Bcrypt password hashing in Golang (compatible with Node.js)?

Cid Huang picture Cid Huang · Apr 24, 2014 · Viewed 36.4k times · Source

I set up a site with Node.js+passport for user authentication.

Now I need to migrate to Golang, and need to do authentication with the user passwords saved in db.

The Node.js encryption code is:

    var bcrypt = require('bcrypt');

    bcrypt.genSalt(10, function(err, salt) {
        if(err) return next(err);

        bcrypt.hash(user.password, salt, function(err, hash) {
            if(err) return next(err);
            user.password = hash;
            next();
        });
    });

How to make the same hashed string as Node.js bcrypt with Golang?

Answer

ANisus picture ANisus · Apr 24, 2014

Using the golang.org/x/crypto/bcrypt package, I believe the equivalent would be:

hashedPassword, err := bcrypt.GenerateFromPassword(password, bcrypt.DefaultCost)

Working example:

package main

import (
    "golang.org/x/crypto/bcrypt"
    "fmt"
)

func main() {
    password := []byte("MyDarkSecret")

    // Hashing the password with the default cost of 10
    hashedPassword, err := bcrypt.GenerateFromPassword(password, bcrypt.DefaultCost)
    if err != nil {
        panic(err)
    }
    fmt.Println(string(hashedPassword))

    // Comparing the password with the hash
    err = bcrypt.CompareHashAndPassword(hashedPassword, password)
    fmt.Println(err) // nil means it is a match
}