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 2.1 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/host-utils.h"
  23 #include "qapi/error.h"
  24 #include "crypto/cipher.h"
  25 #include "cipherpriv.h"
  26
  27
  28 static const size_t alg_key_len[QCRYPTO_CIPHER_ALGO__MAX] = {
  29     [QCRYPTO_CIPHER_ALGO_AES_128] = 16,
  30     [QCRYPTO_CIPHER_ALGO_AES_192] = 24,
  31     [QCRYPTO_CIPHER_ALGO_AES_256] = 32,
  32     [QCRYPTO_CIPHER_ALGO_DES] = 8,
  33     [QCRYPTO_CIPHER_ALGO_3DES] = 24,
  34     [QCRYPTO_CIPHER_ALGO_CAST5_128] = 16,
  35     [QCRYPTO_CIPHER_ALGO_SERPENT_128] = 16,
  36     [QCRYPTO_CIPHER_ALGO_SERPENT_192] = 24,
  37     [QCRYPTO_CIPHER_ALGO_SERPENT_256] = 32,
  38     [QCRYPTO_CIPHER_ALGO_TWOFISH_128] = 16,
  39     [QCRYPTO_CIPHER_ALGO_TWOFISH_192] = 24,
  40     [QCRYPTO_CIPHER_ALGO_TWOFISH_256] = 32,
  41 #ifdef CONFIG_CRYPTO_SM4
  42     [QCRYPTO_CIPHER_ALGO_SM4] = 16,
  43 #endif
  44 };
  45
  46 static const size_t alg_block_len[QCRYPTO_CIPHER_ALGO__MAX] = {
  47     [QCRYPTO_CIPHER_ALGO_AES_128] = 16,
  48     [QCRYPTO_CIPHER_ALGO_AES_192] = 16,
  49     [QCRYPTO_CIPHER_ALGO_AES_256] = 16,
  50     [QCRYPTO_CIPHER_ALGO_DES] = 8,
  51     [QCRYPTO_CIPHER_ALGO_3DES] = 8,
  52     [QCRYPTO_CIPHER_ALGO_CAST5_128] = 8,
  53     [QCRYPTO_CIPHER_ALGO_SERPENT_128] = 16,
  54     [QCRYPTO_CIPHER_ALGO_SERPENT_192] = 16,
  55     [QCRYPTO_CIPHER_ALGO_SERPENT_256] = 16,
  56     [QCRYPTO_CIPHER_ALGO_TWOFISH_128] = 16,
  57     [QCRYPTO_CIPHER_ALGO_TWOFISH_192] = 16,
  58     [QCRYPTO_CIPHER_ALGO_TWOFISH_256] = 16,
  59 #ifdef CONFIG_CRYPTO_SM4
  60     [QCRYPTO_CIPHER_ALGO_SM4] = 16,
  61 #endif
  62 };
  63
  64 static const bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = {
  65     [QCRYPTO_CIPHER_MODE_ECB] = false,
  66     [QCRYPTO_CIPHER_MODE_CBC] = true,
  67     [QCRYPTO_CIPHER_MODE_XTS] = true,
  68     [QCRYPTO_CIPHER_MODE_CTR] = true,
  69 };
  70
  71
  72 size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgo alg)
  73 {
  74     assert(alg < G_N_ELEMENTS(alg_key_len));
  75     return alg_block_len[alg];
  76 }
  77
  78
  79 size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgo alg)
  80 {
  81     assert(alg < G_N_ELEMENTS(alg_key_len));
  82     return alg_key_len[alg];
  83 }
  84
  85
  86 size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgo alg,
  87                                  QCryptoCipherMode mode)
  88 {
  89     if (alg >= G_N_ELEMENTS(alg_block_len)) {
  90         return 0;
  91     }
  92     if (mode >= G_N_ELEMENTS(mode_need_iv)) {
  93         return 0;
  94     }
  95
  96     if (mode_need_iv[mode]) {
  97         return alg_block_len[alg];
  98     }
  99     return 0;
 100 }
 101
 102
 103 static bool
 104 qcrypto_cipher_validate_key_length(QCryptoCipherAlgo alg,
 105                                    QCryptoCipherMode mode,
 106                                    size_t nkey,
 107                                    Error **errp)
 108 {
 109     if ((unsigned)alg >= QCRYPTO_CIPHER_ALGO__MAX) {
 110         error_setg(errp, "Cipher algorithm %d out of range",
 111                    alg);
 112         return false;
 113     }
 114
 115     if (mode == QCRYPTO_CIPHER_MODE_XTS) {
 116         if (alg == QCRYPTO_CIPHER_ALGO_DES ||
 117             alg == QCRYPTO_CIPHER_ALGO_3DES) {
 118             error_setg(errp, "XTS mode not compatible with DES/3DES");
 119             return false;
 120         }
 121         if (nkey % 2) {
 122             error_setg(errp, "XTS cipher key length should be a multiple of 2");
 123             return false;
 124         }
 125
 126         if (alg_key_len[alg] != (nkey / 2)) {
 127             error_setg(errp, "Cipher key length %zu should be %zu",
 128                        nkey, alg_key_len[alg] * 2);
 129             return false;
 130         }
 131     } else {
 132         if (alg_key_len[alg] != nkey) {
 133             error_setg(errp, "Cipher key length %zu should be %zu",
 134                        nkey, alg_key_len[alg]);
 135             return false;
 136         }
 137     }
 138     return true;
 139 }
 140
 141 #ifdef CONFIG_GCRYPT
 142 #include "cipher-gcrypt.c.inc"
 143 #elif defined CONFIG_NETTLE
 144 #include "cipher-nettle.c.inc"
 145 #elif defined CONFIG_GNUTLS_CRYPTO
 146 #include "cipher-gnutls.c.inc"
 147 #else
 148 #include "cipher-builtin.c.inc"
 149 #endif
 150
 151 QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgo alg,
 152                                   QCryptoCipherMode mode,
 153                                   const uint8_t *key, size_t nkey,
 154                                   Error **errp)
 155 {
 156     QCryptoCipher *cipher = NULL;
 157
 158 #ifdef CONFIG_AF_ALG
 159     cipher = qcrypto_afalg_cipher_ctx_new(alg, mode, key, nkey, NULL);
 160 #endif
 161
 162     if (!cipher) {
 163         cipher = qcrypto_cipher_ctx_new(alg, mode, key, nkey, errp);
 164         if (!cipher) {
 165             return NULL;
 166         }
 167     }
 168
 169     cipher->alg = alg;
 170     cipher->mode = mode;
 171
 172     return cipher;
 173 }
 174
 175
 176 int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
 177                            const void *in,
 178                            void *out,
 179                            size_t len,
 180                            Error **errp)
 181 {
 182     const QCryptoCipherDriver *drv = cipher->driver;
 183     return drv->cipher_encrypt(cipher, in, out, len, errp);
 184 }
 185
 186
 187 int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
 188                            const void *in,
 189                            void *out,
 190                            size_t len,
 191                            Error **errp)
 192 {
 193     const QCryptoCipherDriver *drv = cipher->driver;
 194     return drv->cipher_decrypt(cipher, in, out, len, errp);
 195 }
 196
 197
 198 int qcrypto_cipher_setiv(QCryptoCipher *cipher,
 199                          const uint8_t *iv, size_t niv,
 200                          Error **errp)
 201 {
 202     const QCryptoCipherDriver *drv = cipher->driver;
 203     return drv->cipher_setiv(cipher, iv, niv, errp);
 204 }
 205
 206
 207 void qcrypto_cipher_free(QCryptoCipher *cipher)
 208 {
 209     if (cipher) {
 210         cipher->driver->cipher_free(cipher);
 211     }
 212 }