Secure User Authentication and file transfer thru' a web i/f

I would like to use a web interface (front end) to log in to my target which is running on QNX 6.3 platform. I am using slinger web server for this purpose. I am also running a cgi script in the backend which authenticates the user by checking the user information (username and password collected from the web interface) in /etc/passwd and etc/shadow files. After successful authentication i would like the user to be logged in to the target (QNX 6.3) and use the access privileges he is entitled to (while creating his account on the target). The user should ideally be accessing the target the way he would have, had he used login utility on the command line.

Following successful login, the user should also be able to upload/download files to/from the target in a secure way.

Can any body help me in this? Are there libraries in QNX which lets user login and transfer files in a secure way?

Awaiting reply.

Thanking you,

I recall to have seen a SSH-Shell via CGI in webmin, you can get the source for webmin and lookup there.
Alternative you could try programm your own interface, which allows you to send files and execute commands via HTTPS-Upload and CGI
I´ve not seen a ready-to-use app for QNX+slinger like this.

There are some HowTos for backend programming, including cron-job activity for executing root-permission-required-processes