ERR_PUT_ERROR(3ossl)

📦 version 3.5.0, in opensuse-leap 16.0

💅 ERR_PUT_ERROR — the OpenSSL manual, but make it make sense

okay so this is the 3ossl manual page, bestie — the OpenSSL one — and today we're talking about recording an error. Like, actually writing down that something went wrong so future-you can figure out what tf happened. Let's go ✨

🌸 NAME 🌸

ERR_raise, ERR_raise_data, ERR_put_error, ERR_add_error_data, ERR_add_error_vdata, ERR_add_error_txt, ERR_add_error_mem_bio — record an error 🫶

✨ SYNOPSIS ✨

#include <openssl/err.h>

void ERR_raise(int lib, int reason);
void ERR_raise_data(int lib, int reason, const char *fmt, ...);

void ERR_add_error_data(int num, ...);
void ERR_add_error_vdata(int num, va_list arg);
void ERR_add_error_txt(const char *sep, const char *txt);
void ERR_add_error_mem_bio(const char *sep, BIO *bio);

k so, heads up 🙈 — the following function has been deprecated since OpenSSL 3.0, and you can hide it entirely by defining OPENSSL_API_COMPAT with a suitable version value (peep openssl_user_macros(7) for that):

void ERR_put_error(int lib, int func, int reason, const char *file, int line);

🦋 DESCRIPTION 🦋

ERR_raise() adds a brand-new error to the thread's error queue 👑 The error happened in the library lib, for the reason given by the reason code. And on top of that? The name of the file, the line, and the name of the function where the error occurred all get saved with the error record. Receipts, basically 💅

ERR_raise_data() does the exact same thing as ERR_raise(), except it also lets the caller specify extra info as a format string fmt plus an arbitrary number of values — and those get processed with BIO_snprintf(3). Fancy.

ERR_put_error() adds an error code to the thread's error queue. It signals that the error of reason code reason occurred in function func of library lib, in line number line of file. This function is usually called by a macro, jsyk.

ERR_add_error_data() associates the concatenation of its num string arguments as additional data with the error code added last. ERR_add_error_vdata() is basically the same thing except its argument is a va_list. Multiple calls to these functions append to the current top of the error queue. And the total length of the string data per error is limited to 4096 characters — that's the ceiling, no cap fr fr 🧢

ERR_add_error_txt() appends the given text string as additional data to the last error queue entry — but first it inserts the optional separator string, if that separator is not NULL and the top error entry doesn't already have additional data. Also! If the separator is at the end of the text, it does not get appended to the data. The sep argument may be, for instance, "\n", to insert a line break when needed. And if the associated data would become more than 4096 characters long (yep, that same limit from above), it gets split over sufficiently many new copies of the last error queue entry. Iconic behaviour honestly.

ERR_add_error_mem_bio() is the same as ERR_add_error_txt() except that the text string is taken from the given memory BIO. It appends '\0' to the BIO contents if they're not already NUL-terminated.

ERR_load_strings(3) can be used to register error strings, so that the application can generate human-readable error messages for the error code. Bestie, that's the whole point 💖

🌈 Reporting errors 🌈

OpenSSL library reports

Each OpenSSL sub-library has library code ERR_LIB_XXX and has its own set of reason codes XXX_R_.... These are both passed in combination to ERR_raise() and ERR_raise_data(), and that combination ultimately produces the correct error text for the reported error. Chemistry 🧪

All these macros and the numbers they have as values are specific to OpenSSL's libraries. OpenSSL reason codes normally consist of textual error descriptions. For example, the function ssl3_read_bytes() reports a "handshake failure" as follows:

ERR_raise(ERR_LIB_SSL, SSL_R_SSL_HANDSHAKE_FAILURE);

There are two exceptions:

  • ERR_LIB_SYS — this "library code" indicates that a system error is being reported. In this case, the reason code given to ERR_raise() and ERR_raise_data() must be errno(3).
ERR_raise(ERR_LIB_SYS, errno);
  • ERR_R_XXX — this set of error codes is considered global, and may be used in combination with any sub-library code.
ERR_raise(ERR_LIB_RSA, ERR_R_PASSED_INVALID_ARGUMENT);

Other pieces of software

Other pieces of software that may want to use OpenSSL's error reporting system — engines or applications, say — must normally get their own numbers. Like, they can't just borrow OpenSSL's, that's rude 🙈

  • To get a "library" code, call ERR_get_next_error_library(3); this gives the calling code a dynamic number, usable for the duration of the process.
  • Reason codes for each such "library" are determined or generated by the authors of that code. They must be numbers in the range 1 to 524287 — in other words, they must be nonzero unsigned 18 bit integers. No negotiating on that one.

The exceptions mentioned up in "OpenSSL library reports" are valid for other pieces of software too, i.e. they may use ERR_LIB_SYS to report system errors:

ERR_raise(ERR_LIB_SYS, errno);

...and they may use ERR_R_XXX macros together with their own "library" code. Slay 🎀

int app_lib_code = ERR_get_next_error_library();

/* ... */

ERR_raise(app_lib_code, ERR_R_PASSED_INVALID_ARGUMENT);

⭐ RETURN VALUES ⭐

ERR_raise(), ERR_raise_data(), ERR_put_error(), ERR_add_error_data(), ERR_add_error_vdata(), ERR_add_error_txt(), and ERR_add_error_mem_bio() return no values. Nothing. Nada. They just do the thing and dip 💀

🔥 NOTES 🔥

ERR_raise(), ERR_raise() and ERR_put_error() are implemented as macros. Yes bestie, ERR_raise() really is in that list twice — that's genuinely how the original says it, I'm not fixing it, and honestly? She said what she said 💅

💜 SEE ALSO 💜

ERR_load_strings(3), ERR_get_next_error_library(3)

👑 HISTORY 👑

ERR_raise, ERR_raise_data, ERR_add_error_txt() and ERR_add_error_mem_bio() were added in OpenSSL 3.0.

Copyright 2000-2020 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 tea ☕ version 3.5.0, dated 2026-09-25 — ERR_PUT_ERROR(3ossl), out 🦋💖✨

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