Creating a hash in Ruby with a random salt using /dev/random

hash.rb

require 'base64'
require 'digest/sha2'

def create(text)
  salt_bytes = random_salt
  salted_hash_bytes = Digest::SHA256.digest(salt_bytes+text)
  Base64::encode64(salt_bytes+salted_hash_bytes)
end

def verify(hash, text)
  salted_hash_bytes = Base64::decode64(hash)
  salt_bytes = salted_hash_bytes[0..7]
  hash_bytes = salted_hash_bytes[8..39]
  hash_bytes == Digest::SHA256.digest(salt_bytes+text)
end

def random_salt
  random = File.new('/dev/random', 'r')
  random.read(16) #discrard first 16 bytes
  salt = random.read(8)
  random.close
  salt
end