erlang/otp#7431 PoC

test.es

#!/usr/bin/env escript
-mode(compile).

-define(PORT, 2345).
-define(SERVER_TIMEOUT, 1000).
-define(CLIENT_TIMEOUT, 1500).

main(Msg) ->
  application:ensure_all_started(ssl),
  spawn(fun server/0),
  timer:sleep(100),
  client(Msg).

server() ->
  Options = [{certs_keys, [#{certfile => "cert.pem", keyfile => "key.pem"}]},
             {versions, ['tlsv1.2']},
             {verify, verify_none},
             {ciphers, ssl:cipher_suites(all, 'tlsv1.2')}
            ],
  {ok, LS} = ssl:listen(?PORT, Options),
  {ok, TS} = ssl:transport_accept(LS),
  {ok, S} = ssl:handshake(TS),
  receive
    {ssl_closed, S} ->
      io:format("server closed~n");
    {ssl_error, S, Reason} ->
      io:format("server error: ~p~n", [Reason])
  after
    ?SERVER_TIMEOUT ->
      io:format("server timeout~n"),
      ssl:close(S)
  end.

client(Msg) ->
  Options = [{versions, ['tlsv1.2']},
             {verify, verify_none},
             {renegotiate_at, 5}
            ],
  {ok, S} = ssl:connect("localhost", ?PORT, Options, infinity),
  spawn(fun () -> client(S, Msg) end),
  receive
    {ssl_closed, S} ->
      io:format("client closed~n"),
      halt(0);
    {ssl_error, S, Reason} ->
      io:format("client error: ~p~n", [Reason]),
      halt(0)
  after
    ?CLIENT_TIMEOUT ->
      io:format("client timeout~n"),
      ssl:close(S),
      halt(1)
  end.

client(_S, []) ->
  io:format("client is not sending messages!~n");
client(S, Msg) ->
  timer:sleep(10),
  case ssl:send(S, Msg) of
    ok ->
      client(S, Msg);
    {error, Reason} ->
      io:format("client send error: ~p~n", [Reason])
  end.