HN上一个帖子列出了目前SSL的一些问题和安全隐患

SSL is a fine protocol, but it's been badly misconfigured on the Internet. Among other things:
* The overwhelming majority of SSL-speaking sites don't have valid certificates.
* An untenably large number of organizations have been allowed to act as CAs.
* Some of those CA's have in turn been allowed to set up sub-CA's.
* Several CA's use cryptographically weak keys
* Some CA's were spotted sharing keys
* CA's have signed certs for RFC1918 private IP space, sometimes more than once.
* CA's have signed certs for "localhost"
The bad news is that all these things are devastating to the global security of SSL/TLS. The good news is that fixing them doesn't involve a change to SSL/TLS, or even any of the software that implements it. The bad news is that's unlikely to happen in our lifetimes.

没想到CA的问题这么多。。。