der-decode-test.js

var assert = require('assert');
var asn1 = require('..');

var Buffer = require('buffer').Buffer;

describe('asn1.js DER decoder', function() {
  it('should propagate implicit tag', function() {
    var B = asn1.define('B', function() {
      this.seq().obj(
        this.key('b').octstr()
      );
    });

    var A = asn1.define('Bug', function() {
      this.seq().obj(
        this.key('a').implicit(0).use(B)
      );
    });

    var out = A.decode(new Buffer('300720050403313233', 'hex'), 'der');
    assert.equal(out.a.b.toString(), '123');
  });

  it('should decode optional tag to undefined key', function() {
    var A = asn1.define('A', function() {
      this.seq().obj(
        this.key('key').bool(),
        this.optional().key('opt').bool()
      );
    });
    var out = A.decode(new Buffer('30030101ff', 'hex'), 'der');
    assert.deepEqual(out, { 'key': true });
  });

  it('should decode optional tag to default value', function() {
    var A = asn1.define('A', function() {
      this.seq().obj(
        this.key('key').bool(),
        this.optional().key('opt').octstr().def('default')
      );
    });
    var out = A.decode(new Buffer('30030101ff', 'hex'), 'der');
    assert.deepEqual(out, { 'key': true, 'opt': 'default' });
  });

  function test(name, model, inputHex, expected) {
    it(name, function() {
      var M = asn1.define('Model', model);
      var decoded = M.decode(new Buffer(inputHex,'hex'), 'der');
      assert.deepEqual(decoded, expected);
    });
  }

  test('should decode choice', function() {
    this.choice({
      apple: this.bool(),
    });
  }, '0101ff', { 'type': 'apple', 'value': true });

});