Users Guide

Using Public Key Authentication For SSH
iDRAC supports the Public Key Authentication (PKA) over SSH. This is a licensed feature. When the PKA over SSH is set up and
used correctly, you need not enter the user name or password while logging into iDRAC. This is useful for setting up automated
scripts that perform various functions. The uploaded keys must be in RFC 4716 or openssh format. Else, you must convert the
keys into that format.
In any scenario, a pair of private and public key must be generated on the management station. The public key is uploaded to
iDRAC local user and private key is used by the SSH client to establish the trust relationship between the management station
and iDRAC.
You can generate the public or private key pair using:
● PuTTY Key Generator application for clients running Windows
● ssh-keygen CLI for clients running Linux.
CAUTION: This privilege is normally reserved for users who are members of the Administrator user group on
iDRAC. However, users in the ‘Custom’ user group can be assigned this privilege. A user with this privilege can
modify any user’s configuration. This includes creation or deletion of any user, SSH Key management for users,
and so on. For these reasons, assign this privilege carefully.
CAUTION: The capability to upload, view, and/ or delete SSH keys is based on the ’Configure Users’ user
privilege. This privilege allows user(s) to configure another user's SSH key. You should grant this privilege
carefully.
Generating Public Keys for Windows
To use the PuTTY Key Generator application to create the basic key:
1. Start the application and select either SSH-2 RSA or SSH-2 DSA for the type of key to generate. (SSH-1 is not supported).
The supported key generation algorithms are RSA and DSA only.
2. Enter the number of bits for the key. For RSA, it is between 768 and 4096 bits and for DSA, it 1024 bits.
3. Click Generate and move the mouse in the window as directed.
The keys are generated.
4. You can modify the key comment field.
5. Enter a passphrase to secure the key.
6. Save the public and private key.
Generating Public Keys for Linux
To use the ssh-keygen application to create the basic key, open a terminal window and at the shell prompt, enter ssh-keygen
–t rsa –b 1024 –C testing
where:
● -t is either dsa or rsa.
● –b specifies the bit encryption size between 768 and 4096.
● –C allows modifying the public key comment and is optional.
NOTE: The options are case-sensitive.
Follow the instructions. After the command executes, upload the public file.
CAUTION:
Keys generated from the Linux management station using ssh-keygen are in non-4716 format.
Convert the keys into the 4716 format using ssh-keygen -e -f /root/.ssh/id_rsa.pub > std_rsa.pub.
Do not change the permissions of the key file. The conversion must be done using default permissions.
NOTE: iDRAC does not support ssh-agent forward of keys.
112 Setting Up iDRAC Communication