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 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 "qapi/error.h"
  23#include "qemu/bswap.h"
  24#include "crypto/ivgen-plain.h"
  25
  26static int qcrypto_ivgen_plain_init(QCryptoIVGen *ivgen,
  27                                    const uint8_t *key, size_t nkey,
  28                                    Error **errp)
  29{
  30    return 0;
  31}
  32
  33static int qcrypto_ivgen_plain_calculate(QCryptoIVGen *ivgen,
  34                                         uint64_t sector,
  35                                         uint8_t *iv, size_t niv,
  36                                         Error **errp)
  37{
  38    size_t ivprefix;
  39    uint32_t shortsector = cpu_to_le32((sector & 0xffffffff));
  40    ivprefix = sizeof(shortsector);
  41    if (ivprefix > niv) {
  42        ivprefix = niv;
  43    }
  44    memcpy(iv, &shortsector, ivprefix);
  45    if (ivprefix < niv) {
  46        memset(iv + ivprefix, 0, niv - ivprefix);
  47    }
  48    return 0;
  49}
  50
  51static void qcrypto_ivgen_plain_cleanup(QCryptoIVGen *ivgen)
  52{
  53}
  54
  55
  56struct QCryptoIVGenDriver qcrypto_ivgen_plain = {
  57    .init = qcrypto_ivgen_plain_init,
  58    .calculate = qcrypto_ivgen_plain_calculate,
  59    .cleanup = qcrypto_ivgen_plain_cleanup,
  60};
  61
  62