Question

177

How to convert an array of bytes into string with Node.js?

rated 0 times [ 182] [ 5] / answers: 1 / hits: 42948 / 11 Years ago, fri, november 29, 2013, 12:00:00

I need a random sequence of bytes for making a password hash. In Ruby, this would look like:

 File.open(/dev/urandom).read(20).each_byte{|x| rand << sprintf(%02x,x)}

In Node.js, I can get a sequence of random bytes with:

 var randomSource = RandBytes.urandom.getInstance();

 var bytes = randomSource.getRandomBytesAsync(20);

But the problem is, how to convert these to a String?

Also, I need to have them wrapped in promisses. Would this work:

   get_rand()

   .then(function(bytes) {

     authToken = bytes;

   })

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

luna

Add To Favorites

Follow

Total Points: 698

Total Questions: 114

Total Answers: 93

Location: Israel

Member since Wed, Apr 14, 2021

3 Years ago

answered 11 Years ago yosefleod · Accepted Answer

randbytes works asynchronously. If you want to combine it with promises, you need to use a Promises-lib as well. I'm using when as an example:

var when          = require('when');

var RandBytes     = require('randbytes');

var randomSource  = RandBytes.urandom.getInstance();



function get_rand() {

  var dfd = when.defer();

  randomSource.getRandomBytes(20, function(bytes) {

    dfd.resolve( bytes.toString('hex') ); // convert to hex string

  });

  return dfd.promise;

}



// example call:

get_rand().then(function(bytes) {

  console.log('random byte string:', bytes);

});