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 "crypto/cipher.h"
  22
  23
  24 static size_t alg_key_len[QCRYPTO_CIPHER_ALG_LAST] = {
  25     [QCRYPTO_CIPHER_ALG_AES_128] = 16,
  26     [QCRYPTO_CIPHER_ALG_AES_192] = 24,
  27     [QCRYPTO_CIPHER_ALG_AES_256] = 32,
  28     [QCRYPTO_CIPHER_ALG_DES_RFB] = 8,
  29 };
  30
  31 static bool
  32 qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg,
  33                                    size_t nkey,
  34                                    Error **errp)
  35 {
  36     if ((unsigned)alg >= QCRYPTO_CIPHER_ALG_LAST) {
  37         error_setg(errp, "Cipher algorithm %d out of range",
  38                    alg);
  39         return false;
  40     }
  41
  42     if (alg_key_len[alg] != nkey) {
  43         error_setg(errp, "Cipher key length %zu should be %zu",
  44                    alg_key_len[alg], nkey);
  45         return false;
  46     }
  47     return true;
  48 }
  49
  50 #if defined(CONFIG_GNUTLS_GCRYPT) || defined(CONFIG_GNUTLS_NETTLE)
  51 static uint8_t *
  52 qcrypto_cipher_munge_des_rfb_key(const uint8_t *key,
  53                                  size_t nkey)
  54 {
  55     uint8_t *ret = g_new0(uint8_t, nkey);
  56     size_t i;
  57     for (i = 0; i < nkey; i++) {
  58         uint8_t r = key[i];
  59         r = (r & 0xf0) >> 4 | (r & 0x0f) << 4;
  60         r = (r & 0xcc) >> 2 | (r & 0x33) << 2;
  61         r = (r & 0xaa) >> 1 | (r & 0x55) << 1;
  62         ret[i] = r;
  63     }
  64     return ret;
  65 }
  66 #endif /* CONFIG_GNUTLS_GCRYPT || CONFIG_GNUTLS_NETTLE */
  67
  68 #ifdef CONFIG_GNUTLS_GCRYPT
  69 #include "crypto/cipher-gcrypt.c"
  70 #elif defined CONFIG_GNUTLS_NETTLE
  71 #include "crypto/cipher-nettle.c"
  72 #else
  73 #include "crypto/cipher-builtin.c"
  74 #endif