HP 3600 v2 Series Security Configuration Manual page 285

Publickey authentication—The server authenticates the client by the digital signature. During
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publickey authentication, the client sends the server a publickey authentication request that contains
its username, public key, and publickey algorithm information. The server checks whether the public
key is valid. If the public key is invalid, the authentication fails. Otherwise, the server authenticates
the client by the digital signature. Finally, the server sends a message to the client to inform it of the
authentication result. The switch supports using the publickey algorithms RSA and DSA for digital
signature.
An SSH2.0 server might require the client to pass both password authentication and publickey
authentication or either of them. However, if the client is running SSH1, the client only needs to pass
either authentication, regardless of the requirement of the server.
The following gives the steps of the authentication stage:
The client sends the server an authentication request that includes the username, the authentication
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method, and the information related to the authentication method (for example, the password in
the case of password authentication).
The server authenticates the client. If the authentication fails, the server sends the client a message
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to inform the client of the failure and the methods available for re-authentication.
The client selects a method from the list to initiate another authentication.
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The preceding process repeats until the authentication succeeds or the number of failed
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authentication attempts exceeds the maximum of authentication attempts. In the latter case, the
server tears the session down.
NOTE:
Only clients running SSH2.0 or a later version support password re-authentication that is initiated by the
switch acting as the SSH server.
Session request
After passing authentication, the client sends a session request to the server, and the server listens to and
processes the request from the client. If the server successfully processes the request, the server sends an
SSH_SMSG_SUCCESS packet to the client and goes on to the interaction stage with the client. Otherwise,
the server sends an SSH_SMSG_FAILURE packet to the client to indicate that the processing has failed or
it cannot resolve the request.
Interaction
In this stage, the server and the client exchanges data as follows:
The client encrypts and sends the command to be executed to the server.
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The server decrypts and executes the command, and then encrypts and sends the result to the
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client.
The client decrypts and displays the result on the terminal.
3.
NOTE:
In the interaction stage, you can execute commands from the client by pasting the commands in text
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format (the text must be within 2000 bytes). The commands must be available in the same view.
Otherwise, the server might not be able to perform the commands correctly.
If the command text exceeds 2000 bytes, you can execute the commands by saving the text as a
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configuration file, uploading the configuration file to the server through Secure FTP (SFTP), and then
using the configuration file to restart the server.
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