Web Security & Transitions

25. Security: Strict CSP, Nonces & View Transitions

Harden web applications against XSS with cryptographic CSP nonces, strict headers, and coordinate fluid page animations with View Transitions.

csp-transitions.ts
// Strict CSP Nonce Generator & View Transitions Integration
import crypto from 'node:crypto';

export function createSecurityHeaders() {
  const nonce = crypto.randomBytes(16).toString('base64');
  
  const csp = [
    "default-src 'self'",
    `script-src 'self' 'nonce-${nonce}' 'strict-dynamic'`,
    "style-src 'self' 'unsafe-inline'",
    "img-src 'self' data: https:",
    "font-src 'self'",
    "object-src 'none'",
    "base-uri 'self'",
    "frame-ancestors 'none'"
  ].join('; ');

  return { nonce, headers: { 'Content-Security-Policy': csp, 'X-Frame-Options': 'DENY' } };
}

Security: Strict CSP, Nonces & View Transitions

Securing web applications against Cross-Site Scripting (XSS) and clickjacking with strict Content Security Policies while providing fluid navigational animations with the View Transitions API.

  • Cryptographic CSP Nonces: Server-generated nonces ensure that only vetted scripts executed by the framework can run, blocking malicious injected payloads.
  • Clickjacking Mitigation (frame-ancestors 'none'): Prevents unauthorized embedding inside foreign iframes.
  • View Transitions API: Natively morphs DOM elements between pages and route navigations without complex layout calculations.
Strict CSP Header Policy Generator XSS Mitigation
Generated Content-Security-Policy Header:
default-src 'self'; script-src 'self' 'nonce-rAnd0mN0nc3Str1ng==' 'strict-dynamic'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; object-src 'none'; base-uri 'self'; frame-ancestors 'none'
Native View Transitions API Morphing document.startViewTransition
Morphable Element

Compact View