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> Of 16 M IPs listening on 443, 10.8 M started SSL handshake; of those, 4.3 M used CA-signed cert chains (slide 14). Thus, the majority of servers use "invalid"
by rlpb 16y ago
> Of 16 M IPs listening on 443, 10.8 M started SSL handshake; of those, 4.3
M used CA-signed cert chains (slide 14). Thus, the majority of servers use
"invalid"/invalid/self-signed certs.
How many of these IPs listening on 443 are public web servers? I know of a lot of things that listen for SSL on 443 that aren't HTTP as 443 can get through firewalls easily. For all we know, there already exists an out-of-band process to validate those self-signed certs.
For example, I am one of these cases. I listen for SSL on port 443 using a self-signed cert, but all clients have that CA (and only that CA) pre-loaded.
- rlpb 16y agoIn addition, it occurs to me that I've observed many sites that aren't security critical but seem to be running on a self-signed cert. For example, many mailing list archives seem to operate both on HTTP and HTTPS with a self-signed cert. As they are only hosting public data and clearly are happy to provide it without SSL as well, there is no security failure here.
- klync 16y agoI think you would still have to count that as a security failure. For one, you don't know why there is ssl and non-ssl - there could be content that's available over ssl and/or via login which you don't see using the "public" http url schema. The server could be set up to make this transparent to you, making it appear that ssl is superfluous. Second, even if that's the case, a broken SSL implementation is still a broken SSL implementation, even if it's protecting content that doesn't seem to need protecting.
- rlpb 16y ago> ...a broken SSL implementation is still a broken SSL implementation, even if it's protecting content that doesn't seem to need protecting. That depends on what is required of the SSL implementation. A self-signed cert which the client cannot verify still provides some protection. It is MITM-able, but casual snooping is prevented. If this is the specification, then this implementation is not broken. Put it this way. Forget the specifics of SSL for a moment. If unencrypted data is acceptable, then in what way is having the option of weak-but-slightly-better encryption suddenly "broken"? This analysis is flawed because it assumes that strong security was required by all who use SSL at all. Many installations use a self-signed SSL cert by default. These default configurations often remain when security is not required and therefore not configured further. I suspect that this skews the figures far enough to make this sort of analysis meaningless.
- klync 16y agoHey rlpb, Sorry, I tried to reply to your post about 4 times yesterday, and it never went through for some reason. I agree with what you're saying about self-signed certs being not necessarily broken. Maybe I mis-read your original message, but what I was objecting to was the idea that a site that apparently has the same content available over http and [broken] https is not a problem; I'm saying that broken is broken regardless of the content it's protecting. As to what constitutes "broken" ... I think we agree - that would be SSL. :P
- bensummers 16y agoAccess to our non-public systems is (partially) controlled through SSL server and client certificates, both of which use a CA we control. This is probably a good practise for systems you are keen on defending, because the public CA system is so broken.