NAME

ASN1_NULL_new, ASN1_NULL_free — ASN.1 NULL value

SYNOPSIS

#include <openssl/asn1.h>

ASN1_NULL *
ASN1_NULL_new(void);

void
ASN1_NULL_free(ASN1_NULL *val_in);

DESCRIPTION

ASN1_NULL_new() returns a specific invalid pointer that represents the ASN.1 NULL value, which is the only possible value of the ASN.1 NULL type. That pointer is different from a NULL pointer. Dereferencing it almost certainly results in a segmentation fault. This function does not allocate memory and cannot fail.

ASN1_NULL_free() has no effect whatsoever. In particular, it ignores the val_in argument and does not free any memory. In normal use, application programs only pass the invalid pointer obtained from ASN1_NULL_new() to this function. But even if a valid pointer is passed, that pointer does not become invalid.

The ASN.1 NULL type is also represented by the V_ASN1_NULL type identifier constant.

SEE ALSO

ASN1_item_new(3), d2i_ASN1_NULL(3)

STANDARDS

ITU-T Recommendation X.208, also known as ISO/IEC 8824-1: Specification of Abstract Syntax Notation One (ASN.1), section 19: Notation for the null type

HISTORY

ASN1_NULL_new() and ASN1_NULL_free() first appeared in OpenSSL 0.9.5 and have been available since OpenBSD 2.7.