How to Hash and Validate Password in GoLang?

Hash Password

HashPassword hashes a password using the bcrypt algorithm. It takes a password as a string and returns the hashed password as a string. It also returns an error if the hashing process fails.

import "golang.org/x/crypto/bcrypt"

func HashPassword(password string) (res string, err error) {
	// Convert the password to a byte array.
	arrByte := []byte(password)

	// Hash the password using bcrypt algorithm.
	// The second argument is the cost parameter, which determines the
	// computational effort required to generate the hash. The higher the cost,
	// the more secure the hash. Here, we set it to 10.
	hash, err := bcrypt.GenerateFromPassword(arrByte, 10)
	if err != nil {
		return "", err
	}

	// Convert the hashed password to a string and return it.
	return string(hash), nil
}

Validate Password

PasswordValid checks if the provided password matches the hashed password. It takes the hashed password and the password as string arguments. It returns a boolean indicating whether the passwords match.

import "golang.org/x/crypto/bcrypt"

func PasswordValid(hashPassword, password string) bool {
	// Convert the hashed password and the password to byte arrays.
	hash, pass := []byte(hashPassword), []byte(password)

	// Compare the hashed password with the provided password using bcrypt algorithm.
	// It returns an error if the comparison fails.
	err := bcrypt.CompareHashAndPassword(hash, pass)

	// If the error is nil, it means the passwords match.
	// Return true indicating a match.
	return err == nil
}

Experience the magic of coding unfold as you execute this code!

package main

import (
	"fmt"

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

func HashPassword(password string) (res string, err error) {
	hash, err := bcrypt.GenerateFromPassword([]byte(password), 10)
	if err != nil {
		return "", err
	}

	return string(hash), nil
}

func PasswordValid(hashPassword, password string) bool {
	hash, pass := []byte(hashPassword), []byte(password)
	err := bcrypt.CompareHashAndPassword(hash, pass)
	return err == nil
}

func main() {
	passwordA := "secret123"
	hashPasswordA, err := HashPassword(passwordA)
	if err != nil {
		fmt.Println("Failed HashPassword: ", err)
		return
	}

	inputPass := "invalid"
	if PasswordValid(hashPasswordA, inputPass) { // invalid password
		fmt.Println("success password valid")
	} else {
		fmt.Println("invalid password")
	}

	inputPass = passwordA
	if PasswordValid(hashPasswordA, inputPass) { // success password valid
		fmt.Println("success password valid")
	} else {
		fmt.Println("invalid password")
	}

	fmt.Println("Build with love by Adam Nasrudin")
}

enjoy your code!