/usr/src/sys/crypto/arc4 isn't used by kernel nad ppp_mppe

[Jose Luis Rodriguez Garcia <joseyluis%gmail.com@localhost>]

arc4 isn' t used in the kernel. I think that it must be deleted the
directory: /usr/src/sys/crypto/arc4
I have searched for arc4_setkey in OpenGrok and I haven't found a
reference about its use.

Doing a grep for arc4_setkey in syssrc, I have found that it is only
used until NetBSD 3. There is
only a reference for this function in   usr/src/sys/net80211/ieee80211_crypto.c

It was changed by other funtions in revision 1.7 :
http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/net80211/ieee80211_crypto.c?only_with_tag=MAIN

I was polishing the patch of Aran Clauson in gnats 47618, of the
package mppe-lkm :
mppe encryption for pptp (I know that it is weak cryptography, but
better than clear text). This patch
includes the arc4 functions.

I have seen than GENERIC amd64  version 6.1.5 doesn't include the
arc4_setkey function an friends, but in
version 7 BETA they are included in GENERIC.

The question:

What must be done for NetBSD 7 and current?

1- Remove arc4 functions from kernel and add to the package.

2- Or add ppp_mppe to the kernel and keep arc4 functions. The sources
says that it is dual licensed: a
 similar license to the BSD 2-clause license or GPL. mppe is a bad
encryption, but it always will be better
 than clear text.

Best regards