Ruby - HMAC-SHA256 example

gistfile1.rb

require 'openssl'
require 'Base64'

key = "secret-key"
data = "some data to be signed"
Base64.encode64(OpenSSL::HMAC.digest(OpenSSL::Digest::Digest.new('sha256'), key, data)).strip()

secure_hash = OpenSSL::HMAC.hexdigest('SHA256', <key>, <data>)

thx~

OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha256'), <app_secret>, <user_access_token>)

Worked perfectly for Facebook API, thank you @gr8bit