Go scrypt Hash Code Example (Online Runner)

Go scrypt examples with parameters, salt encoding, and derived key length matching the scrypt tool.

Online calculator: use the site scrypt text tool.

Note: This snippet requires locally installed dependencies and will not run in the online runner. Run it locally with: go mod init scrypt-demo && go get golang.org/x/crypto/scrypt && go run scrypt_basic.go

Calculation method

Use golang.org/x/crypto/scrypt to derive a key with configurable N, r, p, salt, and output length.

Implementation notes

Package: golang.org/x/crypto/scrypt.
Implementation: the helper decodes salt (hex/base64/text) and returns hex output.
Notes: N must be a power of two; use parameters appropriate for your environment.

Text hashing example

package main

import (
	"encoding/hex"
	"fmt"

	"golang.org/x/crypto/scrypt"
)

func main() {
	salt, _ := hex.DecodeString("73616c74")
	key, err := scrypt.Key([]byte("password"), salt, 1<<15, 8, 1, 32)
	if err != nil {
		panic(err)
	}
	fmt.Println(hex.EncodeToString(key))
}

Complete script (implementation + tests)

package main

import (
	"encoding/base64"
	"encoding/hex"
	"errors"
	"fmt"

	"golang.org/x/crypto/scrypt"
)

type SaltEncoding string

const (
	SaltHex    SaltEncoding = "hex"
	SaltBase64 SaltEncoding = "base64"
	SaltText   SaltEncoding = "text"
)

func decodeSalt(value string, encoding SaltEncoding) ([]byte, error) {
	if value == "" {
		return nil, errors.New("salt is required")
	}
	switch encoding {
	case SaltHex:
		return hex.DecodeString(value)
	case SaltBase64:
		return base64.StdEncoding.DecodeString(value)
	case SaltText:
		fallthrough
	default:
		return []byte(value), nil
	}
}

func scryptKey(password string, salt string, saltEnc SaltEncoding, N, r, p, keyLen int) (string, error) {
	saltBytes, err := decodeSalt(salt, saltEnc)
	if err != nil {
		return "", err
	}
	key, err := scrypt.Key([]byte(password), saltBytes, N, r, p, keyLen)
	if err != nil {
		return "", err
	}
	return hex.EncodeToString(key), nil
}

func main() {
	dk, err := scryptKey("password", "73616c74", SaltHex, 1<<15, 8, 1, 32)
	if err != nil {
		panic(err)
	}
	fmt.Println("scrypt=", dk)
}