WPS: Workaround broken Credential encoding from some D-Link APs

At least D-Link DIR-600 and DIR-825 have been reported to include
an extra octet after the Network Key attribute within a Credential
attribute. This can happen at least when they are provisioning an
open network.

Add a workaround to detect this incorrectly encoded attribute and
to skip the extra octet when parsing such a Credential.
This commit is contained in:
Jouni Malinen 2010-10-11 16:07:49 +03:00 committed by Jouni Malinen
parent 5582a5d1b3
commit 68d6fe5693

View file

@ -530,6 +530,7 @@ int wps_parse_msg(const struct wpabuf *msg, struct wps_parse_attr *attr)
{ {
const u8 *pos, *end; const u8 *pos, *end;
u16 type, len; u16 type, len;
u16 prev_type = 0;
os_memset(attr, 0, sizeof(*attr)); os_memset(attr, 0, sizeof(*attr));
pos = wpabuf_head(msg); pos = wpabuf_head(msg);
@ -552,6 +553,23 @@ int wps_parse_msg(const struct wpabuf *msg, struct wps_parse_attr *attr)
if (len > end - pos) { if (len > end - pos) {
wpa_printf(MSG_DEBUG, "WPS: Attribute overflow"); wpa_printf(MSG_DEBUG, "WPS: Attribute overflow");
wpa_hexdump_buf(MSG_MSGDUMP, "WPS: Message data", msg); wpa_hexdump_buf(MSG_MSGDUMP, "WPS: Message data", msg);
#ifdef WPS_WORKAROUNDS
/*
* Some deployed APs seem to have a bug in encoding of
* Network Key attribute in the Credential attribute
* where they add an extra octet after the Network Key
* attribute at least when open network is being
* provisioned.
*/
if ((type & 0xff00) != 0x1000 &&
prev_type == ATTR_NETWORK_KEY) {
wpa_printf(MSG_DEBUG, "WPS: Workaround - try "
"to skip unexpected octet after "
"Network Key");
pos -= 3;
continue;
}
#endif /* WPS_WORKAROUNDS */
return -1; return -1;
} }
@ -577,6 +595,7 @@ int wps_parse_msg(const struct wpabuf *msg, struct wps_parse_attr *attr)
if (wps_set_attr(attr, type, pos, len) < 0) if (wps_set_attr(attr, type, pos, len) < 0)
return -1; return -1;
prev_type = type;
pos += len; pos += len;
} }