add render Password tests

index.js

@@ -16,6 +16,7 @@ module.exports = {
     _createHmac: _createHmac,
     _calcEntropy: v2.calcEntropy,
     _getSetOfCharacters: v2.getSetOfCharacters,
+    _renderPassword: v2.renderPassword,
 };
 
 function _encryptLogin(login, masterPassword, options) {

package.json

@@ -23,6 +23,7 @@
     "test:browser": "npm run build && karma start tests/karma.config.js"
   },
   "dependencies": {
+    "big-integer": "^1.6.17",
     "bluebird": "^3.4.6",
     "create-hmac": "^1.1.4",
     "pbkdf2": "^3.0.9",

src/v2.js

@@ -1,5 +1,6 @@
 var Promise = require("bluebird");
 var pbkdf2 = require('pbkdf2');
+var bigInt = require("big-integer");
 
 exports.calcEntropy = function (site, login, masterPassword, passwordProfile) {
     return new Promise(function (resolve, reject) {
@@ -36,4 +37,19 @@ exports.getSetOfCharacters = function (passwordProfile) {
         }
     });
     return setOfCharacters;
+};
+
+function consumeEntropy(generatedPassword, quotient, setOfCharacters, maxLength) {
+    if (generatedPassword.length >= maxLength) {
+        return generatedPassword
+    }
+    var longDivision = quotient.divmod(setOfCharacters.length);
+    generatedPassword += setOfCharacters[longDivision.remainder];
+    return consumeEntropy(generatedPassword, longDivision.quotient, setOfCharacters, maxLength)
+}
+
+exports.renderPassword = function (entropy, setOfCharacters, passwordProfile) {
+    var _passwordProfile = passwordProfile !== undefined ? passwordProfile : {};
+    var length = _passwordProfile.length || 14;
+    return consumeEntropy('', bigInt(entropy, 16), setOfCharacters, length);
 };

tests/v2/renderPassword.tests.js

@@ -0,0 +1,28 @@
+var assert = chai.assert;
+
+describe('LessPass', function () {
+    it('render password use remainder of long division beetween entropy and set of chars length as an index ', function () {
+        var entropy = 'dc33d431bce2b01182c613382483ccdb0e2f66482cbba5e9d07dab34acc7eb1e';
+        var setOfCharacters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
+        assert.equal('y', LessPass._renderPassword(entropy, setOfCharacters)[0]);
+    });
+    it('render password use quotient as second entropy recursively', function () {
+        var entropy = 'dc33d431bce2b01182c613382483ccdb0e2f66482cbba5e9d07dab34acc7eb1e';
+        var setOfCharacters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
+        assert.equal('5', LessPass._renderPassword(entropy, setOfCharacters)[1]);
+    });
+    it('render password has default length of 14', function () {
+        var entropy = 'dc33d431bce2b01182c613382483ccdb0e2f66482cbba5e9d07dab34acc7eb1e';
+        var setOfCharacters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
+        assert.equal(14, LessPass._renderPassword(entropy, setOfCharacters).length);
+    });
+    it('render password can specify length', function () {
+        var entropy = 'dc33d431bce2b01182c613382483ccdb0e2f66482cbba5e9d07dab34acc7eb1e';
+        var setOfCharacters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
+        var passwordProfile = {
+            length: 20
+        };
+        assert.equal(20, LessPass._renderPassword(entropy, setOfCharacters, passwordProfile).length);
+    });
+
+});

tests/v2/renderPassword.tests.py

@@ -0,0 +1,10 @@
+def renderPassword(mdp, quotient, alphabet):
+    if len(mdp) > 14:
+        return mdp
+    quotient, remainder = divmod(quotient, len(alphabet))
+    mdp += alphabet[remainder]
+    return renderPassword(mdp, quotient, alphabet)
+
+
+alphabet = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
+print(renderPassword('', int('dc33d431bce2b01182c613382483ccdb0e2f66482cbba5e9d07dab34acc7eb1e', 16), alphabet))