Smartcard authentication in vCenter fails with error message during logon: "User name and password are required"

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• After enabling smartcard authentication in vCenter, logon with Smart card fails with error message  "User name and password are required"
• In your browser web console you can see the following error

websso.js:928

POST https://VCENTER_FQDN:3128/websso/SAML2/SSOCAC/vsphere.local?SAMLRequest=z....................net::ERR_TIMED_OUT

Cause

This is due to TCP port 3128 or the associated plugin n the browser being blocked in the environment through GPO, firewall or another security mechanism. 

Resolution

Allow TCP 3128 and the websso.js plugin to be permitted to the workstation and browser logging into vCenter via smartcard.

This is per VMware Ports and Protocols for Smart Card Mutual Authentication.