Load and Validate a JWS from a StringBuilder

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.LoadJwsSb, which loads a JWS from a StringBuilder (here read from a file). The example then supplies the MAC key and validates the signature.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

import 'package:chilkat/chilkat.dart';

void main() {
  final jws = CkJws();

  // The file path is relative to the application's current working directory.  An absolute path may
  // also be used.  Supply the path appropriate to your own environment.

  // Load the JWS text from a file into a StringBuilder.
  final sbJws = CkStringBuilder();
  try {
    sbJws.loadFile('qa_data/message.jws', 'utf-8');
  } on ChilkatException {
    print('Failed to load the JWS file.');
    return;
  }

  // Load the JWS from the StringBuilder.
  try {
    jws.loadJwsSb(sbJws);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final base64Key = 'YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=';
  try {
    jws.setMacKey(0, base64Key, 'base64');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final v = jws.validate(0);
  if (v < 0) {
    print(jws.lastErrorText);
    return;
  }

  if (v != 1) {
    print('The signature is not valid.');
    return;
  }

  print('The signature is valid.');
}