Ability to access certificate extensions through `Crypto` API `X509Certificate` class

What is the problem this feature will solve?

Key usages (not extend) are completely different and can only be accessed through certificate extension under OID 2.5.29.15 which contains value in a bit array format.

Key usage can have for definition: Digital signature, Non-repudiation, Key encipherment, Data encipherment, Key agreement, Certificate signing, CRL signing, Encipher only, Decipher only.

As of now Crypto API only provides access to Extended Key usage under the x509.keyUsage but does not provide access to the Key Usage through the certificate Extensions part.

What is the feature you are proposing to solve the problem?

Having a method the class x509 that can allow to have access to the Extension part of a certificate through a safe structure.

What alternatives have you considered?

Using 3rd party libraries like PKIjs or Forge, but I would like a native feature instead.

Comienza con la implementación de X509Certificate de la Node.js Crypto API y el comportamiento existente de x509.keyUsage. Revisa cómo se representan las extensiones de certificado y OID 2.5.29.15; después, define una estructura segura para exponer key usage y verifica que la nueva API lo distinga de extended key usage.