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Encryption Networking Hardware IT

Build an Open Source SSL Accelerator 136

Posted by timothy
from the macguyver-it-up dept.
Amin Zelfani writes "SSL accelerators like Big-IP 6900 from F5 Networks typically carry a $50k or more price tag. An article over at o3magazine.com shows you how to build an SSL accelerator that's on par with the commercial solutions, using Open Source projects. SSL Accelerators offload the encryption / decryption process from web servers, reducing load and reducing the number of certificates needed."
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Build an Open Source SSL Accelerator

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  • Huh? (Score:2, Interesting)

    by TheRaven64 (641858)
    A miniPCI card with an OpenSSL-supported crypto engine that can handle saturate the bus costs around $50. What do you get by spending three orders of magnitude more? Something that can handle multiple, 10GigE connections?
    • Re: (Score:2, Funny)

      by jd (1658)

      You forgot to mention the fancy box with the plush anti-static bag for the card. What, did you think you were just giving the companies those $5,000? It costs a lot to make something that's both plush AND anti-static, you know!

    • Re:Huh? (Score:5, Informative)

      by Trepidity (597) <delirium-slashdo ... org minus author> on Wednesday April 15, 2009 @04:38PM (#27590613)

      Partly the article is quoting prices on a whole box, not just the SSL acceleration. The Big-IP 6900 mentioned in the summary, for example, is a dual-core rackmount server with 10GigE, and hardware SSL and compression. Presumably much of that money you're paying is going for the actual server, not just the SSL-accelerating coprocessor. Of course, you're probably also paying a markup for buying a specialty server of that sort, rather than slapping an SSL accelerator in a server from a commodity vendor.

      • Re: (Score:2, Interesting)

        by Anonymous Coward
        you combine nginx, haproxy, varnish-cache and you've got 80% of what Big-IP does!
        • by Otterley (29945)

          The other 20%, and your time, is what makes it worth $25k.

        • Discloser: I work for F5... You're discounting the real time OS which provides all the integrated SSL offload, compression, caching, etc inline... TMOS. Even a comment on our own Dev Central was asking where they could download our proxy source, just because we use CentOS as a bootstrap and platform for our control plane (GUI). It would be a major technology misunderstanding to believe that we process our real time integrated proxy code in standard SMP interrupt driven I/O ways on the hardware. We don't.
      • by Cylix (55374)

        Still wrong...

        It's support... plain and simple...

        It is rather simple to get an over night RMA if a unit behaves strangely or begins to fail sporadically. At the same time, there is a support channel available to assist with configuration or other types of soft issues.

        I'm not arguing for or against this type of solution, but rather pointing out why it is so high.

        There are multiple components to consider when determining what type of purchase to make.

    • Re: (Score:2, Informative)

      by Anonymous Coward

      Actually you forgot to mention that most licensing systems require multiple licenses per 'machine'. One of the advantages of using one of these SSL accelerators, besides offloading the work, is being able to consolidate certs onto one machine for many front-edge machines.

    • A miniPCI card with an OpenSSL-supported crypto engine that can handle saturate the bus costs around $50.

      You would pay $50.. for a ssl crypto PCI card, and you're implying that 'other' people are being suckered?

      BBH

      • I've not bought one, but I know a couple of people who use them in little embedded firewall boxes. These typically have something like a 266MHz Geode CPU which can't handle SSL or IPSEC at line speed without the accelerator, but can with the (mini)PCI card installed.
        • by Bert64 (520050)

          Dont the geode processors have some sort of AES capability built in? At least the 500mhz Geode-LX does, i have one and it has a kernel driver for the loop-aes device...
          Is there any way to have OpenSSL use this hardware on linux? One of the soekris net5501 boxes would make a good little vpn box if i could do that.

          • Re: (Score:3, Insightful)

            by TheRaven64 (641858)
            I think the newer Geodes do, but the older ones have been around for a long while and are still cheap. No idea about Linux - I've no idea why you'd run anything other than OpenBSD on a machine like that.
    • Re:Huh? (Score:5, Informative)

      by upside (574799) on Wednesday April 15, 2009 @04:49PM (#27590789) Journal

      The BIGIP does load balancing, active-active clustering, routing, packet manipulation using scripts etc. It's extortionately priced but is very powerful and very user friendly.

    • Mini-PCI card? How about doing it on the GPU [manavski.com] instead?

  • by geekoid (135745)

    particle accelerator I can build? cool..oh wait. damn.

    • Re: (Score:2, Funny)

      by jd (1658)

      We did the particle accelerator some time back. Do a search for "scotch tape" and "x-rays".

  • At the moment I have two OpenBSD servers acting as a single firewall infront of two IIS6 Windows 2003 R2 servers - the OpenBSD servers are acting as an Apache2 reverse proxy for IIS. Only one of the IIS6 servers is 'live' at any one time, the second is the spare.

    Currently, the setup has an automatic failover for the OpenBSD servers via CARP, which works great. However, the IIS servers are currently limited to manual failover, they cant use MS Network Load Balancing because I need session based balancin
    • by jd (1658)

      One thing to consider is whether you need session-based fail-over. If you're going to only treat one as live at a time, then send the spare computer the same packets you are sending the live computer, but drop the responses. If the live computer stops responding, allow the responses from the spare to go through.

      The problem will be getting the machines back in sync once the first machine is rebooted. If you assume that the time between the two machines failing is going to be great enough, forward new connect

      • Well, that is one option, but ideally because the IIS servers will be running .Net apps, it would be nice to actually load balance them, so they would both be 'live' in that situation. At the moment, I have to physically repoint the Apache2 proxy at the other server to fail over (or change IP addresses on the IIS box).
    • by awpoopy (1054584)
      What I think you're looking for is "carp" and all flavors of bsd do it. You may want to check out pfsense: http://www.pfsense.org/ [pfsense.org]. I've used it for years. Depending on requirements, just throw the appropriate amount of hardware together. You can fail-over ipsec tunnels with it. Suitable for all enterprise uses.
      • What I think you're looking for is "carp" and all flavors of bsd do it.

        Here is the third sentence of the post you replied to:

        "Currently, the setup has an automatic failover for the OpenBSD servers via CARP, which works great."

        Given that, he's most likely talking about .NET Session state.

        • by awpoopy (1054584)
          Oops. Carp does session failover - at least ipsec tunnel sessions.
          If it's .nut - well I'll pass that over to the nuts that use it.
    • by mat (25086)
      Just use mod_proxy_balancer (included in Apache) either to load-balance sessions between the two servers using session tracking, or to to use a server as a backup with the parameter "status=+H" (only available for the latests Apache versions).
      http://httpd.apache.org/docs/2.3/mod/mod_proxy_balancer.html [apache.org]
  • uh (Score:4, Informative)

    by anthonyclark (17109) on Wednesday April 15, 2009 @04:39PM (#27590621)

    you *do* know that an F5 Big-IP is more than an SSL accelerator? Like, a load balancer with lots of cool features.

    I guess you could duplicate the features of an f5 with nginx and more, but I guess it'd take a developer more than 50k worth of time to do it.

    • Re: (Score:2, Interesting)

      by Puzzleer (309198)

      50k? Are you insane? I worked at a company that built similar products, and we had six developers working on it for five years.

      Don't trivialize how hard it can be do build a piece of high performance equipment (especially where you are doing crypto in hardware).

      • Re:uh (Score:4, Informative)

        by deraj123 (1225722) on Wednesday April 15, 2009 @06:25PM (#27592001)

        but I guess it'd take a developer more than 50k worth of time to do it.

        He wasn't trivializing. He was, in a somewhat roundabout way, saying that 50k is a lot cheaper than what it would cost to implement the same solution yourself. The summary (don't know about the article, didn't read it) was trivializing the difficulty, the GP was refuting the summary.

    • by hackstraw (262471)

      you *do* know that an F5 Big-IP is more than an SSL accelerator? Like, a load balancer with lots of cool features.

      Yes, that is true. What this also means is that after spending the big bucks for the front end like this, you will save money in the long run because you now have the ability to throw as many boxes behind the SSL switch/load balancer box up until all of its links are used. You don't have to buy new certificates or wildcard certificates for any of the backend devices and/or worry about name mismatches, or any of the common issues with SSL certs.

      I didn't see it on their website, and couldn't really read the

    • Sure, But what if you don't need all the cool features ?
      And what if you want several of them (multiple locations, redundancy etc) ? High-end boxes hunt in packs.
      The $50k a pop adds up quickly and I quite like the idea of factoring out each feature into a separate cheap box.
      The argument is also cited that building something in house means that there is only one person who understands it. That may be true, but I've seen bought-in systems deployed where no-one in house understands fully what it does or
  • Ideally... (Score:5, Interesting)

    by jd (1658) <imipak&yahoo,com> on Wednesday April 15, 2009 @04:40PM (#27590647) Homepage Journal

    ...you'd offload the entire TCP/IP stack (Linux' networking isn't the fastest) as well as the SSL. Preferably get the IPSEC in there as well. It shouldn't be too hard to build a card that does the lot. You could then use VCHAN or some other kernel bypass method to forward the data as though Linux had just processed the packets within its own networking stack. The software doesn't need to know where the operation is taking place, so long as the API is the same.

    However, just getting the SSL onto a card is a definite advantage, as SSL is a heavy processor consumer and is used frequently-enough that it's a drag on systems.

    There are many encryption chips out there (Freescale's S1, for example) and there are projects on OpenCores that you can download right into a low-cost FPGA, so you can get pretty much whatever speed you want at whatever budget you're prepared to set aside.

    • Why have an addin card? The acceleration hardware isn't all that complicated. Hell, VIA put it into their proccessors- look at the huge [mini-itx.com] difference it makes. Even if the graph is best-case scenario, that x86 compatable processor is dynamite with encryption.
      • Re:Why a card? (Score:4, Insightful)

        by raddan (519638) on Wednesday April 15, 2009 @09:42PM (#27593445)
        The problem with wiring the accelerator into the CPU is that, although the CPU can perform the calculation faster, it does not actually free the CPU from having to do the packet processing. In addition to CPU time spent, you also need to consider interrupt overhead, which for high-speed networks (like 10GbE) is pretty significant. A separate TCP offload engine, with hardware encryption support, and access to memory via DMA, can significantly reduce the amount of time a CPU spends processing packets. It just interrupts the CPU when a decrypted TCP payload is ready and waiting in memory. And since your add-in card doesn't need a large instruction set, you can make it very, very fast.
      • by jd (1658)

        In order to maintain parallelism, you could put the acceleration hardware on the ethernet card. If it's in the CPU, unless it's a parallel core (in the same way that the IBM Cell operates), you don't gain any offload advantage.

  • by Anonymous Coward on Wednesday April 15, 2009 @04:46PM (#27590733)

    If their solution was really worthwhile, wouldn't the link to the article have been https:/// instead of just http:// ?

  • It'd be nice to see SSL used on all web sites. Apache can now handle SSL virtual hosts so that obstacle is gone.

    • Re: (Score:3, Interesting)

      Y'know who else thinks that it would be nice to see SSL used on all web sites?

      Verisign.
      • by Darby (84953)

        Y'know who else thinks that it would be nice to see SSL used on all web sites?

        Verisign.

        You know who is missing (part of) the point of an SSL accelerator? You are!

        One wildcard cert + one pair of SSL accelerating Load Balancers = All of your sites can now be SSL.

    • Re: (Score:3, Interesting)

      by jd (1658)

      Better yet, it'd be nice to see SSL used on all pages on all web sites. One of the first rules of security is that context can tell you a lot about what is being encrypted and can potentially weaken that encryption. It also allows attackers to distinguish packets of interest from context.

      Using SSL for only critical stuff is like using encryption for only shell passwords. It's better than nothing, but exposes far far too much.

      (One might argue that there's so much valuable data placed on computers in corporat

    • Re: (Score:2, Informative)

      by Goyuix (698012)

      Apache is only half the problem at best, the real issue is the lack of compliant clients at a significant level. Server Name Identifcation (the extension to allow for virtual hosts behind SSL/TLS connections) has been supported in Firefox since v2 I believe, and Internet Explorer 7 - though I think that is only on Vista for some reason. I have no idea what Safari, Opera and other browsers and platforms might support.

      • Apache is only half the problem at best, the real issue is the lack of compliant clients at a significant level.

        What do you mean by significant? All of the major browsers currently support SNI [wikipedia.org].

        • by DavidTC (10147)

          Yeah, except for that whole 'XP running IE6 or IE7', which is something like 60% of all web browsers.

          • Yeah, except for that whole 'XP running IE6 or IE7', which is something like 60% of all web browsers.

            And steadily declining. It's also only relevant if you care about being accessible to everyone. Do you think Amazon.com or Ebay is going to fret over hosting multiple sites behind a single IP address? Of course not. SSL virtual hosts are most important to home users like you and me. That's where the value it. Not all of those sites care about being accessible by every browser. If people can't access my sit

            • by DavidTC (10147)

              It's also only relevant if you care about being accessible to everyone.

              Except that you started off this conversation talking about 'all websites', you loon.

              But from now on you feel free to pretend 'all websites' are run by hobbyists who can afford to ignore 60% or more of the people out there, and everyone else can freely ignore you.

        • You don't consider IE 6, or 7 on XP, to be "major" browsers? What odd traffic patterns you must get. I see over 30% IE 6 on my personal server.

  • Nginx has been getting a lot of press lately, much of which is well deserved.

    This article is simply that -- use a front-end reverse proxy (like nginx) to your backend server, and let nginx handle the ssl transaction and pass the body of the HTTP request to your backend server where it handles the important stuff.

    This is not an uncommon strategy, and lets you have a lot of flexability.

  • that they were building an open source Synchrotron Light Source accelerator.

  • by owlstead (636356) on Wednesday April 15, 2009 @05:17PM (#27591221)

    It doesn't cost 50K to buy a T2 based server from Sun (more like 15K at entry-level prices). This would give you 8 crypto-accelerated cores with 2x 10GBit ports straight into the processor. They are also not that power hungry. You could use this to both accelerate your web server as well as your SSL. Wouldn't this be a better solution than building two servers?

    Just thinking out loud, maybe I've overlooked something as I'm not a network engineer or anything.

    • Done and done... $50k and equivalent performance of the high end BIGIP stuff
      http://www.zeus.com/news/press_articles/zeus-price-performance-press-release.html [zeus.com]

      • by owlstead (636356)

        Yes, but then you are back to the 50K pricepoint. OK, that's INCLUDING the application server, but it might still be a bit steep for many applications. And you'd have to port/reconfigure the applications to run on the T2 server.

        One of the advantages of an SSL-offloader is that you only have to remove the SSL from the port running SSL. Hmm, maybe the T2 is not such a good idea if you're having other deadlines pending. System admin time and knowledge is a costly thing.

        • $50k for something that performs at $150k? And that's for a LB that saturates a 10GB line with full SSL acceleration. That's not trivial to do, and most sites wouldn't even come close to using that. In that case, I'd recommend Intel/AMD gear.

          I've used the Zeus software. Never got trained on it, and had it up and running in less that 2 hours. Its really well designed.

          • by owlstead (636356)

            Interesting stuff indeed, and the 50K/150K is of course interesting. But still only if you need the performance of that 150K server, otherwise other project may be less expensive.

            My X2 Phenom CPU may also not beat many others in price/performance, but it does what I need using not too much power. I probably could buy a 150$ CPU instead, but I would loose 75$ dollars doing it...

      • by pyite (140350)

        Done and done... $50k and equivalent performance of the high end BIGIP stuff

        Zeus is not a valid competitor for a lot of markets until they add Route Health Injection. It's a glaring feature-set hole for site-to-site failover (via routing) that both Citrix NetScaler and F5 BIGIP support as a bread-and-butter function.

        Otherwise, their features like TrafficScript aren't half bad.

  • It's already been done. It's called stunnel. Among other things it lets you do, you can specify a different host to connect to.

    In other words, host A accepts connections on port 443 and can automatically encrypt the traffic and route it through to host B on port 80. It allows you to accept connections on multiple ports, each with its own mapping.

    It also works with name virtual hosts, forwarding the name request through to the other host.

  • Well if you RTFA it says in first paragraph that its NOT a accelerator but off-loader. Beside that it is proxying the connection so you have to change your logging to adept to the Real-IP being inside the http headers. The argument that it is equal secure as true https as it transfers http in the "local subnet only": that vanishes if a machine in this subnet gets compromised. As others mentioned, comparing such (nice) reverse proxy hack with a BIG-IP load balancer is a joke.
  • How does this reduce the number of certificates required? It might reduce the number of copies of the certificate, but you still need either one certificate per subdomain, or one wildcard certificate per domain.

    I'll grant that it makes certificate management simpler, but not significantly so â" it really only saves two minutes every year.

    • by owlstead (636356)

      "How does this reduce the number of certificates required? It might reduce the number of copies of the certificate, but you still need either one certificate per subdomain, or one wildcard certificate per domain."

      I think that would be because in some instances you could serve multiple applications from the same server (with the same certificate). This does of course not work for internet store applications and such, but for many business communications, it might well work. The proxy can then create a connec

  • by Anonymous Coward

    Hmm, why no mention of nginx's thread limitations? By design, nginx does not use threads and as a result has performance issues scaling beyond one CPU or core. Those limitations will become apparent on certain real world workloads and with realistic tests. Those are important issues and this piece, like many nginx discussions, glosses over them. It also disingenuously tries to compare nginx to commercial solutions.

    I like nginx a *lot* and have tested and deployed it in many different situations. But it

  • Big-IP products are not just SSL accelerators. If you want an SSL accelerator go on ebay and pick up an ncipher card for cheap.

    Big-IP products are used for their load balancing abilities, and can be used to build content delivery networks based on pools of application resources/servers. They're for sites that simply cannot go down, because downtime would be tremendously costly. Think military. Think medical. Think ebay or amazon. That's a pretty big farking far cry from a simple SSL accelerator. The only

    • by pyite (140350)

      The only comparable device is a module from Cisco that currently slips my mind.

      The Cisco product is pretty sucky. The only comparable product is really Citrix NetScaler.

  • Any negative interactions?

    I hope that HTTPS can cache like HTTP does.

    Running end-to-end encryption would certainly prevent proxies from stashing away frequently accessed objects.

    • Any negative interactions?

      I hope that HTTPS can cache like HTTP does.

      Running end-to-end encryption would certainly prevent proxies from stashing away frequently accessed objects.

      Your web browser can cache the data in its own cache, but you are correct in guessing that a proxy cannot transparently cache the data.

      However, recently, I was looking at Riverbed Steelhead [riverbed.com], which claims to be able to cache SSL-encrypted data. I'm guessing it would work similar to a replay attack -- you don't know what the data means, but you still know what its encrypted form looks like, so you can still cache it. Might be worth a look.

  • Why do people bother with ssl accelerators ? It's somewhere else, so you're always talking to it via a stream. Doing a round of AES ECB isn't so expensive as to weigh up to all that network traffic, right ? Better to equip your hardware with crypto-coprocessors, crypto-PCI hardware, or run it all on VIA C-7's. They have on-board crypto, accessible via special instructions.

  • Nehalem family CPUs have AES encryption commands in assembler (supported by Linux). UltraSPARC T2 have 8 cryptographic accelerators onboard. By buying modern CPU you have SSL acceleration.

    • by pyite (140350)

      Nehalem family CPUs have AES encryption commands in assembler (supported by Linux).

      Except that AES isn't processor intensive to begin with; it's a bunch of XORs and table lookups for GF(8) exponentiation. The processor intensive part of SSL is the public key work.

  • "The SSL accelerator in front of the servers takes the incoming SSL transactions, decrypts them, and then forwards them on to the servers as HTTP. This is still secure as the connection between the SSL accelerator and the servers is a private local network, there is no unsecured transaction going over the public Internet."

    The problem with that statement is private does not always stay private when web servers are involved. If any one of the web servers on the lan between the webservers and the SSL decryp
  • I guess if you're BofA or Wellsfargo and you have 10gb of traffic and just an army of contractors for your IT staff, this might make sense, but - Seriously! It's been a while since I played with accelerators, and I also hate anything F5 with a passion, but with commodity hardware as cheap as it is (PowerEdge 1950 or Sun X4000-something equivalent), why bother with an expensive magic box which has some cheapo Supermicro-class PC on the inside? Especially if you have an app, like a web app or some random VPN

  • Anyone have any success offloading encryption / decryption functionality using these cards? Not so much for SSL acceleration but for securing database rows?

If entropy is increasing, where is it coming from?

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