6.7U2 finally introduced a REST API for managing certificates. After a few days of struggling to figure out the exact formats the APIs wanted everything in, I managed to create a set of Powershell cmdlets for managing vCenter certificates.
I've packaged as a module and published to github here:
GitHub - azirish1998/vCenterTls
Please see the README for instruction and usage info.
This is my first time using GitHub and making a module for public consumption. If there's anything I should do differently, kindly let me know.
I hope you find this useful!