How to generate/try random keys for 3des?

Hi, I just want to know how to generate random hex keys to bruteforce 3des.
What is the best way to go about this?
Do I use the stats-processor to generate the random key candidates, and then feed them into hashcat as an input?
Or do I have to patch the 3des kernel or the sources, to allow the rand() function to be used?

Thanks.