'\" t
.\"     Title: ne_mknonce
.\"    Author: 
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 03/20/2026
.\"    Manual: neon API reference
.\"    Source: neon
.\"  Language: English
.\"
.TH "NE_MKNONCE" "3" "03/20/2026" "neon" "neon API reference"
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.el       .ds Aq '
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.SH "NAME"
ne_mknonce \- generate a nonce
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <ne_string\&.h>
.fi
.ft
.HP \w'int\ ne_mknonce('u
.BI "int ne_mknonce(unsigned\ char\ *" "nonce" ", size_t\ " "len" ", unsigned\ int\ " "flags" ");"
.SH "DESCRIPTION"
.PP
\fBne_mknonce\fR
fills the buffer pointed to by
\fInonce\fR
with
\fIlen\fR
bytes of random data suitable for use as a nonce\&. The value of
\fIlen\fR
must be greater than zero and no greater than 256\&.
.PP
The
\fIflags\fR
parameter is reserved for future use and must be set to zero\&.
.PP
The caller is responsible for ensuring that the buffer pointed to by
\fInonce\fR
is at least
\fIlen\fR
bytes in size\&.
.SH "RETURN VALUE"
.PP
\fBne_mknonce\fR
returns zero on success\&. On error, a non\-zero
\fBerrno\fR
value is returned indicating the cause of the failure; the buffer contents are undefined\&.
.SH "EXAMPLE"
.PP
The following example generates a 16\-byte nonce and encodes it as a hexadecimal string\&.
.sp
.if n \{\
.RS 4
.\}
.nf
unsigned char buf[16];
unsigned char hex[33];
int i, err;

err = ne_mknonce(buf, sizeof buf, 0);
if (err) {
    fprintf(stderr, "ne_mknonce failed: %s\en", strerror(err));
    return \-1;
}

for (i = 0; i < 16; i++)
    sprintf(hex + 2 * i, "%02x", buf[i]);
hex[32] = \*(Aq\e0\*(Aq;
.fi
.if n \{\
.RE
.\}
.SH "HISTORY"
.PP
\fBne_mknonce\fR
is available in neon 0\&.37\&.0 and later\&.
.SH "COPYRIGHT"
.br
Copyright \(co 2001-2026 Joe Orton
.br