diff --git a/postinstall b/postinstall index df1e84f..e189c6a 100755 --- a/postinstall +++ b/postinstall @@ -395,11 +395,14 @@ harden_ssh(){ if [ $ssh_hardening -gt 0 ]; then log "Hardening ssh server" rm /etc/ssh/ssh_host_* - ssh-keygen -t rsa -b 4096 -f /etc/ssh/ssh_host_rsa_key -N "" - ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N "" + log "Creating new SSH host keys" + ssh-keygen -t rsa -b 4096 -f /etc/ssh/ssh_host_rsa_key -N "" > /dev/null 2>&1 + ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N "" > /dev/null 2>&1 + log "Creating new SSH moduli" awk '$5 >= 3071' /etc/ssh/moduli > /etc/ssh/moduli.safe mv /etc/ssh/moduli.safe /etc/ssh/moduli + log "Writing hardened SSH config" if [[ $VERSION_CODENAME == "bookworm" ]]; then echo -e "\n# Restrict key exchange, cipher, and MAC algorithms, as per sshaudit.com\n# hardening guide.\nKexAlgorithms sntrup761x25519-sha512@openssh.com,curve25519-sha256,curve25519-sha256@libssh.org,gss-curve25519-sha256-,diffie-hellman-group16-sha512,gss-group16-sha512-,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha256\nCiphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr\nMACs hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com\nHostKeyAlgorithms ssh-ed25519,ssh-ed25519-cert-v01@openssh.com,sk-ssh-ed25519@openssh.com,sk-ssh-ed25519-cert-v01@openssh.com,rsa-sha2-512,rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256,rsa-sha2-256-cert-v01@openssh.com" > /etc/ssh/sshd_config.d/ssh-audit_hardening.conf elif [[ $VERSION_CODENAME == "bullseye" ]]; then