ngtcp2

"Call it TCP/2. One More Time."

ngtcp2 project is an effort to implement RFC9000 QUIC protocol.

Documentation

Public test server

The following endpoints are available to try out ngtcp2 implementation:

https://nghttp2.org:4433
https://nghttp2.org:4434 (requires address validation token)
https://nghttp2.org (powered by nghttpx)

This endpoints sends Alt-Svc header field to clients if it is accessed via HTTP/1.1 or HTTP/2 to tell them that HTTP/3 is available at UDP 443.

Requirements

The libngtcp2 C library itself does not depend on any external libraries. The example client, and server are written in C++20, and should compile with the modern C++ compilers (e.g., clang >= 11.0, or gcc >= 11.0).

The following packages are required to configure the build system:

pkg-config >= 0.20
autoconf
automake
autotools-dev
libtool

libngtcp2 uses cunit for its unit test frame work:

cunit >= 2.1

To build sources under the examples directory, libev and nghttp3 are required:

libev
nghttp3 for HTTP/3

ngtcp2 crypto helper library, and client and server under examples directory require at least one of the following TLS backends:

OpenSSL with QUIC support
GnuTLS >= 3.7.2
BoringSSL (commit 31bad2514d21f6207f3925ba56754611c462a873)
Picotls (commit 9398c491cf5b21e123ce409f2d32a1d235d93b7e)
wolfSSL >= 5.5.0

Build from git

$ git clone --depth 1 -b OpenSSL_1_1_1s+quic https://github.com/quictls/openssl
$ cd openssl
$ # For Linux
$ ./config enable-tls1_3 --prefix=$PWD/build
$ make -j$(nproc)
$ make install_sw
$ cd ..
$ git clone https://github.com/ngtcp2/nghttp3
$ cd nghttp3
$ autoreconf -i
$ ./configure --prefix=$PWD/build --enable-lib-only
$ make -j$(nproc) check
$ make install
$ cd ..
$ git clone https://github.com/ngtcp2/ngtcp2
$ cd ngtcp2
$ autoreconf -i
$ # For Mac users who have installed libev with MacPorts, append
$ # ',-L/opt/local/lib' to LDFLAGS, and also pass
$ # CPPFLAGS="-I/opt/local/include" to ./configure.
$ # For OpenSSL >= v3.0.0, replace "openssl/build/lib" with
$ # "openssl/build/lib64".
$ ./configure PKG_CONFIG_PATH=$PWD/../openssl/build/lib/pkgconfig:$PWD/../nghttp3/build/lib/pkgconfig LDFLAGS="-Wl,-rpath,$PWD/../openssl/build/lib"
$ make -j$(nproc) check

Client/Server

After successful build, the client and server executable should be found under examples directory. They talk HTTP/3.

Client

$ examples/client [OPTIONS] <HOST> <PORT> [<URI>...]

The notable options are:

-d, --data=<PATH>: Read data from <PATH> and send it to a peer.

Server

$ examples/server [OPTIONS] <ADDR> <PORT> <PRIVATE_KEY_FILE> <CERTIFICATE_FILE>

The notable options are:

-V, --validate-addr: Enforce stateless address validation.

H09client/H09server

There are h09client and h09server which speak HTTP/0.9. They are written just for quic-interop-runner. They share the basic functionalities with HTTP/3 client and server but have less functions (e.g., h09client does not have a capability to send request body, and h09server does not understand numeric request path, like /1000).

Resumption and 0-RTT

In order to resume a session, a session ticket, and a transport parameters must be fetched from server. First, run examples/client with --session-file, and --tp-file options which specify a path to session ticket, and transport parameter files respectively to save them locally.

Once these files are available, run examples/client with the same arguments again. You will see that session is resumed in your log if resumption succeeds. Resuming session makes server's first Handshake packet pretty small because it does not send its certificates.

To send 0-RTT data, after making sure that resumption works, use -d option to specify a file which contains data to send.

Token (Not something included in Retry packet)

QUIC server might send a token to client after connection has been established. Client can send this token in subsequent connection to the server. Server verifies the token and if it succeeds, the address validation completes and lifts some restrictions on server which might speed up transfer. In order to save and/or load a token, use --token-file option of examples/client. The given file is overwritten if it already exists when storing a token.

Crypto helper library

In order to make TLS stack integration less painful, we provide a crypto helper library which offers the basic crypto operations.

The header file exists under crypto/includes/ngtcp2 directory.

Each library file is built for a particular TLS backend. The available crypto helper libraries are:

libngtcp2_crypto_openssl: Use OpenSSL as TLS backend
libngtcp2_crypto_gnutls: Use GnuTLS as TLS backend
libngtcp2_crypto_boringssl: Use BoringSSL as TLS backend
libngtcp2_crypto_picotls: Use Picotls as TLS backend
libngtcp2_crypto_wolfssl: Use wolfSSL as TLS backend

Because BoringSSL and Picotls are an unversioned product, we only tested their particular revision. See Requirements section above.

We use Picotls with OpenSSL as crypto backend. It does not work with OpenSSL >= 3.0.0.

The examples directory contains client and server that are linked to those crypto helper libraries and TLS backends. They are only built if their corresponding crypto helper library is built:

client: OpenSSL client
server: OpenSSL server
gtlsclient: GnuTLS client
gtlsserver: GnuTLS server
bsslclient: BoringSSL client
bsslserver: BoringSSL server
ptlsclient: Picotls client
ptlsserver: Picotls server
wsslclient: wolfSSL client
wsslserver: wolfSSL server

QUIC protocol extensions

The library implements the following QUIC protocol extensions:

Configuring Wireshark for QUIC

Wireshark can be configured to analyze QUIC traffic using the following steps:

Set SSLKEYLOGFILE environment variable:

$ export SSLKEYLOGFILE=quic_keylog_file

Set the port that QUIC uses

Go to Preferences->Protocols->QUIC and set the port the program listens to. In the case of the example application this would be the port specified on the command line.
Set Pre-Master-Secret logfile

Go to Preferences->Protocols->TLS and set the Pre-Master-Secret log file to the same value that was specified for SSLKEYLOGFILE.
Choose the correct network interface for capturing

Make sure you choose the correct network interface for capturing. For example, if using localhost choose the loopback network interface on macos.
Create a filter

Create A filter for the udp.port and set the port to the port the application is listening to. For example:
```
udp.port == 7777
```

License

The MIT License

dr7ana/ngtcp2