For most hobbyist or basic diagnostic needs, the PCAN-View free download is the appropriate and legal choice. Software: PEAK-System
If you need the software for professional or educational use, here are the legitimate paths: Trial Version:
A powerful, cross-platform open-source tool particularly popular in the automotive hacking and DIY community. Wireshark:
If you need CAN bus software without a license fee, PEAK-System provides these official tools for free: