HP 6120XG HP ProCurve Series 6120 Blade Switches Access Security Guide - Page 245

Configuring Secure Shell (SSH) Further Information on SSH Client Public-Key Authentication 1. The client sends its public key to the switch with a request for authentication. 2. The switch compares the client's public key to those stored in the switch's client-public-key file. (As a prerequisite, you must use the switch's copy tftp command to download this file to flash.) 3. If there is not a match, and you have not configured the switch to accept a login password as a secondary authentication method, the switch denies SSH access to the client. 4. If there is a match, the switch: a. Generates a random sequence of bytes. b. Uses the client's public key to encrypt this sequence. c. Send these encrypted bytes to the client. 5. The client uses its private key to decrypt the byte sequence. 6. The client then: a. Combines the decrypted byte sequence with specific session data. b. Uses a secure hash algorithm to create a hash version of this informa- tion. c. Returns the hash version to the switch. 7. The switch computes its own hash version of the data from step 6 and compares it to the client's hash version. If they match, then the client is authenticated. Otherwise, the client is denied access. Using client public-key authentication requires these steps: 1. Generate a public/private key pair for each client you want to have SSH access to the switch. This can be a separate key for each client or the same key copied to several clients. 2. Copy the public key for each client into a client-public-key text file. 3. Use copy tftp to copy the client-public-key file into the switch. Note that the switch can hold 10 keys. The new key is appended to the client publickey file 4. Use the aaa authentication ssh command to enable client public-key authentication. 6-25