Mechanisms of authentication of the client

Mainly two methods of authentication exist in order to control the access to a serveur ssh:

username/password

The customer supplies a name customer and a password, that they come validated from the serveur. This exchange happens to the inside of a number channel, for which it is not to interception risk.

Procedure:

1. To ==> B: SSH_MSG_USERAUTH_REQUEST, pappy, ssh-userauth, keyboard-interactive

2. B ==> To: SSH_MSG_USERAUTH_INFO_REQUEST, pappy, password-authentication, 1, "Enter Password"

3. To ==> B: SSH_MSG_USERAUTH_INFO_RESPONSE, 1, "love"

4. B ==> To: SSH_MSG_USERAUTH_SUCCESS.

public key

This method of authentication is based on the asymmetric cryptography. In order to use it the customer brace of keys generates one. The public key is copied on the serveur, typically in appropriate rows in the home directory of the customer; the private key must be conserved from the customer, and is well that word is protect with one key (passphrase).

In the phase of access, client ssh the test to the serveur of being in possession of the private key, and in succeeding case of comes concurred the access. In this way, to the customer it is not demanded to supply the own one password to every logon.