X509V3_EXT_PRINT(3ossl)

📦
version 3.5.9 · 6 versions
, in fedora 43, fedora 44

✨ X509V3_EXT_PRINT ✨

okay bestie, so this is the X509V3_EXT_PRINT(3ossl) page, and it's genuinely one of those little utility baddies that does exactly what it says on the tin 💅 we're talking about pretty-printing X509 certificate extensions, and honestly? it's giving "small function, big glow-up".

🌸 NAME 🌸

X509V3_EXT_print, X509V3_EXT_print_fp — pretty print X509 certificate extensions

like… it prints them. prettily. that's the whole vibe 🎀

🦋 SYNOPSIS 🦋

#include <openssl/x509v3.h>

int X509V3_EXT_print(BIO *out, X509_EXTENSION *ext, unsigned long flag, int indent);
int X509V3_EXT_print_fp(FILE *out, X509_EXTENSION *ext, int flag, int indent);

👑 DESCRIPTION 👑

so here's the tea, fr fr: X509V3_EXT_print() and X509V3_EXT_print_fp() parse and print the extension info from ext to bio or out, with the indentation set via indent. cute, right? nesting but make it aesthetic 🌈

but the real main character here is flag, because it decides what happens when an extension just… won't parse 😭 like, the extension said "not today" and you gotta have a plan. flag can be one of these:

  • X509V3_EXT_DEFAULT — equivalent to 0. an unknown or unparsable extension stops the parsing and the function returns a failure. no mercy, no vibes, we're done here 💀
  • X509V3_EXT_PARSE_UNKNOWN — an unknown or unparsable extension is handled by printing it through the ASN1_parse_dump() function, and the function returns success. it's giving "we don't know her but we'll still show her" ✨
  • X509V3_EXT_DUMP_UNKNOWN — an unknown or unparsable extension is handled by printing it through the BIO_dump_indent() function, and the function returns success. raw hex energy, lowkey iconic 🔥
  • X509V3_EXT_ERROR_UNKNOWN — an unknown or unparsable extension is handled by printing either "<Not Supported>" or "<Parse Error>", and the function returns success. it's the polite "no thoughts, just a label" option 🫶
ngl bestie, that last one is so real — sometimes the correct answer is just admitting you don't know and moving on. periodt.

💖 RETURN VALUES 💖

X509V3_EXT_print() and X509V3_EXT_print_fp() return 1 for success and 0 for failure. that's it. binary. no situationship, just yes or no 🌸

🧚 SEE ALSO 🧚

(go read those too, they're the supporting cast and they ate 💅)

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>.

and that's the whole page, bestie!! this was version 3.5.9, dated 2026-09-29, from the OpenSSL girlies themselves 🎀 tysm for reading, go print some extensions, slay responsibly 💜🦋✨

📦 where this page comes from