How to generate hash value using MD5/SHA-256 algorithm for request and response files?

Magento 1.9 – How to find hash key value for onepage checkout page

Checkout URL: www.abc.com/checkout/onepage/

Magento checkout page code : (app/design/frontend/default/theme/template/checkout/onepage/review/item.phtml)

I need request & response hash key value of onepage checkout page.