ASN1_ITEM_NEW(3)           Library Functions Manual           ASN1_ITEM_NEW(3)

NAME
     ASN1_item_new, ASN1_item_free - generic ASN.1 value constructor and
     destructor

SYNOPSIS
     #include <openssl/asn1.h>

     ASN1_VALUE *
     ASN1_item_new(const ASN1_ITEM *it);

     void
     ASN1_item_free(ASN1_VALUE *val_in, const ASN1_ITEM *it);

DESCRIPTION
     ASN1_item_new() allocates and initializes an empty ASN.1 value of the
     type described by the global static object it.

     If the item type described by it is reference counted, ASN1_item_free()
     decrements the reference count of val_in.  Otherwise, or if the reference
     count reaches 0, ASN1_item_free() frees val_in, assuming that it is of
     the type described by it.  If the true type of val_in fails to match the
     specified it, buffer overflows and segmentation faults are likely to
     occur.  It is not possible to recover the type of an ASN1_VALUE object by
     inspecting it; the type always needs to be remembered separately.

     ASN1_VALUE is an incomplete type, and pointers to it always require
     casting to the correct complete type before they can be dereferenced.
     For all practical purposes, a pointer to ASN1_VALUE is equivalent to a
     void pointer.

     Depending on it, there are more than 150 different types that
     ASN1_item_new() may return.  Most of them are pointers to structures or
     pointers to arrays of structures, but there are a few exceptions, for
     example: If it is ASN1_NULL_it, ASN1_item_new() returns a specific
     invalid pointer representing the unique ASN1_NULL object.  If it is
     LONG_it, ASN1_item_new() does not return a pointer at all, but a long
     value cast to ASN1_VALUE *.

RETURN VALUES
     The ASN1_item_new() function returns the new ASN1_VALUE object if
     successful; otherwise NULL is returned and an error code can be retrieved
     with ERR_get_error(3).

SEE ALSO
     ASN1_get_object(3), ASN1_item_d2i(3), ASN1_item_digest(3),
     ASN1_item_pack(3), ASN1_item_sign(3), ASN1_item_verify(3),
     ASN1_NULL_new(3), ASN1_TYPE_new(3), d2i_ASN1_NULL(3), OBJ_nid2obj(3)

HISTORY
     ASN1_item_new() and ASN1_item_free() first appeared in OpenSSL 0.9.7 and
     have been available since OpenBSD 3.2.

BUGS
     The ASN1_VALUE type compromises type safety and invites programming
     mistakes that will typically have severe consequences.

Linux 6.8.2-arch2-1            January 12, 2022            Linux 6.8.2-arch2-1