OPENSSL_USER_MACROS(7ossl)

📦 version 3.5.0, in opensuse-leap 16.0

💖 NAME 💖

Okay bestie, this page is openssl_user_macros from the 7ossl manual — the one about user defined macros, starring OPENSSL_API_COMPAT and OPENSSL_NO_DEPRECATED. ✨

✨ DESCRIPTION ✨

User defined macros let you, the programmer, control certain aspects of what the OpenSSL headers expose. Iconic little switches, fr fr. 🎀

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, order matters. 💅

Other manual pages may refer to this page when declarations depend on user defined macros. So this is like the reference hub, iykyk. 🦋

🎀 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. Poof, gone, lowkey dramatic but accurate. 💀✨

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>.

With love, this page shipped with OpenSSL 3.5.0, dated 2026-09-25, and its footer label is OPENSSL_USER_MACROS(7ossl) 🫶💅🌸

📦 where this page comes from