.\"=============================================================================
.\" Header
.\"
.\" Copyright (c) 2018-2021 Michael Baeuerle
.\"
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.\"
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.\"
.TH libcanlock 3 2021-11-24 Unix "libcanlock 3.3.0 manual"
.\"
.\"
.\"=============================================================================
.\" NAME section
.\"
.SH NAME
cl_clear_secret - Overwrite secret data in memory with libcanlock
.\"
.\"
.\"=============================================================================
.\" SYNOPSIS section
.\"
.SH SYNOPSIS
.nf
.B #include <libcanlock-3/canlock.h>
.sp
.BI "int cl_clear_secret(void *" sec ", size_t " sec_size ,
.BI "                    size_t " buf_size );
.\"
.\"
.\"=============================================================================
.\" DESCRIPTION section
.\"
.SH DESCRIPTION
The
.BR cl_clear_secret ()
function tries to overwrite
.I sec_size
bytes of memory starting at the address specified by the
.I sec
parameter.
.sp
The size
.I buf_size
must be set to the size of the whole buffer.
.sp
If the operating system provides
.BR memset_s (),
it is called with both length values. Otherwise nonportable functions like
.BR explicit_memset ()
are used if available.
.br
If neither
.BR memset_s ()
nor a nonportable replacement is available, a call to
.BR memset ()
is used instead, but the compiler maybe optimize this attempt to NOP.
A positive value is returned as warning.
.\"
.\"
.\"=============================================================================
.\" RETURN VALUE section
.\"
.SH RETURN VALUE
Upon successful completion zero is returned.
.br
Negative values indicate an error.
.br
Positive values indicate a warning.
.sp
The value -1 is returned if the parameter
.I sec
is NULL or if
.I sec_size
is greater than
.IR buf_size .
.sp
The value 1 indicates missing support for explicit memory access from the
operating system.
.\"
.\"
.\"=============================================================================
.\" AUTHORS section
.\"
.SH AUTHORS
Michael Baeuerle
.\"
.\"
.\"=============================================================================
.\" REPORTING BUGS section
.\"
.SH REPORTING BUGS
Report bugs to <mailto:michael.baeuerle@gmx.net>.
.\"
.\"
.\"=============================================================================
.\" STANDARDS section
.\"
.SH STANDARDS
.B libcanlock
tries to comply with the following standards:
.PP
RFC 5537, RFC 6234, RFC 8315
.\"
.\"
.\"=============================================================================
.\" SEE ALSO section
.\"
.SH SEE ALSO
.BR cl_get_key (3),
.BR cl_get_lock (3),
.BR cl_split (3),
.BR cl_verify (3),
.BR cl_verify_multi (3),
.BR canlock (1),
.BR memset (3),
.BR memset_s (3)
.\"
.\"
.\" EOF