why does my ssl work only for domain.co.il and not for www.domain.co.il is it like i read, that we need to order the SSL twice?
and what can be done about it, if this is the truth? how can it be redirected?
You either need two SSL certs one for www.domain.co.il and one for domain.co.il or you need one cert which has both names. We use certs from GoDaddy which when purchasing domain.co.il also includes www.domain.co.il automatically.
A wildcard certificate should work with any subdomain but do you really need both? Just tell your users http://domain.com and get the http to redirect to https://domain.com. Then setup http://www.domain.com to also redirect to https://domain.com If your users try http://www.domain.com it will still work and they probably wont do https://www.domain.com
You need to buy a wild card SSL in order to do that!
You need one of two things.
1) A wildcard certificate for your domain.co.il domain.
2) A certificate that uses the 'subjectAltName' extension, and list all the alternate host names that your server uses (like www.domain.co.il and domain.co.il).
The one place I know sells certificates with the 'subjectAltName' extension is Verisign. There might be others.