OpenSSL s_server with GoodMorning message in clear text

Tomas Mraz tomas at
Tue Sep 26 11:35:42 UTC 2023

In s_client there is already the -starttls option that does this on the
client side. So you could implement the -starttls option similarly on
the server side.

Tomas Mraz, OpenSSL

On Tue, 2023-09-26 at 12:11 +0200, Matthias Apitz wrote:
> Hello,
> Our C-written application servers, which are using OpenSSL, have a
> clear text
> GoodMorning message sent to an connecting client in the form of
> this string (for example):
> 220 SLNP
> CATServer at version:V7.3 at user:sisis at pid:5234 at charset:UTF-8 at ssl:true
> i.e. the connecting client must first read from the socket this
> GoodMorning message and when the server says in this line at the end
> '@ssl:true' must then switch in the socket to SSL which the server
> awaits also with SSL_accept(), BIO_gets(), ...
> This works nicely for many years.
> What I would like to have is a s_server version of OpenSSL where
> this also sends out such GoogMorning message in ASCII before
> switching to SSL, just for testing purpose for our Java written
> application clients.
> What is the best place to hook into the sources such "plugin".
> Thanks
>         matthias

Tomáš Mráz, OpenSSL

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