PHC Crypto - Argon2

According to Wikipedia:

Argon2 is a key derivation function that was selected as the winner of the Password Hashing Competition in July 2015. It was designed by Alex Biryukov, Daniel Dinu, and Dmitry Khovratovich from the University of Luxembourg. The reference implementation of Argon2 is released under a Creative Commons CC0 license (i.e. public domain) or the Apache License 2.0, and provides three related versions:

• Argon2d maximizes resistance to GPU cracking attacks. It accesses the memory array in a password dependent order, which reduces the possibility of time–memory trade-off (TMTO) attacks, but introduces possible side-channel attacks.
• Argon2i is optimized to resist side-channel attacks. It accesses the memory array in a password independent order.
• Argon2id is a hybrid version. It follows the Argon2i approach for the first half pass over memory and the Argon2d approach for subsequent passes. The Internet draft recommends using Argon2id except when there are reasons to prefer one of the other two modes.

All three modes allow specification by three parameters that control:

• execution time
• memory required
• degree of parallelism

Configuration options

Key	Type	Default	Notes
Time	int	32768	Number of iterations to perform
Memory	int	8	Amount of memory (in kilobytes) to use
Parallelism	int	4	Parallelism factor (threads to run in parallel).
Variant	Variant	argon2.ID	Argon2 variant to be used (argon2.ID or argon2.I)
KeyLen	int	64	How many bytes to generate as output.
SaltLen	int	16	Salt length in bytes

Usage with PHC Crypto

package main

import (
	"fmt"
	"github.com/aldy505/phc-crypto"
)

func main() {
	crypto, err := phccrypto.Use(phccrypto.Argon2, phccrypto.Config{
		Parallelism: 3,
	})
	if err != nil {
		fmt.Println(err)
	}

	hash, err := phccrypto.Hash("password")
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(hash) // $argon2id$v=19$m=65536,t=16,p=3$8400b4e5f01f30092b794de34c61a6fdfea6b6b446560fda08a876bd11e9c62e$3fd77927d189...

	verify, err := phccrypto.Verify(hash, "password")
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(verify) // true
}

Standalone usage

package main

import (
	"fmt"
	"github.com/aldy505/phc-crypto/argon2"
)

func main() {
	hash, err := argon2.Hash("password", argon2.Config{
		Parallelism: 3,
		Variant:     argon2.I,
	})
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(hash) // $argon2i$v=19$m=65536,t=16,p=3$8400b4e5f01f30092b794de34c61a6fdfea6b6b446560fda08a876bd11e9c62e$3fd77927d189...

	verify, err := argon2.Verify(hash, "password")
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(verify) // true
}