PKCS8_pkey_get0_attrs, PKCS8_pkey_add1_attr, PKCS8_pkey_add1_attr_by_NID, PKCS8_pkey_add1_attr_by_OBJ -

       Copyright 2020 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>.

3.5.0                                              2025-06-04                         PKCS8_PKEY_ADD1_ATTR(3SSL)

PKCS8_pkey_get0_attrs() returns a const STACK of X509_ATTRIBUTE present in the passed const
       PKCS8_PRIV_KEY_INFO structure p8.

       PKCS8_pkey_add1_attr() adds a constructed X509_ATTRIBUTE attr to the existing PKCS8_PRIV_KEY_INFO
       structure p8.

       PKCS8_pkey_add1_attr_by_NID() and PKCS8_pkey_add1_attr_by_OBJ() construct a new X509_ATTRIBUTE from the
       passed arguments and add it to the existing PKCS8_PRIV_KEY_INFO structure p8.

       PKCS8_pkey_get0_attrs, PKCS8_pkey_add1_attr, PKCS8_pkey_add1_attr_by_NID, PKCS8_pkey_add1_attr_by_OBJ -
       PKCS8 attribute functions

       STACK of X509_ATTRIBUTE is present in many X509-related structures and some of them have the
       corresponding set of similar functions.

PKCS8_pkey_add1_attr(), PKCS8_pkey_add1_attr_by_NID(), and PKCS8_pkey_add1_attr_by_OBJ() return 1 for
       success and 0 for failure.

crypto(7)

        #include <openssl/x509.h>

        const STACK_OF(X509_ATTRIBUTE) *
        PKCS8_pkey_get0_attrs(const PKCS8_PRIV_KEY_INFO *p8);
        int PKCS8_pkey_add1_attr(PKCS8_PRIV_KEY_INFO *p8, X509_ATTRIBUTE *attr);
        int PKCS8_pkey_add1_attr_by_NID(PKCS8_PRIV_KEY_INFO *p8, int nid, int type,
                                        const unsigned char *bytes, int len);
        int PKCS8_pkey_add1_attr_by_OBJ(PKCS8_PRIV_KEY_INFO *p8, const ASN1_OBJECT *obj,
                                       int type, const unsigned char *bytes, int len);