/*
 * This file is part of Cockpit.
 *
 * Copyright (C) 2014 Red Hat, Inc.
 *
 * Cockpit is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * Cockpit is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Cockpit; If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include "cockpithex.h"

#include <stdlib.h>
#include <string.h>

static const char HEX[] = "0123456789abcdef";

char *
cockpit_hex_encode (const void * data,
                    ssize_t length)
{
  const unsigned char *in = data;
  char *out;
  size_t i;

  if (length < 0)
    length = strlen (data);

  out = malloc (length * 2 + 1);
  if (!out)
    return NULL;
  for (i = 0; i < length; i++)
    {
      out[i * 2] = HEX[in[i] >> 4];
      out[i * 2 + 1] = HEX[in[i] & 0xf];
    }
  out[i * 2] = '\0';
  return out;
}

void *
cockpit_hex_decode (const char *hex,
                    ssize_t hexlen,
                    size_t *length)
{
  const char *hpos;
  const char *lpos;
  char *out;
  int i;

  if (hexlen < 0)
    hexlen = strlen (hex);
  if (hexlen % 2 != 0)
    return NULL;

  out = malloc (hexlen * 2 + 1);
  if (!out)
    return NULL;
  for (i = 0; i < hexlen / 2; i++)
    {
      hpos = strchr (HEX, hex[i * 2]);
      lpos = strchr (HEX, hex[i * 2 + 1]);
      if (hpos == NULL || lpos == NULL)
        {
          free (out);
          return NULL;
        }
      out[i] = ((hpos - HEX) << 4) | ((lpos - HEX) & 0xf);
    }

  /* A convenience null termination */
  out[i] = '\0';

  if (length)
    *length = i;
  return out;
}