Add zxcvbn for password strength estimation (#555)

* add zxcvbn

* use zxcvbn for password estimations

* add comments

* update snapshot

app/components/Views/ChoosePassword/__snapshots__/index.test.js.snap

@@ -161,6 +161,7 @@ exports[`ChoosePassword should render correctly 1`] = `
             style={
               Object {
                 "alignSelf": "flex-end",
+                "backgroundColor": "#FFFFFF",
                 "marginTop": 8,
                 "position": "absolute",
               }

app/components/Views/ChoosePassword/index.js

@@ -27,6 +27,7 @@ import { getOnboardingNavbarOptions } from '../../UI/Navbar';
 import SecureKeychain from '../../../core/SecureKeychain';
 import Icon from 'react-native-vector-icons/FontAwesome';
 import AppConstants from '../../../core/AppConstants';
+import zxcvbn from 'zxcvbn';
 
 const styles = StyleSheet.create({
 	mainWrapper: {
@@ -127,6 +128,7 @@ const styles = StyleSheet.create({
 		color: colors.brightGreen
 	},
 	showHideToggle: {
+		backgroundColor: colors.white,
 		position: 'absolute',
 		marginTop: 8,
 		alignSelf: 'flex-end'
@@ -283,12 +285,19 @@ class ChoosePassword extends Component {
 	};
 
 	getPasswordStrengthWord() {
+		// this.state.passwordStrength is calculated by zxcvbn
+		// which returns a score based on "entropy to crack time"
+		// 0 is the weakest, 4 the strongest
 		switch (this.state.passwordStrength) {
+			case 0:
+				return 'weak';
 			case 1:
 				return 'weak';
 			case 2:
-				return 'good';
+				return 'weak';
 			case 3:
+				return 'good';
+			case 4:
 				return 'strong';
 		}
 	}
@@ -330,22 +339,9 @@ class ChoosePassword extends Component {
 	};
 
 	onPasswordChange = val => {
-		let strength = 1;
-
-		// If the password length is greater than 6 and contain alphabet,number,special character respectively
-		if (
-			val.length > 6 &&
-			((val.match(/[a-z]/) && val.match(/\d+/)) ||
-				(val.match(/\d+/) && val.match(/.[!,@,#,$,%,^,&,*,?,_,~,-,(,)]/)) ||
-				(val.match(/[a-z]/) && val.match(/.[!,@,#,$,%,^,&,*,?,_,~,-,(,)]/)))
-		)
-			strength = 2;
-
-		// If the password length is greater than 6 and must contain alphabets,numbers and special characters
-		if (val.length > 6 && val.match(/[a-z]/) && val.match(/\d+/) && val.match(/.[!,@,#,$,%,^,&,*,?,_,~,-,(,)]/))
-			strength = 3;
+		const passInfo = zxcvbn(val);
 
-		this.setState({ password: val, passwordStrength: strength });
+		this.setState({ password: val, passwordStrength: passInfo.score });
 	};
 
 	toggleShowHide = () => {

package.json

@@ -123,7 +123,8 @@
     "url": "0.11.0",
     "url-parse": "1.4.4",
     "valid-url": "1.0.9",
-    "vm-browserify": "0.0.4"
+    "vm-browserify": "0.0.4",
+    "zxcvbn": "4.4.2"
   },
   "devDependencies": {
     "@babel/core": "7.3.4",