---
name: "X509V3_EXT_nconf_nid"
section: "3ssl"
platform: "linux"
package: "openssl"
version: "3.6.5-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/X509V3_EXT_nconf_nid"
---

# X509V3\_EXT\_nconf\_nid(3ssl)

functions to create X.509 certificate extensions based on OpenSSL configuration

## NAME

X509V3\_EXT\_nconf, X509V3\_EXT\_nconf\_nid - functions to create X.509 certificate extensions based on OpenSSL configuration

## SYNOPSIS

```
 #include <openssl/x509v3.h>
 X509_EXTENSION *X509V3_EXT_nconf_nid(CONF *conf, X509V3_CTX *ctx, int ext_nid,
     const char *value);
 X509_EXTENSION *X509V3_EXT_nconf(CONF *conf, X509V3_CTX *ctx, const char *name,
     const char *value);
```

## DESCRIPTION

**X509V3\_EXT\_nconf\_nid()** and **X509V3\_EXT\_nconf()** create a requested X.509 extension identified either by *name* or *ext\_nid* correspondingly using *value* contains the string to encode.

*conf* the configuration information where additional data will be read from. *conf* will typically come from a config file.

In case when *ctx* value is null, the default one is used.

## NOTES

Normally these functions should not be called directly. For many extensions they will not produce the expected results without a suitably configured context (*conf* and *ctx* arguments) that specifies the target object, issuer data etc.

## RETURN VALUES

**X509V3\_EXT\_nconf()** and **X509V3\_EXT\_nconf\_nid()** return an **X509\_EXTENSION** object on success and NULL on failure.

## COPYRIGHT

Copyright 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\>.