How to verify the SHA256 checksum of a downloaded file
When performing firmware upgrades, it is important to verify the SHA256 checksum of the file to ensure its integrity. A corrupted file render a device inoperable in most cases. The process differs among common operating systems, however the result is the same. The output from the command in the terminal will be a string of characters.
Follow the steps below to verify that the SHA256 checksum of the downloaded file matches that of the SHA256 checksum listed at the Hak5 official download site – downloads.hak5.org. If the strings do not match, discard the file and attempt the download again.

SHA256 shown in Download Portal
LINUX
sha256sum /path/to/file
MAC
shasum -a 256 /path/to/file
WINDOWS
CMD
CertUtil -hashfile C:\path\to\file SHA256
Powershell
Get-FileHash C:\path\to\file -Algorithm SHA256
OPEN SOURCE GRAPHICAL USER INTERFACE (GUI)
QuickHash GUI is an open-source data hashing tool for Linux, Windows, and Apple Mac OSX with graphical user interface (GUI). Originally designed for Linux, but is also available for Windows and Apple Mac OSX. MD5, SHA1, SHA256, SHA512, xxHash, SHA-3 (256 bit) and Blake2B (256 bit) hash algorithms are available.