pkce-js/src/helpers.ts

Generate PKCE verifier and code_challenge in a simple way.

import sha256 from 'crypto-js/sha256';
import base64 from 'crypto-js/enc-base64';
//@ts-ignore
import secureRandom from 'secure-random';

export function randomString(length: number): string {
  let rs = '';
  const mask =
    'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._~';

  const bytes = secureRandom(length);
  const scale = 256 / mask.length; // 256 = 0 to 0xFF (randomBytes)

  for (let i = 0; i < length; i++) {
    rs += mask.charAt(Math.floor(bytes[i] / scale));
  }

  return rs;
}

export function b64Sha256Hash(str: string): string {
  return base64.stringify(sha256(str));
}

export function base64Url(str: string): string {
  return str.replace(/=/g, '').replace(/\+/g, '-').replace(/\//g, '_');
}