Can I test authorize.net module for oscommerce without purchased SSL certificate

If I set test mode in Authorize.net account on their website, everything is OK. But if I set live mode, I get:

There has been an error开发者_Go百科 processing your credit card Please try again and if problems persist, please try another payment method.

I suspected SSL certificate, shall I have purchased SSL certificate, or I can set self-issued on PROD server?

I suspect a self-signed cert would work for Authorize.net's purposes, but the browser will probably throw a flag since.

Seeing as this is an old post, I'm wondering if you ever tested it to find out definitively...