Hello,

I am trying to connect the AMQP client to RabbitMQ server over TLSv1.3 and I am facing the following issue:

iex> AMQP.Connection.open([host: "playground.mydomain.net", port: "10001", username: "toto", password: "tata", ssl_options: [versions: [:"tlsv1.3"]]])

[12:36:38.655] - []
[supervisor: {#PID<0.707.0>, :amqp_connection_sup}, started: [pid: #PID<0.709.0>, name: :connection, mfargs: {:amqp_gen_connection, :start_link, [#PID<0.708.0>, {:amqp_params_network, "toto", {:plaintext, "tata"}, "/", 'playground.mydomain.net', 10001, 0, 0, 10, 50000, [server_name_indication: 'playground.mydomain.net', versions: [:"tlsv1.3"]], [&:amqp_auth_mechanisms.plain/3, &:amqp_auth_mechanisms.amqplain/3], [], []}]}, restart_type: :intrinsic, shutdown: :brutal_kill, child_type: :worker]]

when i try to use TLSv1.2, it works fine

iex> AMQP.Connection.open([host: "playground.mydomain.net", port: "10001", username: "toto", password: "tata", ssl_options: [versions: [:"tlsv1.2"]]])
...
{:ok, %AMQP.Connection{pid: #PID<0.693.0>}}

I am running the following versions for Elixir/Erlang:

Erlang/OTP 23 [erts-11.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe]

Elixir 1.10.4 (compiled with Erlang/OTP 23)

RabbitMQ server TLS is done via a TLS terminating proxy, so i enabled/disabled the TLSv1.2/TLSv1.3 for each attempt, they are not working both at the same time. The certs are Let’s Encrypt issued.

The same termination proxy handles :hackney as an HTTP TLSv1.3 client without any issue.

Any idea on what is going on ?

Thanks for your help