curl/docs/HTTP3.md

# HTTP3 (and QUIC)

## Resources

[HTTP/3 Explained](https://daniel.haxx.se/http3-explained/) - the online free
book describing the protocols involved.

[QUIC implementation](https://github.com/curl/curl/wiki/QUIC-implementation) -
the wiki page describing the plan for how to support QUIC and HTTP/3 in curl
and libcurl.

[quicwg.org](https://quicwg.org/) - home of the official protocol drafts

## QUIC libraries

QUIC libraries we're experiementing with:

[ngtcp2](https://github.com/ngtcp2/ngtcp2)

[quiche](https://github.com/cloudflare/quiche)

## Experimental!

HTTP/3 and QUIC support in curl is considered **EXPERIMENTAL** until further
notice. It needs to be enabled at build-time.

Further development and tweaking of the HTTP/3 support in curl will happen in
in the master branch using pull-requests, just like ordinary changes.

# ngtcp2 version

## Build

Build (patched) OpenSSL

     % git clone --depth 1 -b openssl-quic-draft-23 https://github.com/tatsuhiro-t/openssl
     % cd openssl
     % ./config enable-tls1_3 --prefix=<somewhere1>
     % make
     % make install_sw

Build nghttp3

     % cd ..
     % git clone https://github.com/ngtcp2/nghttp3
     % cd nghttp3
     % autoreconf -i
     % ./configure --prefix=<somewhere2> --enable-lib-only
     % make
     % make install

Build ngtcp2

     % cd ..
     % git clone https://github.com/ngtcp2/ngtcp2
     % cd ngtcp2
     % autoreconf -i
     % ./configure PKG_CONFIG_PATH=<somewhere1>/lib/pkgconfig:<somewhere2>/lib/pkgconfig LDFLAGS="-Wl,-rpath,<somehere1>/lib" --prefix=<somewhere3>
     % make
     % make install

Build curl

     % cd ..
     % git clone https://github.com/curl/curl
     % cd curl
     % ./buildconf
     % LDFLAGS="-Wl,-rpath,<somewhere1>/lib" ./configure --with-ssl=<somewhere1> --with-nghttp3=<somewhere2> --with-ngtcp2=<somewhere3>
     % make

# quiche version

## build

Clone quiche and BoringSSL:

     % git clone --recursive https://github.com/cloudflare/quiche

Build BoringSSL (it needs to be built manually so it can be reused with curl):

     % cd quiche/deps/boringssl
     % mkdir build
     % cd build
     % cmake -DCMAKE_POSITION_INDEPENDENT_CODE=on ..
     % make
     % cd ..
     % mkdir -p .openssl/lib
     % cp build/crypto/libcrypto.a build/ssl/libssl.a .openssl/lib
     % ln -s $PWD/include .openssl

Build quiche:

     % cd ../..
     % QUICHE_BSSL_PATH=$PWD/deps/boringssl cargo build --release --features pkg-config-meta

Clone and build curl:

     % cd ..
     % git clone https://github.com/curl/curl
     % cd curl
     % ./buildconf
     % ./configure LDFLAGS="-Wl,-rpath,$PWD/../quiche/target/release" --with-ssl=$PWD/../quiche/deps/boringssl/.openssl --with-quiche=$PWD/../quiche/target/release
     % make

## Run

Use HTTP/3 directly:

    curl --http3 https://nghttp2.org:8443/

Upgrade via Alt-Svc:

    curl --alt-svc altsvc.cache https://quic.aiortc.org/

See this [list of public HTTP/3 servers](https://bagder.github.io/HTTP3-test/)