> On Jun 10, 2019, at 10:54 AM, Jeremy Harris <jgh@xxxxxxxxxxx> wrote: > >> |void SSL_CTX_sess_set_new_cb(SSL_CTX *ctx, int (*new_session_cb)(SSL *, >> SSL_SESSION *));| >> >> >> How do we specify a user-defined callback data pointer in that call? > > You don't; you additionally use > SSL_CTX_set_msg_callback_arg() > which the OP said he was already using. That was a different callback (upthread), the OP is now asking about the new session callback, which has no explicit application argument. Perhaps there should be a new "_ex" version that supports an argument, but in the meantime applications that want an application context with the new session callback have been using ex_data for the last decade or two. -- Viktor.