Purpose: Verify any authorization information. Only basic authorization is currently defined in the HTTP/1.0 specification.
Check for Authorization header in rq->headers that contains the authorization type and uu-encoded user and password information. If header was not sent, return REQ_NOACTION.
If header exists, check authenticity of user and password.
If authentic, create auth-type, plus auth-user and/or auth-group parameter in rq->vars to be used later by PathCheck SAFs.
Return REQ_PROCEED if the user was successfully authenticated, REQ_NOACTION otherwise.