view libutil/revnibbles.c @ 64:dba24129027e

doc/ADM-PIN-numbering article written
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 23 Mar 2021 23:30:00 +0000
parents 34bbb0585cab
children
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/*
 * This module implements some reversed-nibbles parsing functions.
 */

#include <sys/types.h>

decode_reversed_nibbles(bytes, nbytes, dest)
	u_char *bytes;
	unsigned nbytes;
	char *dest;
{
	u_char *sp;
	char *dp;
	unsigned n, c;

	sp = bytes;
	dp = dest;
	for (n = 0; n < nbytes; n++) {
		c = *sp & 0xF;
		*dp++ = encode_hex_digit(c);
		c = *sp >> 4;
		*dp++ = encode_hex_digit(c);
		sp++;
	}
}

pack_reversed_nibbles(nibbles, bytes, nbytes)
	u_char *nibbles, *bytes;
	unsigned nbytes;
{
	u_char *sp, *dp;
	unsigned n;

	sp = nibbles;
	dp = bytes;
	for (n = 0; n < nbytes; n++) {
		*dp++ = sp[0] | (sp[1] << 4);
		sp += 2;
	}
}