'Returns the H(A2) string. See :rfc:`2617` section 3.2.2.3.'

def HA2(self, entity_body=''):

    if ((self.qop is None) or (self.qop == 'auth')):
        a2 = ('%s:%s' % (self.http_method, self.uri))
    elif (self.qop == 'auth-int'):
        a2 = ('%s:%s:%s' % (self.http_method, self.uri, H(entity_body)))
    else:
        raise ValueError(self.errmsg('Unrecognized    value    for    qop!'))
    return H(a2)
