LIBRESSL-X509_STORE_SET_VERIFY_CB_FUNC(3)

🦋 NAME 🦋

X509_STORE_set_verify_cb, X509_STORE_set_verify_cb_func, and X509_STORE_get_verify_cb — the little trio for setting and getting the verification callback, bestie. This is the X509_STORE_SET_VERIFY_CB(3) page from the Library Functions Manual, and it lives in libcrypto. Periodt.

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🌈 SYNOPSIS 🌈

okay so first, library:

library “libcrypto” #include <openssl/x509_vfy.h>

void
X509_STORE_set_verify_cb(X509_STORE *st,
    X509_STORE_CTX_verify_cb verify_cb);

void
X509_STORE_set_verify_cb_func(X509_STORE *st,
    X509_STORE_CTX_verify_cb verify_cb);

X509_STORE_CTX_verify_cb
X509_STORE_get_verify_cb(X509_STORE *st);

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💅 DESCRIPTION 💅

So X509_STORE_set_verify_cb() sets the verification callback of ctx to verify_cb, and it overwrites any existing callback — no stacking, no collecting them like Pokémon, just a clean swap. (The page says ctx right there; I’m keeping the lore exactly as written 🫶.)

X509_STORE_set_verify_cb_func() also sets the verification callback, but plot twist: it is implemented as a macro. ✨

The verification callback from an X509_STORE gets inherited by the corresponding X509_STORE_CTX structure when it is initialized. That’s lowkey the useful part: it lets you set the verification callback when the X509_STORE_CTX is otherwise inaccessible — for example during S/MIME verification. Iykyk.

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🎀 RETURN VALUES 🎀

X509_STORE_get_verify_cb() returns the function pointer set with X509_STORE_set_verify_cb(), or NULL if that function was not called on st. That’s it, bestie — no hidden drama.

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🔥 SEE ALSO 🔥

• X509_STORE_CTX_new(3)
• X509_STORE_CTX_set_verify(3)
• X509_STORE_CTX_set_verify_cb(3)
• X509_STORE_new(3)
• X509_STORE_set_flags(3)
• X509_verify_cert(3)

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👑 HISTORY 👑

• X509_STORE_set_verify_cb_func() first appeared in SSLeay 0.8.0 and has been available since OpenBSD 2.4.
• X509_STORE_set_verify_cb() first appeared in OpenSSL 1.0.0 and has been available since OpenBSD 4.9.
• X509_STORE_get_verify_cb() first appeared in OpenSSL 1.1.0 and has been available since OpenBSD 7.2.

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okay that’s the whole page, bestie 💖 This ✨ Debian ✨ edition of X509_STORE_SET_VERIFY_CB_FUNC(3) is dated June 8, 2025 — mwah, slay, and goodbye 🎀🦋