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ERR(3)                DragonFly Library Functions Manual                ERR(3)

NAME

ERR - OpenSSL error codes

SYNOPSIS

#include <openssl/err.h>

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 ERR library provides functions to obtain these error codes and textual error messages. The ERR_get_error(3) manpage describes how to access error codes. Error codes contain information about where the error occurred, and what went wrong. ERR_GET_LIB(3) describes how to extract this information. A method to obtain human-readable error messages is described in ERR_error_string(3). ERR_clear_error(3) can be used to clear the error queue. Note that ERR_remove_state(3) should be used to avoid memory leaks when threads are terminated.

ADDING NEW ERROR CODES TO OPENSSL

See ERR_put_error(3) if you want to record error codes in the OpenSSL error system from within your application. 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. When you are using new function or reason codes, run make errors. The necessary #defines will then automatically be added to the sub-library's header file. Adding new libraries When adding a new sub-library to OpenSSL, assign it a library number ERR_LIB_XXX, define a macro XXXerr() (both in <openssl/err.h>), add its name to ERR_str_libraries[] (in /usr/src/lib/libcrypto/err/err.c), and add ERR_load_XXX_strings() to the ERR_load_crypto_strings() function (in /usr/src/lib/libcrypto/err/err_all.c). Finally, add an entry L XXX xxx.h xxx_err.c to /usr/src/lib/libcrypto/err/openssl.ec, and add xxx_err.c to the Makefile. Running make errors will then generate a file xxx_err.c, and add all error codes used in the library to xxx.h. Additionally the library include file must have a certain form. Typically it will initially look like this: #ifndef HEADER_XXX_H #define HEADER_XXX_H #ifdef __cplusplus extern "C" { #endif /* Include files */ #include <openssl/bio.h> #include <openssl/x509.h> /* Macros, structures and function prototypes */ /* BEGIN ERROR CODES */ The 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 make errors is run. The closing #endif etc. will be automatically added by the script. The generated C error code file xxx_err.c will load the header files <stdio.h>, <openssl/err.h> and <openssl/xxx.h> so the header file must load any additional header files containing any definitions it uses.

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 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.

INTERNALS

The error queues are stored in a hash table with one ERR_STATE entry for each PID. ERR_get_state() returns the current thread's ERR_STATE. An ERR_STATE can hold up to 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. Error strings are also stored in a hash table. The hash tables can be obtained by calling ERR_get_err_state_table() and ERR_get_string_table().

SEE ALSO

crypto(3), ERR_asprintf_error_data(3), ERR_clear_error(3), ERR_error_string(3), ERR_get_error(3), ERR_GET_LIB(3), ERR_load_crypto_strings(3), ERR_load_strings(3), ERR_print_errors(3), ERR_put_error(3), ERR_remove_state(3), ERR_set_mark(3), SSL_get_error(3) DragonFly 5.9-DEVELOPMENT June 10, 2019 DragonFly 5.9-DEVELOPMENT ERR_error_string(3) OpenSSL ERR_error_string(3)

NAME

ERR_error_string, ERR_error_string_n, ERR_lib_error_string, ERR_func_error_string, ERR_reason_error_string - obtain human-readable error message

SYNOPSIS

#include <openssl/err.h> char *ERR_error_string(unsigned long e, char *buf); void ERR_error_string_n(unsigned long e, char *buf, size_t len); const char *ERR_lib_error_string(unsigned long e); const char *ERR_func_error_string(unsigned long e); const char *ERR_reason_error_string(unsigned long e);

DESCRIPTION

ERR_error_string() generates a human-readable string representing the error code e, and places it at buf. buf must be at least 120 bytes long. If buf is NULL, the error string is placed in a static buffer. ERR_error_string_n() is a variant of ERR_error_string() that writes at most len characters (including the terminating 0) and truncates the string if necessary. For ERR_error_string_n(), buf may not be NULL. The string will have the following format: error:[error code]:[library name]:[function name]:[reason string] error code is an 8 digit hexadecimal number, library name, function name and reason string are ASCII text. ERR_lib_error_string(), ERR_func_error_string() and ERR_reason_error_string() return the library name, function name and reason string respectively. The OpenSSL error strings should be loaded by calling ERR_load_crypto_strings(3) or, for SSL applications, SSL_load_error_strings(3) first. If there is no text string registered for the given error code, the error string will contain the numeric code. ERR_print_errors(3) can be used to print all error codes currently in the queue.

RETURN VALUES

ERR_error_string() returns a pointer to a static buffer containing the string if buf == NULL, buf otherwise. ERR_lib_error_string(), ERR_func_error_string() and ERR_reason_error_string() return the strings, and NULL if none is registered for the error code.

SEE ALSO

err(3), ERR_get_error(3), ERR_load_crypto_strings(3), SSL_load_error_strings(3) ERR_print_errors(3)

HISTORY

ERR_error_string() is available in all versions of SSLeay and OpenSSL. ERR_error_string_n() was added in OpenSSL 0.9.6. 1.0.2h 2016-05-03 ERR_error_string(3)

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