certificate.exportChallenge()

certificate.exportChallenge(spkac)

The spkac data structure includes a public key and a challenge. The certificate.exportChallenge() returns the challenge component in the form of a Node.js Buffer. The spkac argument can be either a string or a Buffer.

const cert = require('crypto').Certificate();
const spkac = getSpkacSomehow();
const challenge = cert.exportChallenge(spkac);
console.log(challenge.toString('utf8'));
  // Prints the challenge as a UTF8 string