SSL_CTX_ADD_EXTRA_CHAIN_CERT(3ossl)

πŸ“¦ version 3.5.0, in opensuse-leap 16.0

πŸŽ€ SSL_CTX_ADD_EXTRA_CHAIN_CERT(3ossl) πŸŽ€

okay bestie, so this is an OpenSSL manual page β€” section 3ossl β€” and it's literally all about the extra chain certs hanging out on your SSL_CTX. adding them, grabbing them, yeeting them. let's go πŸ’…


✨ NAME ✨

SSL_CTX_add_extra_chain_cert, SSL_CTX_get_extra_chain_certs, SSL_CTX_get_extra_chain_certs_only, SSL_CTX_clear_extra_chain_certs β€” add, get or clear extra chain certificates. that's the whole vibe πŸ¦‹


🌸 SYNOPSIS 🌸

#include <openssl/ssl.h>

long SSL_CTX_add_extra_chain_cert(SSL_CTX *ctx, X509 *x509);
long SSL_CTX_get_extra_chain_certs(SSL_CTX *ctx, STACK_OF(X509) **sk);
long SSL_CTX_get_extra_chain_certs_only(SSL_CTX *ctx, STACK_OF(X509) **sk);
long SSL_CTX_clear_extra_chain_certs(SSL_CTX *ctx);

πŸ’– DESCRIPTION πŸ’–

  • SSL_CTX_add_extra_chain_cert() β€” adds the certificate x509 to the extra chain certificates associated with ctx. and like, you can add several certificates one after another, no cap ✨
  • SSL_CTX_get_extra_chain_certs() β€” retrieves the extra chain certificates associated with ctx, or the chain associated with the current certificate of ctx if the extra chain is empty. heads up bestie: the returned stack should not be freed by the caller πŸ™ˆ
  • SSL_CTX_get_extra_chain_certs_only() β€” retrieves the extra chain certificates associated with ctx. and again, the returned stack should not be freed by the caller πŸ’€
  • SSL_CTX_clear_extra_chain_certs() β€” clears all extra chain certificates associated with ctx. poof, gone 🫢
also, these functions are implemented as macros. iconic behavior, honestly πŸŽ€

πŸ¦‹ NOTES πŸ¦‹

when sending a certificate chain, extra chain certificates are sent in order following the end entity certificate. order matters, periodt πŸ’…

if no chain is specified, the library will try to complete the chain from the available CA certificates in the trusted CA storage β€” see SSL_CTX_load_verify_locations(3). it's giving "i got you" energy ngl 🌈

⚠️ important, don't skip this one: the x509 certificate provided to SSL_CTX_add_extra_chain_cert() will be freed by the library when the SSL_CTX is destroyed. an application should not free the x509 object. do not double-free, i'm begging 😭πŸ”₯

πŸ“ RESTRICTIONS πŸ“

only one set of extra chain certificates can be specified per SSL_CTX structure. so like… different chains for different certificates (for example if both RSA and DSA certificates are specified by the same server) or different SSL structures with the same parent SSL_CTX cannot be specified using this function. it's just not that girl πŸ’€

for more flexibility, functions such as SSL_add1_chain_cert() should be used instead. she's the upgrade, iykyk ✨


πŸ‘‘ RETURN VALUES πŸ‘‘

SSL_CTX_add_extra_chain_cert() and SSL_CTX_clear_extra_chain_certs() return 1 on success and 0 for failure.

zero means it flopped β€” check out the error stack to find out the reason for failure πŸ”


🌺 SEE ALSO 🌺

ssl(7), SSL_CTX_use_certificate(3), SSL_CTX_set_client_cert_cb(3), SSL_CTX_load_verify_locations(3) SSL_CTX_set0_chain(3) SSL_CTX_set1_chain(3) SSL_CTX_add0_chain_cert(3) SSL_CTX_add1_chain_cert(3) SSL_set0_chain(3) SSL_set1_chain(3) SSL_add0_chain_cert(3) SSL_add1_chain_cert(3) SSL_CTX_build_cert_chain(3) SSL_build_cert_chain(3)

the whole friend group, fr fr 🫢


Copyright 2000-2018 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>.


aaaand that's the whole page bestie! πŸ’œ this one's from OpenSSL 3.5.0, dated 2026-09-2, so go forth and chain responsibly β€” mwah πŸ§šβœ¨πŸŽ€

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