Daniel P. Berrange | cb73089 | 2015-10-15 12:35:28 +0100 | [diff] [blame] | 1 | /* |
| 2 | * QEMU Crypto block IV generator - essiv |
| 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 |
Thomas Huth | b7cbb87 | 2019-02-13 16:54:59 +0100 | [diff] [blame] | 9 | * version 2.1 of the License, or (at your option) any later version. |
Daniel P. Berrange | cb73089 | 2015-10-15 12:35:28 +0100 | [diff] [blame] | 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" |
Markus Armbruster | 7136fc1 | 2016-03-11 09:20:17 +0100 | [diff] [blame] | 22 | #include "qemu/bswap.h" |
Michael S. Tsirkin | 986bc8d | 2018-05-03 22:50:23 +0300 | [diff] [blame] | 23 | #include "ivgen-essiv.h" |
Daniel P. Berrange | cb73089 | 2015-10-15 12:35:28 +0100 | [diff] [blame] | 24 | |
| 25 | typedef struct QCryptoIVGenESSIV QCryptoIVGenESSIV; |
| 26 | struct QCryptoIVGenESSIV { |
| 27 | QCryptoCipher *cipher; |
| 28 | }; |
| 29 | |
| 30 | static int qcrypto_ivgen_essiv_init(QCryptoIVGen *ivgen, |
| 31 | const uint8_t *key, size_t nkey, |
| 32 | Error **errp) |
| 33 | { |
| 34 | uint8_t *salt; |
| 35 | size_t nhash; |
| 36 | size_t nsalt; |
| 37 | QCryptoIVGenESSIV *essiv = g_new0(QCryptoIVGenESSIV, 1); |
| 38 | |
| 39 | /* Not necessarily the same as nkey */ |
| 40 | nsalt = qcrypto_cipher_get_key_len(ivgen->cipher); |
| 41 | |
| 42 | nhash = qcrypto_hash_digest_len(ivgen->hash); |
| 43 | /* Salt must be larger of hash size or key size */ |
| 44 | salt = g_new0(uint8_t, MAX(nhash, nsalt)); |
| 45 | |
| 46 | if (qcrypto_hash_bytes(ivgen->hash, (const gchar *)key, nkey, |
| 47 | &salt, &nhash, |
| 48 | errp) < 0) { |
| 49 | g_free(essiv); |
Li Qiang | 0072d2a | 2017-01-03 20:31:34 -0800 | [diff] [blame] | 50 | g_free(salt); |
Daniel P. Berrange | cb73089 | 2015-10-15 12:35:28 +0100 | [diff] [blame] | 51 | return -1; |
| 52 | } |
| 53 | |
| 54 | /* Now potentially truncate salt to match cipher key len */ |
| 55 | essiv->cipher = qcrypto_cipher_new(ivgen->cipher, |
| 56 | QCRYPTO_CIPHER_MODE_ECB, |
| 57 | salt, MIN(nhash, nsalt), |
| 58 | errp); |
| 59 | if (!essiv->cipher) { |
| 60 | g_free(essiv); |
| 61 | g_free(salt); |
| 62 | return -1; |
| 63 | } |
| 64 | |
| 65 | g_free(salt); |
| 66 | ivgen->private = essiv; |
| 67 | |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | static int qcrypto_ivgen_essiv_calculate(QCryptoIVGen *ivgen, |
| 72 | uint64_t sector, |
| 73 | uint8_t *iv, size_t niv, |
| 74 | Error **errp) |
| 75 | { |
| 76 | QCryptoIVGenESSIV *essiv = ivgen->private; |
| 77 | size_t ndata = qcrypto_cipher_get_block_len(ivgen->cipher); |
| 78 | uint8_t *data = g_new(uint8_t, ndata); |
| 79 | |
| 80 | sector = cpu_to_le64(sector); |
Marc-AndrĂ© Lureau | 83e3330 | 2018-01-04 17:05:17 +0100 | [diff] [blame] | 81 | memcpy(data, (uint8_t *)§or, MIN(sizeof(sector), ndata)); |
Daniel P. Berrange | cb73089 | 2015-10-15 12:35:28 +0100 | [diff] [blame] | 82 | if (sizeof(sector) < ndata) { |
| 83 | memset(data + sizeof(sector), 0, ndata - sizeof(sector)); |
| 84 | } |
| 85 | |
| 86 | if (qcrypto_cipher_encrypt(essiv->cipher, |
| 87 | data, |
| 88 | data, |
| 89 | ndata, |
| 90 | errp) < 0) { |
| 91 | g_free(data); |
| 92 | return -1; |
| 93 | } |
| 94 | |
| 95 | if (ndata > niv) { |
| 96 | ndata = niv; |
| 97 | } |
| 98 | memcpy(iv, data, ndata); |
| 99 | if (ndata < niv) { |
| 100 | memset(iv + ndata, 0, niv - ndata); |
| 101 | } |
| 102 | g_free(data); |
| 103 | return 0; |
| 104 | } |
| 105 | |
| 106 | static void qcrypto_ivgen_essiv_cleanup(QCryptoIVGen *ivgen) |
| 107 | { |
| 108 | QCryptoIVGenESSIV *essiv = ivgen->private; |
| 109 | |
| 110 | qcrypto_cipher_free(essiv->cipher); |
| 111 | g_free(essiv); |
| 112 | } |
| 113 | |
| 114 | |
| 115 | struct QCryptoIVGenDriver qcrypto_ivgen_essiv = { |
| 116 | .init = qcrypto_ivgen_essiv_init, |
| 117 | .calculate = qcrypto_ivgen_essiv_calculate, |
| 118 | .cleanup = qcrypto_ivgen_essiv_cleanup, |
| 119 | }; |
| 120 | |