a2a-php - change: updated documentation

Author: andreibesleaga

A2A_HTTPS_IMPLEMENTATION.md

@@ -1,336 +1,120 @@
-# A2A Protocol HTTPS/TLS Security Implementation
+# A2A Protocol HTTPS/TLS Implementation
 
-## 🔐 Overview
+## Overview
 
-This implementation adds comprehensive HTTPS/TLS support to the A2A Protocol server while maintaining full backward compatibility with existing HTTP functionality. The server now provides production-grade security features without breaking any existing functionality.
+The reference server includes optional HTTPS-aware behaviour that lets operators terminate TLS in front of the PHP process while preserving full backward compatibility with the existing HTTP flow. The implementation introduces security headers, environment-based mode detection, and documentation for deploying behind nginx or Apache.
 
-## ✅ **VERIFIED: ALL TESTS PASSING**
+## Test status
 
-The HTTPS-enabled server has been thoroughly tested and **maintains 100% compatibility**:
+| Suite       | Result (HTTPS mode) |
+| ----------- | ------------------- |
+| Mandatory   | 25 / 25 passing     |
+| Capability  | 14 / 14 passing     |
+| Quality     | 12 / 12 passing     |
+| Features    | 15 / 15 passing     |
 
-- ✅ **Mandatory Tests: 25/25 PASSED** (A2A Protocol compliance)
-- ✅ **Capability Tests: 19/19 PASSED** (All declared features work)
-- ✅ **Quality Tests: 12/12 PASSED** (Production readiness)
-- ✅ **Feature Tests: 15/15 PASSED** (Optional features complete)
+HTTPS orchestration reuses the same protocol handlers as the HTTP server, so compliance remains unchanged.
 
-## 🚀 Key Features
+## Key additions
 
-### Security Enhancements
-- **HTTPS/TLS Support**: Encrypted communication for production environments
-- **Automatic Certificate Management**: Self-signed certificates for development
-- **Security Headers**: HSTS, CORS, and other security headers
-- **Production Mode Detection**: Automatic HTTPS mode switching
-- **Protocol Detection**: Smart HTTP/HTTPS detection and logging
+- HTTPS-aware server entry point (`https_a2a_server.php`) that detects production mode and applies security headers.
+- Self-signed certificate helper invoked by `start_https_server.sh` for local testing.
+- Support for the `A2A_MODE=production` environment variable to toggle strict security behaviour.
+- Logging extensions that capture whether a request arrived via HTTP or HTTPS (based on proxy headers).
+- Documentation covering nginx and Apache reverse-proxy setups.
 
-### Backward Compatibility
-- **Zero Breaking Changes**: All existing functionality preserved
-- **Dual Mode Operation**: HTTP for development, HTTPS for production
-- **Seamless Switching**: Environment variable controls mode
-- **Existing API Intact**: All current endpoints and responses unchanged
+## Running the server
 
-### Production Features
-- **Certificate Auto-Generation**: Self-signed certs for development
-- **Security Logging**: Enhanced logging with security context
-- **HTTPS Redirect Support**: Optional HTTP to HTTPS redirection
-- **Production Headers**: Security headers in production mode
+### Development (HTTP)
 
-## 📁 Files Added
-
-1. **`https_a2a_server.php`** - Main HTTPS-enabled server implementation
-2. **`start_https_server.sh`** - Interactive script for server management
-3. **Documentation** - This comprehensive guide
-
-## 🔧 Usage
-
-### Development Mode (HTTP)
 ```bash
-# Standard HTTP mode - no changes needed
 php -S localhost:8081 https_a2a_server.php
-
-# Agent Card: http://localhost:8081/.well-known/agent-card.json
-# Server Info: http://localhost:8081/server-info
 ```
 
-### Production Mode (HTTPS-aware)
-```bash
-# Enable production mode
-A2A_MODE=production php -S localhost:8443 https_a2a_server.php
+### Production-style execution
 
-# Note: PHP built-in server doesn't support HTTPS directly
-# For real HTTPS, deploy behind nginx/Apache with SSL termination
+```bash
+A2A_MODE=production php -S localhost:8081 https_a2a_server.php
 ```
 
-### Interactive Management
+> The PHP built-in server does not provide native TLS. For encrypted traffic, place nginx or Apache in front and forward requests to the PHP process.
+
+### Interactive helper
+
 ```bash
-# Use the interactive setup script
 ./start_https_server.sh
 ```
 
-## 🏗️ Production Deployment
+The script guides users through generating self-signed certificates, configuring environment variables, and starting the server.
+
+## Reverse-proxy configuration
+
+### nginx example
 
-### Option 1: Nginx SSL Termination (Recommended)
 ```nginx
 server {
     listen 443 ssl http2;
-    server_name your-domain.com;
-    
-    ssl_certificate /path/to/your/certificate.crt;
-    ssl_certificate_key /path/to/your/private.key;
-    
-    # Security headers
+    server_name a2a.example.com;
+
+    ssl_certificate /etc/letsencrypt/live/a2a.example.com/fullchain.pem;
+    ssl_certificate_key /etc/letsencrypt/live/a2a.example.com/privkey.pem;
+
     add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
     add_header X-Content-Type-Options nosniff;
     add_header X-Frame-Options DENY;
-    
+
     location / {
-        proxy_pass http://localhost:8081;
+        proxy_pass http://127.0.0.1:8081;
         proxy_set_header Host $host;
         proxy_set_header X-Real-IP $remote_addr;
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_set_header X-Forwarded-Proto https;
     }
 }
 
-# HTTP to HTTPS redirect
 server {
     listen 80;
-    server_name your-domain.com;
-    return 301 https://$server_name$request_uri;
+    server_name a2a.example.com;
+    return 301 https://$host$request_uri;
 }
 ```
 
-### Option 2: Apache SSL Termination
+### Apache example
+
 ```apache
 <VirtualHost *:443>
-    ServerName your-domain.com
-    
+    ServerName a2a.example.com
+
     SSLEngine on
-    SSLCertificateFile /path/to/your/certificate.crt
-    SSLCertificateKeyFile /path/to/your/private.key
-    
-    # Security headers
+    SSLCertificateFile /etc/letsencrypt/live/a2a.example.com/fullchain.pem
+    SSLCertificateKeyFile /etc/letsencrypt/live/a2a.example.com/privkey.pem
+
     Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"
     Header always set X-Content-Type-Options nosniff
     Header always set X-Frame-Options DENY
-    
+
     ProxyPreserveHost On
-    ProxyPass / http://localhost:8081/
-    ProxyPassReverse / http://localhost:8081/
+    ProxyPass / http://127.0.0.1:8081/
+    ProxyPassReverse / http://127.0.0.1:8081/
 </VirtualHost>
 
 <VirtualHost *:80>
-    ServerName your-domain.com
-    Redirect permanent / https://your-domain.com/
+    ServerName a2a.example.com
+    Redirect permanent / https://a2a.example.com/
 </VirtualHost>
 ```
 
-### Option 3: Let's Encrypt (Free SSL)
-```bash
-# Install certbot
-sudo apt install certbot python3-certbot-nginx
-
-# Get SSL certificate
-sudo certbot --nginx -d your-domain.com
-
-# Auto-renewal
-sudo certbot renew --dry-run
-```
-
-## 🔍 Security Features
-
-### Environment Detection
-The server automatically detects production mode via:
-- `A2A_MODE=production` environment variable
-- HTTPS headers from proxy
-- Port-based detection (8443 = HTTPS mode)
-
-### Certificate Management
-```php
-// Automatic self-signed certificate generation for development
-class HttpsConfigManager {
-    // - 2048-bit RSA keys
-    // - SHA-256 signing
-    // - 1-year validity
-    // - Proper file permissions
-}
-```
-
-### Security Headers
-In production mode, the server adds:
-- `Strict-Transport-Security` (HSTS)
-- `X-Content-Type-Options: nosniff`
-- `X-Frame-Options: DENY`
-- CORS headers for API access
-
-### Enhanced Logging
-All security events are logged with context:
-```
-[2025-07-18 18:09:07] INFO: Request received {
-    "method": "POST",
-    "uri": "/",
-    "https": true,
-    "user_agent": "curl/8.5.0",
-    "remote_addr": "127.0.0.1"
-} (Protocol: HTTPS)
-```
-
-## 🧪 Testing
-
-### Test HTTP Mode
-```bash
-curl -X POST -H "Content-Type: application/json" \
-     -d '{"jsonrpc": "2.0", "method": "ping", "params": {}, "id": "test"}' \
-     http://localhost:8081
-```
-
-### Test HTTPS Mode (behind proxy)
-```bash
-curl -X POST -H "Content-Type: application/json" \
-     -d '{"jsonrpc": "2.0", "method": "ping", "params": {}, "id": "test"}' \
-     https://your-domain.com
-```
-
-### Run Full Test Suite
-```bash
-# Test HTTP mode
-cd a2a-tck
-python3 run_tck.py --sut-url http://localhost:8081 --category all
-
-# Test HTTPS mode (with proper SSL setup)
-python3 run_tck.py --sut-url https://your-domain.com --category all
-```
-
-## 📊 Performance Impact
-
-### Minimal Overhead
-- **HTTP Mode**: Zero performance impact (identical to original)
-- **HTTPS Mode**: Only logging enhancements added
-- **Memory Usage**: < 1MB additional for SSL context
-- **CPU Impact**: Negligible (SSL handled by proxy)
-
-### Benchmarks
-```bash
-# Original server performance maintained
-ab -n 1000 -c 10 http://localhost:8081/.well-known/agent-card.json
-
-# HTTPS performance (behind nginx)
-ab -n 1000 -c 10 https://your-domain.com/.well-known/agent-card.json
-```
-
-## 🔧 Configuration Options
-
-### Environment Variables
-- `A2A_MODE=production` - Enable production/HTTPS mode
-- `A2A_FORCE_HTTPS=true` - Force HTTPS redirects
-- `A2A_CERT_DIR=/path/to/certs` - Custom certificate directory
-
-### Runtime Detection
-```php
-// The server automatically detects:
-// 1. Environment variables
-// 2. Server headers (X-Forwarded-Proto)
-// 3. Port numbers (8443 = HTTPS)
-// 4. SSL context availability
-```
-
-## 🚧 Migration Guide
-
-### From HTTP to HTTPS
-
-1. **Development Environment**
-   ```bash
-   # No changes needed - both modes supported
-   php -S localhost:8081 https_a2a_server.php  # HTTP mode
-   A2A_MODE=production php -S localhost:8081 https_a2a_server.php  # HTTPS-aware mode
-   ```
-
-2. **Production Environment**
-   ```bash
-   # 1. Set up SSL proxy (nginx/Apache)
-   # 2. Update environment variables
-   # 3. Test with TCK suite
-   # 4. Monitor logs for security events
-   ```
-
-3. **Zero Downtime Migration**
-   - Deploy HTTPS server alongside existing HTTP server
-   - Test thoroughly with TCK suite
-   - Switch traffic gradually via load balancer
-   - Monitor for any issues
-
-## 🔐 Security Best Practices
-
-### Development
-- Use HTTP mode for local development
-- Self-signed certificates are auto-generated
-- Security headers still applied
-
-### Staging
-- Use proper SSL certificates
-- Test with production-like setup
-- Validate security headers
-
-### Production
-- Use certificates from trusted CA
-- Enable HSTS with long max-age
-- Monitor SSL certificate expiration
-- Regular security audits
-
-## 📈 Monitoring
-
-### Security Events
-Monitor these log patterns:
-```bash
-# HTTPS mode activation
-grep "Protocol: HTTPS" a2a_server.log
-
-# Security header application
-grep "Strict-Transport-Security" access.log
-
-# Certificate generation events
-grep "SSL certificate generated" a2a_server.log
-```
-
-### Health Checks
-```bash
-# HTTP health check
-curl -f http://localhost:8081/.well-known/agent-card.json
-
-# HTTPS health check
-curl -f https://your-domain.com/.well-known/agent-card.json
-
-# SSL certificate validation
-openssl s_client -connect your-domain.com:443 -servername your-domain.com
-```
-
-## 🎯 Benefits Achieved
-
-### ✅ **Security Enhanced**
-- End-to-end encryption for production
-- Industry-standard TLS implementation
-- Comprehensive security headers
-- Certificate management automation
-
-### ✅ **Zero Breaking Changes**
-- All existing functionality preserved
-- Same API endpoints and responses
-- Backward compatibility guaranteed
-- Seamless mode switching
-
-### ✅ **Production Ready**
-- Proper SSL termination support
-- Security logging and monitoring
-- Performance optimization
-- Best practices implementation
+## Security features
 
-### ✅ **Developer Friendly**
-- Interactive setup scripts
-- Comprehensive documentation
-- Easy local development
-- Clear migration path
+- HSTS (`Strict-Transport-Security`) enabled in production mode.
+- `X-Content-Type-Options: nosniff` and `X-Frame-Options: DENY` headers for clickjacking and MIME hardening.
+- Proxy detection through `X-Forwarded-Proto` to mark requests as HTTPS in logs.
+- Ability to force HTTPS redirects with `A2A_FORCE_HTTPS=true` when using the helper script.
 
-## 🎉 **MISSION ACCOMPLISHED**
+## Monitoring
 
-The A2A Protocol server now provides **production-grade HTTPS/TLS security** while maintaining **100% compatibility** with existing functionality. All tests continue to pass, and the implementation follows security best practices for modern web applications.
+- Application logs note whether HTTPS was detected: `"https": true` entries confirm TLS termination upstream.
+- Use `curl -v https://a2a.example.com/.well-known/agent-card.json` to verify certificate chains and headers.
+- Rotate and renew certificates with your preferred tooling (for example, `certbot` for Let's Encrypt).
 
-**🔐 Your A2A server is now enterprise-ready with full HTTPS/TLS support!**
+These adjustments provide a clear path to deploying the A2A PHP server in secure environments without altering protocol behaviour.