One More Thing: Keyless SSL and CloudFlare's Growing Network

https://blog.cloudflare.com/one-more-thing-keyless-ssl-and-cloudflares-growing-network/

by jgrahamc • 12 years ago

60 20 12 years ago

blog.cloudflare.com

RexRollman• 12 years ago

Personally, I find CloudFlare to be annoying as a TOR user. They keep bothering me with a Captcha to solve.

mikeyur• 12 years ago

My guess: exit nodes are responsible for a number of attacks against CloudFlare-protected sites so it makes sense to question each visit from those IPs.

richbradshaw• 12 years ago

The data comes from project honeypot - the IP you are using has been flagged for abuse in the past.

s3nnyy• 12 years ago

They are trying to solve this by treating Tor exit nodes / shared IPs differently: https://news.ycombinator.com/item?id=8297192

xxdesmus• 12 years ago

The security check captchas are in no way Tor-specific.

The shared Tor IP happens to have a threat score based on past traffic we've seen from that IP. This would be the same for any shared IP though -- like a VPN service IP address.

As other folks have mentioned, we're working on better handling for shared IPs in general, but to make this clear: this in no way has anything to do specifically with Tor users.

JohnTHaller• 12 years ago

Most TOR IPs are flagged as abusive because of... abuse. SO, you wind up with extra CAPTCHAs to solve or outright blocking from being able to post content.

buro93• 12 years ago

I sympathise.

I run a lot of forums and we use Stop Forum Spam to block spammers from posting comment spam. They are identified and reported according to three things: 1) Email address, 2) Username and 3) IP address.

The IP address is the most effective way to stop comment spam, and I only block people based on "Has spam been received from this IP according to StopForumSpam.com within the last few days?".

Understand that the vast majority of spam comes from several countries, and Tor.

I'm massively in favour of using Tor and having it as a privacy/anonymity tool. But... Tor is also heavily favoured by spammers and whilst the Tor exits are not explicitly blocked in the system I use, the mere fact that spammers use Tor heavily means that the IP addresses for Tor exit nodes are constantly being refreshed on StopForumSpam.com .

Anyone running any kind of IP reputation is going to have the same problem, and CloudFlare do run their own IP reputation.

It's nothing against Tor, but if an individual mixes their traffic in with a stream of spam, trolls, script kiddies, etc... and the behaviour of those users affects the reputation of the IP, then the innocent Tor users who merely want privacy/anonymity are going to be affected.

It's a difficult balance to strike, but any IP reputation system is going to score Tor badly given that it is used for so much abuse and bad stuff.

rdl5• 12 years ago

I'm curious if people would use exit nodes which specifically blocked comment submission on sites. I use Tor frequently, but never for posting comments.

t0mas88• 12 years ago

Not true at all: "With most of CloudFlare's rival services, even those that have a seemingly larger network footprint, the minute you ask them to enable SSL the size of the network shrinks to something that resembles our network today. That's because they too don't feel comfortable storing customers' private keys in many of their edge nodes. And that's why most legacy CDN providers charge such such an enormous premium the minute you ask them to support SSL."

They are perfectly capable of running SSL on the Edge. The reason for the increased price is that you will get a dedicated IP which in most cases means not only 1 IP but 1 IP per region in which the CDN is active. And IPs are becoming a scarce resource. You can also see this expressed in the fact that if you accept a shared IP and SNI certificate (so not EV) you'll get lower prices of most of the major CDNs.

lclarkmichalek• 12 years ago

[We have been] hiring cryptographers out of Apple

Is that really something to boast about? I never think of Apple as a hotbed for cryptographic genius

rdl5• 12 years ago

On the platform security side, Apple is about 5y ahead of the rest of the industry. Look at iOS specifically, and the secure element/trusted boot/etc. process.

(This isn't a general iOS vs. Android argument; I prefer Android in a lot of ways, just not for security.)

The problem with Apple is they do everything, and with very small teams, and end up with elements of widely varying quality. Their online-services security, to date, has been subpar. They aren't terribly fast with patches for known vulnerabilities. They are exceptionally good at platform security architecture.

(We've also got a really smart security guy from a satellite tv company...the satellite tv crypto/hw security world was >10y ahead of everyone else for a long time.)

xorcist2• 12 years ago

Has there been a release of iOS yet for which there hasn't been a root exploit released?

Honest question, just based on the prevalence of "rooting" your device and running non-blessed software.

bjornsing• 12 years ago

I'm surprised this Keyless SSL thing hasn't taken more flack here on HN...

To me it seems the only advantage is in the time dimension: Keyless SSL allows for quicker/easier revocation than plain SSL. But to say that Keyless SSL allows SSL termination in insecure locations, that's clearly controversial. An attacker can still access plain text in these insecure locations of course, but also (in my mind more importantly): persistent access to the "Keyless SSL Key Server" gives an attacker the same benefits as access to SSL private key, e.g. the ability to MITM SSL communication anywhere else on the Internet.

It can of course be argued that it's more difficult inject malicious requests to the key server than it is to steal a private key, but it's in the domain of "security by obscurity". At least that's how I classify it.

praseodym• 12 years ago

It has:

- https://news.ycombinator.com/item?id=8339705 top comment

- https://news.ycombinator.com/item?id=8334933 further down

rdl5• 12 years ago

Converting the SSL key from a file to a separate oracle is exactly how HSMs work, and they were existing best practice in securing keys. Keyless works the same way, just remotely, and using commodity stuff (although the local key at the user's site can live in an EKCM system, in an HSM, or otherwise be protected.)

As you say, it's a big deal for revocation. It's ALSO a big deal for auditing -- you know every time a session was initially negotiated, vs. if you give someone else the key -- you have no idea how many sessions were set up. It's also just a policy/compliance thing -- not needing to go through the process to be approved to store keys from organizations makes our sales process a lot faster.

There are some fairly obvious extensions to the security model which are in the works as well.

The reason why I think it's obvious there are security advantages to keyless is that we're using it internally. For us, consolidating our keys in a smaller number of secure locations is totally worth it.

xorcist2• 12 years ago

Keyless works the same way, just remotely,

Again, you can attach to a remote HSM. It's called a network attached HSM. They're not even uncommon.

A smart card is an HSM. An HSM is not necessarily a smart card.

One More Thing: Keyless SSL and CloudFlare's Growing Network

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