checkExtendedKeyUsage

Standalone EKU check against a verified certificate chain. Validates that the leaf has the requested purpose and that intermediate CA EKU constraints (if present) permit it.

function checkExtendedKeyUsage(
	chain: readonly ParsedCertificate[],
	purpose: EkuCheckPurpose,
): EkuCheckResult

Parameters

• chain: readonly ParsedCertificate[]
• purpose: EkuCheckPurpose

Examples

import { checkExtendedKeyUsage } from 'micro509';

const result = checkExtendedKeyUsage(chain, 'serverAuth');
if (!result.ok) {
  console.error(result.error.code, result.error.message);
}