How to verify SHA (or MD5) hash of files on Mac OS and Windows 7 and up using the built-in command line tools provided with the OS. You would use this to verify a downloaded file wasn't modified from the original, for example, the Linux Mint ISO file hack of February 21, 2016.
To verify MD5 in Windows append MD5 to the end of the command:
c:\Users\Admin\certutil -hashfile file1.txt MD5
*On a Mac/Linux system use the command: md5 file1.txt