OPENSSL_USER_MACROS(7ossl)

🎀 NAME 🎀

okay bestie, this is the openssl_user_macros page from the 7ossl manual — the one all about user defined macros. It covers OPENSSL_API_COMPAT, OPENSSL_NO_DEPRECATED, and the whole "user defined macros" situation. iykyk 💅

✨ DESCRIPTION ✨

User defined macros are literally how you, the programmer, get to control certain aspects of what the OpenSSL headers expose. main character energy for your build config 🫶

NOTE: to be effective, a user defined macro must be defined before including any header file that depends on it, either in the compilation command (cc -DMACRO=value) or by defining the macro in source before including any headers. no cap — timing matters, bestie ⏰

Other manual pages may refer to this page when declarations depend on user defined macros. so if another page sends you here, you're in the right place 💖

🌈 The macros 🌈

🦋 OPENSSL_API_COMPAT 🦋

The value is a version number, given in one of the following two forms:

• "0xMNNFF000L" — this is the form supported for all versions up to 1.1.x, where "M" represents the major number, "NN" represents the minor number, and "FF" represents the fix number, as a hexadecimal number. For version 1.1.0, that's "0x10100000L".

Any version number may be given, but these numbers are the current known major deprecation points, making them the most meaningful:

• "0x00908000L" (version 0.9.8)
• "0x10000000L" (version 1.0.0)
• "0x10100000L" (version 1.1.0)

For convenience, higher numbers are accepted as well, as long as feasible. For example, "0x60000000L" will work as expected. However, it is recommended to start using the second form instead:

• "mmnnpp" — this form is a simple decimal number calculated with this formula:

major * 10000 + minor * 100 + patch

where major, minor and patch are the desired major, minor and patch components of the version number. For example:

30000 corresponds to version 3.0.0
10002 corresponds to version 1.0.2
420101 corresponds to version 42.1.1

If OPENSSL_API_COMPAT is undefined, this default value is used in its place: 30500

💀 OPENSSL_NO_DEPRECATED 💀

If this macro is defined, all deprecated public symbols in all OpenSSL versions up to and including the version given by OPENSSL_API_COMPAT (or the default value given above, when OPENSSL_API_COMPAT isn't defined) will be hidden.

👑 COPYRIGHT 👑

legal bestie moment, but make it cute:

Copyright 2018-2021 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.

and that's the whole page, bestie 💖 this edition is chillin' with OpenSSL 3.5.9, dated 2026-09-29, on the OPENSSL_USER_MACROS(7ossl) manual page — mwah 💋