---
name: "PKCS8_pkey_add1_attr"
section: "3ssl"
platform: "linux"
package: "openssl"
version: "3.6.5-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/PKCS8_pkey_add1_attr"
---

# PKCS8\_pkey\_add1\_attr(3ssl)

PKCS8 attribute functions

## NAME

PKCS8\_pkey\_get0\_attrs, PKCS8\_pkey\_add1\_attr, PKCS8\_pkey\_add1\_attr\_by\_NID, PKCS8\_pkey\_add1\_attr\_by\_OBJ - PKCS8 attribute functions

## SYNOPSIS

```
 #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);
```

## DESCRIPTION

**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**.

## RETURN VALUES

**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.

## NOTES

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

## SEE ALSO

[**crypto**(7)](/crypto/7.md)

## COPYRIGHT

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\>.