DragonFly On-Line Manual Pages
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) man-
page 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. Typi-
cally 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_set_locking_callback(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 5.5 November 23, 2016 DragonFly 5.5
ERR_get_error(3) OpenSSL ERR_get_error(3)
NAME
ERR_get_error, ERR_peek_error, ERR_peek_last_error, ERR_get_error_line,
ERR_peek_error_line, ERR_peek_last_error_line, ERR_get_error_line_data,
ERR_peek_error_line_data, ERR_peek_last_error_line_data - obtain error
code and data
SYNOPSIS
#include <openssl/err.h>
unsigned long ERR_get_error(void);
unsigned long ERR_peek_error(void);
unsigned long ERR_peek_last_error(void);
unsigned long ERR_get_error_line(const char **file, int *line);
unsigned long ERR_peek_error_line(const char **file, int *line);
unsigned long ERR_peek_last_error_line(const char **file, int *line);
unsigned long ERR_get_error_line_data(const char **file, int *line,
const char **data, int *flags);
unsigned long ERR_peek_error_line_data(const char **file, int *line,
const char **data, int *flags);
unsigned long ERR_peek_last_error_line_data(const char **file, int *line,
const char **data, int *flags);
DESCRIPTION
ERR_get_error() returns the earliest error code from the thread's error
queue and removes the entry. This function can be called repeatedly
until there are no more error codes to return.
ERR_peek_error() returns the earliest error code from the thread's
error queue without modifying it.
ERR_peek_last_error() returns the latest error code from the thread's
error queue without modifying it.
See ERR_GET_LIB(3) for obtaining information about location and reason
of the error, and ERR_error_string(3) for human-readable error
messages.
ERR_get_error_line(), ERR_peek_error_line() and
ERR_peek_last_error_line() are the same as the above, but they
additionally store the file name and line number where the error
occurred in *file and *line, unless these are NULL.
ERR_get_error_line_data(), ERR_peek_error_line_data() and
ERR_peek_last_error_line_data() store additional data and flags
associated with the error code in *data and *flags, unless these are
NULL. *data contains a string if *flags&ERR_TXT_STRING is true.
An application MUST NOT free the *data pointer (or any other pointers
returned by these functions) with OPENSSL_free() as freeing is handled
automatically by the error library.
RETURN VALUES
The error code, or 0 if there is no error in the queue.
SEE ALSO
err(3), ERR_error_string(3), ERR_GET_LIB(3)
HISTORY
ERR_get_error(), ERR_peek_error(), ERR_get_error_line() and
ERR_peek_error_line() are available in all versions of SSLeay and
OpenSSL. ERR_get_error_line_data() and ERR_peek_error_line_data() were
added in SSLeay 0.9.0. ERR_peek_last_error(),
ERR_peek_last_error_line() and ERR_peek_last_error_line_data() were
added in OpenSSL 0.9.7.
1.0.2h 2016-05-03 ERR_get_error(3)