This adds mostly feature complete external Registrar support with the
main missing part being proper support for multiple external Registrars
working at the same time and processing of concurrent registrations when
using an external Registrar.
This code is based on Sony/Saice implementation
(https://www.saice-wpsnfc.bz/) and the changes made by Ted Merrill
(Atheros) to make it more suitable for hostapd design and embedded
systems. Some of the UPnP code is based on Intel's libupnp. Copyrights
and licensing are explained in src/wps/wps_upnp.c in more detail.
WPS spec is not very specific on the presentation used for the DH
values. The Public Key attribute is described to be 192 octets long, so
that could be interpreted to imply that other places use fixed length
presentation for the DH keys. Change the DH derivation to use fixed
length bufferd by zero padding them from beginning if needed. This can
resolve infrequent (about 1/256 chance for both Public Key and Shared
Key being shorter) interop issues.
The configuration parsing functions seemed to have worked fine before,
but these were real bugs even if they did not show up in practice.
hostapd_ip_diff() was broken for IPv6 addresses (overwrote address and
always returned 1.
Generate a SHA1 hash -based UUID from the local MAC address if the UUID
was not configured. This makes it easier to prepare for WPS since there
is no need to generate an UUID.
In situations where the driver does background scanning and sends a
steady stream of scan results, wpa_supplicant would continually
reschedule the scan. This resulted in specific SSID scans never
happening for a hidden AP, and the supplicant never connecting to the AP
because it never got found. Instead, if there's an already scheduled
scan, and a request comes in to reschedule it, and there are enabled
scan_ssid=1 network blocks, let the scan happen anyway so the hidden
SSID has a chance to be found.
Number of TLVs were processed in groups and these cases were now separated
into more flexible processing of one TLV at the time. wpabuf_concat()
function was added to make it easier to concatenate TLVs. EAP Sequences are
now supported in both server and peer code, but the server side is not
enabled by default.
