smartid-calls/authhash.ts

Smart-ID client module for Node.JS with proxy layer

import * as crypto from 'crypto';

class AuthHash {
  public static async generateRandomHash(hashType = 'sha512'): Promise<{ raw: Buffer, digest: string }> {
    const buf = await crypto.randomBytes(64);
    return { raw: buf, digest: crypto.createHash(hashType).update(buf).digest('base64') }
  }


  public static calculateVerificationCode(digestBase64: string, hashType = 'sha512'): string {
    const sha256HashedInput = crypto.createHash(hashType).update(Buffer.from(digestBase64, 'base64')).digest();
    const integer = sha256HashedInput.readUIntBE(sha256HashedInput.length-2, 2);
    const verificationCode = String('0000' + (integer % 10000).toString().substr(-4)).slice(-4);
    return verificationCode;
  }
}

export default AuthHash;