X509_LOOKUP_METH_NEW(3ossl)

✨ X509_LOOKUP_METH_NEW ✨

okay bestie, so this is the OpenSSL manual page for X509_LOOKUP_METH_NEW(3ossl) — and it's literally the whole toolkit for building your own X509_LOOKUP methods. we're talking the entire squad: X509_LOOKUP_METHOD, X509_LOOKUP_meth_new, X509_LOOKUP_meth_free, X509_LOOKUP_meth_set_new_item, X509_LOOKUP_meth_get_new_item, X509_LOOKUP_meth_set_free, X509_LOOKUP_meth_get_free, X509_LOOKUP_meth_set_init, X509_LOOKUP_meth_get_init, X509_LOOKUP_meth_set_shutdown, X509_LOOKUP_meth_get_shutdown, X509_LOOKUP_ctrl_fn, X509_LOOKUP_meth_set_ctrl, X509_LOOKUP_meth_get_ctrl, X509_LOOKUP_get_by_subject_fn, X509_LOOKUP_meth_set_get_by_subject, X509_LOOKUP_meth_get_get_by_subject, X509_LOOKUP_get_by_issuer_serial_fn, X509_LOOKUP_meth_set_get_by_issuer_serial, X509_LOOKUP_meth_get_get_by_issuer_serial, X509_LOOKUP_get_by_fingerprint_fn, X509_LOOKUP_meth_set_get_by_fingerprint, X509_LOOKUP_meth_get_get_by_fingerprint, X509_LOOKUP_get_by_alias_fn, X509_LOOKUP_meth_set_get_by_alias, X509_LOOKUP_meth_get_get_by_alias, X509_OBJECT_set1_X509, X509_OBJECT_set1_X509_CRL 💖

one-line vibe: these are the routines to build up X509_LOOKUP methods. iconic, honestly.

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🌸 SYNOPSIS 🌸

#include <openssl/x509_vfy.h>

typedef x509_lookup_method_st X509_LOOKUP_METHOD;

X509_LOOKUP_METHOD *X509_LOOKUP_meth_new(const char *name);
void X509_LOOKUP_meth_free(X509_LOOKUP_METHOD *method);

int X509_LOOKUP_meth_set_new_item(X509_LOOKUP_METHOD *method,
                                  int (*new_item) (X509_LOOKUP *ctx));
int (*X509_LOOKUP_meth_get_new_item(const X509_LOOKUP_METHOD* method))
    (X509_LOOKUP *ctx);

int X509_LOOKUP_meth_set_free(X509_LOOKUP_METHOD *method,
                              void (*free) (X509_LOOKUP *ctx));
void (*X509_LOOKUP_meth_get_free(const X509_LOOKUP_METHOD* method))
    (X509_LOOKUP *ctx);

int X509_LOOKUP_meth_set_init(X509_LOOKUP_METHOD *method,
                              int (*init) (X509_LOOKUP *ctx));
int (*X509_LOOKUP_meth_get_init(const X509_LOOKUP_METHOD* method))
    (X509_LOOKUP *ctx);

int X509_LOOKUP_meth_set_shutdown(X509_LOOKUP_METHOD *method,
                                  int (*shutdown) (X509_LOOKUP *ctx));
int (*X509_LOOKUP_meth_get_shutdown(const X509_LOOKUP_METHOD* method))
    (X509_LOOKUP *ctx);

typedef int (*X509_LOOKUP_ctrl_fn)(X509_LOOKUP *ctx, int cmd, const char *argc,
                                   long argl, char **ret);
int X509_LOOKUP_meth_set_ctrl(X509_LOOKUP_METHOD *method,
    X509_LOOKUP_ctrl_fn ctrl_fn);
X509_LOOKUP_ctrl_fn X509_LOOKUP_meth_get_ctrl(const X509_LOOKUP_METHOD *method);

typedef int (*X509_LOOKUP_get_by_subject_fn)(X509_LOOKUP *ctx,
                                             X509_LOOKUP_TYPE type,
                                             const X509_NAME *name,
                                             X509_OBJECT *ret);
int X509_LOOKUP_meth_set_get_by_subject(X509_LOOKUP_METHOD *method,
    X509_LOOKUP_get_by_subject_fn fn);
X509_LOOKUP_get_by_subject_fn X509_LOOKUP_meth_get_get_by_subject(
    const X509_LOOKUP_METHOD *method);

typedef int (*X509_LOOKUP_get_by_issuer_serial_fn)(X509_LOOKUP *ctx,
                                                   X509_LOOKUP_TYPE type,
                                                   const X509_NAME *name,
                                                   const ASN1_INTEGER *serial,
                                                   X509_OBJECT *ret);
int X509_LOOKUP_meth_set_get_by_issuer_serial(
    X509_LOOKUP_METHOD *method, X509_LOOKUP_get_by_issuer_serial_fn fn);
X509_LOOKUP_get_by_issuer_serial_fn X509_LOOKUP_meth_get_get_by_issuer_serial(
    const X509_LOOKUP_METHOD *method);

typedef int (*X509_LOOKUP_get_by_fingerprint_fn)(X509_LOOKUP *ctx,
                                                 X509_LOOKUP_TYPE type,
                                                 const unsigned char* bytes,
                                                 int len,
                                                 X509_OBJECT *ret);
int X509_LOOKUP_meth_set_get_by_fingerprint(X509_LOOKUP_METHOD *method,
    X509_LOOKUP_get_by_fingerprint_fn fn);
X509_LOOKUP_get_by_fingerprint_fn X509_LOOKUP_meth_get_get_by_fingerprint(
    const X509_LOOKUP_METHOD *method);

typedef int (*X509_LOOKUP_get_by_alias_fn)(X509_LOOKUP *ctx,
                                           X509_LOOKUP_TYPE type,
                                           const char *str,
                                           int len,
                                           X509_OBJECT *ret);
int X509_LOOKUP_meth_set_get_by_alias(X509_LOOKUP_METHOD *method,
    X509_LOOKUP_get_by_alias_fn fn);
X509_LOOKUP_get_by_alias_fn X509_LOOKUP_meth_get_get_by_alias(
    const X509_LOOKUP_METHOD *method);

int X509_OBJECT_set1_X509(X509_OBJECT *a, X509 *obj);
int X509_OBJECT_set1_X509_CRL(X509_OBJECT *a, X509_CRL *obj);

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💅 DESCRIPTION 💅

so the X509_LOOKUP_METHOD type is a struct that exists so you can implement brand-new X509_LOOKUP types. it's basically a lil bundle of function pointers that OpenSSL uses to implement all the various X509 and X509_CRL lookup capabilities. and here's the slay part: one instance of an X509_LOOKUP_METHOD can be associated to many instantiations of an X509_LOOKUP structure. efficiency queen. 👑

X509_LOOKUP_meth_new() creates a shiny new X509_LOOKUP_METHOD structure. you gotta hand it a human-readable string containing a brief description of the lookup method. (name your children, bestie.)

X509_LOOKUP_meth_free() destroys a X509_LOOKUP_METHOD structure. and if the argument is NULL, nothing happens — it's giving very chill, no crashes, we love that for us. ✨

X509_LOOKUP_get_new_item() and X509_LOOKUP_set_new_item() get and set the function that gets called when an X509_LOOKUP object is created with X509_LOOKUP_new(). if an X509_LOOKUP_METHOD needs any per-X509_LOOKUP specific data, the supplied new_item function should allocate that data and invoke X509_LOOKUP_set_method_data(3).

X509_LOOKUP_get_free() and X509_LOOKUP_set_free() get and set the function used to free any method data that was allocated and set from within the new_item function. (cleanup era. we stan.)

X509_LOOKUP_meth_get_init() and X509_LOOKUP_meth_set_init() get and set the function used to initialize the method data that was set with X509_LOOKUP_set_method_data(3) as part of the new_item routine.

X509_LOOKUP_meth_get_shutdown() and X509_LOOKUP_meth_set_shutdown() get and set the function used to shut down the method data whose state was previously initialized in the init function.

X509_LOOKUP_meth_get_ctrl() and X509_LOOKUP_meth_set_ctrl() get and set a function to be used to handle arbitrary control commands issued by X509_LOOKUP_ctrl(). the control function gets handed the X509_LOOKUP ctx, along with the arguments passed by X509_LOOKUP_ctrl. here's the breakdown, no cap:

• cmd is an arbitrary integer that defines some operation.
• argc is a pointer to an array of characters.
• argl is an integer.
• ret, if set, points to a location where any return data should be written to.

how argc and argl are used depends entirely on the control function. it's giving choose-your-own-adventure. 🦋

X509_LOOKUP_set_get_by_subject(), X509_LOOKUP_set_get_by_issuer_serial(), X509_LOOKUP_set_get_by_fingerprint(), X509_LOOKUP_set_get_by_alias() set the functions used to retrieve an X509 or X509_CRL object by the object's subject, issuer, fingerprint, and alias respectively. these functions are given the X509_LOOKUP context, the type of the X509_OBJECT being requested, parameters related to the lookup, and an X509_OBJECT that will receive the requested object.

⚠️ okay important one, listen up: implementations must add objects they find to the X509_STORE object using X509_STORE_add_cert() or X509_STORE_add_crl(). this increments its reference count. however, the X509_STORE_CTX_get_by_subject(3) function also increases the reference count, which leads to one too many references being held. so applications should additionally call X509_free() or X509_CRL_free() to decrement the reference count again. the way that refcount math does NOT math by default 😭

implementations should also use either X509_OBJECT_set1_X509() or X509_OBJECT_set1_X509_CRL() to set the result. note that this also increments the result's reference count. (yes, another one. keep track, bestie. 📝)

any method data that was created as a result of the new_item function set by X509_LOOKUP_meth_set_new_item() can be accessed with X509_LOOKUP_get_method_data(3). the X509_STORE object that owns the X509_LOOKUP may be accessed with X509_LOOKUP_get_store(3). successful lookups should return 1, and unsuccessful lookups should return 0. simple as. periodt.

X509_LOOKUP_get_get_by_subject(), X509_LOOKUP_get_get_by_issuer_serial(), X509_LOOKUP_get_get_by_fingerprint(), X509_LOOKUP_get_get_by_alias() retrieve the function set by the corresponding setter. (yes the double-get naming is real, and yes it's a lot, we don't talk about it 💀)

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🎀 RETURN VALUES 🎀

the X509_LOOKUP_meth_set functions return 1 on success or 0 on error. classic.

the X509_LOOKUP_meth_get functions return the corresponding function pointers.

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🌈 SEE ALSO 🌈

• X509_STORE_CTX_get_by_subject(3)
• X509_STORE_new(3)
• SSL_CTX_set_cert_store(3)

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⭐ HISTORY ⭐

the functions described here were added in OpenSSL 1.1.0i. so they've been around, lowkey iconic since day one.

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👑 COPYRIGHT 👑

Copyright 2018-2024 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

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and that's the whole page, bestie 🫶 this was X509_LOOKUP_METH_NEW(3ossl) from the OpenSSL fam — version 3.5.9, dated 2026-09-29. go forth and build your lookup methods, you absolute main character 💖✨🎀