SMC Networks 8648T - annexe 1, Руководство по управлению

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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).