cb730894ae
There are a number of different algorithms that can be used to generate initialization vectors for disk encryption. This introduces a simple internal QCryptoBlockIV object to provide a consistent internal API to the different algorithms. The initially implemented algorithms are 'plain', 'plain64' and 'essiv', each matching the same named algorithm provided by the Linux kernel dm-crypt driver. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
/*
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* QEMU Crypto block IV generator - plain
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*
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* Copyright (c) 2015-2016 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include "qemu/osdep.h"
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#include "crypto/ivgen-plain.h"
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static int qcrypto_ivgen_plain_init(QCryptoIVGen *ivgen,
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const uint8_t *key, size_t nkey,
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Error **errp)
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{
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return 0;
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}
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static int qcrypto_ivgen_plain_calculate(QCryptoIVGen *ivgen,
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uint64_t sector,
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uint8_t *iv, size_t niv,
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Error **errp)
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{
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size_t ivprefix;
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uint32_t shortsector = cpu_to_le32((sector & 0xffffffff));
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ivprefix = sizeof(shortsector);
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if (ivprefix > niv) {
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ivprefix = niv;
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}
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memcpy(iv, &shortsector, ivprefix);
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if (ivprefix < niv) {
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memset(iv + ivprefix, 0, niv - ivprefix);
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}
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return 0;
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}
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static void qcrypto_ivgen_plain_cleanup(QCryptoIVGen *ivgen)
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{
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}
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struct QCryptoIVGenDriver qcrypto_ivgen_plain = {
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.init = qcrypto_ivgen_plain_init,
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.calculate = qcrypto_ivgen_plain_calculate,
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.cleanup = qcrypto_ivgen_plain_cleanup,
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};
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