Is there a place that could give me a free certificate to use it for tests of your code?

There are various tools available to generate certificates. Makecert.exe, that ships with the .NET SDK if I'm not mistaken, does this. OpenSSL can also generate test certificates. If you own a copy of Windows 2000 Server or Windows Server 2003, these versions of Windows contain a program called "Certificate Services" that can also generate test certificates.