Pure Dart QUIC + HTTP/3 + WebTransport

A pure Dart implementation of:

  • QUIC transport
  • TLS 1.3 over QUIC
  • HTTP/3
  • WebTransport
  • WebTransport DATAGRAM
  • basic QPACK / HTTP/3 SETTINGS handling

This project demonstrates a full end-to-end QUIC stack written in Dart, including:

  • Initial secret derivation
  • QUIC packet protection / header protection
  • TLS handshake message exchange over QUIC CRYPTO frames
  • 1-RTT key installation
  • HTTP/3 control stream bootstrap
  • WebTransport CONNECT
  • WebTransport datagram echo

Status

Implemented

  • QUIC Initial / Handshake / 1-RTT packet protection
  • Packet number spaces
  • ACK generation and parsing
  • CRYPTO frame reassembly
  • TLS 1.3 handshake:
    • ClientHello
    • ServerHello
    • EncryptedExtensions
    • Certificate
    • CertificateVerify
    • Finished
  • HTTP/3:
    • SETTINGS frame
    • control stream bootstrap
    • basic HEADERS / DATA framing
  • QPACK:
    • static-table-based header encoding / decoding
  • WebTransport:
    • Extended CONNECT
    • DATAGRAM frames
    • session establishment
    • datagram echo test
  • Client bootstrap streams:
    • client control stream
    • client QPACK encoder stream
    • client QPACK decoder stream

What this project proves

This implementation is not just a toy packet parser — it demonstrates a real protocol stack capable of:

  • speaking QUIC over UDP
  • negotiating TLS 1.3 inside QUIC CRYPTO frames
  • deriving handshake and application secrets correctly
  • speaking HTTP/3 on top of QUIC
  • establishing a WebTransport session
  • exchanging WebTransport datagrams

It has been tested successfully:

  • against the included pure Dart server
  • against stricter real HTTP/3 / WebTransport servers

Project structure

A simplified view of the important pieces:

lib/
├── buffer.dart
├── constants.dart
├── utils.dart
├── packet/
│   └── quic_packet.dart
├── frames/
│   └── quic_ack.dart
├── streams/
│   └── stream.dart
├── handshake/
│   ├── client_hello.dart
│   ├── server_hello.dart
│   └── tls_server_builder.dart
├── h3/
│   └── h3.dart
├── cipher/
│   ├── cert_utils.dart
│   ├── fingerprint.dart
│   ├── hash.dart
│   ├── hkdf.dart
│   └── x25519.dart
└── connection/
    ├── client/
    │   ├── client3.dart
    │   └── quic_session3.dart
    └── server/
        ├── server2.dart
        └── quic_server_session.dart

Libraries

buffer
byte_reader
cipher/aes_gcm
cipher/cert_utils
cipher/ecdsa
cipher/fingerprint
cipher/hash
cipher/hkdf
cipher/p256
cipher/x25519
connection/client/client3
connection/client/quic_session3
connection/server/quic_server_session
connection/server/server
connection/server/server2
constants
frames/quic_ack
frames/quic_frames
h3/h3
h3/web_transport
handshake/certificate
handshake/certificate_verify
handshake/client_hello
handshake/client_hello_builder
handshake/encrypted_extensions
handshake/finished
handshake/keyshare
handshake/server_hello
handshake/tls_messages
handshake/tls_messages2
handshake/tls_msg
handshake/tls_server_builder
packet/crypto_utils
packet/header_protector
packet/quic_header
packet/quic_packet
pure_dart_quic
streams/stream
utils