Thursday, May 26, 2016

H2O version 1.7.3 / 2.0.0-beta5 released with a vulnerability fix

We have just released version 1.7.3 and 2.0.0-beta5 of the H2O HTTP/2 server.

The releases include a fix for a security issue (CVE-2016-4817). Existing users are encouraged to update their installations.

The details of the issue can be found here.

We would like to thank Tim Newsham for reporting the issue and Frederik Deweerdt for providing a fix.

Monday, May 9, 2016

H2O HTTP/2 server 1.7.2 / 2.0.0-beta3 released

Today I have released H2O HTTP/2 server version 1.7.2 and 2.0.0-beta3.

The releases include an updated version of LibreSSL that fixes CVE-2016-2107; users of H2O built with the bundled version of LibreSSL are advised to update their installations.

In addition to the fix, 2.0.0-beta3 includes many new features and bug fixes.

Especially, support for reverse-proxying over HTTPS (#875) and the new configuration directives for tweaking environment variables passed to FastCGI (#868) might be helpful to the users who have wanted them.

We plan to release the final version of 2.0 soon, and then proceed to optimizing the server even further. Stay tuned!

Wednesday, March 23, 2016

H2O version 2.0.0-beta2 released, with a new "status" handler

Today I am happy to announce the release of H2O HTTP/2 server version 2.0.0-beta2.

The release comes with the new status handler that shows the HTTP requests in-flight. Now, you can monitor what's going on inside H2O!

Some notable features are:
  • both HTTP/1 and HTTP/2 requests are shown
  • HTTP/2 priorities are shown
  • the screen can be updated automatically by clicking the Refresh checkbox


Under the hood, the status is served via a JSON API (lib/handler/status.c L169), and rendered by a static HTML document(share/h2o/status/index.html). So it would be easy for anyone to extend the status or retrieve and use the status from another program.

The documentation of the status handler can be found here.

Thursday, March 17, 2016

File-level mapping introduced in H2O version 2.0

As the developer of H2O, the lack of ability to define a mapping for a specific path (not a directory) has been one of the complaints I hear the most. Finally, we have a fix for the issue, and that is why the next release will be given the number 2.0.

Starting from H2O version 2.0.0beta-1, it is possible to write a configuration like the following. The example maps all requests to a FastCGI server, with the exception of /robots.txt and /favicon.ico being served statically.
paths:
  /:
    fastcgi.connect:
      port: /tmp/fcgi.sock
      type: unix
  /robots.txt:
    file.file: /path/to/robots.txt
  /favicon.ico:
    file.file: /path/to/favicon.png
Pretty straight forward, isn't it?

For details, please refer to the updated documentation of paths directive, or refer to the discussion in the pull request.

Tuesday, March 15, 2016

H2O HTTP/2 server goes 2.0 adding support for Brotli

Today, I am happy to announce the release of H2O version 2.0.0-beta1, the first release of the 2.0 series. In the release, we have added support for Brotli in two ways.

For those who do not know, Brotli is a new compression method developed by Google. It is said to compress files ~20% smaller than gzip - means less bandwidth consumed and faster rendering on the client side. Mozilla has already added support for Brotli in Firefox 44, and Chrome is gradually turning the knob on as well.

Starting with H2O version 2.0.0-beta1, when the file.send-compressed directive is set to ON, the server sends a file with .br or .gz suffix instead of file being requested should such file exist. For example, if index.html is requested with a Accept-Encoding: br request header, and if a file named index.html.br exists, the server sends the contents of index.hmtl.br as the response with the Content-Encoding: br response header being set. In case the client is capable of decompressing both algorithms both algorithms and if both of .br and .gz files exist, the .br file is selected as the response.
# send pre-compressed files (.br or .gz)
file.send-compressed: ON

The other directive: compress controls on-the-fly compression. When turned on, it compresses the response as it is being sent to the client, using either brotli or gzip depending on the configuration and browser support. This can be used for compressing output from PHP and other dynamically-generated content.
# perform on-the-fly compression (brotli or gzip)
compress: [ brotli, gzip ]
Server administrators may also be interested in fine-tuning the compression quality of the compression methods. The following configuration sets the compression quality of brotli to 4 and gzip to 6, a suggested setting by Understanding Brotli's Potential - The Akamai Blog. The compression speed becomes about half of the default (1 for both gzip and brotli), but the size of the content after compression is expected to become ~15% smaller for both methods.
# perform more effective (but CPU-intensive) compression
compress:
  brotli: 4
  gzip:   6

In my upcoming blogposts I will cover other changes in the 2.0 release of H2O. Stay tuned!

Friday, March 11, 2016

H2O version 1.7.1 released

Today we have shipped version 1.7.1 of the H2O HTTP/2 server.

It includes several bug fixes and stability improvements from 1.7.0. Users of existing versions are recommended to upgrade to 1.7.1.

Please refer to the Changelog of 1.7.1 for details.

Wednesday, February 10, 2016

Name Constraints を使った独自CAの運用手順

ウェブブラウザが新機能をHTTPSでしか有効にしないことが多くなってきたので、開発環境でもHTTPSを使いたい。でも、開発環境用にサーバ証明書を買うのは手間。Let's Encryptも運用がめんどくさいとか、社内からしかアクセスできないサーバへの証明書発行が難しいとかいろいろあるし…ってそこでName Constraintsを使った独自CAですよ奥さん。

Name Constraints が何であるかについては、以前オレオレ認証局の適切な運用とName Constraintsに書いたとおり。

本稿では、Name Constraintsを使うCAの運用手順を説明する。

1. CA鍵と証明書の作成

1.1. CAの秘密鍵を作成
% openssl genrsa -out ca.key 2048

1.2. openssl.cnfにCA証明書に設定する属性を指定するセクションを追記
[private_ca]
subjectKeyIdentifier=hash
authorityKeyIdentifier=keyid:always,issuer
basicConstraints=critical,CA:true
nameConstraints=critical,permitted;DNS:.example.com
注:nameConstraintsの項がCAが証明書を発行できる対象のドメインを指定。この例では.example.com。

1.3. CA証明書の作成
% openssl req -new -x509 -days 3650 -key ca.key -out ca.crt \
  -extensions private_ca

2. 証明書管理用ディレクトリを作成
% mkdir -p demoCA/newcerts
% touch demoCA/index.txt
% echo 00 > demoCA/serial
注:ディレクトリ名(demoCA)はopenssl.cnfの設定で変更可能。

3. 証明書発行要求を受け取って証明書を発行
% openssl ca -keyfile ca.key -cert ca.crt \
  -extensions usr_cert -policy policy_anything -days 365 \
  -md sha256 -in foo.example.com.csr -out foo.example.com.crt

以上です。

難点としては、SafariおよびOSXで動作するChromeではこのルート証明書で署名されたサーバ証明書を正当なものとして認識してくれないところ(手動でサーバ証明書を登録すれば使えるはず)。他のウェブブラウザ+モダンなOSなら問題ないはず。