Do you know any portable software which is able to calculate Whirlpool hash of a file?
I know HashTab, but this app requires OS installation, not portable.
Assuming that you are looking for a truly portable solution, i.e. will run on any machine regardless of OS, I would suggest getting a USB key and installing portable python and adding the pure python implementation of Whirlpool.
Note that the original code needed to be extended to allow use from the command line to hash files - I have uploaded the modified file to github.
The portable python will let you run the python Whirlpool on any windows machine with an accessible USB port and the pure python should work on any machine that has Python 2 installed, (i.e. Some windows machines, (just about) all OS-X, most Linux installations, many mainframes/servers, clusters, etc., even RaspberryPi).