Validate Github Webhook Signature

validate_webhook.rb

require "openssl"
module ValidateWebhook
  def validate(payload, shared_secret, signature)
    # in case "sha1=" is not stripped off the beginning of signature before calling 
    signature = signature.sub("sha1=", "")
    signature == OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new("sha1"), shared_secret, payload)
  end
end