Explicit CSP nonce management

When implementing Content Security Policy (CSP) protections, always explicitly pass nonce values to components rather than auto-applying them. This gives developers more control over security aspects and prevents potential security bypasses when integrating components from different sources.

Key implementation guidelines:

• Pass nonces explicitly to components that need them (like style and script elements)
• Be aware that different content types may require different nonce values (style-src and script-src directives)
• Ensure elements with different nonces aren’t inappropriately merged
• Handle nonces consistently across your application

Example in React:

// Correct: Explicitly passing nonce to style elements
<style
  href="foo"
  precedence="default"
  nonce={CSPnonce}>{`.foo { color: hotpink; }`}</style>

// When rendering on server, pass nonce to the renderer
renderToPipeableStream(
  <App />,
  { nonce: CSPnonce }
);

// For preinitialized styles, ensure nonces are added consistently
// to maintain security guarantees
const preinitOptions = {
  precedence: 'default',
  nonce: CSPnonce // Explicitly add nonce here too
};

Properly implemented CSP with nonces is one of the strongest defenses against cross-site scripting (XSS) attacks, but only if nonces are managed correctly and consistently throughout your application.