.\" $OpenBSD: ERR.3,v 1.6 2019/03/10 14:50:05 schwarze Exp $ .\" OpenSSL 186bb907 Apr 13 11:05:13 2015 -0700 .\" .\" This file was written by Ulf Moeller and .\" Dr. Stephen Henson . .\" Copyright (c) 2000, 2015 The OpenSSL Project. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in .\" the documentation and/or other materials provided with the .\" distribution. .\" .\" 3. All advertising materials mentioning features or use of this .\" software must display the following acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" .\" .\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to .\" endorse or promote products derived from this software without .\" prior written permission. For written permission, please contact .\" openssl-core@openssl.org. .\" .\" 5. Products derived from this software may not be called "OpenSSL" .\" nor may "OpenSSL" appear in their names without prior written .\" permission of the OpenSSL Project. .\" .\" 6. Redistributions of any form whatsoever must retain the following .\" acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" .\" .\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY .\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: March 10 2019 $ .Dt ERR 3 .Os .Sh NAME .Nm ERR .Nd OpenSSL error codes .Sh SYNOPSIS .In openssl/err.h .Sh DESCRIPTION When a call to the OpenSSL library fails, this is usually signaled by the return value, and an error code is stored in an error queue associated with the current thread. The .Nm library provides functions to obtain these error codes and textual error messages. The .Xr ERR_get_error 3 manpage describes how to access error codes. .Pp Error codes contain information about where the error occurred, and what went wrong. .Xr ERR_GET_LIB 3 describes how to extract this information. A method to obtain human-readable error messages is described in .Xr ERR_error_string 3 . .Pp .Xr ERR_clear_error 3 can be used to clear the error queue. .Pp Note that .Xr ERR_remove_state 3 should be used to avoid memory leaks when threads are terminated. .Sh ADDING NEW ERROR CODES TO OPENSSL See .Xr ERR_put_error 3 if you want to record error codes in the OpenSSL error system from within your application. .Pp The remainder of this section is of interest only if you want to add new error codes to OpenSSL or add error codes from external libraries. .Pp When you are using new function or reason codes, run .Sy make errors . The necessary .Sy #define Ns s will then automatically be added to the sub-library's header file. .Ss Adding new libraries When adding a new sub-library to OpenSSL, assign it a library number .Dv ERR_LIB_XXX , define a macro .Fn XXXerr (both in .In openssl/err.h ) , add its name to .Va ERR_str_libraries[] (in .Pa /usr/src/lib/libcrypto/err/err.c ) , and add .Fn ERR_load_XXX_strings to the .Fn ERR_load_crypto_strings function (in .Sy /usr/src/lib/libcrypto/err/err_all.c ) . Finally, add an entry .Pp .Dl L XXX xxx.h xxx_err.c .Pp to .Sy /usr/src/lib/libcrypto/err/openssl.ec , and add .Pa xxx_err.c to the .Pa Makefile . Running .Sy make errors will then generate a file .Pa xxx_err.c , and add all error codes used in the library to .Pa xxx.h . .Pp Additionally the library include file must have a certain form. Typically it will initially look like this: .Bd -literal -offset indent #ifndef HEADER_XXX_H #define HEADER_XXX_H #ifdef __cplusplus extern "C" { #endif /* Include files */ #include #include /* Macros, structures and function prototypes */ /* BEGIN ERROR CODES */ .Ed .Pp The .Sy BEGIN ERROR CODES sequence is used by the error code generation script as the point to place new error codes. Any text after this point will be overwritten when .Sy make errors is run. The closing #endif etc. will be automatically added by the script. .Pp The generated C error code file .Pa xxx_err.c will load the header files .In stdio.h , .In openssl/err.h and .In openssl/xxx.h so the header file must load any additional header files containing any definitions it uses. .Sh USING ERROR CODES IN EXTERNAL LIBRARIES It is also possible to use OpenSSL's error code scheme in external libraries. The library needs to load its own codes and call the OpenSSL error code insertion script .Pa mkerr.pl explicitly to add codes to the header file and generate the C error code file. This will normally be done if the external library needs to generate new ASN.1 structures but it can also be used to add more general purpose error code handling. .Sh INTERNALS The error queues are stored in a hash table with one .Vt ERR_STATE entry for each PID. .Fn ERR_get_state returns the current thread's .Vt ERR_STATE . An .Vt ERR_STATE can hold up to .Dv ERR_NUM_ERRORS error codes. When more error codes are added, the old ones are overwritten, on the assumption that the most recent errors are most important. .Pp Error strings are also stored in a hash table. The hash tables can be obtained by calling .Fn ERR_get_err_state_table and .Fn ERR_get_string_table . .Sh SEE ALSO .Xr ERR_clear_error 3 , .Xr ERR_error_string 3 , .Xr ERR_get_error 3 , .Xr ERR_GET_LIB 3 , .Xr ERR_load_crypto_strings 3 , .Xr ERR_load_strings 3 , .Xr ERR_print_errors 3 , .Xr ERR_put_error 3 , .Xr ERR_remove_state 3 , .Xr ERR_set_mark 3 , .Xr SSL_get_error 3