I'm testing my server application (TLS 1.3) using s_client program from the openssl library and I need to force the s_client generating my "random" values in it's ClientHello. Could you tell me, how can I do it using command line options - where I should point my random sequence to be generated ?

  • 1
    $\begingroup$ There is no command line option to set a specific random value in the ClientHello. $\endgroup$ Commented Jun 12, 2023 at 17:28
  • $\begingroup$ @Steffen Ullrich, may be it is possible to do it programmatically (rebuild s_client after adding some API calls) ? I use s_client for debugging my server only. So I don't use openssl directly as a library for my programming. $\endgroup$
    – LUN
    Commented Jun 13, 2023 at 19:54
  • $\begingroup$ Since openssl is open source you could adapt it to your needs. But from my understanding there is no API inside openssl which would make what you are trying to do easy to implement. Anyway, how this could be done is a programming question, i.e. off-topic here. $\endgroup$ Commented Jun 13, 2023 at 20:36
  • $\begingroup$ @Steffen Ullrich, thank you very much! $\endgroup$
    – LUN
    Commented Jun 14, 2023 at 19:48


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.