Class DigestMD5ClientAuthenticator

ClientAuthenticator --+
                      |
                     DigestMD5ClientAuthenticator

Provides PLAIN SASL authentication for a client.

:Ivariables:
    - `password`: current authentication password
    - `pformat`: current authentication password format
    - `realm`: current authentication realm

Initialize a `DigestMD5ClientAuthenticator` object.

:Parameters:
    - `password_manager`: name of the password manager object providing
      authentication credentials.
:Types:
    - `password_manager`: `PasswordManager`

Process a challenge and return the response.

:Parameters:
    - `challenge`: the challenge from server.
:Types:
    - `challenge`: `str`

:return: the response or a failure indicator.
:returntype: `sasl.Response` or `sasl.Failure`

Process success indicator from the server.

Process any addicional data passed with the success.
Fail if the server was not authenticated.

:Parameters:
    - `data`: an optional additional data with success.
:Types:
    - `data`: `str`

:return: success or failure indicator.
:returntype: `sasl.Success` or `sasl.Failure`

Start the authentication process initializing client state.

:Parameters:
    - `username`: username (authentication id).
    - `authzid`: authorization id.
:Types:
    - `username`: `unicode`
    - `authzid`: `unicode`

:return: the (empty) initial response
:returntype: `sasl.Response` or `sasl.Failure`