Thank you for the last answer.

The last question.
How do I pass a csrf_token(post)..?

So I've tried, but failed :

config.doksoft_uploader_url = 'http://domain.com/blog/upload_image/?csrf_token=<?php echo $this->security->get_csrf_hash(); ?>';

in codeigniter

CSRF protection is a feature of popular frameworks and to pass it you need to go by one of these ways:
1) Disable CSRF, maybe only for uploader script.
2) To pass it using POST variable. Unfortunately URL you try to set will be used as GET parameters by many frameworks (I guess by Codeigniter too). So currently you are to use way #1.