Bug#774711: update of current openssh crypto support

[Matt Taggart <taggart@debian.org>]

It's been a while since I have updated #774711 with current status of
openssh crypto. Since my last update the following things were deprecated,

7.4:
* cipher: drops 3des-cbc from client proposal

7.2:
* cipher: drops blowfish-cbc, cast128-cbc, all arcfour variants
   and the rijndael-cbc aliases for AES
* HMAC: drops MD5-based and truncated HMAC algorithms
* increase the minimum modulus size supported for
   diffie-hellman-group-exchange to 2048 bits

7.0:
* protocol: v.1 disabled by default at compile time
* 1024-bit diffie-hellman-group1-sha1 key exchange disabled by default
   at run time
* ssh-dss, ssh-dss-cert-* host and user keys is disabled
   by default at run-time
* legacy v00 cert format has been removed

We also know that around Aug 2017 the following is coming:
* protocol: fully dropping support for v.1 (already disabled)
* ciphers: removing Blowfish and RC4
* HMAC: remove RIPE-MD160
* keys: refuse RSA keys smaller than 1024 bits

Of the things I listed that should be considered for removal in my mail 
to this bug on 10 Sep 2015
( https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=774711#65 )
only the following things remain supported:

Keys:
* NIST curves

Kex:
* NIST curves
* diffie-hellman-group14-sha1
* diffie-hellman-group-exchange-sha1 (min 2048 now at least)

Ciphers: done!

MACs:
* sha1
* umac-64

Anyone know the upstream status of these remaining things?

Thanks,

-- 
Matt Taggart
taggart@debian.org