LXR qemu/crypto/ivgen-plain.c

   1/*
   2 * QEMU Crypto block IV generator - plain
   3 *
   4 * Copyright (c) 2015-2016 Red Hat, Inc.
   5 *
   6 * This library is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU Lesser General Public
   8 * License as published by the Free Software Foundation; either
   9 * version 2.1 of the License, or (at your option) any later version.
  10 *
  11 * This library is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * Lesser General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU Lesser General Public
  17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18 *
  19 */
  20
  21#include "qemu/osdep.h"
  22#include "qemu/bswap.h"
  23#include "ivgen-plain.h"
  24
  25static int qcrypto_ivgen_plain_init(QCryptoIVGen *ivgen,
  26                                    const uint8_t *key, size_t nkey,
  27                                    Error **errp)
  28{
  29    return 0;
  30}
  31
  32static int qcrypto_ivgen_plain_calculate(QCryptoIVGen *ivgen,
  33                                         uint64_t sector,
  34                                         uint8_t *iv, size_t niv,
  35                                         Error **errp)
  36{
  37    size_t ivprefix;
  38    uint32_t shortsector = cpu_to_le32((sector & 0xffffffff));
  39    ivprefix = sizeof(shortsector);
  40    if (ivprefix > niv) {
  41        ivprefix = niv;
  42    }
  43    memcpy(iv, &shortsector, ivprefix);
  44    if (ivprefix < niv) {
  45        memset(iv + ivprefix, 0, niv - ivprefix);
  46    }
  47    return 0;
  48}
  49
  50static void qcrypto_ivgen_plain_cleanup(QCryptoIVGen *ivgen)
  51{
  52}
  53
  54
  55struct QCryptoIVGenDriver qcrypto_ivgen_plain = {
  56    .init = qcrypto_ivgen_plain_init,
  57    .calculate = qcrypto_ivgen_plain_calculate,
  58    .cleanup = qcrypto_ivgen_plain_cleanup,
  59};
  60
  61