Author: Daniel Baumann <daniel.baumann@progress-linux.org>
Description: Setting KexAlgorithms in sshd_config to Curve25519 and Diffie-Hellman.

diff -Naurp openssh.orig/sshd_config openssh/sshd_config
--- openssh.orig/sshd_config
+++ openssh/sshd_config
@@ -24,6 +24,7 @@ CASignatureAlgorithms ssh-ed25519,rsa-sh
 
 # Ciphers and keying
 Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
+KexAlgorithms curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group18-sha512,diffie-hellman-group16-sha512,diffie-hellman-group14-sha256,diffie-hellman-group-exchange-sha256
 #RekeyLimit default none
 
 # Logging