# Based on https://infosec.mozilla.org/guidelines/openssh and further cipher hardening

Include /etc/ssh/sshd_config.d/*.conf

HostKey /etc/ssh/ssh_host_ed25519_key
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_ecdsa_key

KexAlgorithms curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256,curve25519-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,sntrup761x25519-sha512@openssh.com
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
HostKeyAlgorithms ssh-ed25519,rsa-sha2-512,rsa-sha2-256
MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com

LogLevel VERBOSE

AuthenticationMethods publickey

MaxAuthTries 3
MaxSessions 2

Compression no
TCPKeepAlive no
ClientAliveCountMax 2

PubkeyAuthentication yes
Banner /etc/login_banner

PermitRootLogin no
PasswordAuthentication no
PermitEmptyPasswords no

KbdInteractiveAuthentication no
KerberosAuthentication no
GSSAPIAuthentication no

UsePAM yes

AllowAgentForwarding no
AllowTcpForwarding no
X11Forwarding no
PrintMotd no

# Allow client to pass locale environment variables
AcceptEnv LANG LC_*

# override default of no subsystems
Subsystem	sftp	/usr/lib/openssh/sftp-server