e6a669c 12345670
If the UUID-E is not available (e.g., Enrollee waits for the Registrar
to be selected before connecting), wildcard UUID may be used to allow the PIN to be used once with any UUID:
hostapd_cli wps_pin any 12345670
After this, the Enrollee can connect to the AP again and complete WPS
negotiation. At that point, a new, random WPA PSK is generated for the
client device and the client can then use that key to connect to the

10
hostapd/wps_hostapd.c
View file

@ -543,9 +543,15 @@ int hostapd_wps_add_pin(struct hostapd_data *hapd, const char *uuid,
const char *pin)
{
u8 u[UUID_LEN];
if (hapd->wps == NULL || uuid_str2bin(uuid, u))
int any = 0;
if (hapd->wps == NULL)
return -1;
return wps_registrar_add_pin(hapd->wps->registrar, u,
if (os_strcmp(uuid, "any") == 0)
any = 1;
else if (uuid_str2bin(uuid, u))
return -1;
return wps_registrar_add_pin(hapd->wps->registrar, any ? NULL : u,
(const u8 *) pin, os_strlen(pin));
}

62
src/wps/wps_registrar.c
View file

@ -26,6 +26,7 @@
struct wps_uuid_pin {
struct wps_uuid_pin *next;
u8 uuid[WPS_UUID_LEN];
int wildcard_uuid;
u8 *pin;
size_t pin_len;
int locked;
@ -339,7 +340,10 @@ int wps_registrar_add_pin(struct wps_registrar *reg, const u8 *uuid,
p = os_zalloc(sizeof(*p));
if (p == NULL)
return -1;
os_memcpy(p->uuid, uuid, WPS_UUID_LEN);
if (uuid == NULL)
p->wildcard_uuid = 1;
else
os_memcpy(p->uuid, uuid, WPS_UUID_LEN);
p->pin = os_malloc(pin_len);
if (p->pin == NULL) {
os_free(p);
@ -394,26 +398,43 @@ static const u8 * wps_registrar_get_pin(struct wps_registrar *reg,
pin = reg->pins;
while (pin) {
if (os_memcmp(pin->uuid, uuid, WPS_UUID_LEN) == 0) {
/*
* Lock the PIN to avoid attacks based on concurrent
* re-use of the PIN that could otherwise avoid PIN
* invalidations.
*/
if (pin->locked) {
wpa_printf(MSG_DEBUG, "WPS: Selected PIN "
"locked - do not allow concurrent "
"re-use");
return NULL;
}
*pin_len = pin->pin_len;
pin->locked = 1;
return pin->pin;
}
if (!pin->wildcard_uuid &&
os_memcmp(pin->uuid, uuid, WPS_UUID_LEN) == 0)
break;
pin = pin->next;
}
return NULL;
if (!pin) {
/* Check for wildcard UUIDs since none of the UUID-specific
* PINs matched */
pin = reg->pins;
while (pin) {
if (pin->wildcard_uuid == 1) {
wpa_printf(MSG_DEBUG, "WPS: Found a wildcard "
"PIN. Assigned it for this UUID-E");
pin->wildcard_uuid = 2;
os_memcpy(pin->uuid, uuid, WPS_UUID_LEN);
break;
}
pin = pin->next;
}
}
if (!pin)
return NULL;
/*
* Lock the PIN to avoid attacks based on concurrent re-use of the PIN
* that could otherwise avoid PIN invalidations.
*/
if (pin->locked) {
wpa_printf(MSG_DEBUG, "WPS: Selected PIN locked - do not "
"allow concurrent re-use");
return NULL;
}
*pin_len = pin->pin_len;
pin->locked = 1;
return pin->pin;
}
@ -424,6 +445,11 @@ int wps_registrar_unlock_pin(struct wps_registrar *reg, const u8 *uuid)
pin = reg->pins;
while (pin) {
if (os_memcmp(pin->uuid, uuid, WPS_UUID_LEN) == 0) {
if (pin->wildcard_uuid == 2) {
wpa_printf(MSG_DEBUG, "WPS: Invalidating used "
"wildcard PIN");
return wps_registrar_invalidate_pin(reg, uuid);
}
pin->locked = 0;
return 0;
}