Edge-Core ES4524M-PoE, Management Manual, Page: 107 / 560

User Authentication
3-63
Authenticating SSH v2 Clients
a. The client first queries the switch to determine if DSA public key
authentication using a preferred algorithm is acceptable.
b. If the specified algorithm is supported by the switch, it notifies the client to
proceed with the authentication process. Otherwise, it rejects the request.
c. The client sends a signature generated using the private key to the switch.
d. When the server receives this message, it checks whether the supplied key
is acceptable for authentication, and if so, it then checks whether the
signature is correct. If both checks succeed, the client is authenticated.
Note:
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).
Field Attributes
• Public-Key of Host-Key – The public key for the host.
• RSA: The first field indicates the size of the host key (e.g., 1024), the second
field is the encoded public exponent (e.g., 65537), and the last string is the
encoded modulus.
• DSA: The first field indicates that the encryption method used by SSH is based
on the Digital Signature Standard (DSS). The last string is the encoded modulus.
• Host-Key Type – The key type used to generate the host key pair (i.e., public and
private keys). (Range: RSA, DSA, Both: Default: RSA)
The SSH server uses RSA or DSA for key exchange when the client first
establishes a connection with the switch, and then negotiates with the client to
select either DES (56-bit) or 3DES (168-bit) for data encryption.
Note: The switch uses only RSA Version 1 for SSHv1.5 clients and DSA Version 2 for
SSHv2 clients.
• Save Host-Key from Memory to Flash – Saves the host key from RAM (i.e.,
volatile memory to flash memory. Otherwise, the host key pair is stored to RAM by
default. Note that you must select this item prior to generating the host-key pair.
• Generate – This button is used to generate the host key pair. Note that you must
first generate the host key pair before you can enable the SSH server on the SSH
Server Settings page.
• Clear – This button clears the host key from both volatile memory (RAM) and
non-volatile memory (Flash).