X509_EXTENSION_SET_OBJECT(3)

NAME
X509_EXTENSION_set_object, X509_EXTENSION_set_critical, X509_EXTENSION_set_data, X509_EXTENSION_create_by_NID, X509_EXTENSION_create_by_OBJ, X509_EXTENSION_get_object, X509_EXTENSION_get_critical, X509_EXTENSION_get_data - extension utility functions

SYNOPSIS
 int X509_EXTENSION_set_object(X509_EXTENSION *ex, const ASN1_OBJECT *obj);
 int X509_EXTENSION_set_critical(X509_EXTENSION *ex, int crit);
 int X509_EXTENSION_set_data(X509_EXTENSION *ex, const ASN1_OCTET_STRING *data);

 X509_EXTENSION *X509_EXTENSION_create_by_NID(X509_EXTENSION **ex,
                                              int nid, int crit,
                                              ASN1_OCTET_STRING *data);
 X509_EXTENSION *X509_EXTENSION_create_by_OBJ(X509_EXTENSION **ex,
                                              const ASN1_OBJECT *obj, int crit,
                                              ASN1_OCTET_STRING *data);

 const ASN1_OBJECT *X509_EXTENSION_get_object(const X509_EXTENSION *ex);
 int X509_EXTENSION_get_critical(const X509_EXTENSION *ex);
 const ASN1_OCTET_STRING *X509_EXTENSION_get_data(const X509_EXTENSION *ne);

DESCRIPTION
X509_EXTENSION_set_object() sets the extension type of ex to obj. The obj pointer is duplicated internally so obj should be freed up after use.

X509_EXTENSION_set_critical() sets the criticality of ex to crit. If crit is zero the extension in non-critical otherwise it is critical.

X509_EXTENSION_set_data() sets the data in extension ex to data. The data pointer is duplicated internally.

X509_EXTENSION_create_by_NID() creates an extension of type nid, criticality crit using data data. The created extension is returned and written to *ex reusing or allocating a new extension if necessary so *ex should either be NULL or a valid X509_EXTENSION structure it must not be an uninitialised pointer.

X509_EXTENSION_create_by_OBJ() is identical to X509_EXTENSION_create_by_NID() except it creates and extension using obj instead of a NID.

X509_EXTENSION_get_object() returns the extension type of ex as an ASN1_OBJECT pointer. The returned pointer is an internal value which must not be freed up.

X509_EXTENSION_get_critical() returns the criticality of extension ex it returns 1 for critical and 0 for non-critical.

X509_EXTENSION_get_data() returns the data of extension ex. The returned pointer is an internal value which must not be freed up.

NOTES
These functions manipulate the contents of an extension directly. Most applications will want to parse or encode and add an extension: they should use the extension encode and decode functions instead such as X509_add1_ext_i2d() and X509_get_ext_d2i().

The data associated with an extension is the extension encoding in an ASN1_OCTET_STRING structure.

RETURN VALUES
X509_EXTENSION_set_object() X509_EXTENSION_set_critical() and X509_EXTENSION_set_data() return 1 for success and 0 for failure.

X509_EXTENSION_create_by_NID() and X509_EXTENSION_create_by_OBJ() return an X509_EXTENSION pointer or NULL if an error occurs.

X509_EXTENSION_get_object() returns an ASN1_OBJECT pointer.

X509_EXTENSION_get_critical() returns 0 for non-critical and 1 for critical.

X509_EXTENSION_get_data() returns an ASN1_OCTET_STRING pointer.

SEE ALSO
X509V3_get_d2i(3)

COPYRIGHT
Copyright 2015-2026 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>.