AZURE SAS URL Generator

url.rb

require 'time'
require 'openssl'
require "base64"
require 'uri'
require 'addressable/uri'

def create_signature(path = '/', resource = 'b', permissions = 'r', start = '', expiry = '', identifier = '')
  # If resource is a container, remove the last part (which is the filename)
  path = path.split('/').reverse.drop(1).reverse.join('/') if resource == 'c'
  canonicalizedResource = "/mediasvc78m7lfh2gnn2x/#{path}"

  stringToSign  = []
  stringToSign << permissions
  stringToSign << start
  stringToSign << expiry
  stringToSign << canonicalizedResource
  stringToSign << identifier

  stringToSign = stringToSign.join("\n")
  signature    = OpenSSL::HMAC.digest('sha256', wms_api_key, stringToSign.encode(Encoding::UTF_8))
  signature    = Base64.encode64(signature)

  return signature
end

def createSignedQueryString(path = '/', query_string = '', resource = 'b', permissions = 'r', start = '', expiry = '', identifier = '')
  base = 'https://mediasvc78m7lfh2gnn2x.blob.core.windows.net'
  uri  = Addressable::URI.new

  # Parts
  parts       = {}
  parts[:st]  = URI.unescape(start) unless start == ''
  parts[:se]  = URI.unescape(expiry)
  parts[:sr]  = URI.unescape(resource)
  parts[:sp]  = URI.unescape(permissions)
  parts[:si]  = URI.unescape(identifier) unless identifier == ''
  parts[:sig] = URI.unescape( create_signature(path, 'b', 'r', start, expiry) )

  uri.query_values = parts
  return "#{base}/#{path}?#{uri.query}"
end