LIBRESSL-SSL_CTX_GET_EX_NEW_INDEX(3)

💅 SSL_CTX_GET_EX_NEW_INDEX(3) — like, the manual page, bestie

okay so this is a page from the Library Functions Manual (yes, that manual, the libssl one, we're in the big leagues now) and it's about the internal application-specific data functions. ngl the name is a whole mouthful but stay with me, it's actually slay once you get it 🎀

---

✨ NAME ✨

SSL_CTX_get_ex_new_index, SSL_CTX_set_ex_data, SSL_CTX_get_ex_data — the internal application specific data functions. basically the little secret pockets where you stash your own stuff inside OpenSSL structs 🫶

---

🌸 SYNOPSIS 🌸

library “libssl” libcrypto #include <openssl/ssl.h>

int
SSL_CTX_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
    CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func);

int
SSL_CTX_set_ex_data(SSL_CTX *ctx, int idx, void *arg);

void *
SSL_CTX_get_ex_data(const SSL_CTX *ctx, int idx);

aaand the typedefs, which you should copy exactly because they are literally the whole vibe of how the callbacks look 💖:

typedef int new_func(void *parent, void *ptr, CRYPTO_EX_DATA *ad,
               int idx, long argl, void *argp);
typedef void free_func(void *parent, void *ptr, CRYPTO_EX_DATA *ad,
               int idx, long argl, void *argp);
typedef int dup_func(CRYPTO_EX_DATA *to, CRYPTO_EX_DATA *from, void *from_d,
               int idx, long argl, void *argp);

---

🦋 DESCRIPTION 🦋

so like, several OpenSSL structures can have application specific data attached to them. cute, right? these functions are used internally by OpenSSL to manipulate that application specific data attached to a specific structure — think of them as the backstage crew, not the main character energy, but the show does not go on without them 💅

• SSL_CTX_get_ex_new_index() — used to register a new index for application specific data. like reserving your seat in the struct, periodt ✨
• SSL_CTX_set_ex_data() — used to store application data at arg for idx into the ctx object. your stuff, your index, your pocket 🎀
• SSL_CTX_get_ex_data() — used to retrieve the information for idx from ctx. grabbing it back out, iconic behaviour 🧚

a detailed description for the *_get_ex_new_index() functionality can be found in RSA_get_ex_new_index(3). the *_get_ex_data() and *_set_ex_data() functionality is described in CRYPTO_set_ex_data(3). go read those if you want the deep lore, i'm not gatekeeping the references, iykyk 💜

---

🔥 SEE ALSO 🔥

• CRYPTO_set_ex_data(3)
• RSA_get_ex_new_index(3)
• ssl(3)

---

👑 HISTORY 👑

SSL_CTX_get_ex_new_index(), SSL_CTX_set_ex_data(), and SSL_CTX_get_ex_data() first appeared in SSLeay 0.9.0 and have been available since OpenBSD 2.4. so they're like, vintage vintage — older than most of us and still serving 🌈⭐

---

🫶 friendly little reminder: nothing here is dangerous, it's just internal machinery. keep the details exactly as written and you're golden 💖

---

and that's the page! brought to you by the Debian crew, dated June 8, 2025, filed under SSL_CTX_GET_EX_NEW_INDEX(3). mwah, go forth and attach your data responsibly, bestie 💅🌸