Configure ScyllaDB SSL encryption and authentication with certificate management and security hardening

Install ScyllaDB and SSL tools

First install ScyllaDB and the SSL certificate tools needed for encryption.

sudo apt update
wget -qO - https://downloads.scylladb.com/deb/ubuntu/scylla-6.0-key.asc | sudo gpg --dearmor -o /etc/apt/keyrings/scylladb.gpg
echo "deb [arch=amd64 signed-by=/etc/apt/keyrings/scylladb.gpg] https://downloads.scylladb.com/deb/ubuntu/ $(lsb_release -sc) scylla-6.0" | sudo tee /etc/apt/sources.list.d/scylladb.list
sudo apt update
sudo apt install -y scylla openssl

sudo dnf update -y
sudo rpm --import https://downloads.scylladb.com/rpm/scylladb-6.0-key.asc
sudo curl -o /etc/yum.repos.d/scylladb-6.0.repo https://downloads.scylladb.com/rpm/centos/scylladb-6.0.repo
sudo dnf install -y scylla openssl

Create SSL certificate directory structure

Set up directories for SSL certificates with proper ownership and permissions.

sudo mkdir -p /etc/scylla/ssl/ca
sudo mkdir -p /etc/scylla/ssl/server
sudo mkdir -p /etc/scylla/ssl/client
sudo chown -R scylla:scylla /etc/scylla/ssl
sudo chmod -R 750 /etc/scylla/ssl

Generate Certificate Authority (CA)

Create a private CA to sign all ScyllaDB certificates. This CA will be used for both client and server certificates.

cd /etc/scylla/ssl/ca
sudo openssl genrsa -out ca-key.pem 4096
sudo openssl req -new -x509 -key ca-key.pem -out ca-cert.pem -days 3650 -subj "/C=US/ST=CA/L=San Francisco/O=ScyllaDB/OU=Database/CN=ScyllaDB-CA"
sudo chown scylla:scylla ca-*.pem
sudo chmod 600 ca-key.pem
sudo chmod 644 ca-cert.pem

Generate server certificates

Create SSL certificates for ScyllaDB servers. Replace the IP addresses with your actual server IPs.

cd /etc/scylla/ssl/server
sudo openssl genrsa -out server-key.pem 2048
sudo openssl req -new -key server-key.pem -out server.csr -subj "/C=US/ST=CA/L=San Francisco/O=ScyllaDB/OU=Database/CN=scylla-server"

Create server certificate extensions
sudo tee server-ext.cnf > /dev/null << 'EOF'
subjectAltName = @alt_names
[alt_names]
DNS.1 = localhost
DNS.2 = scylla-server
IP.1 = 127.0.0.1
IP.2 = 203.0.113.10
IP.3 = 203.0.113.11
IP.4 = 203.0.113.12
EOF

sudo openssl x509 -req -in server.csr -CA ../ca/ca-cert.pem -CAkey ../ca/ca-key.pem -out server-cert.pem -days 365 -extensions v3_req -extfile server-ext.cnf
sudo chown scylla:scylla server-*.pem
sudo chmod 600 server-key.pem
sudo chmod 644 server-cert.pem
sudo rm server.csr server-ext.cnf

Generate client certificates

Create certificates for client authentication. Each client application should have its own certificate.

cd /etc/scylla/ssl/client
sudo openssl genrsa -out client-key.pem 2048
sudo openssl req -new -key client-key.pem -out client.csr -subj "/C=US/ST=CA/L=San Francisco/O=ScyllaDB/OU=Client/CN=scylla-client"
sudo openssl x509 -req -in client.csr -CA ../ca/ca-cert.pem -CAkey ../ca/ca-key.pem -out client-cert.pem -days 365
sudo chown scylla:scylla client-*.pem
sudo chmod 600 client-key.pem
sudo chmod 644 client-cert.pem
sudo rm client.csr

Configure ScyllaDB SSL encryption

Enable SSL encryption for both client connections and inter-node communication.

# Client-server SSL configuration
client_encryption_options:
    enabled: true
    optional: false
    certificate: /etc/scylla/ssl/server/server-cert.pem
    keyfile: /etc/scylla/ssl/server/server-key.pem
    truststore: /etc/scylla/ssl/ca/ca-cert.pem
    require_client_auth: true
    protocol: TLSv1.2

Inter-node SSL configuration
server_encryption_options:
    internode_encryption: all
    certificate: /etc/scylla/ssl/server/server-cert.pem
    keyfile: /etc/scylla/ssl/server/server-key.pem
    truststore: /etc/scylla/ssl/ca/ca-cert.pem
    require_client_auth: true
    protocol: TLSv1.2

Enable password authentication

Configure ScyllaDB to use password-based authentication for additional security.

# Authentication configuration
authenticator: PasswordAuthenticator
authorizer: CassandraAuthorizer
role_manager: CassandraRoleManager

Increase authentication cache to improve performance
authentication_cache_size_mb: 128
authentication_cache_update_interval_in_ms: 2000
permissions_cache_max_entries: 1000
permissions_validity_in_ms: 10000

Configure network and security settings

Set additional security parameters for production deployment.

# Network configuration
listen_address: 203.0.113.10
rpc_address: 203.0.113.10
broadcast_address: 203.0.113.10
broadcast_rpc_address: 203.0.113.10

Security hardening
enable_user_defined_functions: false
enable_scripted_user_defined_functions: false
enable_materialized_views: false

Connection limits
native_transport_max_concurrent_connections: 1024
native_transport_max_concurrent_connections_per_ip: 256

Request timeouts
request_timeout_in_ms: 10000
read_request_timeout_in_ms: 5000
write_request_timeout_in_ms: 2000

Start ScyllaDB with SSL

Enable and start ScyllaDB with the new SSL configuration.

sudo systemctl enable scylla-server
sudo systemctl start scylla-server
sudo systemctl status scylla-server

Create administrative user

Connect to ScyllaDB and create a secure administrative user to replace the default cassandra user.

# Connect using default credentials initially
cqlsh 203.0.113.10 9042 -u cassandra -p cassandra --ssl

In the CQL shell, create a new admin user and remove default access:

CREATE ROLE scylladb_admin WITH LOGIN = true AND SUPERUSER = true AND PASSWORD = 'SecureAdminPass123!';
ALTER ROLE cassandra WITH PASSWORD = 'RandomSecurePassword456!' AND SUPERUSER = false;
LIST ROLES;

Configure SSL client connection

Create a client configuration file for SSL connections.

[connection]
hostname = 203.0.113.10
port = 9042
username = scylladb_admin
password = SecureAdminPass123!

[ssl]
certfile = /etc/scylla/ssl/client/client-cert.pem
validate = true
userkey = /etc/scylla/ssl/client/client-key.pem
usercert = /etc/scylla/ssl/client/client-cert.pem
version = TLSv1_2

mkdir -p ~/.cassandra
sudo cp /etc/scylla/ssl/client/client-*.pem ~/.cassandra/
sudo cp /etc/scylla/ssl/ca/ca-cert.pem ~/.cassandra/
sudo chown $USER:$USER ~/.cassandra/*

Create application-specific roles

Set up role-based access control for different applications and users.

cqlsh --ssl

# Create keyspace for application
CREATE KEYSPACE IF NOT EXISTS app_data 
WITH REPLICATION = {'class': 'SimpleStrategy', 'replication_factor': 3};

Create application user with limited permissions
CREATE ROLE app_user WITH LOGIN = true AND PASSWORD = 'AppUserSecure789!';
GRANT SELECT, INSERT, UPDATE, DELETE ON KEYSPACE app_data TO app_user;

Create read-only analytics user
CREATE ROLE analytics_user WITH LOGIN = true AND PASSWORD = 'AnalyticsRead456!';
GRANT SELECT ON KEYSPACE app_data TO analytics_user;

Create backup user
CREATE ROLE backup_user WITH LOGIN = true AND PASSWORD = 'BackupSecure123!';
GRANT SELECT ON ALL KEYSPACES TO backup_user;

Configure audit logging

Enable audit logging for security compliance and monitoring.

# Audit logging configuration
audit_logging_options:
    enabled: true
    logger: BinAuditLogger
    audit_logs_dir: /var/lib/scylla/audit
    included_keyspaces: "system_auth,app_data"
    included_categories: "QUERY,DML,DDL,DCL,AUTH"
    included_users: "scylladb_admin,app_user"

sudo mkdir -p /var/lib/scylla/audit
sudo chown scylla:scylla /var/lib/scylla/audit
sudo chmod 750 /var/lib/scylla/audit
sudo systemctl restart scylla-server

Set up certificate renewal

Create automated certificate renewal to prevent expiration issues.

#!/bin/bash
set -euo pipefail

ScyllaDB SSL Certificate Renewal Script
SSL_DIR="/etc/scylla/ssl"
BACKUP_DIR="/var/backups/scylla-ssl-$(date +%Y%m%d)"
LOG_FILE="/var/log/scylla-cert-renewal.log"

echo "$(date): Starting certificate renewal" >> $LOG_FILE

Create backup
mkdir -p $BACKUP_DIR
cp -r $SSL_DIR/* $BACKUP_DIR/

Check certificate expiry (renew if < 30 days)
if openssl x509 -checkend 2592000 -noout -in $SSL_DIR/server/server-cert.pem; then
    echo "$(date): Certificate valid for 30+ days, skipping renewal" >> $LOG_FILE
    exit 0
fi

echo "$(date): Certificate expires soon, renewing..." >> $LOG_FILE

Generate new server certificate
cd $SSL_DIR/server
openssl genrsa -out server-key-new.pem 2048
openssl req -new -key server-key-new.pem -out server-new.csr -subj "/C=US/ST=CA/L=San Francisco/O=ScyllaDB/OU=Database/CN=scylla-server"

Create extensions file
cat > server-ext.cnf << EOF
subjectAltName = @alt_names
[alt_names]
DNS.1 = localhost
DNS.2 = scylla-server
IP.1 = 127.0.0.1
IP.2 = 203.0.113.10
IP.3 = 203.0.113.11
IP.4 = 203.0.113.12
EOF

openssl x509 -req -in server-new.csr -CA ../ca/ca-cert.pem -CAkey ../ca/ca-key.pem -out server-cert-new.pem -days 365 -extensions v3_req -extfile server-ext.cnf

Replace old certificates
mv server-key.pem server-key-old.pem
mv server-cert.pem server-cert-old.pem
mv server-key-new.pem server-key.pem
mv server-cert-new.pem server-cert.pem

chown scylla:scylla server-*.pem
chmod 600 server-key.pem
chmod 644 server-cert.pem

Clean up
rm server-new.csr server-ext.cnf

echo "$(date): Certificate renewal completed" >> $LOG_FILE
echo "$(date): Restarting ScyllaDB..." >> $LOG_FILE

Restart ScyllaDB
systemctl restart scylla-server

if systemctl is-active --quiet scylla-server; then
    echo "$(date): ScyllaDB restarted successfully" >> $LOG_FILE
else
    echo "$(date): ERROR - ScyllaDB failed to restart" >> $LOG_FILE
    # Rollback certificates
    mv server-key.pem server-key-failed.pem
    mv server-cert.pem server-cert-failed.pem
    mv server-key-old.pem server-key.pem
    mv server-cert-old.pem server-cert.pem
    systemctl start scylla-server
    exit 1
fi

sudo chmod +x /usr/local/bin/scylla-cert-renewal.sh
sudo chown root:root /usr/local/bin/scylla-cert-renewal.sh

Schedule certificate monitoring

Set up automated monitoring and renewal using systemd timers.

[Unit]
Description=ScyllaDB SSL Certificate Check
After=network.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/scylla-cert-renewal.sh
User=root
Group=root

[Unit]
Description=Run ScyllaDB certificate check weekly
Requires=scylla-cert-check.service

[Timer]
OnCalendar=weekly
Persistent=true

[Install]
WantedBy=timers.target

sudo systemctl daemon-reload
sudo systemctl enable scylla-cert-check.timer
sudo systemctl start scylla-cert-check.timer
sudo systemctl list-timers scylla-cert-check.timer

Configure firewall rules

Restrict network access to only necessary ports and IP addresses.

# Allow ScyllaDB ports for specific IP ranges
sudo ufw allow from 203.0.113.0/24 to any port 9042 comment 'ScyllaDB CQL SSL'
sudo ufw allow from 203.0.113.0/24 to any port 7001 comment 'ScyllaDB Inter-node SSL'
sudo ufw allow from 203.0.113.0/24 to any port 7199 comment 'ScyllaDB JMX'

Allow monitoring from management network
sudo ufw allow from 203.0.113.100/32 to any port 9180 comment 'ScyllaDB Prometheus'

Enable firewall
sudo ufw --force enable
sudo ufw status numbered

# Create ScyllaDB service for firewalld
sudo firewall-cmd --permanent --new-service=scylladb-ssl
sudo firewall-cmd --permanent --service=scylladb-ssl --add-port=9042/tcp
sudo firewall-cmd --permanent --service=scylladb-ssl --add-port=7001/tcp
sudo firewall-cmd --permanent --service=scylladb-ssl --add-port=7199/tcp
sudo firewall-cmd --permanent --service=scylladb-ssl --add-port=9180/tcp

Apply rules to trusted zone with specific sources
sudo firewall-cmd --permanent --zone=trusted --add-source=203.0.113.0/24
sudo firewall-cmd --permanent --zone=trusted --add-service=scylladb-ssl

Reload firewall
sudo firewall-cmd --reload
sudo firewall-cmd --list-all-zones

Enable system audit logging

Configure system-level auditing for ScyllaDB processes and files.

# Monitor ScyllaDB configuration changes
-w /etc/scylla/scylla.yaml -p wa -k scylladb_config
-w /etc/scylla/ssl/ -p wa -k scylladb_ssl

Monitor ScyllaDB data directory
-w /var/lib/scylla/ -p wa -k scylladb_data

Monitor ScyllaDB process execution
-w /usr/bin/scylla -p x -k scylladb_exec

Monitor authentication attempts
-w /var/lib/scylla/audit/ -p wa -k scylladb_auth

sudo systemctl enable auditd
sudo systemctl restart auditd
sudo auditctl -l

Set up log monitoring

Configure centralized logging for security events and SSL certificate monitoring.

# ScyllaDB logging
if $programname == 'scylla' then {
    /var/log/scylladb/scylla.log
    stop
}

SSL certificate events
if $msg contains 'SSL' or $msg contains 'certificate' then {
    /var/log/scylladb/ssl.log
    stop
}

Authentication events
if $msg contains 'authentication' or $msg contains 'login' then {
    /var/log/scylladb/auth.log
    stop
}

sudo mkdir -p /var/log/scylladb
sudo chown scylla:scylla /var/log/scylladb
sudo systemctl restart rsyslog
sudo logrotate -d /etc/logrotate.conf