This issue came with this commit: f627b92 BUG/MEDIUM: quic: always validate sender address on 0-RTT and could be easily reproduced with picoquic QUIC client with -Q option which splits a big ClientHello TLS message into two Initial datagrams. A second condition must be fulfilled to reprodue this issue: picoquic must not send the token provided by haproxy (NEW_TOKEN). To do that, haproxy must be patched to prevent it to send such tokens. Under these conditions, if haproxy has enough time to reply to the first Initial datagrams, when it receives the second Initial datagram it sends a Retry paquet. Then the client ignores the Retry paquet as mentionned by RFC 9000: 17.2.5.2. Handling a Retry Packet A client MUST accept and process at most one Retry packet for each connection attempt. After the client has received and processed an Initial or Retry packet from the server, it MUST discard any subsequent Retry packets that it receives. On its side, haproxy has closed the connection. When it receives the second Initial datagram, it open a new connection but with Initial packets it cannot decrypt (wrong ODCID) leaving the client without response. To fix this, as the aim of the token (NEW_TOKEN) sent by haproxy is to validate the peer address, in place of closing the connection when no token was received for a 0RTT connection, one leaves this validation to the handshake process. Indeed, the peer adress is validated during the handshake when a valid handshake packet is received by the listener. But as one does not want haproxy to process 0RTT data when no token was received, one does not accept the connection before the successful handshake completion. In addition to this, the 0RTT packets are not released after successful handshake completion when no token was received to leave a chance to haproxy to process these 0RTT data in such case (see quic_conn_io_cb()). Must be backported as far as 2.9.
HAProxy
HAProxy is a free, very fast and reliable reverse-proxy offering high availability, load balancing, and proxying for TCP and HTTP-based applications.
Installation
The INSTALL file describes how to build HAProxy. A list of packages is also available on the wiki.
Getting help
The discourse and the mailing-list are available for questions or configuration assistance. You can also use the slack or IRC channel. Please don't use the issue tracker for these.
The issue tracker is only for bug reports or feature requests.
Documentation
The HAProxy documentation has been split into a number of different files for ease of use. It is available in text format as well as HTML. The wiki is also meant to replace the old architecture guide.
Please refer to the following files depending on what you're looking for:
- INSTALL for instructions on how to build and install HAProxy
- BRANCHES to understand the project's life cycle and what version to use
- LICENSE for the project's license
- CONTRIBUTING for the process to follow to submit contributions
The more detailed documentation is located into the doc/ directory:
- doc/intro.txt for a quick introduction on HAProxy
- doc/configuration.txt for the configuration's reference manual
- doc/lua.txt for the Lua's reference manual
- doc/SPOE.txt for how to use the SPOE engine
- doc/network-namespaces.txt for how to use network namespaces under Linux
- doc/management.txt for the management guide
- doc/regression-testing.txt for how to use the regression testing suite
- doc/peers.txt for the peers protocol reference
- doc/coding-style.txt for how to adopt HAProxy's coding style
- doc/internals for developer-specific documentation (not all up to date)
License
HAProxy is licensed under GPL 2 or any later version, the headers under LGPL 2.1. See the LICENSE file for a more detailed explanation.