dchest / Scrypt

!!! NOTE !!!

Official go.crypto repository now includes scrypt implementation. (http://code.google.com/p/go/source/detail?r=ad8a96e038bb&repo=crypto) Please use it instead of this one, as it will be supported there.

Link: http://code.google.com/p/go/source/browse?repo=crypto

It is compatible with this implementation, so to switch to it, just change the import path to "code.google.com/p/go.crypto/scrypt".

!!!

Go implementation of scrypt key derivation function. (http://www.tarsnap.com/scrypt.html)

INSTALLATION

$ go get github.com/dchest/scrypt

PACKAGE import "github.com/dchest/scrypt"

Package scrypt implements the scrypt key derivation function as defined
in Colin Percival's paper "Stronger Key Derivation via Sequential
Memory-Hard Functions".

FUNCTIONS

func Key(password, salt []byte, N, r, p, keyLen int) ([]byte, error)

Key derives a key from the password, salt and cost parameters, returning
a byte slice of length keyLen that can be used as cryptographic key.

N is a CPU/memory cost parameter, must be a power of two greater than 1.
r and p must satisfy r * p < 2³⁰. If the parameters do not satisfy the
limits, the function returns a nil byte slice and an error.

For example, you can get a derived key for e.g. AES-256 (which needs a
32-byte key) by doing:

    dk := scrypt.Key([]byte("some password"), salt, 16384, 8, 1, 32)

The recommended parameters for interactive logins as of 2009 are N=16384,
r=8, p=1. They should be increased as memory latency and CPU parallelism
increases. Remember to get a good random salt.

KEYWORDS

go, golang, scrypt, kdf