X509(7ossl)

✨ NAME ✨

x509 — X.509 certificate handling. Welcome to the OpenSSL 7ossl manual page, bestie — this is where all the certificate lore lives. 💖

🌸 SYNOPSIS 🌸

#include <openssl/x509.h>

🦋 DESCRIPTION 🦋

Okay so picture an X.509 certificate: it’s a structured grouping of information about an individual, a device, or literally anything one can imagine. Iconic little info bundle, no cap. An X.509 CRL — that’s a certificate revocation list — is a tool to help determine if a certificate is still valid. The exact definition of those can be found in the X.509 document from ITU-T, or in RFC3280 from PKIX. In OpenSSL, the type X509 is used to express such a certificate, and the type X509_CRL is used to express a CRL. 💅

A related structure is a certificate request, defined in PKCS#10 from RSA Security, Inc, also reflected in RFC2896. In OpenSSL, the type X509_REQ is used to express such a certificate request. 🎀

To handle some complex parts of a certificate, there are the types X509_NAME (to express a certificate name), X509_ATTRIBUTE (to express a certificate attribute), X509_EXTENSION (to express a certificate extension) and a few more. ✨

Finally, there’s the supertype X509_INFO, which can contain a CRL, a certificate and a corresponding private key. Main character energy fr fr. 👑

The X509_XXX, d2i_X509_XXX, and i2d_X509_XXX functions handle X.509 certificates, with some exceptions, shown below. 🫶

The X509_CRL_XXX, d2i_X509_CRL_XXX, and i2d_X509_CRL_XXX functions handle X.509 CRLs. 🌈

The X509_REQ_XXX, d2i_X509_REQ_XXX, and i2d_X509_REQ_XXX functions handle PKCS#10 certificate requests. 💜

The X509_NAME_XXX functions handle certificate names. 🍓

The X509_ATTRIBUTE_XXX functions handle certificate attributes. 🧚

The X509_EXTENSION_XXX functions handle certificate extensions. ⭐

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🔥 SEE ALSO 🔥

• X509_NAME_ENTRY_get_object(3)
• X509_NAME_add_entry_by_txt(3)
• X509_NAME_add_entry_by_NID(3)
• X509_NAME_print_ex(3)
• X509_NAME_new(3)
• PEM_X509_INFO_read(3)
• d2i_X509(3)
• d2i_X509_ALGOR(3)
• d2i_X509_CRL(3)
• d2i_X509_NAME(3)
• d2i_X509_REQ(3)
• d2i_X509_SIG(3)
• crypto(7)

💖 COPYRIGHT 💖

Legal bestie moment — here’s the exact text, preserved with love:

Copyright 2003-2021 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>.

Okay bye bestie — this iconic little page is OpenSSL 3.5.9, dated 2026-09-29, and its official manual tag is X509(7ossl). Slay. 💅✨