4 ms·

Now you don't want to hand over this private key to Cloudflare if you don't need to, because then they can read all traffic. Generally the key you would give t

by personZ 12y ago

Now you don't want to hand over this private key to Cloudflare if you don't need to, because then they can read all traffic. Generally the key you would give them is for, and limited to, the resources that they cache/reverse proxy, so the same "read all traffic" concern exists. What Cloudflare did is essentially, as others have mentioned, PKCS11 over the internet. PKCS11 is an existing, very well proven technique of sequestering the key in a hardware device, that hardware device doing what Cloudflare is moving to the client location here. It's neat enough, but they seem to kind of exaggerating the innovation a bit.

willvarfar 12y ago
It is very obvious... In hindsight?
- powertower 12y ago
  Not sure why all the negative reactions here... Was anyone else doing or providing this type of "Keyless SSL" setup? You'd think if this was a known technique, the mentioned banks would already have been asking for it, implementing it, or doing it. Personally, I think CloudFlare is one of the few companies on here doing innovating stuff, and solving real issues. And if not - if they've pulled the wool over my eyes - then at least I can respect their marketing.
  - personZ 12y ago
    You'd think if this was a known technique Isolating the key for security/control purposes is a well known technique. It's what ssh-agent/putty paegent does, where you can even forward key usage over the network to different machines. It's what PKCS11 does to SSL/TLS, where generally the key is a hardware security module (CAs and banks don't have keys sitting on their public facing machines, but instead generally have dedicated hardware for it -- they are generally doing, at a different scale, what is described), though there have been various implementations and proposals over the years to do it over the network (e.g. https://svn.opendnssec.org/docs/p11proxy.png https://svn.opendnssec.org/docs/p11proxy.png and pkcs11-proxy). Why isn't it commonly done as Rackspace proposes? Well it's kind of an odd need for limited gain, but is effectively PKCS11 used in a different context. If they are solving a specific need for some of their clients then fantastic, but it's the narrative of the innovation that makes it a bit weird, and yielded a lot of the purportedly negative commentary.
  - mentat 12y ago
    PKCS11 and Hardware Security Modules (HSM) have been around for a long time. There's in wide use in companies like NetFlix and Square including "over the network". This is not new.
- buro9 12y ago
  Sometimes the innovation is merely being able to rephrase the apparently impossible question into the one that has an obvious answer. It's worth remembering, no-one else was offering this or doing this... no-one else had phrased the problem such that the answer (even though it was known) became apparent.
ChuckMcM 12y ago
I think the exaggeration is because its a sales pitch, but it illustrates an important concept -- doing something "known" but in a generic way can be more valuable than having a proprietary solution. Of course someone could come up and offer a 'Cloudflare' box that just does key sequestration and sell that. And while I think banks and others will find this useful, its even more useful if I can do it from a far away place. When you create an SSL connection in Europe to a west coast server there are a number of round trips. If those can be avoided you can cut the latency of the transaction. That is a good thing too.
- Perseids 12y ago
  > When you create an SSL connection in Europe to a west coast server there are a number of round trips. If those can be avoided you can cut the latency of the transaction. That is a good thing too. Note that this will at most cut the connection setup time by half, as your premaster secret (RSA) or handshake data (ephemeral DH) still has to cross the Atlantic and get back to you (and the TLS handshake has 2 roundtrips). Furthermore, because of > Generally the key you would give them is for, and limited to, the resources that they cache/reverse proxy, all dynamic data still is supposed to come from your server. So the browser will have to wait for that, while everything from the European mirror is cached anyway.
Perseids 12y ago
> Generally the key you would give them is for, and limited to, the resources that they cache/reverse proxy That got me wondering: Why don't attackers then only DOS the dynamic pages? Those that can't be migrated easily, like the login?
- rdl 12y ago
  The dynamic pages still go through CloudFlare; there's a Web Application Firewall which can block abuse directed at a specific URL, pattern, etc. The cache is only one part of the DDoS mitigation. (We've been working on a lot of great updates to the WAF for just this kind of thing) Generally with CloudFlare people put as much of their site behind the CloudFlare proxy as possible, for origin-hiding and other reasons, even if we can't cache it (yet).

by personZ 12y ago

willvarfar 12y ago

It is very obvious... In hindsight?

powertower 12y ago
Not sure why all the negative reactions here... Was anyone else doing or providing this type of "Keyless SSL" setup? You'd think if this was a known technique, the mentioned banks would already have been asking for it, implementing it, or doing it. Personally, I think CloudFlare is one of the few companies on here doing innovating stuff, and solving real issues. And if not - if they've pulled the wool over my eyes - then at least I can respect their marketing.
- personZ 12y ago
  You'd think if this was a known technique Isolating the key for security/control purposes is a well known technique. It's what ssh-agent/putty paegent does, where you can even forward key usage over the network to different machines. It's what PKCS11 does to SSL/TLS, where generally the key is a hardware security module (CAs and banks don't have keys sitting on their public facing machines, but instead generally have dedicated hardware for it -- they are generally doing, at a different scale, what is described), though there have been various implementations and proposals over the years to do it over the network (e.g. https://svn.opendnssec.org/docs/p11proxy.png https://svn.opendnssec.org/docs/p11proxy.png and pkcs11-proxy). Why isn't it commonly done as Rackspace proposes? Well it's kind of an odd need for limited gain, but is effectively PKCS11 used in a different context. If they are solving a specific need for some of their clients then fantastic, but it's the narrative of the innovation that makes it a bit weird, and yielded a lot of the purportedly negative commentary.
- mentat 12y ago
  PKCS11 and Hardware Security Modules (HSM) have been around for a long time. There's in wide use in companies like NetFlix and Square including "over the network". This is not new.
buro9 12y ago
Sometimes the innovation is merely being able to rephrase the apparently impossible question into the one that has an obvious answer. It's worth remembering, no-one else was offering this or doing this... no-one else had phrased the problem such that the answer (even though it was known) became apparent.

ChuckMcM 12y ago

I think the exaggeration is because its a sales pitch, but it illustrates an important concept -- doing something "known" but in a generic way can be more valuable than having a proprietary solution. Of course someone could come up and offer a 'Cloudflare' box that just does key sequestration and sell that. And while I think banks and others will find this useful, its even more useful if I can do it from a far away place. When you create an SSL connection in Europe to a west coast server there are a number of round trips. If those can be avoided you can cut the latency of the transaction. That is a good thing too.

Perseids 12y ago
> When you create an SSL connection in Europe to a west coast server there are a number of round trips. If those can be avoided you can cut the latency of the transaction. That is a good thing too. Note that this will at most cut the connection setup time by half, as your premaster secret (RSA) or handshake data (ephemeral DH) still has to cross the Atlantic and get back to you (and the TLS handshake has 2 roundtrips). Furthermore, because of > Generally the key you would give them is for, and limited to, the resources that they cache/reverse proxy, all dynamic data still is supposed to come from your server. So the browser will have to wait for that, while everything from the European mirror is cached anyway.

Perseids 12y ago

> Generally the key you would give them is for, and limited to, the resources that they cache/reverse proxy That got me wondering: Why don't attackers then only DOS the dynamic pages? Those that can't be migrated easily, like the login?

rdl 12y ago
The dynamic pages still go through CloudFlare; there's a Web Application Firewall which can block abuse directed at a specific URL, pattern, etc. The cache is only one part of the DDoS mitigation. (We've been working on a lot of great updates to the WAF for just this kind of thing) Generally with CloudFlare people put as much of their site behind the CloudFlare proxy as possible, for origin-hiding and other reasons, even if we can't cache it (yet).