This is a Java version of zxcvbn, a password strength estimator originally written in JavaScript and inspired by password cracking tools. It uses pattern matching and conservative estimation to assess the strength of passwords. It can identify and evaluate the strength of over 30,000 common passwords, as well as common names and surnames based on US census data. It also recognizes popular English words from Wikipedia, US television shows, and movies. Additionally, it can detect other common password patterns such as dates, repeated characters (aaa), sequences (abcd), keyboard patterns (qwertyuiop), and l33t speak.
Related articles:
- Mapping Original to Ported Versions
- Special Features
- Install
- Development
- Usage
- Requires Java
- Using this library
- Bugs and Feedback
- License
| Ported Version | Original zxcvbn Version |
|---|---|
| 1.2.3 - latest | 4.4.2 |
| 1.2.1 - 1.2.2 | 4.4.1 |
| 1.1.0 - 1.2.0 | 4.4.0 |
| 1.0.0 - 1.0.2 | 4.2.0 |
- You can customize the dictionary and keyboard layout used by the measurement algorithm to better suit your specific needs.
- zxcvbn4j allows you to localize the default English feedback messages into other languages.
- English (default)
- Japanese (ja)
- Dutch (nl)
- German (de)
- French (fr)
- Italian (it)
- Spanish (es)
- Portuguese (pt)
- zxcvbn4j includes support for the JIS keyboard layout in spatial matching.
- This feature provides greater flexibility in the format of the password input.
- It also aims to avoid using Strings for any sensitive intermediate objects, enhancing security.
https://central.sonatype.com/artifact/com.nulab-inc/zxcvbn/1.9.0
Gradle:
compile 'com.nulab-inc:zxcvbn:1.9.0'
Maven:
<dependency>
<groupId>com.nulab-inc</groupId>
<artifactId>zxcvbn</artifactId>
<version>1.9.0</version>
</dependency>
$ git clone https://github.com/nulab/zxcvbn4j.git
$ cd ./zxcvbn4j
$ ./gradlew build # build
$ ./gradlew test # test
$ ./gradlew jmh # benchmarkThis 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 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);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
Zxcvbn can build with ZxcvbnBuilder.
ZxcvbnBuilder can customize dictionaries and keyboards used in measurements.
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();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();
}
}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);
}
}StandardDictionaries.loadAllDictionaries() loads all default dictionary files.
StandardDictionaries.loadAllKeyboards() loads all default keyboard files.
Zxcvbn zxcvbn = new Zxcvbn();or
Zxcvbn zxcvbn = new ZxcvbnBuilder()
.dictionaries(StandardDictionaries.loadAllDictionaries())
.keyboards(StandardKeyboards.loadAllKeyboards())
.build();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();The zxcvbn4j can be localized the english feedback message to other languages.
// 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.
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);- Java 1.7+
- Backlog
- Cacoo
- Typetalk
- JetBrains Hub
- Cryptomator
- And many Open Source Software
For bugs, questions and discussions please use the GitHub Issues.
MIT License
