ERR_GET_LIB, ERR_GET_FUNC, ERR_GET_REASON, ERR_FATAL_ERROR - get information from error codes

#include <openssl/err.h>

int ERR_GET_LIB(unsigned long e);

int ERR_GET_FUNC(unsigned long e);

int ERR_GET_REASON(unsigned long e);

int ERR_FATAL_ERROR(unsigned long e);

The error code returned by ERR_get_error() consists of a library number, function code and reason code. ERR_GET_LIB(), ERR_GET_FUNC() and ERR_GET_REASON() can be used to extract these.

ERR_FATAL_ERROR() indicates whether a given error code is a fatal error.

The library number and function code describe where the error occurred, the reason code is the information about what went wrong.

Each sub-library of OpenSSL has a unique library number; function and reason codes are unique within each sub-library. Note that different libraries may use the same value to signal different functions and reasons.

ERR_R_... reason codes such as ERR_R_MALLOC_FAILURE are globally unique. However, when checking for sub-library specific reason codes, be sure to also compare the library number.


The library number, function code, reason code, and whether the error is fatal, respectively.


ERR_GET_LIB(), ERR_GET_FUNC() and ERR_GET_REASON() are available in all versions of OpenSSL.

Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (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

2021-02-17 1.1.1j