72 iRMC S2/S3
Local user management for the iRMC S2/S3

4.3.3 SSHv2 public key authentication for iRMC S2/S3

users

In addition to authentication by means of a user name and password, the
iRMC S2/S3 also supports SSHv2-based public key authentication using pairs
of public and private keys for local users. To implement SSHv2 public key
authentication, the SSHv2 key of an iRMC S2/S3 user is uploaded to the
iRMC S2/S3 and the iRMC S2/S3 user uses their private key with the program
PuTTY or the OpenSSH client program ssh, for example.
The iRMC S2/S3 supports the following types of public keys:
SSH DSS (minimum requirement)
SSH RSA (recommended)
The public SSHv2 keys that you upload to the iRMC S2/S3 can be available
either in RFC4716 format or in OpenSSH format (see page 84).
Public key authentication
In outline, public key authentication of a user on the iRMC S2/S3 happens as
follows:
The user who wishes to log into the iRMC S2/S3 creates the key pair:
The private key is read-protected and remains on the user's computer.
The user (or administrator) uploads the public key to the iRMC S2/S3.
If the configuration allows this, the user can now log into the iRMC S2/S3
extremely securely and without the need to enter a password. The user is only
responsible for keeping their private key secret.
The following steps are necessary to set up private key authentication. They are
described in the subsequent sections:
1. Creating the public and private SSHv2 keys with the program PuTTYgen or
ssh-keygen and saving them in separate files (see page 73).
2. Loading the public SSHv2 key onto the iRMC S2/S3 from a file
(see page 77).
3. Configuring the program PuTTY or ssh for SSHv2 access to the iRMC S2/S3
(see page 79).