ESP32 WebServer Library -headerName()

/*
 * Author: Avant Maker
 * Date: June 16, 2025
 * Version: 1.0
 * License: MIT 
 * 
 * Description: 
 * This example demonstrates the fundamental usage of headerName() to
 * retrieve and display all collected header names along with their values.
 * 
 * How to use this example: 
 * Upload this code to your ESP32 and replace the WiFi credentials. 
 * After connecting, visit the ESP32's IP address in your browser. 
 * The server will display all collected header names and their corresponding
 * values. Try accessing with different browsers or tools like curl to see
 * how header sets vary: curl -H "Custom-Header: test-value" http://ESP32_IP
 *
 * Code Source:
 * This example code is sourced from the Comprehensive Guide
 * to the ESP32 Arduino Core Library, accessible on AvantMaker.com.
 * For additional code examples and in-depth documentation related to
 * the ESP32 Arduino Core Library, please visit:
 *
 * https://avantmaker.com/home/all-about-esp32-arduino-core-library/
 *
 * AvantMaker.com, your premier destination for all things
 * DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated
 * to empowering makers, learners, and enthusiasts with
 * the resources they need to bring their nnovative ideas to life.
 */

#include <WiFi.h>
#include <WebServer.h>

const char* ssid = "your_wifi_ssid";
const char* password = "your_wifi_password";

WebServer server(80);

void handleRoot() {
  String message = "AvantMaker ESP32 Example: Header Names and Values\n";
  message += "==============================\n\n";
  
  int headerCount = server.headers();
  message += "Total headers collected: " + String(headerCount) + "\n\n";
  
  // Iterate through all headers using headerName() and header()
  for (int i = 0; i < headerCount; i++) {
    String name = server.headerName(i);
    String value = server.header(i);
    
    message += "Header " + String(i) + ":\n";
    message += "  Name:  " + name + "\n";
    message += "  Value: " + value + "\n\n";
  }
  
  if (headerCount == 0) {
    message += "No headers were collected.\n";
    message += "Headers must be configured with collectHeaders() first.\n";
  }
  
  server.send(200, "text/plain", message);
}

void setup() {
  Serial.begin(115200);
  
  // Connect to WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  
  // Collect all headers to demonstrate headerName()
  server.collectAllHeaders();
  
  // Set up route handler
  server.on("/", handleRoot);
  
  // Start server
  server.begin();
  Serial.println("HTTP server started");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  server.handleClient();
}

/*
 * Author: Avant Maker
 * Date: June 16, 2025
 * Version: 1.0
 * License: MIT 
 * 
 * Description: 
 * This example shows how to use headerName() to analyze and categorize
 * headers, demonstrating practical applications for header inspection
 * and processing.
 * 
 * How to use this example: 
 * After uploading and connecting to WiFi, visit the ESP32's IP
 * address to see the categorized header analysis. Test with different
 * clients: browsers, curl, or mobile apps to see how header patterns
 * differ. Access the /analyze endpoint to get detailed header categorization.
 *
 * Code Source:
 * This example code is sourced from the Comprehensive Guide
 * to the ESP32 Arduino Core Library, accessible on AvantMaker.com.
 * For additional code examples and in-depth documentation related to
 * the ESP32 Arduino Core Library, please visit:
 *
 * https://avantmaker.com/home/all-about-esp32-arduino-core-library/
 *
 * AvantMaker.com, your premier destination for all things
 * DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated
 * to empowering makers, learners, and enthusiasts with
 * the resources they need to bring their nnovative ideas to life.
 */

#include <WiFi.h>
#include <WebServer.h>

const char* ssid = "your_wifi_ssid";
const char* password = "your_wifi_password";

WebServer server(80);

void analyzeHeaders() {
  String message = "AvantMaker Header Analysis Report\n";
  message += "=====================\n\n";
  
  int headerCount = server.headers();
  int authHeaders = 0;
  int contentHeaders = 0;
  int cacheHeaders = 0;
  int customHeaders = 0;
  
  message += "Collected Headers (" + String(headerCount) + " total):\n";
  message += "----------------------------------------\n";
  
  for (int i = 0; i < headerCount; i++) {
    String headerName = server.headerName(i);
    String headerValue = server.header(i);
    
    // Categorize headers based on their names
    if (headerName.indexOf("Auth") != -1 || headerName.equals("Authorization")) {
      authHeaders++;
      message += "[AUTH] ";
    } else if (headerName.indexOf("Content") != -1 || headerName.indexOf("Accept") != -1) {
      contentHeaders++;
      message += "[CONTENT] ";
    } else if (headerName.indexOf("Cache") != -1 || headerName.indexOf("ETag") != -1 || 
               headerName.indexOf("Modified") != -1) {
      cacheHeaders++;
      message += "[CACHE] ";
    } else if (headerName.indexOf("X-") == 0 || headerName.indexOf("Custom") != -1) {
      customHeaders++;
      message += "[CUSTOM] ";
    } else {
      message += "[STANDARD] ";
    }
    
    message += headerName + ": " + headerValue + "\n";
  }
  
  message += "\nSummary:\n";
  message += "--------\n";
  message += "Authentication headers: " + String(authHeaders) + "\n";
  message += "Content-related headers: " + String(contentHeaders) + "\n";
  message += "Cache-related headers: " + String(cacheHeaders) + "\n";
  message += "Custom headers: " + String(customHeaders) + "\n";
  message += "Other standard headers: " + String(headerCount - authHeaders - contentHeaders - cacheHeaders - customHeaders) + "\n";
  
  server.send(200, "text/plain", message);
}

void handleRoot() {
  String html = "<html><body>";
  html += "<h1>AvantMaker ESP32 Header Analysis Tool</h1>";
  html += "<p>This tool analyzes and categorizes HTTP headers sent by your client.</p>";
  html += "<h2>Available Endpoints:</h2>";
  html += "<ul>";
  html += "<li><a href='/analyze'>/analyze</a> - Detailed header analysis</li>";
  html += "<li><a href='/count'>/count</a> - Quick header count</li>";
  html += "</ul>";
  html += "<p>Try sending custom headers with curl:<br>";
  html += "<code>curl -H \"X-Custom-Header: test\" -H \"Authorization: Bearer token\" http://" + WiFi.localIP().toString() + "/analyze</code></p>";
  html += "</body></html>";
  
  server.send(200, "text/html", html);
}

void handleCount() {
  String message = "Quick Header Count\n";
  message += "==================\n\n";
  
  int count = server.headers();
  message += "Total headers: " + String(count) + "\n\n";
  
  message += "Header names:\n";
  for (int i = 0; i < count; i++) {
    message += String(i + 1) + ". " + server.headerName(i) + "\n";
  }
  
  server.send(200, "text/plain", message);
}

void setup() {
  Serial.begin(115200);
  
  // Connect to WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  
  // Collect all headers for comprehensive analysis
  server.collectAllHeaders();
  
  // Set up route handlers
  server.on("/", handleRoot);
  server.on("/analyze", analyzeHeaders);
  server.on("/count", handleCount);
  
  // Start server
  server.begin();
  Serial.println("HTTP server started");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  server.handleClient();
}

/*
 * Author: Avant Maker
 * Date: June 16, 2025
 * Version: 1.0
 * License: MIT 
 * 
 * Description: 
 * This example demonstrates advanced usage of headerName()
 * for implementing security monitoring and comprehensive request
 * logging, showing real-world applications.
 * 
 * How to use this example: 
 * This creates a security monitoring system that logs all requests
 * and analyzes headers for potential security concerns. Test with 
 * various scenarios: 
 * curl -H "X-Forwarded-For: 192.168.1.100" http://ESP32_IP/secure
 * for proxy detection, or
 * curl -H "User-Agent: SecurityScanner" http://ESP32_IP/secure
 * for suspicious user agent detection.
 * Check the Serial Monitor for detailed logs.
 *
 * Code Source:
 * This example code is sourced from the Comprehensive Guide
 * to the ESP32 Arduino Core Library, accessible on AvantMaker.com.
 * For additional code examples and in-depth documentation related to
 * the ESP32 Arduino Core Library, please visit:
 *
 * https://avantmaker.com/home/all-about-esp32-arduino-core-library/
 *
 * AvantMaker.com, your premier destination for all things
 * DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated
 * to empowering makers, learners, and enthusiasts with
 * the resources they need to bring their nnovative ideas to life.
 */

#include <WiFi.h>
#include <WebServer.h>

const char* ssid = "your_wifi_ssid";
const char* password = "your_wifi_password";

WebServer server(80);

// Security monitoring functions
void logRequest() {
  Serial.println("=== REQUEST LOG ===");
  Serial.print("Timestamp: ");
  Serial.println(millis());
  Serial.print("Client IP: ");
  Serial.println(server.client().remoteIP());
  Serial.print("Method: ");
  Serial.println((server.method() == HTTP_GET) ? "GET" : 
                 (server.method() == HTTP_POST) ? "POST" : "OTHER");
  Serial.print("URI: ");
  Serial.println(server.uri());
  
  int headerCount = server.headers();
  Serial.print("Headers (");
  Serial.print(headerCount);
  Serial.println("):");
  
  for (int i = 0; i < headerCount; i++) {
    String name = server.headerName(i);
    String value = server.header(i);
    Serial.print("  ");
    Serial.print(name);
    Serial.print(": ");
    Serial.println(value);
  }
  Serial.println("==================");
}

bool checkSuspiciousHeaders() {
  int headerCount = server.headers();
  bool suspicious = false;
  
  for (int i = 0; i < headerCount; i++) {
    String name = server.headerName(i);
    String value = server.header(i);
    
    // Check for suspicious patterns
    if (name.indexOf("X-Forwarded") != -1 && value.indexOf("localhost") == -1) {
      Serial.println("WARNING: Proxy detected - " + name + ": " + value);
      suspicious = true;
    }
    
    if (name.equals("User-Agent") && 
        (value.indexOf("bot") != -1 || value.indexOf("crawler") != -1 || 
         value.indexOf("scanner") != -1)) {
      Serial.println("WARNING: Automated client detected - " + value);
      suspicious = true;
    }
    
    if (name.indexOf("X-") == 0 && value.length() > 100) {
      Serial.println("WARNING: Unusually long custom header - " + name);
      suspicious = true;
    }
  }
  
  return suspicious;
}

void handleSecure() {
  // Log all requests
  logRequest();
  
  // Check for suspicious activity
  bool suspicious = checkSuspiciousHeaders();
  
  String response = "Security Check Results\n";
  response += "======================\n\n";
  
  if (suspicious) {
    response += "⚠️  SECURITY ALERT: Suspicious headers detected!\n";
    response += "Check Serial Monitor for details.\n\n";
  } else {
    response += "✅ Headers appear normal.\n\n";
  }
  
  response += "Request Details:\n";
  response += "Client IP: " + server.client().remoteIP().toString() + "\n";
  response += "User Agent: " + server.header("User-Agent") + "\n";
  response += "Referer: " + server.header("Referer") + "\n";
  
  // List all header names for transparency
  response += "\nAll Header Names:\n";
  int count = server.headers();
  for (int i = 0; i < count; i++) {
    response += String(i + 1) + ". " + server.headerName(i) + "\n";
  }
  
  server.send(200, "text/plain", response);
}

void handleStats() {
  String response = "Header Statistics\n";
  response += "=================\n\n";
  
  int headerCount = server.headers();
  response += "Total headers in this request: " + String(headerCount) + "\n\n";
  
  // Count header types
  int standardHeaders = 0;
  int customHeaders = 0;
  
  for (int i = 0; i < headerCount; i++) {
    String name = server.headerName(i);
    if (name.indexOf("X-") == 0 || name.indexOf("Custom") != -1) {
      customHeaders++;
    } else {
      standardHeaders++;
    }
  }
  
  response += "Standard headers: " + String(standardHeaders) + "\n";
  response += "Custom headers: " + String(customHeaders) + "\n";
  response += "Custom header ratio: " + String((float)customHeaders / headerCount * 100) + "%\n";
  
  server.send(200, "text/plain", response);
}

void handleRoot() {
  String html = "<html><body>";
  html += "<h1>AvantMaker ESP32 Security Monitor</h1>";
  html += "<p>Monitoring and logging HTTP headers for security analysis.</p>";
  html += "<h2>Endpoints:</h2>";
  html += "<ul>";
  html += "<li><a href='/secure'>/secure</a> - Security check with detailed logging</li>";
  html += "<li><a href='/stats'>/stats</a> - Header statistics</li>";
  html += "</ul>";
  html += "<p><strong>Note:</strong> All requests are logged to Serial Monitor.</p>";
  html += "</body></html>";
  
  server.send(200, "text/html", html);
}

void setup() {
  Serial.begin(115200);
  
  // Connect to WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  
  // Collect all headers for comprehensive monitoring
  server.collectAllHeaders();
  
  // Set up route handlers
  server.on("/", handleRoot);
  server.on("/secure", handleSecure);
  server.on("/stats", handleStats);
  
  // Start server
  server.begin();
  Serial.println("HTTP server started");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println("Security monitoring active - check Serial Monitor for logs");
}

void loop() {
  server.handleClient();
}