fernet/test/decode_test.js

Javascript implementation of Fernet symmetric encryption https://github.com/kr/fernet-spec

// for browser compatibility
if (!chai) var chai = require('chai');
if (!sinon) var sinon = require("sinon");
if (!sinonChai) var sinonChai = require("sinon-chai");
if (!fernet) var fernet = require('../fernet');

var assert = chai.assert
chai.use(sinonChai);

var testData = {
  "token": "gAAAAAAdwJ6wAAECAwQFBgcICQoLDA0ODy021cpGVWKZ_eEwCGM4BLLF_5CV9dOPmrhuVUPgJobwOz7JcbmrR64jVmpU4IwqDA==",
  "now": "1985-10-26T01:20:00-07:00",
  "iv": [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15],
  "src": "hello",
  "secret": "cw_0x689RpI-jtRR7oE8h_eQsKImvJapLeSbXpwF4e4="
}

var unacceptableClockSkewTestData = {
  "token": "gAAAAAAdwStRAAECAwQFBgcICQoLDA0OD3HkMATM5lFqGaerZ-fWPAnja1xKYyhd-Y6mSkTOyTGJmw2Xc2a6kBd-iX9b_qXQcw==",
  "now": "1985-10-26T01:20:01-07:00",
  "secret": "cw_0x689RpI-jtRR7oE8h_eQsKImvJapLeSbXpwF4e4="
}


describe('fernet.Token.prototype.decode', function () {
  var _fernet = new fernet({ ttl: 0 })
  var secret = new fernet.Secret(testData.secret);

  it("decode()", function () {
    var token = new _fernet.Token({
      secret: secret,
      token: testData.token
    })

    assert.equal("hello", token.decode())
    assert.equal("hello", token.toString())
  })

  it("decode(token)", function () {
    var token = new _fernet.Token({ secret: secret })
    assert.equal("hello", token.decode(testData.token))
    assert.equal("hello", token.toString())
  })

  it("decode(token) with top-level secret", function () {
    var f = new fernet({ secret: testData.secret, ttl: 0 })
    var token = new f.Token()
    assert.equal("hello", token.decode(testData.token))
    assert.equal("hello", token.toString())
  })

  it('recovers version', function () {
    var token = new _fernet.Token({
      secret: secret,
      token: testData.token,
      version: 1
    })
    assert.equal(token.version, 1);
    token.decode();
    assert.equal(token.version, 128);
  })

  it('recovers time', function () {
    var token = new _fernet.Token({
      secret: secret,
      token: testData.token
    })
    token.decode();
    var now = new Date(Date.parse(testData.now));
    assert.equal(token.time.toUTCString(), now.toUTCString());
  })

  it('recovers iv', function () {
    var token = new _fernet.Token({
      secret: secret,
      token: testData.token
    })
    token.decode();
    var ivHex = fernet.ArrayToHex(testData.iv);
    assert.equal(token.ivHex, ivHex);
  })

  it('recovers hmac', function () {
    var token = new _fernet.Token({
      secret: secret,
      token: testData.token
    })
    token.decode();
    var computedHmac = fernet.createHmac(secret.signingKey, fernet.timeBytes(token.time), token.iv, token.cipherText);
    assert.equal(token.hmacHex, computedHmac.toString(fernet.Hex));
  })

  it('inherits parent TTL', function () {
    var f = new fernet({ ttl: 1 });
    var token = new f.Token({
      secret: secret,
      token: testData.token,
    })

    assert.throws(function () {
      token.decode();
    }, Error, 'Invalid Token: TTL');
  })

  it('raises new Error("Invalid Token: TTL") on invalid ttl', function () {
    var token = new fernet.Token({
      secret: secret,
      token: testData.token,
      ttl: 1
    })

    assert.throws(function () {
      token.decode();
    }, Error, 'Invalid Token: TTL');
  })

  it('raises new Error("Invalid version") on wrong version byte', function () {
    var tokenHex = fernet.decode64toHex(testData.token);
    var versionOffset = fernet.hexBits(8);
    var dirtyToken = '01' + tokenHex.slice(versionOffset);
    var tokenWords = fernet.Hex.parse(dirtyToken);
    var token = fernet.urlsafe(tokenWords.toString(fernet.Base64));
    var t = new _fernet.Token({ secret: secret })

    assert.throws(function () {
      t.decode(token);
    }, Error, 'Invalid version');
  })

  it('raises new Error("Invalid Token: HMAC") on wrong Hmac', function () {
    var s = testData.token;
    var i = s.length - 5;
    var mutation = String.fromCharCode(s.charCodeAt(i) + 1);
    var dirtyHmacString = s.slice(0, i) + mutation + s.slice(i + 1);
    var token = new _fernet.Token({
      secret: secret,
      token: dirtyHmacString
    })

    assert.throws(function () {
      token.decode();
    }, Error, 'Invalid Token: HMAC');
  })

  it('raises new Error("far-future timestamp") on unacceptable clock skew', function () {
    var token = new fernet.Token({
      secret: new fernet.Secret(unacceptableClockSkewTestData.secret),
      token: unacceptableClockSkewTestData.token,
      ttl: 1
    })

    clock = sinon.useFakeTimers(new Date(Date.parse(unacceptableClockSkewTestData.now)).getTime());

    assert.throws(function () {
      token.decode();
    }, Error, 'far-future timestamp');

    clock.restore();

  })
})