NE_MKNONCE(3)                 neon API reference                 NE_MKNONCE(3)

NAME
       ne_mknonce - generate a nonce

SYNOPSIS
       #include <ne_string.h>

       int ne_mknonce(unsigned char *nonce, size_t len, unsigned int flags);

DESCRIPTION
       ne_mknonce fills the buffer pointed to by nonce with len bytes of
       random data suitable for use as a nonce. The value of len must be
       greater than zero and no greater than 256.

       The flags parameter is reserved for future use and must be set to zero.

       The caller is responsible for ensuring that the buffer pointed to by
       nonce is at least len bytes in size.

RETURN VALUE
       ne_mknonce returns zero on success. On error, a non-zero errno value is
       returned indicating the cause of the failure; the buffer contents are
       undefined.

EXAMPLE
       The following example generates a 16-byte nonce and encodes it as a
       hexadecimal string.

           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\n", strerror(err));
               return -1;
           }

           for (i = 0; i < 16; i++)
               sprintf(hex + 2 * i, "%02x", buf[i]);
           hex[32] = '\0';

HISTORY
       ne_mknonce is available in neon 0.37.0 and later.

COPYRIGHT
       Copyright (C) 2001-2026 Joe Orton

neon                              03/20/2026                     NE_MKNONCE(3)