vCenter ssh key based password less authentication configuration is not working and prompting for the password

Products

• VMware vCenter Server
• VMware vCenter Server 7.0
• VMware vCenter Server 8.0

Issue/Introduction

vCenter ssh key based password less authentication configuration is not working and promting for the password

Environment

VMware vCenter Server 7.x

VMware vCenter Server 8.x

Cause

If the vCenter appliance shell is configured as the default shell (/bin/appliancesh) for root, the key based authentication will still ask for the password.

ssh root@<vCenter_IP_Address> -v will show a successful authentication. However, it will still ask for the password

VMware vCenter Server 8.0.2.00400

Type: vCenter Server with an embedded Platform Services Controller

debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: publickey
debug1: Offering public key: C:\\Users\\Administrator/.ssh/id_rsa RSA SHA256:/<id>
debug1: Server accepts key: C:\\Users\\Administrator/.ssh/id_rsa RSA SHA256:/<id>
debug1: Authentication succeeded (publickey).
Authenticated to #.#.#.# ([#.#.#.# ]:22).
debug1: channel 0: new [client-session]
debug1: Requesting [email protected]
debug1: Entering interactive session.
debug1: pledge: network
debug1: ENABLE_VIRTUAL_TERMINAL_INPUT is supported. Reading the VTSequence from console
debug1: ENABLE_VIRTUAL_TERMINAL_PROCESSING is supported. Console supports the ansi parsing
debug1: client_input_global_request: rtype [email protected] want_reply 0
debug1: Remote: /root/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
debug1: Remote: /root/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
Last login: dd/mm/yy from #.#.#.#
Password:

Resolution

User need to change the default shell to /bin/bash by running the below command for the key based authentication to login without password.

chsh -s /bin/bash root

Additional Information

To enable password less authentication in the VCSA, the shell needs to be set to bash shell as the Appliance Shell is a controlled environment designed to execute only specific VCSA commands and utilities.