USER AUTHENTICATION

6.Challenge-Response Authentication – When an SSH client attempts to contact the switch, the SSH server uses the host key pair to negotiate a session key and encryption method. Only clients that have a private key corresponding to the public keys stored on the switch can access. The following exchanges take place during this process:

a.The client sends its public key to the switch.

b.The switch compares the client's public key to those stored in memory.

c.If a match is found, the switch uses the public key to encrypt a random sequence of bytes, and sends this string to the client.

d.The client uses its private key to decrypt the bytes, and sends the decrypted bytes back to the switch.

e.The switch compares the decrypted bytes to the original bytes it sent. If the two sets match, this means that the client's private key corresponds to an authorized public key, and the client is authenticated.

Notes: 1. To use SSH with only password authentication, the host public key must still be given to the client, either during initial connection or manually entered into the known host file. However, you do not need to configure the client’s keys.

2.The SSH server supports up to four client sessions. The maximum number of client sessions includes both current Telnet sessions and SSH sessions.

Generating the Host Key Pair

A host public/private key pair is used to provide secure communications between an SSH client and the switch. After generating this key pair, you must provide the host public key to SSH clients and import the client’s public key to the switch as described in the proceeding section (Command Usage).

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SMC Networks SMC8624/48T manual Generating the Host Key Pair