D-Bus support for password=hash:

[Evan Broder]

wpa_supplicant config files support just specifying the NtPasswordHash
for a MS-CHAPv2 connection instead of providing the password itself by
setting password=hash:1234deadbeefetc.

However, it does this check before parsing the string value, and the
D-Bus interfaces will only set the password to either a quoted string
(if it comes in as a D-Bus string) or an array of hex bytes (if it
comes in as a byte array), which means there's no way to invoke this
functionality over D-Bus.

I'd like to fix that, but I'm not really sure of the best way to
expose it. Does anybody have thoughts on how to do it?

It seems like the cleanest option would be a new config file
option/D-Bus key ("password_hash"?), which is checked if "password"
isn't populated, and is assumed to be a hex byte string (so it would
come over D-Bus as an array of bytes), but I don't feel that I have a
good enough sense of hostap/wpa_supplicant's style to dive into
writing a patch, so I'd appreciated feedback before I start on
implementation.

Thanks for your feedback,
 - Evan