ERR_ERROR_STRING(3)        Library Functions Manual        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
     OpenSSL error messages

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 in buf.  buf must be at least 256 bytes long.
     If buf is NULL, the error string is placed in a static buffer.  Note that
     this function is not thread-safe and does no checks on the size of the
     buffer; use ERR_error_string_n() instead.

     ERR_error_string_n() is a variant of ERR_error_string() that writes at
     most len characters (including the terminating NUL) 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]

     The error code is an 8-digit hexadecimal number.  The library name, the
     function name, and the reason string are ASCII text.

     ERR_lib_error_string(), ERR_func_error_string(), and
     ERR_reason_error_string() return the library name, the function name, and
     the 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 is NULL, or buf otherwise.

     ERR_lib_error_string(), ERR_func_error_string(), and
     ERR_reason_error_string() return the strings, or NULL if none is
     registered for the error code.

SEE ALSO
     ERR(3), ERR_get_error(3), ERR_load_crypto_strings(3),
     ERR_print_errors(3), SSL_load_error_strings(3)

HISTORY
     ERR_error_string(), ERR_lib_error_string(), ERR_func_error_string(), and
     ERR_reason_error_string() first appeared in SSLeay 0.4.4 and have been
     available since OpenBSD 2.4.

     ERR_error_string_n() first appeared in OpenSSL 0.9.6 and has been
     available since OpenBSD 2.9.

Linux 6.8.2-arch2-1             March 27, 2018             Linux 6.8.2-arch2-1