I hope that every vSphere administrator or operator by now is familiar with the extremely powerful vSphere Guest Operations API functionality (details here and here), which can easily be consumed using PowerCLI's Invoke-VMScript cmdlet. If not, highly recommend you check out the links referenced. I know the GuestOps API is certainly my top favorite with sending VM keystrokes capability a very close second!
Not only does the GuestOps API unlock functionality that simply may not be possible (e.g. there's no API or automation interface) but it also enables automation within a VM without requiring any type of remote management services enabled (e.g. SSH or WinRM) or even networking to the VM for that matter!
The reason I am bringing all this up is that although there is not an API for managing and retrieving vCenter Single Sign-On (SSO) configurations which includes password policies, there is a way in which customers can still automate and retrieve this and other information by leveraging the GuestOps API. In fact, back in 2015 I demonstrated on how you can retrieve VCSA SSO password policy and configurations and we can simply apply the GuestOps API to help us automate this task. In addition, most customers do not enable SSH by default and we can still apply the GuestOps API technique and perform automation tasks to VSCSA without requiring SSH as described in this blog post back in 2016.
With this context and putting this all together, I have created a simple PowerCLI module VCSAPasswordPolicy.psm1 which includes a function called Get-VCSAPasswordPolicy which will retrieve BOTH the local OS (root) and SSO password policy configuration given a VCSA VM and its respective credentials.
Step 1 - Import the PowerCLI module
Step 2 - Run the Get-VCSAPasswordPolicy providing the name of the VCSA VM, the root password (needed to authenticate into the VM via GuestOps API) and then SSO Domain and password to perform the actual query of the SSO configurations
Get-VCSAPasswordPolicy -VCSAName "MGMT-VCSA-01" -VCSARootPassword "VMware1!" -SSODomain "vsphere.local" -SSOPassword "VMware1!"