Security Best Practices
Comprehensive security guide for Caxton multi-agent systems covering WebAssembly isolation, network security, authentication, secrets management, and incident response.
Security Best Practices
This guide covers essential security practices for deploying and maintaining Caxton multi-agent systems in production environments, including WebAssembly isolation, network security, authentication, authorization, secrets management, and incident response procedures.
WebAssembly Isolation
Sandbox Security Model
Caxton’s security model is built on WebAssembly’s capability-based sandboxing, providing multiple layers of isolation:
Memory Isolation
# Security configuration for WASM runtime
[runtime.security]
# Memory limits per agent
max_memory_pages = 1024 # 64MB limit
max_stack_size = "1MB"
enable_memory_protection = true
# Prevent memory corruption attacks
enable_guard_pages = true
enable_stack_canaries = true
zero_memory_on_free = true
System Call Filtering
Caxton implements a strict allowlist of permitted system calls:
[runtime.syscalls]
# Allowed WASI calls
allowed_wasi_calls = [
"fd_read",
"fd_write",
"fd_close",
"clock_time_get",
"random_get"
]
# Blocked dangerous calls
blocked_calls = [
"proc_exec",
"sock_bind",
"sock_connect",
"fd_fdstat_set_flags"
]
# Network access restrictions
allow_network_access = false
allow_file_system_access = "restricted" # Only virtual filesystem
Resource Limits
[runtime.limits]
# CPU limits
max_execution_time = "30s"
cpu_quota_per_agent = "100m" # 0.1 CPU core
# I/O limits
max_file_descriptors = 10
max_network_connections = 0 # Disable by default
max_disk_io_bytes = "10MB"
# Concurrency limits
max_threads_per_agent = 1
max_spawned_processes = 0
Code Validation
Implement strict WebAssembly module validation:
// Example validation pipeline
use wasmtime::*;
pub struct SecureValidator {
config: Config,
}
impl SecureValidator {
pub fn new() -> Self {
let mut config = Config::new();
// Security hardening
config.wasm_threads(false); // Disable threads
config.wasm_reference_types(false); // Disable reference types
config.wasm_simd(false); // Disable SIMD
config.wasm_bulk_memory(false); // Disable bulk memory ops
// Resource limits
config.max_wasm_stack(1024 * 1024); // 1MB stack
config.consume_fuel(true); // Enable fuel metering
config.epoch_interruption(true); // Enable interruption
Self { config }
}
pub fn validate_module(&self, wasm_bytes: &[u8]) -> Result<Module, SecurityError> {
let engine = Engine::new(&self.config)?;
// Parse and validate
let module = Module::from_binary(&engine, wasm_bytes)?;
// Additional security checks
self.check_imports(&module)?;
self.check_exports(&module)?;
self.check_memory_usage(&module)?;
Ok(module)
}
fn check_imports(&self, module: &Module) -> Result<(), SecurityError> {
for import in module.imports() {
match (import.module(), import.name()) {
("wasi_snapshot_preview1", name) => {
if !ALLOWED_WASI_FUNCTIONS.contains(&name) {
return Err(SecurityError::UnauthorizedImport(name.to_string()));
}
}
_ => return Err(SecurityError::UnauthorizedModule(import.module().to_string())),
}
}
Ok(())
}
}
const ALLOWED_WASI_FUNCTIONS: &[&str] = &[
"fd_read", "fd_write", "fd_close",
"clock_time_get", "random_get"
];
Network Security
TLS Configuration
Enable TLS for all communications:
[networking.tls]
# Certificate configuration
cert_file = "/etc/caxton/certs/server.crt"
key_file = "/etc/caxton/certs/server.key"
ca_file = "/etc/caxton/certs/ca.crt"
# TLS settings
min_tls_version = "1.3"
cipher_suites = [
"TLS_AES_256_GCM_SHA384",
"TLS_CHACHA20_POLY1305_SHA256",
"TLS_AES_128_GCM_SHA256"
]
# Client certificate verification
require_client_cert = true
verify_client_cert = true
# OCSP stapling
enable_ocsp_stapling = true
ocsp_responder_url = "http://ocsp.example.com"
Certificate Management
Automate certificate lifecycle management:
#!/bin/bash
# /opt/caxton/scripts/renew-certificates.sh
CERT_DIR="/etc/caxton/certs"
DOMAIN="caxton.example.com"
# Generate new certificates using certbot
certbot certonly \
--webroot \
--webroot-path=/var/www/html \
--email admin@example.com \
--agree-tos \
--non-interactive \
--domains $DOMAIN
# Copy certificates to Caxton directory
cp /etc/letsencrypt/live/$DOMAIN/fullchain.pem $CERT_DIR/server.crt
cp /etc/letsencrypt/live/$DOMAIN/privkey.pem $CERT_DIR/server.key
# Set proper permissions
chown caxton:caxton $CERT_DIR/*
chmod 600 $CERT_DIR/server.key
chmod 644 $CERT_DIR/server.crt
# Reload Caxton service
systemctl reload caxton
Network Segmentation
Firewall Rules
#!/bin/bash
# /opt/caxton/scripts/configure-firewall.sh
# Clear existing rules
iptables -F
iptables -X
# Default policies
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT
# Allow loopback
iptables -A INPUT -i lo -j ACCEPT
# Allow established connections
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# Allow Caxton API (HTTPS only)
iptables -A INPUT -p tcp --dport 443 -j ACCEPT
# Allow metrics (from monitoring network only)
iptables -A INPUT -p tcp --dport 9090 -s 10.0.2.0/24 -j ACCEPT
# Allow SSH (from management network only)
iptables -A INPUT -p tcp --dport 22 -s 10.0.1.0/24 -j ACCEPT
# Log dropped packets
iptables -A INPUT -j LOG --log-prefix "CAXTON-DROP: "
iptables -A INPUT -j DROP
# Save rules
iptables-save > /etc/iptables/rules.v4
Network Policies (Kubernetes)
# network-policy.yaml
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: caxton-network-policy
namespace: caxton-system
spec:
podSelector:
matchLabels:
app: caxton-runtime
policyTypes:
- Ingress
- Egress
ingress:
# Allow traffic from load balancer
- from:
- namespaceSelector:
matchLabels:
name: ingress-nginx
ports:
- protocol: TCP
port: 8080
# Allow monitoring scraping
- from:
- namespaceSelector:
matchLabels:
name: monitoring
ports:
- protocol: TCP
port: 9090
egress:
# Allow DNS resolution
- to: []
ports:
- protocol: UDP
port: 53
# Allow Redis access
- to:
- namespaceSelector:
matchLabels:
name: caxton-system
podSelector:
matchLabels:
app: redis
ports:
- protocol: TCP
port: 6379
# Allow external HTTPS for webhooks
- to: []
ports:
- protocol: TCP
port: 443
Authentication and Authorization
JWT Authentication
Configure JWT-based authentication:
[security.authentication]
provider = "jwt"
jwt_secret = "${JWT_SECRET}"
jwt_algorithm = "RS256"
jwt_issuer = "caxton-auth"
jwt_audience = "caxton-api"
jwt_expiry = "1h"
# Public key for verification
jwt_public_key_file = "/etc/caxton/keys/jwt-public.pem"
# Refresh token settings
refresh_token_expiry = "24h"
refresh_token_rotation = true
Role-Based Access Control (RBAC)
[security.authorization]
model = "rbac"
policy_file = "/etc/caxton/policies/rbac.conf"
# Default roles
[security.roles]
admin = [
"agent:create",
"agent:delete",
"agent:update",
"system:configure",
"metrics:view"
]
operator = [
"agent:create",
"agent:update",
"agent:view",
"metrics:view"
]
viewer = [
"agent:view",
"metrics:view"
]
agent = [
"message:send",
"message:receive"
]
RBAC Policy Configuration
# /etc/caxton/policies/rbac.conf
[request_definition]
r = sub, obj, act
[policy_definition]
p = sub, obj, act
[role_definition]
g = _, _
[policy_effect]
e = some(where (p.eft == allow))
[matchers]
m = g(r.sub, p.sub) && r.obj == p.obj && r.act == p.act
API Key Management
[security.api_keys]
# API key configuration
header_name = "X-API-Key"
hash_algorithm = "sha256"
salt = "${API_KEY_SALT}"
# Key rotation
auto_rotate = true
rotation_interval = "30d"
grace_period = "7d"
# Rate limiting per API key
rate_limit_per_key = 1000 # requests per hour
burst_limit = 100 # burst requests
OAuth 2.0 Integration
[security.oauth2]
provider = "custom"
authorization_endpoint = "https://auth.example.com/oauth2/authorize"
token_endpoint = "https://auth.example.com/oauth2/token"
userinfo_endpoint = "https://auth.example.com/oauth2/userinfo"
client_id = "${OAUTH2_CLIENT_ID}"
client_secret = "${OAUTH2_CLIENT_SECRET}"
redirect_uri = "https://caxton.example.com/auth/callback"
scopes = ["openid", "profile", "caxton:access"]
Secrets Management
HashiCorp Vault Integration
[security.vault]
address = "https://vault.example.com:8200"
auth_method = "kubernetes"
role = "caxton-runtime"
secret_mount = "secret/caxton"
# Auto-renewal
auto_renew = true
renew_threshold = "1h" # Renew when lease has 1h left
# Secret paths
secrets = [
{ path = "database/redis", env = "REDIS_PASSWORD" },
{ path = "auth/jwt-secret", env = "JWT_SECRET" },
{ path = "external/webhook-key", env = "WEBHOOK_SECRET" }
]
Kubernetes Secrets Integration
# vault-secret-injection.yaml
apiVersion: v1
kind: Secret
metadata:
name: caxton-secrets
namespace: caxton-system
annotations:
vault.hashicorp.com/agent-inject: "true"
vault.hashicorp.com/role: "caxton-runtime"
vault.hashicorp.com/agent-inject-secret-redis: "database/redis"
vault.hashicorp.com/agent-inject-secret-jwt: "auth/jwt"
type: Opaque
Environment Variable Security
# Secure environment variable handling
# /opt/caxton/scripts/load-secrets.sh
#!/bin/bash
set -euo pipefail
# Load secrets from Vault
VAULT_TOKEN=$(cat /var/run/secrets/kubernetes.io/serviceaccount/token)
export VAULT_TOKEN
# Fetch secrets
REDIS_PASSWORD=$(vault kv get -field=password secret/caxton/redis)
JWT_SECRET=$(vault kv get -field=secret secret/caxton/jwt)
# Export with restricted permissions
(
umask 0077
cat > /opt/caxton/config/secrets.env << EOF
REDIS_PASSWORD=$REDIS_PASSWORD
JWT_SECRET=$JWT_SECRET
EOF
)
# Clear variables from memory
unset REDIS_PASSWORD JWT_SECRET VAULT_TOKEN
Security Updates
Automated Security Updates
# security-update-cronjob.yaml
apiVersion: batch/v1
kind: CronJob
metadata:
name: security-updates
namespace: caxton-system
spec:
schedule: "0 2 * * *" # Daily at 2 AM
jobTemplate:
spec:
template:
spec:
serviceAccountName: security-updater
containers:
- name: updater
image: caxton/security-updater:latest
command:
- /bin/sh
- -c
- |
# Check for security updates
apt list --upgradable | grep -i security
# Update security packages only
apt-get update
apt-get upgrade -y \
-o Dpkg::Options::="--force-confdef" \
-o Dpkg::Options::="--force-confold" \
$(apt list --upgradable 2>/dev/null | grep -i security | cut -d'/' -f1)
# Restart Caxton if needed
if [ -f /var/run/reboot-required ]; then
kubectl rollout restart deployment/caxton-runtime
fi
securityContext:
privileged: true
restartPolicy: OnFailure
Dependency Scanning
# .github/workflows/security-scan.yml
name: Security Scan
on:
schedule:
- cron: '0 2 * * 1' # Weekly on Monday
push:
branches: [main]
jobs:
security-scan:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Run Trivy vulnerability scanner
uses: aquasecurity/trivy-action@master
with:
image-ref: 'caxton/caxton:latest'
format: 'sarif'
output: 'trivy-results.sarif'
- name: Upload Trivy scan results
uses: github/codeql-action/upload-sarif@v2
with:
sarif_file: 'trivy-results.sarif'
- name: Run Snyk security scan
uses: snyk/actions/docker@master
env:
SNYK_TOKEN: $
with:
image: caxton/caxton:latest
args: --severity-threshold=high
Vulnerability Scanning
Container Image Scanning
#!/bin/bash
# /opt/caxton/scripts/scan-images.sh
IMAGES=(
"caxton/caxton:latest"
"redis:7-alpine"
"nginx:1.25-alpine"
)
for image in "${IMAGES[@]}"; do
echo "Scanning $image..."
# Trivy scan
trivy image --severity HIGH,CRITICAL --format json $image > "${image//\//_}-trivy.json"
# Grype scan
grype $image --fail-on high
# Clair scan (if available)
if command -v clair-scanner &> /dev/null; then
clair-scanner --ip $(hostname -I | awk '{print $1}') $image
fi
done
Runtime Vulnerability Detection
[security.runtime_protection]
# Enable runtime security monitoring
enable_runtime_monitoring = true
monitoring_interval = "60s"
# File integrity monitoring
monitor_config_files = true
config_file_paths = [
"/etc/caxton/",
"/opt/caxton/config/"
]
# Process monitoring
monitor_processes = true
allowed_processes = [
"caxton",
"redis-server"
]
# Network monitoring
monitor_network_connections = true
allowed_outbound_ports = [53, 443, 6379, 9090]
Incident Response
Security Incident Playbook
1. Detection and Analysis
#!/bin/bash
# /opt/caxton/scripts/security-incident-response.sh
# Incident types
INCIDENT_TYPE=${1:-"unknown"}
case $INCIDENT_TYPE in
"unauthorized-access")
echo "Responding to unauthorized access..."
# Revoke all active sessions
kubectl exec -it caxton-runtime-0 -- caxton admin revoke-all-sessions
# Change API keys
vault kv put secret/caxton/api-keys key="$(openssl rand -hex 32)"
# Force pod restart
kubectl rollout restart deployment/caxton-runtime
;;
"suspicious-agent")
AGENT_ID=${2:-""}
echo "Responding to suspicious agent: $AGENT_ID"
# Quarantine agent
kubectl exec -it caxton-runtime-0 -- caxton admin quarantine-agent $AGENT_ID
# Collect forensic data
kubectl exec -it caxton-runtime-0 -- caxton admin dump-agent-state $AGENT_ID > /tmp/agent-$AGENT_ID-dump.json
;;
"data-breach")
echo "Responding to data breach..."
# Rotate all secrets
./rotate-all-secrets.sh
# Enable audit logging
kubectl patch configmap caxton-config -p '{"data":{"audit_level":"debug"}}'
# Notify security team
curl -X POST "$SLACK_WEBHOOK" -d '{"text":"SECURITY INCIDENT: Data breach detected in Caxton system"}'
;;
esac
2. Containment
# Emergency lockdown configuration
[security.emergency]
# Lockdown mode disables all non-essential operations
enable_lockdown_mode = false
lockdown_allowed_operations = [
"health_check",
"metrics",
"audit_log"
]
# Emergency contacts
notification_webhook = "${SECURITY_WEBHOOK_URL}"
emergency_contacts = [
"security@example.com",
"oncall@example.com"
]
# Automatic containment
auto_quarantine_suspicious_agents = true
auto_block_suspicious_ips = true
max_failed_auth_attempts = 3
3. Evidence Collection
#!/bin/bash
# /opt/caxton/scripts/collect-forensics.sh
INCIDENT_ID=${1:-$(date +%Y%m%d_%H%M%S)}
EVIDENCE_DIR="/opt/caxton/incidents/$INCIDENT_ID"
mkdir -p "$EVIDENCE_DIR"
echo "Collecting forensic evidence for incident $INCIDENT_ID..."
# System logs
journalctl -u caxton -S "1 hour ago" > "$EVIDENCE_DIR/system-logs.txt"
# Audit logs
kubectl logs -n caxton-system -l app=caxton-runtime --since=1h > "$EVIDENCE_DIR/application-logs.txt"
# Network connections
ss -tulpn > "$EVIDENCE_DIR/network-connections.txt"
netstat -an > "$EVIDENCE_DIR/network-stats.txt"
# Process information
ps aux > "$EVIDENCE_DIR/processes.txt"
# File system changes
find /etc/caxton -newer /tmp/baseline -ls > "$EVIDENCE_DIR/config-changes.txt"
# Memory dump (if needed)
if [[ "$2" == "full" ]]; then
kubectl exec -it caxton-runtime-0 -- gcore $(pgrep caxton)
kubectl cp caxton-runtime-0:core.* "$EVIDENCE_DIR/"
fi
# Create evidence archive
tar -czf "/opt/caxton/incidents/incident-$INCIDENT_ID.tar.gz" "$EVIDENCE_DIR"
echo "Evidence collected: /opt/caxton/incidents/incident-$INCIDENT_ID.tar.gz"
4. Recovery Procedures
#!/bin/bash
# /opt/caxton/scripts/security-recovery.sh
echo "Starting security recovery procedures..."
# 1. Verify system integrity
echo "Verifying system integrity..."
kubectl exec -it caxton-runtime-0 -- caxton admin verify-integrity
# 2. Restore from clean backup
echo "Restoring from clean backup..."
kubectl apply -f /opt/caxton/backups/clean-state/
# 3. Update security configurations
echo "Updating security configurations..."
kubectl apply -f /opt/caxton/security/hardened-config.yaml
# 4. Rotate all credentials
echo "Rotating credentials..."
./rotate-all-secrets.sh
# 5. Restart all services
echo "Restarting services..."
kubectl rollout restart deployment/caxton-runtime
# 6. Verify recovery
echo "Verifying recovery..."
kubectl exec -it caxton-runtime-0 -- caxton admin health-check --security
echo "Recovery completed. System ready for operation."
Security Monitoring and Alerting
Security Event Detection
# security-monitoring.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: security-rules
data:
rules.yml: |
groups:
- name: security.rules
rules:
- alert: SuspiciousAgentBehavior
expr: rate(caxton_agent_executions_total{status="error"}[5m]) > 10
for: 2m
labels:
severity: warning
type: security
annotations:
summary: "Suspicious agent behavior detected"
- alert: UnauthorizedAPIAccess
expr: rate(caxton_http_requests_total{status=~"401|403"}[5m]) > 5
for: 1m
labels:
severity: critical
type: security
annotations:
summary: "Multiple unauthorized API access attempts"
- alert: AnomalousNetworkTraffic
expr: rate(caxton_network_bytes_total[5m]) > 1000000 # 1MB/s
for: 5m
labels:
severity: warning
type: security
annotations:
summary: "Anomalous network traffic detected"
Compliance and Audit
Audit Logging Configuration
[security.audit]
# Enable comprehensive audit logging
enable_audit_logging = true
audit_log_level = "info"
audit_log_file = "/var/log/caxton/audit.log"
# Events to audit
audit_events = [
"authentication",
"authorization",
"agent_creation",
"agent_deletion",
"configuration_change",
"admin_action"
]
# Log format
audit_log_format = "json"
include_request_body = false
include_response_body = false
include_user_agent = true
include_source_ip = true
Compliance Reporting
#!/usr/bin/env python3
# /opt/caxton/scripts/compliance-report.py
import json
import subprocess
from datetime import datetime, timedelta
def generate_compliance_report():
report = {
"report_date": datetime.utcnow().isoformat(),
"compliance_checks": []
}
# Check TLS configuration
tls_check = check_tls_configuration()
report["compliance_checks"].append(tls_check)
# Check access controls
access_check = check_access_controls()
report["compliance_checks"].append(access_check)
# Check audit logging
audit_check = check_audit_logging()
report["compliance_checks"].append(audit_check)
# Generate report file
with open(f"/opt/caxton/reports/compliance-{datetime.now().strftime('%Y%m%d')}.json", "w") as f:
json.dump(report, f, indent=2)
def check_tls_configuration():
# Implementation for TLS compliance check
return {
"check": "TLS Configuration",
"status": "compliant",
"details": "TLS 1.3 enabled, strong ciphers configured"
}
if __name__ == "__main__":
generate_compliance_report()
Security Best Practices Checklist
Development Security
- Implement secure coding practices
- Conduct regular security code reviews
- Use static analysis security testing (SAST)
- Implement dynamic application security testing (DAST)
- Maintain software bill of materials (SBOM)
Deployment Security
- Enable WebAssembly sandboxing
- Configure TLS for all communications
- Implement network segmentation
- Use least-privilege access controls
- Enable comprehensive audit logging
Operational Security
- Regular security updates
- Vulnerability scanning
- Security monitoring and alerting
- Incident response procedures
- Regular security training
Compliance
- Document security procedures
- Regular compliance audits
- Maintain audit trails
- Data protection measures
- Business continuity planning
For additional operational guidance, see the Deployment Guide and Monitoring Guide.