crypto/cipher.c

   1 /*
   2  * QEMU Crypto cipher algorithms
   3  *
   4  * Copyright (c) 2015 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 "crypto/cipher.h"
  23
  24
  25 static size_t alg_key_len[QCRYPTO_CIPHER_ALG__MAX] = {
  26     [QCRYPTO_CIPHER_ALG_AES_128] = 16,
  27     [QCRYPTO_CIPHER_ALG_AES_192] = 24,
  28     [QCRYPTO_CIPHER_ALG_AES_256] = 32,
  29     [QCRYPTO_CIPHER_ALG_DES_RFB] = 8,
  30     [QCRYPTO_CIPHER_ALG_CAST5_128] = 16,
  31     [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
  32     [QCRYPTO_CIPHER_ALG_SERPENT_192] = 24,
  33     [QCRYPTO_CIPHER_ALG_SERPENT_256] = 32,
  34     [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
  35     [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 24,
  36     [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 32,
  37 };
  38
  39 static size_t alg_block_len[QCRYPTO_CIPHER_ALG__MAX] = {
  40     [QCRYPTO_CIPHER_ALG_AES_128] = 16,
  41     [QCRYPTO_CIPHER_ALG_AES_192] = 16,
  42     [QCRYPTO_CIPHER_ALG_AES_256] = 16,
  43     [QCRYPTO_CIPHER_ALG_DES_RFB] = 8,
  44     [QCRYPTO_CIPHER_ALG_CAST5_128] = 8,
  45     [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
  46     [QCRYPTO_CIPHER_ALG_SERPENT_192] = 16,
  47     [QCRYPTO_CIPHER_ALG_SERPENT_256] = 16,
  48     [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
  49     [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 16,
  50     [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 16,
  51 };
  52
  53 static bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = {
  54     [QCRYPTO_CIPHER_MODE_ECB] = false,
  55     [QCRYPTO_CIPHER_MODE_CBC] = true,
  56 };
  57
  58
  59 size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgorithm alg)
  60 {
  61     if (alg >= G_N_ELEMENTS(alg_key_len)) {
  62         return 0;
  63     }
  64     return alg_block_len[alg];
  65 }
  66
  67
  68 size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgorithm alg)
  69 {
  70     if (alg >= G_N_ELEMENTS(alg_key_len)) {
  71         return 0;
  72     }
  73     return alg_key_len[alg];
  74 }
  75
  76
  77 size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgorithm alg,
  78                                  QCryptoCipherMode mode)
  79 {
  80     if (alg >= G_N_ELEMENTS(alg_block_len)) {
  81         return 0;
  82     }
  83     if (mode >= G_N_ELEMENTS(mode_need_iv)) {
  84         return 0;
  85     }
  86
  87     if (mode_need_iv[mode]) {
  88         return alg_block_len[alg];
  89     }
  90     return 0;
  91 }
  92
  93
  94 static bool
  95 qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg,
  96                                    size_t nkey,
  97                                    Error **errp)
  98 {
  99     if ((unsigned)alg >= QCRYPTO_CIPHER_ALG__MAX) {
 100         error_setg(errp, "Cipher algorithm %d out of range",
 101                    alg);
 102         return false;
 103     }
 104
 105     if (alg_key_len[alg] != nkey) {
 106         error_setg(errp, "Cipher key length %zu should be %zu",
 107                    nkey, alg_key_len[alg]);
 108         return false;
 109     }
 110     return true;
 111 }
 112
 113 #if defined(CONFIG_GCRYPT) || defined(CONFIG_NETTLE)
 114 static uint8_t *
 115 qcrypto_cipher_munge_des_rfb_key(const uint8_t *key,
 116                                  size_t nkey)
 117 {
 118     uint8_t *ret = g_new0(uint8_t, nkey);
 119     size_t i;
 120     for (i = 0; i < nkey; i++) {
 121         uint8_t r = key[i];
 122         r = (r & 0xf0) >> 4 | (r & 0x0f) << 4;
 123         r = (r & 0xcc) >> 2 | (r & 0x33) << 2;
 124         r = (r & 0xaa) >> 1 | (r & 0x55) << 1;
 125         ret[i] = r;
 126     }
 127     return ret;
 128 }
 129 #endif /* CONFIG_GCRYPT || CONFIG_NETTLE */
 130
 131 #ifdef CONFIG_GCRYPT
 132 #include "crypto/cipher-gcrypt.c"
 133 #elif defined CONFIG_NETTLE
 134 #include "crypto/cipher-nettle.c"
 135 #else
 136 #include "crypto/cipher-builtin.c"
 137 #endif