Interactive
$ aptitude install augeas-tools
$ augtool -b #make backup file
augtool> set KexAlgorithms diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1
augtool> save
Show errors
Augeas within puppet
## permit root login no and switch off ubuntu
augeas { "sshd_config":
context => "/files/etc/ssh/sshd_config",
changes => [
"set PermitRootLogin no",
"set DenyUsers/1 ubuntu",
"set Ciphers aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes128-ctr",
"set KexAlgorithms diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1",
"set MACs/1 umac-128-etm@openssh.com",
"set MACs/2 hmac-sha2-512",
"set MACs/3 mac-sha2-256",
"set MACs/4 hmac-ripemd160",
],
}