Kickstart 3.2 is a paid, commercial firmware upgrade. The is to purchase from Hyperion Entertainment or via Amiga Forever. No free download is legitimate.
Do not risk your vintage system or your PC security with shady ROM sites. Support Amiga development so that OS 3.3 or 4.0 for classic hardware remains a possibility. amiga kickstart 3.2 download
Upgrading to Kickstart 3.2 (and the subsequent 3.2.3 update) unlocks over and hundreds of bug fixes: AmigaOS 3.2 for all Classic Amigas - Hyperion Entertainment Kickstart 3