polar ssl for robotic


Dec 10, 2010 19:52
Jean-Marc

Hi I am looking around on the polarssl website. It does not seem to have much documentation so I guess I will be doing some source diving.

I have a robot running on a arm processor and it need to fetch data from a website threw ssl. I have looked at the examples and they use fucntions like ssl_write. To my understanding ssl_write will encrypt your buffer then send it out the socket (like winsock ect).

the think is that I am communicating with my network module on my arm so its not really on an os.

is there a way that I can pull the data my self from the socket and encrypt the data but it in a buffer then send that buffer any functions I should look at?

I guess for now I will look into the polarssl/net and maybe write my own ssl_write

any thoughts?
 
Dec 12, 2010 14:42
Paul Bakker

Hi jmlb,

Just wait a little while for the documentation.. It's all getting there soon.

In the mean time I think you will indeed need to do some own glue logic. The main question is if you really need SSL. If the website does real SSL, then I would advise you to indeed adapt the current layer..

But don't do it in ssl_write()!

The SSL layer uses two function pointers (f_send() and f_recv() ) to communicate with the network layer! Those functions you should adapt to use your network module.

Good luck.

If you need any more help, please ask again!

Best regards,
Paul
 
Dec 13, 2010 14:52
Jean-Marc

I need to connect to a web site that supports only https. This data would then go to my robot.
 
Feb 22, 2011 14:58
Jean-Marc

quick question. I don't know much about how ssl works but what is the used of ssl->session->start. If I set it to null will there be a big impact?

I searched quickly in the source and it seems like it only does a time out?

thanks
JM
 
Feb 22, 2011 15:09
Paul Bakker

Hi JM,

You should initialize the ssl_session structure to all zeroes.. ssl->session->start is a value internally used to check if a session can be resumed..

Paul
 
Feb 22, 2011 15:18
Jean-Marc

What circumstances would a session need to be resumed? what is the impact of sessions never resuming and all ways timing out?

I am trying to remove calls to time()
 
Feb 22, 2011 15:23
Paul Bakker

The impact would be key re-negotiation. Thus performance impact..

Every time your session times out you need to set up a full session. With resuming, you can re-use past session keys.

Paul