ivgen-plain.c (1846B)
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 25 static int qcrypto_ivgen_plain_init(QCryptoIVGen *ivgen, 26 const uint8_t *key, size_t nkey, 27 Error **errp) 28 { 29 return 0; 30 } 31 32 static 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 50 static void qcrypto_ivgen_plain_cleanup(QCryptoIVGen *ivgen) 51 { 52 } 53 54 55 struct QCryptoIVGenDriver qcrypto_ivgen_plain = { 56 .init = qcrypto_ivgen_plain_init, 57 .calculate = qcrypto_ivgen_plain_calculate, 58 .cleanup = qcrypto_ivgen_plain_cleanup, 59 }; 60