---
title: Security Best Practices
layout: documentation
description: 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
```toml
# 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:
```toml
[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
```toml
[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:
```rust
// 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:
```toml
[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:
```bash
#!/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 $CERT_DIR/server.crt
# Reload Caxton service
systemctl reload caxton
```
### Network Segmentation
#### Firewall Rules
```bash
#!/bin/bash
# /opt/caxton/scripts/configure-firewall.sh
# Clear existing rules
iptables -F
iptables -X
# Default policies
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT
# Allow loopback
iptables -A INPUT -i lo -j ACCEPT
# Allow established connections
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# Allow Caxton API (HTTPS only)
iptables -A INPUT -p tcp --dport 443 -j ACCEPT
# Allow metrics (from monitoring network only)
iptables -A INPUT -p tcp --dport 9090 -s 10.0.2.0/24 -j ACCEPT
# Allow SSH (from management network only)
iptables -A INPUT -p tcp --dport 22 -s 10.0.1.0/24 -j ACCEPT
# Log dropped packets
iptables -A INPUT -j LOG --log-prefix "CAXTON-DROP: "
iptables -A INPUT -j DROP
# Save rules
iptables-save > /etc/iptables/rules.v4
```
#### Network Policies (Kubernetes)
```yaml
# network-policy.yaml
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: caxton-network-policy
namespace: caxton-system
spec:
podSelector:
matchLabels:
app: caxton-runtime
policyTypes:
- Ingress
- Egress
ingress:
# Allow traffic from load balancer
- from:
- namespaceSelector:
matchLabels:
name: ingress-nginx
ports:
- protocol: TCP
port: 8080
# Allow monitoring scraping
- from:
- namespaceSelector:
matchLabels:
name: monitoring
ports:
- protocol: TCP
port: 9090
egress:
# Allow DNS resolution
- to: []
ports:
- protocol: UDP
port: 53
# Allow Redis access
- to:
- namespaceSelector:
matchLabels:
name: caxton-system
podSelector:
matchLabels:
app: redis
ports:
- protocol: TCP
port: 6379
# Allow external HTTPS for webhooks
- to: []
ports:
- protocol: TCP
port: 443
```
## Authentication and Authorization
### JWT Authentication
Configure JWT-based authentication:
```toml
[security.authentication]
provider = "jwt"
jwt_secret = "${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)
```toml
[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
```ini
# /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
```toml
[security.api_keys]
# API key configuration
header_name = "X-API-Key"
hash_algorithm = "sha256"
salt = "${API_KEY_SALT}"
# Key rotation
auto_rotate = true
rotation_interval = "30d"
grace_period = "7d"
# Rate limiting per API key
rate_limit_per_key = 1000 # requests per hour
burst_limit = 100 # burst requests
```
### OAuth 2.0 Integration
```toml
[security.oauth2]
provider = "custom"
authorization_endpoint = "https://auth.example.com/oauth2/authorize"
token_endpoint = "https://auth.example.com/oauth2/token"
userinfo_endpoint = "https://auth.example.com/oauth2/userinfo"
client_id = "${OAUTH2_CLIENT_ID}"
client_secret = "${OAUTH2_CLIENT_SECRET}"
redirect_uri = "https://caxton.example.com/auth/callback"
scopes = ["openid", "profile", "caxton:access"]
```
## Secrets Management
### HashiCorp Vault Integration
```toml
[security.vault]
address = "https://vault.example.com:8200"
auth_method = "kubernetes"
role = "caxton-runtime"
secret_mount = "secret/caxton"
# Auto-renewal
auto_renew = true
renew_threshold = "1h" # Renew when lease has 1h left
# Secret paths
secrets = [
{ path = "database/redis", env = "REDIS_PASSWORD" },
{ path = "auth/jwt-secret", env = "JWT_SECRET" },
{ path = "external/webhook-key", env = "WEBHOOK_SECRET" }
]
```
### Kubernetes Secrets Integration
```yaml
# vault-secret-injection.yaml
apiVersion: v1
kind: Secret
metadata:
name: caxton-secrets
namespace: caxton-system
annotations:
vault.hashicorp.com/agent-inject: "true"
vault.hashicorp.com/role: "caxton-runtime"
vault.hashicorp.com/agent-inject-secret-redis: "database/redis"
vault.hashicorp.com/agent-inject-secret-jwt: "auth/jwt"
type: Opaque
```
### Environment Variable Security
```bash
# Secure environment variable handling
# /opt/caxton/scripts/load-secrets.sh
#!/bin/bash
set -euo pipefail
# Load secrets from Vault
VAULT_TOKEN=$(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
```yaml
# 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
```yaml
# .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: ${{ secrets.SNYK_TOKEN }}
with:
image: caxton/caxton:latest
args: --severity-threshold=high
```
## Vulnerability Scanning
### Container Image Scanning
```bash
#!/bin/bash
# /opt/caxton/scripts/scan-images.sh
IMAGES=(
"caxton/caxton:latest"
"redis:7-alpine"
"nginx:1.25-alpine"
)
for image in "${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}') $image
fi
done
```
### Runtime Vulnerability Detection
```toml
[security.runtime_protection]
# Enable runtime security monitoring
enable_runtime_monitoring = true
monitoring_interval = "60s"
# File integrity monitoring
monitor_config_files = true
config_file_paths = [
"/etc/caxton/",
"/opt/caxton/config/"
]
# Process monitoring
monitor_processes = true
allowed_processes = [
"caxton",
"redis-server"
]
# Network monitoring
monitor_network_connections = true
allowed_outbound_ports = [53, 443, 6379, 9090]
```
## Incident Response
### Security Incident Playbook
#### 1. Detection and Analysis
```bash
#!/bin/bash
# /opt/caxton/scripts/security-incident-response.sh
# Incident types
INCIDENT_TYPE=${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 "$SLACK_WEBHOOK" -d '{"text":"SECURITY INCIDENT: Data breach detected in Caxton system"}'
;;
esac
```
#### 2. Containment
```toml
# Emergency lockdown configuration
[security.emergency]
# Lockdown mode disables all non-essential operations
enable_lockdown_mode = false
lockdown_allowed_operations = [
"health_check",
"metrics",
"audit_log"
]
# Emergency contacts
notification_webhook = "${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
```bash
#!/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
```bash
#!/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
```yaml
# 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
```toml
[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
```python
#!/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