Get X.509 Certificate SHA-1 Thumbprint (nodejs)

script.ts

import crypto from 'crypto'

const x509Certificate = '[insert certificate here]'
const certificateStrings = x509Certificate.match(/-----BEGIN CERTIFICATE-----\s*([\s\S]+?)\s*-----END CERTIFICATE-----/i)

if (certificateStrings && certificateStrings[1]) {
  throw new Error('Invalid certificate')
}

const sha1Thumbprint = crypto
   .createHash('sha1')
   .update(Buffer.from(certificateStrings[1], 'base64'))
   .digest('hex')
   .toUpperCase()
const base64UrlSha1Thumbprint = Buffer.from(sha1Thumbprint, 'hex').toString('base64url')

console.log('SHA-1 Thumbprint', sha1Thumbprint)
console.log('SHA-1 Thumbprint Base64Url', base64UrlSha1Thumbprint)