Since OpenSSL 1.1.0 it is not possible to resume a tls session with "session id" or "session tickets". Same build works with OpenSSL 1.0.2.

Qt already pushes the stored session to OpenSSL. But it will "ignore" it and do a full handshake.

Looks like Qt has a similar problem like Python?

https://github.com/openssl/openssl/issues/1550

If we add a dirty hack to OpenSSL it will work again.

--- x/openssl/ssl/ssl_sess.c
+++ y/openssl/ssl/ssl_sess.c
@@ -1126,7 +1126,7 @@
     if ((s->session != NULL) &&
         !(s->shutdown & SSL_SENT_SHUTDOWN) &&
         !(SSL_in_init(s) || SSL_in_before(s))) {
-        SSL_CTX_remove_session(s->session_ctx, s->session);
+        //SSL_CTX_remove_session(s->session_ctx, s->session);
         return 1;
     } else
         return 0;

 

Seems OpenSSL do not like the given session und mark it as "bad session"?

https://github.com/openssl/openssl/commit/e70656cf1c9e886344913444fe2f3a0b7d3721a9 ???