I'd like to know is it possible to have a web proxy that can block specific https websites ? We have a national web proxy that blocks Http websites for porn ,..etc but we have a problem of intercepting https websites , how can we solve it ?
There are two basic options for this. The first is to block websites by IP address. This has the obvious issue that it's going to require resolving all of the names on your blacklist, which may change over time, and that it will block innocent sites which happen to share an IP addr. with porn sites (although, if you're only blocking the IPs for https, the second issue should be reasonably minor - most sites use one IP per SSL site, to prevent cert errors).
The other way is to get a proxy that can do SSL MitM. Obviously, this will either present your users with certificate errors on accessing any https website, or require the installation of your CA on every computer using the proxy. It will also leave you with important privacy issues.