1. <?php
2. // Any other existing functions or code here
3.  
4. // Security headers functions
5. function add_security_headers() {
6.     // Strict-Transport-Security (HSTS)
7.     header('Strict-Transport-Security: max-age=31536000; includeSubDomains');
8.  
9.     // Content-Security-Policy (CSP) with nonce
10.     $nonce = wp_create_nonce('my-nonce');
11.     header("Content-Security-Policy: default-src 'self'; script-src 'self' 'nonce-$nonce' 'strict-dynamic'; style-src 'self' 'unsafe-inline';");
12.  
13.     // Feature-Policy
14.     header('Feature-Policy: accelerometer none; camera none; geolocation none; gyroscope none; magnetometer none; microphone none; payment none; usb none;');
15.  
16.     // Permissions-Policy
17.     header('Permissions-Policy: accelerometer=(), camera=(), geolocation=(), gyroscope=(), magnetometer=(), microphone=(), payment=(), usb=()');
18.  
19.     // X-Content-Type-Options
20.     header('X-Content-Type-Options: nosniff');
21.  
22.     // X-Frame-Options
23.     header('X-Frame-Options: DENY');
24.  
25.     // Referer-Policy
26.     header('Referrer-Policy: strict-origin-when-cross-origin');
27.  
28.     // Other security policies
29.     header('Interest-Cohort-Report-Only: "require-corp"');
30.     header('Public-Key-Pins: max-age=31536000; includeSubDomains');
31.     header('Screen-Wake-Lock: src self');
32.     header('Sync-Xhr-Mode: deny');
33.     header('Autoplay: none');
34.     header('Serial: none');
35.     header('Browsing-Topics: none');
36.  
37.     // Other security policies or directives
38.     header('Clipboard-Write: write');
39.  
40.     // CORS policies
41.     header('Access-Control-Allow-Origin: *');
42.     header('Access-Control-Allow-Methods: POST, GET, OPTIONS');
43.     header('Access-Control-Allow-Headers: X-Requested-With');
44.     header('Access-Control-Allow-Credentials: true');
45.  
46.     // Expect-CT
47.     header('Expect-CT: enforce, max-age=604800');
48. }
49.  
50. // Add action before sending headers
51. add_action('send_headers', 'add_security_headers');
52. ?>
53.