SSL_CTX_SESS_NUMBER(3)

📦 version 4.4.0, in alpine 3.24, arch rolling

💅 SSL_CTX_SESS_NUMBER(3) ✨

okay so this is a page from the Library Functions Manual, bestie, and the whole squad of functions here is literally just "gimme the numbers on your session cache." Numbers girlies, rise 🫶

🌸 NAME 🌸

SSL_CTX_sess_number, SSL_CTX_sess_connect, SSL_CTX_sess_connect_good, SSL_CTX_sess_connect_renegotiate, SSL_CTX_sess_accept, SSL_CTX_sess_accept_good, SSL_CTX_sess_accept_renegotiate, SSL_CTX_sess_hits, SSL_CTX_sess_cb_hits, SSL_CTX_sess_misses, SSL_CTX_sess_timeouts, SSL_CTX_sess_cache_full — obtain session cache statistics 💖

✨ SYNOPSIS ✨

it lives in library “libssl” libcrypto, and you get to it like this:

#include <openssl/ssl.h>

and every single one of these returns a long and takes an SSL_CTX *ctx, no cap:

long
SSL_CTX_sess_number(SSL_CTX *ctx);

long
SSL_CTX_sess_connect(SSL_CTX *ctx);

long
SSL_CTX_sess_connect_good(SSL_CTX *ctx);

long
SSL_CTX_sess_connect_renegotiate(SSL_CTX *ctx);

long
SSL_CTX_sess_accept(SSL_CTX *ctx);

long
SSL_CTX_sess_accept_good(SSL_CTX *ctx);

long
SSL_CTX_sess_accept_renegotiate(SSL_CTX *ctx);

long
SSL_CTX_sess_hits(SSL_CTX *ctx);

long
SSL_CTX_sess_cb_hits(SSL_CTX *ctx);

long
SSL_CTX_sess_misses(SSL_CTX *ctx);

long
SSL_CTX_sess_timeouts(SSL_CTX *ctx);

long
SSL_CTX_sess_cache_full(SSL_CTX *ctx);

🦋 DESCRIPTION 🦋

okay so this is where it gets fun — each one of these is a little counter, a little vibe check on your session cache. let's go one by one 💅

  • SSL_CTX_sess_number() returns the current number of sessions in the internal session cache. that's it, that's the count.
  • SSL_CTX_sess_connect() returns the number of started SSL/TLS handshakes in client mode. started, not finished — careful 👀
  • SSL_CTX_sess_connect_good() returns the number of successfully established SSL/TLS sessions in client mode. the slay count 💖
  • SSL_CTX_sess_connect_renegotiate() returns the number of started renegotiations in client mode.
  • SSL_CTX_sess_accept() returns the number of started SSL/TLS handshakes in server mode.
  • SSL_CTX_sess_accept_good() returns the number of successfully established SSL/TLS sessions in server mode.
  • SSL_CTX_sess_accept_renegotiate() returns the number of started renegotiations in server mode.
  • SSL_CTX_sess_hits() returns the number of successfully reused sessions. In client mode, a session set with SSL_set_session(3) that gets successfully reused counts as a hit. In server mode, a session successfully retrieved from the internal or external cache counts as a hit. reuse era 🎀
  • SSL_CTX_sess_cb_hits() returns the number of successfully retrieved sessions from the external session cache in server mode.
  • SSL_CTX_sess_misses() returns the number of sessions proposed by clients that were not found in the internal session cache in server mode. sad but true 😭
  • SSL_CTX_sess_timeouts() returns the number of sessions proposed by clients that were found in the internal or external session cache in server mode, but that were invalid due to timeout. and listen — these sessions are not included in the SSL_CTX_sess_hits() count. don't double-count, bestie 🙈
  • SSL_CTX_sess_cache_full() returns the number of sessions that were removed because the maximum session cache size was exceeded. evicted 💀
fr fr everything here is just read-only stat grabbing — you're not changing anything, you're just asking your cache how it's doing.

🔥 SEE ALSO 🔥

👑 HISTORY 👑

ok bestie, storytime 📖:

  • SSL_CTX_sess_number(), SSL_CTX_sess_connect(), SSL_CTX_sess_connect_good(), SSL_CTX_sess_accept(), SSL_CTX_sess_accept_good(), SSL_CTX_sess_hits(), SSL_CTX_sess_misses(), and SSL_CTX_sess_timeouts() first appeared in SSLeay 0.5.2.
  • SSL_CTX_sess_cb_hits() first appeared in SSLeay 0.6.0.
  • SSL_CTX_sess_connect_renegotiate(), SSL_CTX_sess_accept_renegotiate(), and SSL_CTX_sess_cache_full() first appeared in SSLeay 0.9.0.

and all of these functions have been available since OpenBSD 2.4. longevity icon behavior, honestly 🌈⭐

mwah, that's the whole page — this Debian build is dated June 8, 2025, and SSL_CTX_SESS_NUMBER(3) says byeee 💜✨

📦 where this page comes from