Package org.springframework.security.crypto.scrypt

Class SCryptPasswordEncoder

  • All Implemented Interfaces:
    PasswordEncoder
    public class SCryptPasswordEncoder
extends java.lang.Object
implements PasswordEncoder

    Implementation of PasswordEncoder that uses the SCrypt hashing function. Clients can optionally supply a cpu cost parameter, a memory cost parameter and a parallelization parameter.

    A few warnings:

    • The currently implementation uses Bouncy castle which does not exploit parallelism/optimizations that password crackers will, so there is an unnecessary asymmetry between attacker and defender.
    • Scrypt is based on Salsa20 which performs poorly in Java (on par with AES) but performs awesome (~4-5x faster) on SIMD capable platforms
    • While there are some that would disagree, consider reading - Why I Don't Recommend Scrypt (for password storage)

    • Constructor Summary

      Constructors 
      Constructor Description
      SCryptPasswordEncoder()  
      SCryptPasswordEncoder​(int cpuCost, int memoryCost, int parallelization, int keyLength, int saltLength)
      Creates a new instance

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String encode​(java.lang.CharSequence rawPassword)
      Encode the raw password.
      boolean matches​(java.lang.CharSequence rawPassword, java.lang.String encodedPassword)
      Verify the encoded password obtained from storage matches the submitted raw password after it too is encoded.
      boolean upgradeEncoding​(java.lang.String encodedPassword)
      Returns true if the encoded password should be encoded again for better security, else false.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • SCryptPasswordEncoder

        public SCryptPasswordEncoder()

      • SCryptPasswordEncoder

        public SCryptPasswordEncoder​(int cpuCost,
                             int memoryCost,
                             int parallelization,
                             int keyLength,
                             int saltLength)
        Creates a new instance
        Parameters:
        cpuCost - cpu cost of the algorithm (as defined in scrypt this is N). must be power of 2 greater than 1. Default is currently 16,384 or 2^14)
        memoryCost - memory cost of the algorithm (as defined in scrypt this is r) Default is currently 8.
        parallelization - the parallelization of the algorithm (as defined in scrypt this is p) Default is currently 1. Note that the implementation does not currently take advantage of parallelization.
        keyLength - key length for the algorithm (as defined in scrypt this is dkLen). The default is currently 32.
        saltLength - salt length (as defined in scrypt this is the length of S). The default is currently 64.

    • Method Detail

      • encode

        public java.lang.String encode​(java.lang.CharSequence rawPassword)
        Description copied from interface: PasswordEncoder
        Encode the raw password. Generally, a good encoding algorithm applies a SHA-1 or greater hash combined with an 8-byte or greater randomly generated salt.
        Specified by:
        encode in interface PasswordEncoder

      • matches

        public boolean matches​(java.lang.CharSequence rawPassword,
                       java.lang.String encodedPassword)
        Description copied from interface: PasswordEncoder
        Verify the encoded password obtained from storage matches the submitted raw password after it too is encoded. Returns true if the passwords match, false if they do not. The stored password itself is never decoded.
        Specified by:
        matches in interface PasswordEncoder
        Parameters:
        rawPassword - the raw password to encode and match
        encodedPassword - the encoded password from storage to compare with
        Returns:
        true if the raw password, after encoding, matches the encoded password from storage

      • upgradeEncoding

        public boolean upgradeEncoding​(java.lang.String encodedPassword)
        Description copied from interface: PasswordEncoder
        Returns true if the encoded password should be encoded again for better security, else false. The default implementation always returns false.
        Specified by:
        upgradeEncoding in interface PasswordEncoder
        Parameters:
        encodedPassword - the encoded password to check
        Returns:
        true if the encoded password should be encoded again for better security, else false.