dvbcsa_bs_algo.c

libdvbcsa is a implementation of the DVB Common Scrambling Algorithm

/*

    This file is part of libdvbcsa.

    libdvbcsa is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published
    by the Free Software Foundation; either version 2 of the License,
    or (at your option) any later version.

    libdvbcsa 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
    General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with libdvbcsa; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA

    Based on FFdecsa, Copyright (C) 2003-2004  fatih89r

    (c) 2006-2008 Alexandre Becoulet <[e-mail]>

*/

#if defined(DVBCSA_DEBUG)
#include <stdio.h>
#endif

#include "dvbcsa/dvbcsa.h"
#include "dvbcsa_bs.h"

#ifdef HAVE_ASSERT_H
#include <assert.h>
#endif

void dvbcsa_bs_decrypt(const struct dvbcsa_bs_key_s *key,
		       const struct dvbcsa_bs_batch_s *pcks,
		       unsigned int maxlen)
{
#ifdef HAVE_ASSERT_H
  assert(maxlen % 8 == 0);
#endif

#ifndef DVBCSA_DISABLE_STREAM
  dvbcsa_bs_stream_cipher_batch(key, pcks, maxlen);
#endif
#ifndef DVBCSA_DISABLE_BLOCK
  dvbcsa_bs_block_decrypt_batch(key, pcks, maxlen);
#endif

  BS_EMPTY ();			// restore CPU multimedia state
}

void dvbcsa_bs_encrypt(const struct dvbcsa_bs_key_s *key,
		       const struct dvbcsa_bs_batch_s *pcks,
		       unsigned int maxlen)
{
#ifdef HAVE_ASSERT_H
  assert(maxlen % 8 == 0);
#endif

#ifndef DVBCSA_DISABLE_BLOCK
  dvbcsa_bs_block_encrypt_batch(key, pcks, maxlen);
#endif
#ifndef DVBCSA_DISABLE_STREAM
  dvbcsa_bs_stream_cipher_batch(key, pcks, maxlen);
#endif

  BS_EMPTY ();			// restore CPU multimedia state
}

struct dvbcsa_bs_key_s * dvbcsa_bs_key_alloc()
{
  void *p;

#ifdef HAVE_POSIX_MEMALIGN
  return posix_memalign(&p, sizeof(dvbcsa_bs_word_t), sizeof (struct dvbcsa_bs_key_s)) ? NULL : p;
#else
  p = malloc(sizeof (struct dvbcsa_bs_key_s));
# ifdef HAVE_ASSERT_H
  assert((uintptr_t)p % sizeof(dvbcsa_bs_word_t) == 0);
# endif
  return p;
#endif
}

void dvbcsa_bs_key_free(struct dvbcsa_bs_key_s *key)
{
  free(key);
}

unsigned int dvbcsa_bs_batch_size (void)
{
  return BS_BATCH_SIZE;
}

#if defined(DVBCSA_DEBUG)
void
worddump (const char *str, const void *data, size_t len, size_t ws)
{
  const uint8_t *p = data;
  uint32_t i;

  printf ("- %s - %zu bytes\n", str, len);
  for (i = 0; i < len; i++)
    {
      const char *s;

      if ((i + 1) % 32 == 0)
	s = "\n";
      else if ((i + 1) % ws == 0)
	s = " ";
      else
	s = "";

      printf("%02x%s", p[i ^ (ws - 1)], s);
    }

  if (i % 32)
    putchar ('\n');
}
#endif