crypt4j

A Java implementation of the crypt(3) function provided in the GNU C library (glibc). This implementation supports the MD5, SHA-256, and SHA-512 variants. Additionally, it supports legacy DES by way of the Commons Codec library.

Maven Artifacts

To use crypt4j in a Maven project, simply include the following dependency in your POM. Crypt4j is available via [Maven Central] (http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22org.soulwing%22).

<dependencies>
  ...
  <dependency>
    <groupId>org.soulwing</groupId>
    <artifactId>crypt4j</artifactId>
    <version>1.0.0</version>
  </dependency>
  <!-- optional: needed only if you require DES password encryption -->
  <dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
    <version>1.10</version>
  </dependency>
  ...  
</dependencies>

Usage

The Crypt.crypt static method provides the main entry point. The calling arguments are consistent with the crypt(3) function.

import org.soulwing.crypt4j.Crypt;

... {
  // SHA-512 
  String sha512 = Crypt.crypt("Hello world!".toCharArray(), "$6$saltstring");
  assert sha512.equals("$6$saltstring$svn8UoSVapNtMuq1ukKS4tPQd8iKwSMHWjl/O817G3uBnIFNjnQJuesI68u4OTLiBFdcbYEdFCoEOfaS35inz1");
  
  // SHA-256
  String sha256 = Crypt.crypt("Hello world!".toCharArray(), "$5$saltstring");
  assert sha256.equals("$5$saltstring$5B8vYYiY.CVt1RlTTf8KbXBH3hsxY/GNooZaBBGWEc5");
  
  // MD5
  String md5 = Crypt.crypt("Hello world!".toCharArray(), "$1$saltstring");
  assert md5.equals("$1$saltstri$YMyguxXMBpd2TEZ.vS/3q1");
  
  // DES
  // Requires Commons Codec
  // or a NoSuchAlgorithmException will be thrown
  String des = Crypt.crypt("Hello world!".toCharArray(), "saltstring");
  assert des.equals("saszt8mUri4AI");
}

For simple testing you can simply run it as a jar file, passing the password and salt string as quoted command line arguments.

The resulting encrypted password string will be written to standard output.

$ java -jar crypt4j.jar 'topsecret' '$6$tRiCkYsAlT'
$6$tRiCkYsAlT$NqxbcVeBHENLGNhXmZY5EB7RZFuLHuzei..4YthS9/SQmwa81pyZBocelML3OXWhSf4ihk9L4VB0dDIdQALtv0