Digest authentication is a method of HTTP authentication that
improves upon Basic authentication by providing a way to
authenticate without having to transmit the password in clear
text across the network. This adapter allows authentication
against text files containing lines having the basic elements of
Digest authentication: - username, such as “joe.user“ - realm,
such as “Administrative Area“ - MD5 hash of the username, realm,
and password, separated by colons The above elements are
separated by colons, as in the following example (in which the
password is “somePassword”): The digest authentication adapter,
Zend\Authentication\Adapter\Digest, requires several input
parameters: - filename - Filename against which authentication
queries are performed - realm - Digest authentication realm -
username - Digest authentication user - password - Password for
the user of the realm These parameters must be set prior to
calling authenticate(). The digest authentication adapter
returns a Zend\Authentication\Result obj