simplefileupload-server/docs/SECURITY.md

Security Documentation

Overview

This document outlines the security measures implemented in the Simple File Upload Server and provides guidelines for secure deployment and operation.

Security Features

Authentication

1. API Key Authentication

   • Required for all upload endpoints
   • Configured via CLIENT_KEY environment variable
   • Transmitted via X-Client-Key HTTP header
   • No default keys allowed in production

2. Download Security

   • 6-digit alphanumeric codes
   • One-time use downloads (configurable)
   • Automatic expiration
   • No directory listing

File Security

1. Upload Security

   • Secure filename sanitization
   • No executable permissions
   • Temporary storage with cleanup
   • Chunked upload verification

2. Storage Security

   • Files stored outside web root
   • Metadata separation from files
   • Automatic cleanup of expired files
   • Abandoned upload detection

3. Download Controls

   • Maximum download limits
   • Expiry time enforcement
   • Force download headers
   • Content-Type verification

Network Security

1. SSL/TLS

   • Required for production
   • Modern cipher configuration
   • Perfect forward secrecy
   • SSL certificate validation

2. Headers

   • Secure response headers
   • No version disclosure
   • XSS protection
   • Content security policy

Secure Deployment

Production Requirements

1. SSL Configuration

ssl_protocols TLSv1.2 TLSv1.3;
ssl_prefer_server_ciphers on;
ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;

2. Environment Setup

# Required settings
export CLIENT_KEY="strong-random-key"
export UPLOAD_FOLDER="/secure/path/uploads"

# SSL settings
export SSL_CERT="/path/to/cert.pem"
export SSL_KEY="/path/to/key.pem"

3. File Permissions

# Storage directory
chmod 750 /secure/path/uploads
chown www-data:www-data /secure/path/uploads

# SSL files
chmod 600 /path/to/key.pem
chmod 644 /path/to/cert.pem

Docker Security

1. Container Configuration

   • Non-root user
   • Read-only root filesystem
   • Limited capabilities
   • Resource limits

2. Volume Management

   • Separate volumes for uploads
   • Proper permissions
   • Regular cleanup
   • Backup strategy

Security Monitoring

Logging

1. Access Logs

   • Upload attempts
   • Download tracking
   • Error logging
   • Authentication failures

2. Audit Trail

   • File operations
   • Configuration changes
   • System events
   • Cleanup activities

Monitoring Requirements

1. System Monitoring

   • Disk usage
   • Memory utilization
   • Network traffic
   • Error rates

2. Security Alerts

   • Authentication failures
   • Unusual activity
   • Storage warnings
   • SSL certificate expiry

Security Best Practices

Server Configuration

1. Firewall Rules

   • Allow only required ports
   • Rate limit connections
   • Block suspicious IPs
   • Monitor access patterns

2. Process Isolation

   • Run as dedicated user
   • Minimal permissions
   • Resource limits
   • Process supervision

Data Protection

1. File Handling

   • Validate file types
   • Scan for malware
   • Enforce size limits
   • Secure deletion

2. Metadata Protection

   • Regular backups
   • Access controls
   • Data validation
   • Secure storage

Future Security Enhancements

Planned Features

1. Rate Limiting

   • Per-IP limits
   • Token bucket algorithm
   • Configurable thresholds
   • Automatic blocking

2. Advanced Authentication

   • API key rotation
   • IP whitelisting
   • Two-factor auth option
   • Access tokens

3. Enhanced Monitoring

   • Real-time alerts
   • Usage analytics
   • Threat detection
   • Performance tracking

Security Roadmap

1. Short Term

   • Implement rate limiting
   • Add file type restrictions
   • Enhance logging
   • Add health checks

2. Long Term

   • Access audit system
   • Advanced monitoring
   • Automated backups
   • High availability

Incident Response

Response Plan

1. Detection

   • Monitor logs
   • Track metrics
   • Alert on anomalies
   • User reports

2. Response

   • Assess impact
   • Contain threat
   • Notify stakeholders
   • Document incident

3. Recovery

   • Restore service
   • Update security
   • Review procedures
   • Implement fixes

Security Contacts

For security issues or vulnerabilities:

1. Create a GitHub issue with [SECURITY] prefix
2. For critical issues, contact maintainers directly
3. Follow responsible disclosure guidelines
4. Allow time for patches before public disclosure