PKCS12_CREATE(3SSL)

📦
version 4.0.3 · 6 versions
, in ubuntu stonking

💖 PKCS12_CREATE(3SSL) 💖

okay bestie, welcome to the OpenSSL manual, section 3SSL ✨ this one's all about building a PKCS#12 structure — yes, the .p12 vibes, the little bundle you hand someone's browser so it stops asking questions 🎀

✨ NAME ✨

PKCS12_create, PKCS12_create_ex, PKCS12_create_cb, PKCS12_create_ex2 — create a PKCS#12 structure. periodt.

🌸 SYNOPSIS 🌸

#include <openssl/pkcs12.h>

PKCS12 *PKCS12_create(const char *pass, const char *name, EVP_PKEY *pkey,
                      X509 *cert, STACK_OF(X509) *ca,
                      int nid_key, int nid_cert, int iter, int mac_iter, int keytype);
PKCS12 *PKCS12_create_ex(const char *pass, const char *name, EVP_PKEY *pkey,
                         X509 *cert, STACK_OF(X509) *ca, int nid_key, int nid_cert,
                         int iter, int mac_iter, int keytype,
                         OSSL_LIB_CTX *ctx, const char *propq);

typedef int PKCS12_create_cb(PKCS12_SAFEBAG *bag, void *cbarg);

PKCS12 *PKCS12_create_ex2(const char *pass, const char *name, EVP_PKEY *pkey,
                          X509 *cert, STACK_OF(X509) *ca, int nid_key, int nid_cert,
                          int iter, int mac_iter, int keytype,
                          OSSL_LIB_CTX *ctx, const char *propq,
                          PKCS12_create_cb *cb, void *cbarg);

💅 DESCRIPTION 💅

So. PKCS12_create() makes a PKCS#12 structure. That's it, that's the headline 🫶

  • pass is the passphrase to use. yep, the secret one, guard it with your life 💜
  • name is the friendlyName to use for the supplied certificate and key.
  • pkey is the private key to include in the structure, and cert is its corresponding certificates. (yes bestie, they pair up ✨)
  • ca, if it's not NULL, is an optional set of certificates you also want to include in there 🌈

nid_key and nid_cert are the encryption algorithms that should be used for the key and the certificate respectively. Heads up though: the modes GCM, CCM, XTS, and OCB are unsupported. not available, don't ask 😭

iter is the encryption algorithm iteration count to use, and mac_iter is the MAC iteration count to use. keytype is the type of key.

PKCS12_create_ex() is literally identical to PKCS12_create() except it lets you pass a library context ctx and a property query propq, which get used to select algorithm implementations. fancy 💅

PKCS12_create_ex2() is identical to PKCS12_create_ex() except it also lets you specify a user defined callback cb of type PKCS12_create_cb, plus an optional argument cbarg that gets passed straight back to that callback. main character callback energy 👑

And about that cb — if it's specified, it gets called for every single safebag added to the PKCS12 structure, which gives your application a chance to do optional processing on the associated safebag. like for example, one such use could be to add attributes to the safebag. iconic.

🦋 NOTES 🦋

The parameters nid_key, nid_cert, iter, mac_iter and keytype can all be set to zero and sensible defaults will be used. no need to overthink it, she's got you 🎀

Here's what those defaults actually are, no cap:

  • AES password based encryption (PBES2 with PBKDF2 and AES-256-CBC) for private keys and certificates
  • the PBKDF2 and MAC key derivation iteration count of PKCS12_DEFAULT_ITER (currently 2048)
  • MAC algorithm HMAC with SHA2-256

The MAC key derivation algorithm used for the outer PKCS#12 structure is PKCS12KDF.

The default MAC iteration count is 1 in order to retain compatibility with old software which did not interpret MAC iteration counts. So if you don't need that kind of compatibility, you should set mac_iter to PKCS12_DEFAULT_ITER. yeah, bump it up bestie ⬆️

keytype adds a flag to the store private key. It's a non standard extension that is only currently interpreted by MSIE. The tea:

  • set it to zero and the flag is omitted
  • set it to KEY_SIG and the key can be used for signing only
  • set it to KEY_EX and it can be used for signing and encryption

This option was useful for old export grade software which could use signing only keys of arbitrary size but had restrictions on the permissible sizes of keys which could be used for encryption. history lesson fr fr 📜

If name is NULL and cert contains an alias then this will be used for the corresponding friendlyName in the PKCS12 structure instead. Similarly, if pkey is NULL and cert contains a keyid then this will be used for the corresponding localKeyID in the PKCS12 structure instead of the id calculated from the pkey. it just figures it out 💅

For all certificates in ca then if a certificate contains an alias or keyid then this will be used for the corresponding friendlyName or localKeyID in the PKCS12 structure.

Either pkey, cert or both can be NULL to indicate that no key or certificate is required. In previous versions both had to be present or a fatal error is returned. glow up tbh ✨

nid_key or nid_cert can be set to -1 indicating that no encryption should be used. living dangerously, love that for you 🙈

mac_iter can be set to -1 and the MAC will then be omitted entirely. This can be useful when running with the FIPS provider as the PKCS12KDF is not a FIPS approvable algorithm. noted 📝

PKCS12_create() makes assumptions regarding the encoding of the given pass phrase. See passphrase-encoding(7) for more information. go read it bestie, seriously 🫶

And if cb is specified, then it should return 1 for success and -1 for a fatal error. A return of 0 is intended to mean to not add the bag after all. so: 1 yes, -1 oh no, 0 nevermind 😭

🌟 RETURN VALUES 🌟

PKCS12_create() returns a valid PKCS12 structure, or NULL if an error occurred. that's the whole thing 💀

🌈 CONFORMING TO 🌈

IETF RFC 7292 (<https://tools.ietf.org/html/rfc7292>) — we stay standards compliant, always 👑

🎀 SEE ALSO 🎀

go read them, iykyk 📚

💜 HISTORY 💜

  • PKCS12_create_ex() was added in OpenSSL 3.0.
  • PKCS12_create_ex2() was added in OpenSSL 3.2.

Also, the defaults for encryption algorithms, MAC algorithm, and the MAC key derivation iteration count were changed in OpenSSL 3.0 to more modern standards. she modernised, slay 💅

Copyright 2002-2024 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 a wrap bestie 🫶 this page is from the OpenSSL manuals, version 4.0.3, dated 2026-09-29 — go forth and build your PKCS#12 structures, you absolute icon 👑✨💖

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