Tag Archives: HTTP/3

QUIC with wolfSSL

We have started the work on extending wolfSSL to provide the necessary API calls to power QUIC and HTTP/3 implementations!

Small, fast and FIPS

The TLS library known as wolfSSL is already very often a top choice when users are looking for a small and yet very fast TLS stack that supports all the latest protocol features; including TLS 1.3 support – open source with commercial support available.

As manufacturers of IoT devices and other systems with memory, CPU and footprint constraints are looking forward to following the Internet development and switching over to upcoming QUIC and HTTP/3 protocols, wolfSSL is here to help users take that step.

A QUIC reminder

In case you have forgot, here’s a schematic view of HTTPS stacks, old vs new. On the right side you can see HTTP/3, QUIC and the little TLS 1.3 box there within QUIC.

ngtcp2

There are no plans to write a full QUIC stack. There are already plenty of those. We’re talking about adjustments and extensions of the existing TLS library API set to make sure wolfSSL can be used as the TLS component in a QUIC stack.

One of the leading QUIC stacks and so far the only one I know of that does this, ngtcp2 is written to be TLS library agnostic and allows different TLS libraries to be plugged in as different backends. I believe it makes perfect sense to make such a plugin for wolfSSL to be a sensible step as soon as there’s code to try out.

A neat effect of that, would be that once wolfSSL works as a backend to ngtcp2, it should be possible to do full-fledged HTTP/3 transfers using curl powered by ngtcp2+wolfSSL. Contact us with other ideas for QUIC stacks you would like us to test wolfSSL with!

FIPS 140-2

We expect wolfSSL to be the first FIPS-based implementation to add support for QUIC. I hear this is valuable to a number of users.

When

This work begins now and this is just a blog post of our intentions. We and I will of course love to get your feedback on this and whatever else that is related. We’re also interested to get in touch with people and companies who want to be early testers of our implementation. You know where to find us!

I can promise you that the more interest we can sense to exist for this effort, the sooner we will see the first code to test out.

It seems likely that we’re not going to support any older TLS drafts for QUIC than draft-29.

HTTP/3 for everyone

FOSDEM 2020 is over for this time and I had an awesome time in Brussels once again.

Stickers

I brought a huge collection of stickers this year and I kept going back to the wolfSSL stand to refill the stash and it kept being emptied almost as fast. Hundreds of curl stickers were given away! The photo on the right shows my “sticker bag” as it looked before I left Sweden.

Lesson for next year: bring a larger amount of stickers! If you missed out on curl stickers, get in touch and I’ll do my best to satisfy your needs.

The talk

“HTTP/3 for everyone” was my single talk this FOSDEM. Just two days before the talk, I landed updated commits in curl’s git master branch for doing HTTP/3 up-to-date with the latest draft (-25). Very timely and I got to update the slide mentioning this.

As I talked HTTP/3 already last year in the Mozilla devroom, I also made sure to go through the slides I used then to compare and make sure I wouldn’t do too much of the same talk. But lots of things have changed and most of the content is updated and different this time around. Last year, literally hundreds of people were lining up outside wanting to get into room when the doors were closed. This year, I talked in the room Janson, which features 1415 seats. The biggest one on campus. It was pack full!

It is kind of an adrenaline rush to stand in front of such a wall of people. At one time in my talk I paused for a brief moment and then I felt I could almost hear the complete silence when a huge amount of attentive faces captured what I had to say.

The audience, photographed by Sidsel Jensen who had to sit in the stairs…
Photo by Mirza Krak
Photo by Wolfgang Gassler

I got a lot of positive feedback on the presentation. I also thought that my decision to not even try to take question in the big room was a correct and I ended up talking and discussing details behind the scene for a good while after my talk was done. Really fun!

The video

The video is also available from the FOSDEM site in webm and mp4 formats.

The slides

If you want the slides only, run over to slideshare and view them.

Coming to FOSDEM 2020

I’m going to FOSDEM again in 2020, this will be my 11th consecutive year I’m travling to this awesome conference in Brussels, Belgium.

At this my 11th FOSDEM visit I will also deliver my 11th FOSDEM talk: “HTTP/3 for everyone“. It will happen at 16:00 Saturday the 1st of February 2020, in Janson, the largest room on the campus. (My third talk in the main track.)

For those who have seen me talk about HTTP/3 before, this talk will certainly have overlaps but I’m also always refreshing and improving slides and I update them as the process moves on, things changes and I get feedback. I spoke about HTTP/3 already at FODEM 2019 in the Mozilla devroom (at which time there was a looong line of people who tried, but couldn’t get a seat in the room) – but I think you’ll find that there’s enough changes and improvements in this talk to keep you entertained this year as well!

If you come to FOSDEM, don’t hesitate to come say hi and grab a curl sticker or two – I intend to bring and distribute plenty – and talk curl, HTTP and Internet transfers with me!

You will most likely find me at my talk, in the cafeteria area or at the wolfSSL stall. (DM me on twitter to pin me down! @bagder)

Summing up My 2019

2019 is special in my heart. 2019 was different than many other years to me in several ways. It was a great year! This is what 2019 was to me.

curl and wolfSSL

I quit Mozilla last year and in the beginning of the year I could announce that I joined wolfSSL. For the first time in my life I could actually work with curl on my day job. As the project turned 21 I had spent somewhere in the neighborhood of 15,000 unpaid spare time hours on it and now I could finally do it “for real”. It’s huge.

Still working from home of course. My commute is still decent.

HTTP/3

Just in November 2018 the name HTTP/3 was set and this year has been all about getting it ready. I was proud to land and promote HTTP/3 in curl just before the first browser (Chrome) announced their support. The standard is still in progress and we hope to see it ship not too long into next year.

curl

Focusing on curl full time allows a different kind of focus. I’ve landed more commits in curl during 2019 than any other year going back all the way to 2005. We also reached 25,000 commits and 3,000 forks on github.

We’ve added HTTP/3, alt-svc, parallel transfers in the curl tool, tiny-curl, fixed hundreds of bugs and much, much more. Ten days before the end of the year, I’ve authored 57% (over 700) of all the commits done in curl during 2019.

We ran our curl up conference in Prague and it was awesome.

We also (re)started our own curl Bug Bounty in 2019 together with Hackerone and paid over 1000 USD in rewards through-out the year. It was so successful we’re determined to raise the amounts significantly going into 2020.

Public speaking

I’ve done 28 talks in six countries. A crazy amount in front of a lot of people.

In media

Dagens Nyheter published this awesome article on me. I’m now shown on the internetmuseum. I was interviewed and highlighted in Bloomberg Businessweek’s “Open Source Code Will Survive the Apocalypse in an Arctic Cave” and Owen William’s Medium post The Internet Relies on People Working for Free.

When Github had their Github Universe event in November and talked about their new sponsors program on stage (which I am part of, you can sponsor me) this huge quote of mine was shown on the big screen.

Maybe not media, but in no less than two Mr Robot episodes we could see curl commands in a TV show!

Podcasts

I’ve participated in three podcast episodes this year, all in Swedish. Kompilator episode 5 and episode 8, and Kodsnack episode 331.

Live-streamed

I’ve toyed with live-streamed programming and debugging sessions. That’s been a lot of fun and I hope to continue doing them on and off going forward as well. They also made me consider and get started on my libcurl video tutorial series. We’ll see where that will end…

2020?

I figure it can become another fun year too!

curl 7.66.0 – the parallel HTTP/3 future is here

I personally have not done this many commits to curl in a single month (August 2019) for over three years. This increased activity is of course primarily due to the merge of and work with the HTTP/3 code. And yet, that is still only in its infancy…

Download curl here.

Numbers

the 185th release
6 changes
54 days (total: 7,845)

81 bug fixes (total: 5,347)
214 commits (total: 24,719)
1 new public libcurl function (total: 81)
1 new curl_easy_setopt() option (total: 269)

4 new curl command line option (total: 225)
46 contributors, 23 new (total: 2,014)
29 authors, 14 new (total: 718)
2 security fixes (total: 92)
450 USD paid in Bug Bounties

Two security advisories

TFTP small blocksize heap buffer overflow

(CVE-2019-5482) If you told curl to do TFTP transfers using a smaller than default “blocksize” (default being 512), curl could overflow a heap buffer used for the protocol exchange. Rewarded 250 USD from the curl bug bounty.

FTP-KRB double-free

(CVE-2019-5481) If you used FTP-kerberos with curl and the server maliciously or mistakenly responded with a overly large encrypted block, curl could end up doing a double-free in that exit path. This would happen on applications where allocating a large 32 bit max value (up to 4GB) is a problem. Rewarded 200 USD from the curl bug bounty.

Changes

The new features in 7.66.0 are…

HTTP/3

This experimental feature is disabled by default but can be enabled and works (by some definition of “works”). Daniel went through “HTTP/3 in curl” in this video from a few weeks ago:

Parallel transfers

You can now do parallel transfers with the curl tool’s new -Z / –parallel option. This is a huge change that might change a lot of use cases going forward!

Retry-after

There’s a standard HTTP header that some servers return when they can’t or won’t respond right now, which indicates after how many seconds or at what point in the future the request might be fulfilled. libcurl can now return that number easily and curl’s –retry option makes use of it (if present).

curl_multi_poll

curl_multi_poll is a new function offered that is very similar to curl_multi_wait, but with one major benefit: it solves the problem for applications of what to do for the occasions when libcurl has no file descriptor at all to wait for. That has been a long-standing and perhaps far too little known issue.

SASL authzid

When using SASL authentication, curl and libcurl now can provide the authzid field as well!

Bug-fixes

Some interesting bug-fixes included in this release..

.netrc and .curlrc on Windows

Starting now, curl and libcurl will check for and use the dot-prefixed versions of these files even on Windows and only fall back and check for and use the underscore-prefixed versions for compatibility if the dotted one doesn’t exist. This unifies curl’s behavior across platforms.

asyn-thread: create a socketpair to wait on

With this perhaps innocuous-sounding change, libcurl on Linux and other Unix systems will now provide a file descriptor for the application to wait on while name resolving in a background thread. This lets applications know better when to call libcurl again and avoids having to just blindly wait and retry. A performance gain.

Credentials in URL when using HTTP proxy

We found and fixed a regression that made curl not use credentials properly from the URL when doing multi stage authentication (like HTTP Digest) with a proxy.

Move code into vssh for SSH backends

A mostly janitor-style fix that also now abstracted away more SSH-using code to not know what particular SSH backend that is being used while at the same time making it easier to write and provide new SSH backends in the future. I’m personally working a little slowly on one, to be talked about at a later point.

Disable HTTP/0.9 by default

If you want libcurl to accept and deliver HTTP/0.9 responses to your application, you need to tell it to do that. Starting in this version, curl will consider those invalid HTTP responses by default.

alt-svc improvements

We introduced alt-svc support a while ago but as it is marked experimental and nobody felt a strong need to use it, it clearly hasn’t been used or tested much in real life. When we’ve worked on using alt-svc to bootstrap into HTTP/3 we found and fixed a whole range of little issues with the alt-svc support and it is now in a much better shape. However, it is still marked experimental.

IPv6 addresses in URLs

It was reported that the URL parser would accept malformatted IPv6 addresses that subsequently and counter-intuitively would get resolved as a host name internally! An example URL would be “https://[ab.de]/’ – where all the letters and symbols within the brackets are individually allowed components of a IPv6 numerical address but it still isn’t a valid IPv6 syntax and instead is a legitimate and valid host name.

Going forward!

We recently ran a poll among users of what we feel are the more important things to work on, and with that the rough roadmap has been updated. Those are things I want to work on next but of course I won’t guarantee anything and I will greatly appreciate all help and assistance that I can get. And sure, we can and will work on other things too!

First HTTP/3 with curl

In the afternoon of August 5 2019, I successfully made curl request a document over HTTP/3, retrieve it and then exit cleanly again.

(It got a 404 response code, two HTTP headers and 10 bytes of content so the actual response was certainly less thrilling to me than the fact that it actually delivered that response over HTTP version 3 over QUIC.)

The components necessary for this to work, if you want to play along at home, are reasonably up-to-date git clones of curl itself and the HTTP/3 library called quiche (and of course quiche’s dependencies too, like boringssl), then apply pull-request 4193 (build everything accordingly) and run a command line like:

curl --http3-direct https://quic.tech:8443

The host name used here (“quic.tech”) is a server run by friends at Cloudflare and it is there for testing and interop purposes and at the time of this test it ran QUIC draft-22 and HTTP/3.

The command line option --http3-direct tells curl to attempt HTTP/3 immediately, which includes using QUIC instead of TCP to the host name and port number – by default you should of course expect a HTTPS:// URL to use TCP + TLS.

The official way to bootstrap into HTTP/3 from HTTP/1 or HTTP/2 is via the server announcing it’s ability to speak HTTP/3 by returning an Alt-Svc: header saying so. curl supports this method as well, it just needs it to be explicitly enabled at build-time since that also is still an experimental feature.

To use alt-svc instead, you do it like this:

curl --alt-svc altcache https://quic.tech:8443

The alt-svc method won’t “take” on the first shot though since it needs to first connect over HTTP/2 (or HTTP/1) to get the alt-svc header and store that information in the “altcache” file, but if you then invoke it again and use the same alt-svc cache curl will know to use HTTP/3 then!

Early days

Be aware that I just made this tiny GET request work. The code is not cleaned up, there are gaps in functionality, we’re missing error checks, we don’t have tests and chances are the internals will change quite a lot going forward as we polish this.

You’re of course still more than welcome to join in, play with it, report bugs or submit pull requests! If you help out, we can make curl’s HTTP/3 support better and getting there sooner than otherwise.

QUIC and TLS backends

curl currently supports two different QUIC/HTTP3 backends, ngtcp2 and quiche. Only the latter currently works this good though. I hope we can get up to speed with the ngtcp2 one too soon.

quiche uses and requires boringssl to be used while ngtcp2 is TLS library independent and will allow us to support QUIC and HTTP/3 with more TLS libraries going forward. Unfortunately it also makes it more complicated to use…

The official OpenSSL doesn’t offer APIs for QUIC. QUIC uses TLS 1.3 but in a way it was never used before when done over TCP so basically all TLS libraries have had to add APIs and do some adjustments to work for QUIC. The ngtcp2 team offers a patched version of OpenSSL that offers such an API so that OpenSSL be used.

Draft what?

Neither the QUIC nor the HTTP/3 protocols are entirely done and ready yet. We’re using the protocols as they are defined in the 22nd version of the protocol documents. They will probably change a little more before they get carved in stone and become the final RFC that they are on their way to.

The libcurl API so far

The command line options mentioned above of course have their corresponding options for libcurl using apps as well.

Set the right bit with CURLOPT_H3 to get direct connect with QUIC and control how to do alt-svc using libcurl with CURLOPT_ALTSVC and CURLOPT_ALTSVC_CTRL.

All of these marked EXPERIMENTAL still, so they might still change somewhat before they become stabilized.

Update

Starting on August 8, the option is just --http3 and you ask libcurl to use HTTP/3 directly with CURLOPT_HTTP_VERSION.

Workshop Season 4 Finale

The 2019 HTTP Workshop ended today. In total over the years, we have now done 12 workshop days up to now. This day was not a full day and we spent it on only two major topics that both triggered long discussions involving large parts of the room.

Cookies

Mike West kicked off the morning with his cookies are bad presentation.

One out of every thousand cookie header values is 10K or larger in size and even at the 50% percentile, the size is 480 bytes. They’re a disaster on so many levels. The additional features that have been added during the last decade are still mostly unused. Mike suggests that maybe the only way forward is to introduce a replacement that avoids the issues, and over longer remove cookies from the web: HTTP state tokens.

A lot of people in the room had opinions and thoughts on this. I don’t think people in general have a strong love for cookies and the way they currently work, but the how-to-replace-them question still triggered lots of concerns about issues from routing performance on the server side to the changed nature of the mechanisms that won’t encourage web developers to move over. Just adding a new mechanism without seeing the old one actually getting removed might not be a win.

We should possibly “worsen” the cookie experience over time to encourage switch over. To cap allowed sizes, limit use to only over HTTPS, reduce lifetimes etc, but even just that will take effort and require that the primary cookie consumers (browsers) have a strong will to hurt some amount of existing users/sites.

(Related: Mike is also one of the authors of the RFC6265bis draft in progress – a future refreshed cookie spec.)

HTTP/3

Mike Bishop did an excellent presentation of HTTP/3 for HTTP people that possibly haven’t kept up fully with the developments in the QUIC working group. From a plain HTTP view, HTTP/3 is very similar feature-wise to HTTP/2 but of course sent over a completely different transport layer. (The HTTP/3 draft.)

Most of the questions and discussions that followed were rather related to the transport, to QUIC. Its encryption, it being UDP, DOS prevention, it being “CPU hungry” etc. Deploying HTTP/3 might be a challenge for successful client side implementation, but that’s just nothing compared the totally new thing that will be necessary server-side. Web developers should largely not even have to care…

One tidbit that was mentioned is that in current Firefox telemetry, it shows about 0.84% of all requests negotiates TLS 1.3 early data (with about 12.9% using TLS 1.3)

Thought-worthy quote of the day comes from Willy: “everything is a buffer”

Future Workshops

There’s no next workshop planned but there might still very well be another one arranged in the future. The most suitable interval for this series isn’t really determined and there might be reasons to try tweaking the format to maybe change who will attend etc.

The fact that almost half the attendees this time were newcomers was certainly good for the community but that not a single attendee traveled here from Asia was less good.

Thanks

Thanks to the organizers, the program committee who set this up so nicely and the awesome sponsors!

The HTTP Workshop 2019 begins

The forth season of my favorite HTTP series is back! The HTTP Workshop skipped over last year but is back now with a three day event organized by the very best: Mark, Martin, Julian and Roy. This time we’re in Amsterdam, the Netherlands.

35 persons from all over the world walked in the room and sat down around the O-shaped table setup. Lots of known faces and representatives from a large variety of HTTP implementations, client-side or server-side – but happily enough also a few new friends that attend their first HTTP Workshop here. The companies with the most employees present in the room include Apple, Facebook, Mozilla, Fastly, Cloudflare and Google – having three or four each in the room.

Patrick Mcmanus started off the morning with his presentation on HTTP conventional wisdoms trying to identify what have turned out as successes or not in HTTP land in recent times. It triggered a few discussions on the specific points and how to judge them. I believe the general consensus ended up mostly agreeing with the slides. The topic of unshipping HTTP/0.9 support came up but is said to not be possible due to its existing use. As a bonus, Anne van Kesteren posted a new bug on Firefox to remove it.

Mark Nottingham continued and did a brief presentation about the recent discussions in HTTPbis sessions during the IETF meetings in Prague last week.

Martin Thomson did a presentation about HTTP authority. Basically how a client decides where and who to ask for a resource identified by a URI. This triggered an intense discussion that involved a lot of UI and UX but also trust, certificates and subjectAltNames, DNS and various secure DNS efforts, connection coalescing, DNSSEC, DANE, ORIGIN frame, alternative certificates and more.

Mike West explained for the room about the concept for Signed Exchanges that Chrome now supports. A way for server A to host contents for server B and yet have the client able to verify that it is fine.

Tommy Pauly then talked to his slides with the title of Website Fingerprinting. He covered different areas of a browser’s activities that are current possible to monitor and use for fingerprinting and what counter-measures that exist to work against furthering that development. By looking at the full activity, including TCP flows and IP addresses even lots of our encrypted connections still allow for pretty accurate and extensive “Page Load Fingerprinting”. We need to be aware and the discussion went on discussing what can or should be done to help out.

The meeting is going on somewhere behind that red door.

Lucas Pardue discussed and showed how we can do TLS interception with Wireshark (since the release of version 3) of Firefox, Chrome or curl and in the end make sure that the resulting PCAP file can get the necessary key bundled in the same file. This is really convenient when you want to send that PCAP over to your protocol debugging friends.

Roberto Peon presented his new idea for “Generic overlay networks”, a suggested way for clients to get resources from one out of several alternatives. A neighboring idea to Signed Exchanges, but still different. There was an interested to further and deepen this discussion and Roberto ended up saying he’d at write up a draft for it.

Max Hils talked about Intercepting QUIC and how the ability to do this kind of thing is very useful in many situations. During development, for debugging and for checking what potentially bad stuff applications are actually doing on your own devices. Intercepting QUIC and HTTP/3 can thus also be valuable but at least for now presents some challenges. (Max also happened to mention that the project he works on, mitmproxy, has more stars on github than curl, but I’ll just let it slide…)

Poul-Henning Kamp showed us vtest – a tool and framework for testing HTTP implementations that both Varnish and HAproxy are now using. Massaged the right way, this could develop into a generic HTTP test/conformance tool that could be valuable for and appreciated by even more users going forward.

Asbjørn Ulsberg showed us several current frameworks that are doing GET, POST or SEARCH with request bodies and discussed how this works with caching and proposed that SEARCH should be defined as cacheable. The room mostly acknowledged the problem – that has been discussed before and that probably the time is ripe to finally do something about it. Lots of users are already doing similar things and cached POST contents is in use, just not defined generically. SEARCH is a already registered method but could get polished to work for this. It was also suggested that possibly POST could be modified to also allow for caching in an opt-in way and Mark volunteered to author a first draft elaborating how it could work.

Indonesian and Tibetan food for dinner rounded off a fully packed day.

Thanks Cory Benfield for sharing your notes from the day, helping me get the details straight!

Diversity

We’re a very homogeneous group of humans. Most of us are old white men, basically all clones and practically indistinguishable from each other. This is not diverse enough!

A big thank you to the HTTP Workshop 2019 sponsors!


The future of HTTP Symposium

This year’s version of curl up started a little differently: With an afternoon of HTTP presentations. The event took place the same week the IETF meeting has just ended here in Prague so we got the opportunity to invite people who possibly otherwise wouldn’t have been here… Of course this was only possible thanks to our awesome sponsors, visible in the image above!

Lukáš Linhart from Apiary started out with “Web APIs: The Past, The Present and The Future”. A journey trough XML-RPC, SOAP and more. One final conclusion might be that we’re not quite done yet…

James Fuller from MarkLogic talked about “The Defenestration of Hypermedia in HTTP”. How HTTP web technologies have changed over time while the HTTP paradigms have survived since a very long time.

I talked about DNS-over-HTTPS. A presentation similar to the one I did before at FOSDEM, but in a shorter time so I had to talk a little faster!

Mike Bishop from Akamai (editor of the HTTP/3 spec and a long time participant in the HTTPbis work) talked about “The evolution of HTTP (from HTTP/1 to HTTP/3)” from HTTP/0.9 to HTTP/3 and beyond.

Robin Marx then rounded off the series of presentations with his tongue in cheek “HTTP/3 (QUIC): too big to fail?!” where we provided a long list of challenges for QUIC and HTTP/3 to get deployed and become successful.

We ended this afternoon session with a casual Q&A session with all the presenters discussing various aspects of HTTP, the web, REST, APIs and the benefits and deployment challenges of QUIC.

I think most of us learned things this afternoon and we could leave the very elegant Charles University room enriched and with more food for thoughts about these technologies.

We ended the evening with snacks and drinks kindly provided by Apiary.

(This event was not streamed and not recorded on video, you had to be there in person to enjoy it.)