upstream: Add support for a PQC KEX/KEM:

sntrup4591761x25519-sha512@tinyssh.org using the Streamlined NTRU Prime
4591^761 implementation from SUPERCOP coupled with X25519 as a stop-loss. Not
enabled by default.

introduce KEM API; a simplified framework for DH-ish KEX methods.

from markus@ feedback & ok djm@

OpenBSD-Commit-ID: d687f76cffd3561dd73eb302d17a1c3bf321d1a7

1 files changed, 2 insertions, 1 deletions

diff --git a/sshd.c b/sshd.c
index f6927672e..330b8052d 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.527 2019/01/19 21:43:56 djm Exp $ */
+/* $OpenBSD: sshd.c,v 1.528 2019/01/21 10:20:12 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2219,6 +2219,7 @@ do_ssh2_kex(struct ssh *ssh)
 # endif
 #endif
         kex->kex[KEX_C25519_SHA256] = kexc25519_server;
+        kex->kex[KEX_KEM_SNTRUP4591761X25519_SHA512] = kex_kem_server;
         kex->load_host_public_key=&get_hostkey_public_by_type;
         kex->load_host_private_key=&get_hostkey_private_by_type;
         kex->host_key_index=&get_hostkey_index;