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<article name="Support for QUIC and HTTP/3"
         link="/en/docs/quic.html"
         lang="en"
         rev="1">

<section>

<para>
<link url="https://datatracker.ietf.org/doc/html/rfc9000">QUIC</link>
and
<link url="https://datatracker.ietf.org/doc/html/rfc9114">HTTP/3</link>
protocols are supported since 1.23.4 and are available
as a separate <literal>nginx-quic</literal>
<link id="linux">prebult Linux package</link>
or as part of our
<commercial_version>commercial subscription</commercial_version>
in a separate <literal>nginx-plus-http3</literal> package.
</para>

<para>
<note>
The QUIC and HTTP/3 support is experimental, caveat emptor applies.
</note>
</para>

</section>


<section id="linux" name="Installation on Linux">

<para>
For Linux, <literal>nginx-quic</literal> packages
from nginx.org can be used.
The packages
are available for the following Linux distributions and
versions:
<list type="bullet">

<listitem>
<link id="rhel">RHEL 9 and derivatives</link>: amd64, arm64
</listitem>

<listitem>
<link id="rhel">Ubuntu 22.04</link>: amd64, arm64
</listitem>

</list>
</para>

<para>
The <literal>nginx-quic</literal> packages are dynamically linked with the
<link url="https://github.com/quictls/openssl">QuicTLS</link> library.
It will be installed as a runtime dependency
alongside system-wide OpenSSL packages.
QuicTLS differs from operating system-provided OpenSSL package in the following:
<list type="bullet">

<listitem>
does not follow system-wide crypto policies
</listitem>

<listitem>
does not have distribution-specific patches applied
</listitem>

<listitem>
uses configuration from <literal>/etc/pki/quictls</literal> (RHEL9)
or <literal>/etc/quictls</literal> (Ubuntu 22.04)
</listitem>

</list>
</para>

<para>
The <literal>nginx-quic</literal> packages
cannot be installed alongside nginx or nginx-plus packages.
</para>

<para>
Please back up your configuration files
before installing <literal>nginx-quic</literal>:
<programlisting>
sudo cp -a /etc/nginx /etc/nginx-quic-backup
</programlisting>
</para>


<section name="RHEL" id="rhel">

<para>
The <literal>nginx-quic</literal> package and be installed on
Red Hat Enterprise Linux and its derivatives such as
CentOS, Oracle Linux, Rocky Linux, AlmaLinux.
</para>

<para>
Install the prerequisites:
<programlisting>
sudo dnf install yum-utils
</programlisting>

To set up the yum repository, create the file named
<path>/etc/yum.repos.d/nginx-quic.repo </path>
with the following contents:

<programlisting>
[nginx-quic]
name=nginx-quic repo
baseurl=https://packages.nginx.org/nginx-quic/rhel/9/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key
</programlisting>

To install nginx-quic, run the following commands:
<programlisting>
sudo dnf install nginx-quic
</programlisting>

When prompted to accept the GPG key, verify that the fingerprint matches
<command>573B FD6B 3D8F BC64 1079 A6AB ABF5 BD82 7BD9 BF62</command>,
and if so, accept it.
</para>

</section>


<section name="Ubuntu" id="ubuntu">

<para>
Install the prerequisites:
<programlisting>
sudo apt update &amp;&amp; sudo apt install curl gnupg2 ca-certificates lsb-release ubuntu-keyring
</programlisting>
</para>

<para>
Import an official nginx signing key so apt could verify the packages
authenticity.
Fetch the key:
<programlisting>
curl https://nginx.org/keys/nginx_signing.key | gpg --dearmor \
    | sudo tee /usr/share/keyrings/nginx-archive-keyring.gpg >/dev/null
</programlisting>

To set up the apt repository for nginx-quic packages, run the following command:
<programlisting>
echo "deb [signed-by=/usr/share/keyrings/nginx-archive-keyring.gpg] \
            https://packages.nginx.org/nginx-quic/ubuntu `lsb_release -cs` nginx-quic" \
            | sudo tee /etc/apt/sources.list.d/nginx-quic.list
</programlisting>
</para>

<para>
To install nginx-quic, run the following commands:
<programlisting>
sudo apt update
sudo apt install nginx-quic
</programlisting>
</para>

</section>

</section>


<section id="building" name="Building from sources">

<para>
The build is configured using the <command>configure</command> command.
Please refer to <link doc="configure.xml"/> for details.
</para>

<para>
When configuring nginx, it is possible to enable QUIC and HTTP/3
using the following configuration options:

<list type="tag">

<tag-name>
<literal>--with-http_v3_module</literal><br/>
</tag-name>
<tag-desc>
enables QUIC and HTTP/3.
</tag-desc>

</list>
</para>

<para>
An SSL library that provides QUIC support is recommended to build nginx, such as
<link url="https://boringssl.googlesource.com/boringssl">BoringSSL</link>,
<link url="https://www.libressl.org">LibreSSL</link>, or
<link url="https://github.com/quictls/openssl">QuicTLS</link>.
Otherwise, the <link url="https://openssl.org">OpenSSL</link>
compatibility layer will be used that does not support
<link doc="http/ngx_http_ssl_module.xml" id="ssl_early_data">early data</link>.
</para>

<para>
Use the following command to configure nginx with
<link url="https://boringssl.googlesource.com/boringssl">BoringSSL</link>:
<programlisting>
./auto/configure --with-debug --with-http_v3_module         \
                 --with-cc-opt="-I../boringssl/include"     \
                 --with-ld-opt="-L../boringssl/build/ssl    \
                                -L../boringssl/build/crypto"
</programlisting>
</para>

<para>
Alternatively, nginx can be configured with
<link url="https://github.com/quictls/openssl">QuicTLS</link>:
<programlisting>
./auto/configure --with-debug --with-http_v3_module         \
                 --with-cc-opt="-I../quictls/build/include" \
                 --with-ld-opt="-L../quictls/build/lib"
</programlisting>
</para>

<para>
Alternatively, nginx can be configured with a modern version of
<link url="https://www.libressl.org">LibreSSL</link>:
<programlisting>
./auto/configure --with-debug --with-http_v3_module          \
                 --with-cc-opt="-I../libressl/build/include" \
                 --with-ld-opt="-L../libressl/build/lib"
</programlisting>
</para>

<para>
After configuration,
nginx is compiled and installed using <command>make</command>.
</para>

</section>


<section id="configuration" name="Configuration">

<para>
The <link doc="http/ngx_http_core_module.xml" id="listen"/> directive in
<link doc="http/ngx_http_core_module.xml">ngx_http_core_module</link>
module got a new parameter
<link doc="http/ngx_http_core_module.xml" id="quic">quic</link>
which enables HTTP/3 over QUIC on the specified port.
</para>

<para>
Along with the <literal>quic</literal> parameter
it is also possible to specify the
<link doc="http/ngx_http_core_module.xml" id="reuseport">reuseport</link>
parameter to make it work properly with multiple workers.
</para>

<para>
To <link doc="http/ngx_http_v3_module.xml" id="quic_retry">enable</link>
address validation:
<programlisting>
quic_retry on;
</programlisting>

To <link doc="http/ngx_http_ssl_module.xml" id="ssl_early_data">enable</link>
0-RTT:
<programlisting>
ssl_early_data on;
</programlisting>

To <link doc="http/ngx_http_v3_module.xml" id="quic_gso">enable</link>
GSO (Generic Segmentation Offloading):
<programlisting>
quic_gso on;
</programlisting>

To <link doc="http/ngx_http_v3_module.xml" id="quic_mtu">limit</link>
maximum UDP payload size on receive path:
<programlisting>
quic_mtu &lt;size&gt;;
</programlisting>

To <link doc="http/ngx_http_v3_module.xml" id="quic_host_key">set</link>
host key for various tokens:
<programlisting>
quic_host_key &lt;filename&gt;;
</programlisting>

</para>

<para>
QUIC requires TLSv1.3 protocol version which is enabled by default
in the <link doc="http/ngx_http_ssl_module.xml" id="ssl_protocols"/> directive.
</para>

<para>
By default,
<link url="http://vger.kernel.org/lpc_net2018_talks/willemdebruijn-lpc2018-udpgso-paper-DRAFT-1.pdf">GSO Linux-specific optimization</link>
is disabled.
Enable it in case a corresponding network interface is configured
to support GSO.
</para>

</section>


<section id="example" name="Example Configuration">

<para>
<example>
http {
    log_format quic '$remote_addr - $remote_user [$time_local] '
                    '"$request" $status $body_bytes_sent '
                    '"$http_referer" "$http_user_agent" "$http3"';

    access_log logs/access.log quic;

    server {
        # for better compatibility it's recommended
        # to use the same port for quic and https
        listen 8443 quic reuseport;
        listen 8443 ssl;

        ssl_certificate     certs/example.com.crt;
        ssl_certificate_key certs/example.com.key;

        location / {
            # required for browsers to direct them into quic port
            add_header Alt-Svc 'h3=":8443"; ma=86400';
        }
    }
}
</example>
</para>

</section>


<section id="directives" name="Directives">

<para>
For the list of directives, please refer to
<link doc="http/ngx_http_v3_module.xml">ngx_http_v3_module</link>
module documentation.
</para>

</section>


<section id="troubleshooting " name="Troubleshooting">

<para>
Tips that may help to identify problems:
<list type="bullet">

<listitem>
Ensure nginx is built with the proper SSL library that supports QUIC.
</listitem>

<listitem>
Ensure nginx is using the proper SSL library in runtime
(the <literal>nginx -V</literal> shows what it is currently used).
</listitem>

<listitem>
Ensure a client is actually sending requests over QUIC
(see the <link id="clients">Clients</link> section
for information about browsers and cache).
We recommend starting with a simple console client such as
<link url="https://nghttp2.org/ngtcp2">ngtcp2</link>
to ensure the server is configured properly before trying
with real browsers that may be quite picky with certificates.
</listitem>

<listitem>
Build nginx with <link doc="debugging_log.xml">debug support</link>
and check the debug log.
It should contain all details about the connection and why it failed.
All related messages contain the “<literal>quic</literal>” prefix
and can be easily filtered out.
</listitem>

<listitem>
For a deeper investigation, please enable additional debugging in
<literal>src/event/quic/ngx_event_quic_connection.h</literal>:

<para>
<example>
#define NGX_QUIC_DEBUG_PACKETS
#define NGX_QUIC_DEBUG_FRAMES
#define NGX_QUIC_DEBUG_ALLOC
#define NGX_QUIC_DEBUG_CRYPTO
</example>
</para>
</listitem>

</list>
</para>

</section>


<section id="contributing" name="Contributing">

<para>
Please refer to <link doc="contributing_changes.xml"/>.
</para>

</section>

</article>