NAME
OBJ_new_nid,
OBJ_add_object, OBJ_create,
OBJ_create_objects,
obj_cleanup_defer,
OBJ_cleanup, check_defer
— modify the table of ASN.1
object identifiers
SYNOPSIS
#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);
extern int obj_cleanup_defer;
void
OBJ_cleanup(void);
void
check_defer(int
nid);
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
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.
The global variable
obj_cleanup_defer controls the behaviour of
OBJ_cleanup()
and EVP_cleanup(3).
If obj_cleanup_defer has
the default value of 0,
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(). Otherwise,
OBJ_cleanup() only sets
obj_cleanup_defer to 2, which defers the cleanup of
the internal object table to the next call of
EVP_cleanup(3).
By default,
EVP_cleanup(3) has no effect on the internal object table.
Only if obj_cleanup_defer is 2, it resets
obj_cleanup_defer to 0 and calls
OBJ_cleanup(),
which then resets the table to its default state.
The function
check_defer()
sets obj_cleanup_defer to 1 unless
nid is a built-in numeric identifier, but it has no
effect if obj_cleanup_defer already differs from 0.
This function is called internally by various functions in the EVP library,
in particular by subroutines of
OpenSSL_add_all_ciphers(3) and
OpenSSL_add_all_digests(3).
To reliably reset the internal object table no
matter what the current state may be, an application program needs to call
both
OBJ_cleanup()
and EVP_cleanup(3), in this order. The opposite order will
usually not work.
RETURN VALUES
OBJ_new_nid() returns the new NID.
OBJ_add_object() returns the NID
associated with the object or
NID_undef if memory allocation fails.
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), EVP_cleanup(3), OBJ_add_sigid(3), OBJ_NAME_add(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.
obj_cleanup_defer and
check_defer() first appeared in OpenSSL 1.0.0 and
have been available since OpenBSD 4.9.
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.