OBJ_CREATE(3) | Library Functions Manual | OBJ_CREATE(3)

# NAME

`OBJ_new_nid`, `OBJ_add_object`, `OBJ_create`, `OBJ_create_objects`, `OBJ_cleanup` — modify the table of ASN.1 object identifiers

# SYNOPSIS

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

int
`OBJ_new_nid`(int increment);

int
`OBJ_add_object`(const ASN1_OBJECT *object);

int
`OBJ_create`(const char *oid, const char *sn, const char *ln);

int
`OBJ_create_objects`(BIO *in_bio);

void
`OBJ_cleanup`(void);

# DESCRIPTION

`OBJ_new_nid`() returns the smallest currently unassigned ASN.1 numeric object identifier (NID) and reserves increment consecutive NIDs starting with it. Passing an argument of 1 is usually recommended. The return value can be assigned to a new object by passing it as the nid argument to ASN1_OBJECT_create(3) and by passing the resulting object to `OBJ_add_object`().

`OBJ_add_object`() adds a copy of the object to the internal table of ASN.1 object identifiers for use by OBJ_nid2obj(3) and related functions.

`OBJ_create`() provides a simpler way to add a new object to the internal table. oid is the numerical form of the object, sn the short name and ln the long name. A new NID is automatically assigned using `OBJ_new_nid`().

`OBJ_create_objects`() reads text lines of the form

oid sn ln

from in_bio and calls `OBJ_create`(oid, sn, ln) for every line read. The three fields of the input lines are separated by one or more whitespace characters.

For all three functions, the objects added to the internal table and all the data contained in them is marked as not dynamically allocated. Consequently, retrieving them with OBJ_nid2obj(3) or a similar function and then calling ASN1_OBJECT_free(3) on the returned pointer will have no effect.

`OBJ_cleanup`() resets the internal object table to its default state, removing and freeing all objects that were added with `OBJ_add_object`(), `OBJ_create`(), or `OBJ_create_objects`().

# RETURN VALUES

`OBJ_new_nid`() returns the new NID.

`OBJ_add_object`() returns the NID of the added object or `NID_undef` if no object was added because the object argument was `NULL`, did not contain an NID, or memory allocation failed.

`OBJ_create`() returns the new NID or `NID_undef` if oid is not a valid representation of an object identifier or if memory allocation fails.

`OBJ_create_objects`() returns the number of objects added.

In some cases of failure of `OBJ_add_object`(), `OBJ_create`(), and `OBJ_create_objects`(), the reason can be determined with ERR_get_error(3).

# EXAMPLES

Create a new NID and initialize an object from it:

    int new_nid;
    ASN1_OBJECT *obj;

    new_nid = OBJ_create("1.2.3.4", "NewOID", "New Object Identifier");
    obj = OBJ_nid2obj(new_nid);

# SEE ALSO

ASN1_OBJECT_new(3), OBJ_nid2obj(3)

# HISTORY

`OBJ_new_nid`(), `OBJ_add_object`(), and `OBJ_cleanup`() first appeared in SSLeay 0.8.0 and `OBJ_create`() in SSLeay 0.9.0. These functions have been available since OpenBSD 2.4.

# CAVEATS

`OBJ_add_object`() indicates success even after adding an incomplete object that was created with ASN1_OBJECT_create(3) but lacks a short name, a long name, or an OID.

Even `OBJ_create`() tolerates `NULL` pointers being passed for the sn and/or ln arguments, in which case OBJ_nid2sn(3) and OBJ_sn2nid(3) or OBJ_nid2ln(3) and OBJ_ln2nid(3) will not work on the added object, respectively.

# BUGS

`OBJ_new_nid`() does not reserve any return value to indicate an error. Consequently, to avoid conflicting NID assignments and integer overflows, care must be taken to not pass negative, zero, or large arguments to `OBJ_new_nid`().

`OBJ_create_objects`() does not distinguish between end of file, I/O errors, temporary unavailability of data on a non-blocking BIO, invalid input syntax, and memory allocation failure. In all these cases, reading is aborted and the number of objects that were already added is returned.

June 8, 2025 | Debian