at.favre.lib.crypto.bkdf

Interface PasswordHasher

All Known Implementing Classes:

PasswordHasher.Default

public interface PasswordHasher

Implementation for the BKDF Password Hash protocol used for key stretching of weak user passwords and hash storage.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	PasswordHasher.Default Default implementation
static class	PasswordHasher.HashData + Model containing all the parts required for the "BKDF Password Hash Message Format"

Method Summary

Modifier and Type	Method and Description
String	hash(char[] password, int costFactor) For given password and cost-factor create password hash.
PasswordHasher.HashData	hashRaw(char[] password, int costFactor) For given password and cost-factor create password hash.

Method Detail

hash

String hash(char[] password,
            int costFactor)

For given password and cost-factor create password hash.

The internal salt will be created automatically with a secure CPRNG. Usually implementations support passing your own implementation of a CPRNG (i.e. SecureRandom).

Parameters:

password - from user

costFactor - exponential cost (log2 factor) between 4 and 31 e.g. 12 --> 2^12 = 4,096 iterations (higher == slower == more secure)

Returns:

"BKDF Password Hash Message Format 2" ie. Base64 encoded password hash for storage

hashRaw

PasswordHasher.HashData hashRaw(char[] password,
                                int costFactor)

For given password and cost-factor create password hash. This method will return a more flexible model to be used to either access all the parts of the format or create different message formats from it.

Parameters:

password - from user

costFactor - exponential cost (log2 factor) between 4 and 31 e.g. 12 --> 2^12 = 4,096 iterations (higher == slower == more secure)

Returns:

password hash in flexible PasswordHasher.HashData model