Protocol 2

# LogLevel VERBOSE

HostKey /etc/ssh/host_keys/rsa

# https://cipherli.st/
KexAlgorithms curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,umac-128@openssh.com

PermitRootLogin no
PasswordAuthentication no
StrictModes no
# separated by spaces
AllowUsers _

ForceCommand /usr/bin/rrsync /data
AllowAgentForwarding no
AllowTcpForwarding no
GatewayPorts no
X11Forwarding no
PermitUserEnvironment no
PermitTTY no
PrintMotd no