Generating A Dsa Or Rsa Key Pair; Enabling The Ssh Server Function; Configuring The User Interfaces For Ssh Clients - HP A5830 Series Configuration Manual

Generating a DSA or RSA key pair

In the key and algorithm negotiation stage, the DSA or RSA key pair is required to generate the session
key and session ID and for the client to authenticate the server.
To generate a DSA or RSA key pair on the SSH server:
To do...
1. Enter system view.
2. Generate a DSA or RSA key
pair.
For more information about the public-key local create command, see Security Command Reference.
To support SSH clients that use different types of key pairs, generate both DSA and RSA key pairs on the
SSH server.
The public-key local create rsa command generates a server RSA key pair and a host RSA key pair.
Each of the key pairs consists of a public key and a private key. The public key in the server key pair of
the SSH server is used in SSH1 to encrypt the session key for secure transmission of the key. Because
SSH2.0 uses the DH algorithm to generate the session key on the SSH server and client, respectively, no
session key transmission is required in SSH2.0, and the server key pair is not used.
The length of the modulus of RSA server keys and host keys must be in the range of 512 to 2048 bits.
Some SSH2.0 clients require that the length of the key modulus be at least 768 bits on the SSH server
side.
The public-key local create dsa command generates only the host key pair. SSH1 does not support the
DSA algorithm.
The length of the modulus of DSA host keys must be in the range of 512 to 2048 bits. Some SSH2.0
clients require that the length of the key modulus be at least 768 bits on the SSH server side.

Enabling the SSH server function

To do...
1. Enter system view.
2. Enable the SSH server
function.

Configuring the user interfaces for SSH clients

An SSH client accesses the switch through a VTY user interface. You must configure the user interfaces
for SSH clients to allow SSH login. The configuration takes effect only for clients that log in after the
configuration.
To configure the protocols for a user interface to support:
To do...
1. Enter system view.
Use the command...
system-view
public-key local create { dsa | rsa
}
Use the command...
system-view
ssh server enable
Use the command...
system-view
171
Remarks
—
Required.
By default, neither DSA key pair
nor RSA key pair exists.
Remarks
—
Required
Disabled by default
Remarks
—