6.0.3

Table Of Contents
Enabling SSH and adding SSH keys to the host has inherent risks and is not recommended in a hardened
environment. See “Disable Authorized (SSH) Keys,” on page 159.
N For ESXi 5.0 and earlier, a user with an SSH key can access the host even when the host is in
lockdown mode. This is xed in ESXi 5.1.
SSH Security
You can use SSH to remotely log in to the ESXi Shell and perform troubleshooting tasks for the host.
SSH conguration in ESXi is enhanced to provide a high security level.
Version 1 SSH protocol
disabled
VMware does not support Version 1 SSH protocol and uses Version 2
protocol exclusively. Version 2 eliminates certain security problems present
in Version 1 and provides you with a safe way to communicate with the
management interface.
Improved cipher
strength
SSH supports only 256-bit and 128-bit AES ciphers for your connections.
These seings are designed to provide solid protection for the data you transmit to the management
interface through SSH. You cannot change these seings.
Upload an SSH Key Using a vifs Command
If you decide you want to use authorized keys to log in to a host with SSH, you can upload authorized keys
with a vifs command.
N Because authorized keys allow SSH access without requiring user authentication, consider carefully
whether you want to use SSH keys in your environment.
Authorized keys allow you to authenticate remote access to a host. When users or scripts try to access a host
with SSH, the key provides authentication without a password. With authorized keys you can automate
authentication, which is useful when you write scripts to perform routine tasks.
You can upload the following types of SSH keys to a host:
n
Authorized keys le for root user
n
RSA key
n
RSA public key
Starting with the vSphere 6.0 Update 2 release, DSS/DSA keys are no longer supported.
I Do not modify the /etc/ssh/sshd_config le.
Procedure
u
At the command line or an administration server, use the vifs command to upload the SSH key to
appropriate location on the ESXi host.
vifs --server hostname --username username --put filename /host/ssh_host_dsa_key_pub
Type of key Location
Authorized key files for the root
user
/host/ssh_root_authorized keys
You must have full administrator privileges to upload this le.
RSA keys
/host/ssh_host_rsa_key
RSA public keys
/host/ssh_host_rsa_key_pub
vSphere Security
200 VMware, Inc.