zxcvbn4j

This is a java port of zxcvbn, which is a password strength estimator inspired by password crackers written on JavaScript. Through pattern matching and conservative estimation, it recognizes and weighs 30k common passwords, common names and surnames according to US census data, popular English words from Wikipedia and US television and movies, and other common patterns like dates, repeats (aaa), sequences (abcd), keyboard patterns (qwertyuiop), and l33t speak.

Related articles:

Five Algorithms to Measure Real Password Strength

Table Contents

Update
Special Features
- Customize internal dictionaries and keyboards
- Localize feedback messages
- JIS keyboard layout
- Support some languages by default
- Password args accept CharSequence as well as String
Install
Development
Usage
- Basic
- Strength Properties
- Customize internal dictionaries and keyboards
  - Use resources on the classpath
  - Use resources get via HTTP
  - Use file resources other than classpath
  - Use all default resources
  - Select from and use default resources
- Localize feedback messages
  - Localize each feedback
  - Localize each locale
Requires Java
Using this library
Bugs and Feedback
License

Update

The following version is a port of zxcvbn 4.4.2

2022/04/13 1.7.0 released.
2022/04/05 1.6.0 released.
2021/06/08 1.5.2 released.
2021/06/05 1.5.1 released.
2021/04/26 1.5.0 released.
2021/03/22 1.4.1 released.
2021/02/19 1.4.0 released.
2021/02/09 1.3.6 released.
2021/02/02 1.3.5 released.
2021/01/26 1.3.4 released.
2021/01/21 1.3.3 released.
2021/01/19 1.3.2 released.
2020/10/28 1.3.1 released.
2019/10/19 1.3.0 released.
2019/07/23 1.2.7 released.
2019/07/16 1.2.6 released.
2018/03/30 1.2.5 released.
2018/02/27 1.2.4 released.
2017/03/27 1.2.3 released.

The following version is a port of zxcvbn 4.4.1

2016/12/07 1.2.2 released.
2016/12/03 1.2.1 released.

The following version is a port of zxcvbn 4.4.0

2016/10/29 1.2.0 released.

The following version is a port of zxcvbn 4.3.0

2016/10/01 1.1.6 released.
2016/09/27 1.1.5 released.
2016/07/08 1.1.4 released.
2016/05/27 1.1.3 released.
2016/05/25 1.1.2 released.
2016/03/19 1.1.1 released.
2016/03/06 1.1.0 released.

The following version is a port of zxcvbn 4.2.0

2016/01/28 1.0.2 released.
2016/01/27 1.0.1 released.
2015/12/24 1.0.0 released.

Special Features

Customize internal dictionaries and keyboards

Customize the dictionary and keyboard layout used by the measurement algorithm.

Localize feedback messages

The zxcvbn4j can be localized the english feedback message to other languages.

Support some languages by default

English (default)
Japanese (ja)
Dutch (nl)
German (de)
French (fr)
Italian (it)

JIS keyboard layout

It includes JIS keyboard layout in spatial matching.

Password args accept CharSequence as well as String

This gives a lot more flexibility in what format the password can be in.
Also attempts to avoid using Strings for any sensitive intermediate objects.

Install

https://mvnrepository.com/artifact/com.nulab-inc/zxcvbn/1.7.0

Gradle:

compile 'com.nulab-inc:zxcvbn:1.7.0'

Maven:

<dependency>
  <groupId>com.nulab-inc</groupId>
  <artifactId>zxcvbn</artifactId>
  <version>1.7.0</version>
</dependency>

Development

$ git clone https://github.com/nulab/zxcvbn4j.git
$ cd ./zxcvbn4j
$ ./gradlew build    # build
$ ./gradlew test     # test
$ ./gradlew jmh      # benchmark

Usage

Basic

This is also available Android.

Zxcvbn zxcvbn = new Zxcvbn();
Strength strength = zxcvbn.measure("This is password");

If you want to add your own dictionary, put the keyword list of List <String> type to the second argument.

List<String> sanitizedInputs = new ArrayList();
sanitizedInputs.add("nulab");
sanitizedInputs.add("backlog");
sanitizedInputs.add("cacoo");
sanitizedInputs.add("typetalk");

Zxcvbn zxcvbn = new Zxcvbn();
Strength strength = zxcvbn.measure("This is password", sanitizedInputs);

Strength Properties

The return result is "Strength". It's almost the same as zxcvbn.

# estimated guesses needed to crack password
strength.guesses

# order of magnitude of strength.guesses
strength.guessesLog10

# dictionary of back-of-the-envelope crack time
# estimations, in seconds, based on a few scenarios
strength.crackTimeSeconds
{
  # online attack on a service that ratelimits password auth attempts.
  onlineThrottling100PerHour

  # online attack on a service that doesn't ratelimit,
  # or where an attacker has outsmarted ratelimiting.
  onlineNoThrottling10PerSecond

  # offline attack. assumes multiple attackers,
  # proper user-unique salting, and a slow hash function
  # w/ moderate work factor, such as bcrypt, scrypt, PBKDF2.
  offlineSlowHashing1e4PerSecond

  # offline attack with user-unique salting but a fast hash
  # function like SHA-1, SHA-256 or MD5. A wide range of
  # reasonable numbers anywhere from one billion - one trillion
  # guesses per second, depending on number of cores and machines.
  # ballparking at 10B/sec.
  offlineFastHashing1e10PerSecond
}

# same keys as result.crack_time_seconds,
# with friendlier display string values:
# "less than a second", "3 hours", "centuries", etc.
strength.crackTimeDisplay

# Integer from 0-4 (useful for implementing a strength bar)
# 0 Weak        （guesses < 10^3 + 5）
# 1 Fair        （guesses < 10^6 + 5）
# 2 Good        （guesses < 10^8 + 5）
# 3 Strong      （guesses < 10^10 + 5）
# 4 Very strong （guesses >= 10^10 + 5）
strength.score

# verbal feedback to help choose better passwords. set when score <= 2.
strength.feedback
{
  # explains what's wrong, eg. 'this is a top-10 common password'.
  # not always set -- sometimes an empty string
  warning

  # a possibly-empty list of suggestions to help choose a less
  # guessable password. eg. 'Add another word or two'
  suggestions
}

# the list of patterns that zxcvbn based the guess calculation on.
strength.sequence

# how long it took zxcvbn to calculate an answer, in milliseconds.
strength.calc_time

Customize internal dictionaries and keyboards

Zxcvbn can build with ZxcvbnBuilder. ZxcvbnBuilder can customize dictionaries and keyboards used in measurements.

Use resources on the classpath

ClasspathResource can get your own dictionary and keyboard file on the classpath. DictionaryLoader load dictionary file. SlantedKeyboardLoader and AlignedKeyboardLoader load keyboard file.

Zxcvbn zxcvbn = new ZxcvbnBuilder()
        .dictionary(new DictionaryLoader("us_tv_and_film", new ClasspathResource("/com/nulabinc/zxcvbn/matchers/dictionarys/us_tv_and_film.txt")).load())
        .keyboard(new SlantedKeyboardLoader("qwerty", new ClasspathResource("/com/nulabinc/zxcvbn/matchers/keyboards/qwerty.txt")).load())
        .keyboard(new AlignedKeyboardLoader("keypad", new ClasspathResource("/com/nulabinc/zxcvbn/matchers/keyboards/keypad.txt")).load())
        .build();

Use resources get via HTTP

To use dictionary and keyboard files other than the classpath, implement the Resource interface. This code is an example of getting and loading a file via HTTP(s).

URL dictionaryURL = new URL("https://example.com/foo/dictionary.txt");
Resource myDictionaryResource = new MyResourceOverHTTP(dictionaryURL);

URL keyboardURL = new URL("https://example.com/bar/keyboard.txt");
Resource myKeyboardURLResource = new MyResourceOverHTTP(keyboardURL);

Zxcvbn zxcvbn = new ZxcvbnBuilder()
        .dictionary(new DictionaryLoader("my_dictionary", myDictionaryResource).load())
        .keyboard(new SlantedKeyboardLoader("my_keyboard", myKeyboardURLResource).load())
        .build();

public class MyResourceOverHTTP implements Resource {

    private URL url;

    public MyResourceOverHTTP(URL url) {
        this.url = url;
    }

    @Override
    public InputStream getInputStream() throws IOException {
        HttpURLConnection conn = (HttpURLConnection) this.url.openConnection();
        return conn.getInputStream();
    }
}

Use file resources other than classpath

This code is an example of using files in other directories than the classpath.

File dictionaryFile = new File("/home/foo/dictionary.txt");
Resource myDictionaryResource = new MyResourceFromFile(dictionaryFile);

File keyboardFile = new File("/home/bar/keyboard.txt");
Resource myKeyboardURLResource = new MyResourceFromFile(keyboardFile);

Zxcvbn zxcvbn = new ZxcvbnBuilder()
    .dictionary(new DictionaryLoader("my_dictionary", myDictionaryResource).load())
    .keyboard(new SlantedKeyboardLoader("my_keyboard", myKeyboardURLResource).load())
    .build();

public class MyResourceFromFile implements Resource {

    private File file;

    public MyResourceFromFile(File file) {
        this.file = file;
    }

    @Override
    public InputStream getInputStream() throws IOException {
        return new FileInputStream(this.file);
    }
}

Use all default resources

StandardDictionaries.loadAllDictionaries() loads all default dictionary files. StandardDictionaries.loadAllKeyboards() loads all default keyboard files.

Zxcvbn zxcvbn = new Zxcvbn();

Zxcvbn zxcvbn = new ZxcvbnBuilder()
    .dictionaries(StandardDictionaries.loadAllDictionaries())
    .keyboards(StandardKeyboards.loadAllKeyboards())
    .build();

Select from and use default resources

The following code selects some from the default dictionary files and keyboards.

Zxcvbn zxcvbn = new ZxcvbnBuilder()
    .dictionary(StandardDictionaries.ENGLISH_WIKIPEDIA_LOADER.load())
    .dictionary(StandardDictionaries.PASSWORDS_LOADER.load())
    .keyboard(StandardKeyboards.QWERTY_LOADER.load())
    .keyboard(StandardKeyboards.DVORAK_LOADER.load())
    .build();

Localize feedback messages

The zxcvbn4j can be localized the english feedback message to other languages.

Localize each feedback

// Get the Strength instance.
Zxcvbn zxcvbn = new Zxcvbn();
Strength strength = zxcvbn.measure("This is password");

// Get the ResourceBundle based on the name and locale of the property file(※).
ResourceBundle resourceBundle = ResourceBundle.getBundle("This is bundle name", Locale.JAPAN);

// Feedback to pass the ResourceBundle. And to generate a localized Feedback.
Feedback feedback = strength.getFeedback();
Feedback localizedFeedback = feedback.withResourceBundle(resourceBundle);

// getSuggestions() and getWarning() returns localized feedback message.
List<String> localizedSuggestions = localizedFeedback.getSuggestions();
String localizedWarning = localizedFeedback.getWarning();

Defined Key and the message in the properties file. Reference the messages.properties.

Localize each locale

Strength strength = zxcvbn.measure(password);
Feedback feedback = strength.getFeedback();

Map<Locale, ResourceBundle> messages = new HashMap<>();
messages.put(Locale.JAPANESE, ResourceBundle.getBundle("This is bundle name", Locale.JAPANESE));
messages.put(Locale.ITALIAN, ResourceBundle.getBundle("This is bundle name", Locale.ITALIAN));
Feedback replacedFeedback = feedback.replaceResourceBundle(messages);

Requires Java

Java 1.7+

Using this library

Backlog
Cacoo
Typetalk
JetBrains Hub
Cryptomator
And many Open Source Software
- https://github.com/search?q=com.nulab-inc+zxcvbn&type=code
- https://mvnrepository.com/artifact/com.nulab-inc/zxcvbn/usages

Bugs and Feedback

For bugs, questions and discussions please use the GitHub Issues.

License

MIT License

http://www.opensource.org/licenses/mit-license.php

zxcvbn4j
zxcvbn4j copied to clipboard

Metadata

zxcvbn4j

Table Contents

Update

Special Features

Customize internal dictionaries and keyboards

Localize feedback messages

Support some languages by default

JIS keyboard layout

Password args accept CharSequence as well as String

Install

Development

Usage

Basic

Strength Properties

Customize internal dictionaries and keyboards

Use resources on the classpath

Use resources get via HTTP

Use file resources other than classpath

Use all default resources

Select from and use default resources

Localize feedback messages

Localize each feedback

Localize each locale

Requires Java

Using this library

Bugs and Feedback

License

← Metadata

Owner

Metadata

zxcvbn4j zxcvbn4j copied to clipboard

Metadata

zxcvbn4j

Table Contents

Update

Special Features

Customize internal dictionaries and keyboards

Localize feedback messages

Support some languages by default

JIS keyboard layout

Password args accept CharSequence as well as String

Install

Development

Usage

Basic

Strength Properties

Customize internal dictionaries and keyboards

Use resources on the classpath

Use resources get via HTTP

Use file resources other than classpath

Use all default resources

Select from and use default resources

Localize feedback messages

Localize each feedback

Localize each locale

Requires Java

Using this library

Bugs and Feedback

License

← Metadata

Owner

Metadata

zxcvbn4j
zxcvbn4j copied to clipboard