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       1                 :             : /*
       2                 :             :  * Copyright (c) 2010, XenSource Inc.
       3                 :             :  * All rights reserved.
       4                 :             :  *
       5                 :             :  * Redistribution and use in source and binary forms, with or without
       6                 :             :  * modification, are permitted provided that the following conditions are met:
       7                 :             :  *     * Redistributions of source code must retain the above copyright
       8                 :             :  *       notice, this list of conditions and the following disclaimer.
       9                 :             :  *     * Redistributions in binary form must reproduce the above copyright
      10                 :             :  *       notice, this list of conditions and the following disclaimer in the
      11                 :             :  *       documentation and/or other materials provided with the distribution.
      12                 :             :  *     * Neither the name of XenSource Inc. nor the names of its contributors
      13                 :             :  *       may be used to endorse or promote products derived from this software
      14                 :             :  *       without specific prior written permission.
      15                 :             :  *
      16                 :             :  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      17                 :             :  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      18                 :             :  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      19                 :             :  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
      20                 :             :  * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
      21                 :             :  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
      22                 :             :  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
      23                 :             :  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
      24                 :             :  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
      25                 :             :  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
      26                 :             :  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      27                 :             :  */
      28                 :             : 
      29                 :             : /*
      30                 :             :  * Copyright (c) 2014 Citrix Systems, Inc.
      31                 :             :  */
      32                 :             : 
      33                 :             : 
      34                 :             : extern struct crypto_blkcipher *xts_aes_setup(void);
      35                 :             : 
      36                 :             : int xts_aes_setkey(struct crypto_blkcipher *cipher, const uint8_t *key, unsigned int keysize);
      37                 :             : 
      38                 :             : typedef uint64_t sector_t;
      39                 :             : 
      40                 :             : static inline void
      41                 :           0 : xts_aes_plain_iv_generate(uint8_t *iv, int iv_size, sector_t sector)
      42                 :             : {
      43                 :           0 :     memset(iv, 0, iv_size);
      44                 :           0 :     *(uint32_t *)iv = sector & 0xffffffff; /* LITTLE ENDIAN */
      45                 :           0 : }
      46                 :             : 
      47                 :             : static inline int
      48                 :           0 : xts_aes_plain_encrypt(struct crypto_blkcipher *xts_tfm, sector_t sector,
      49                 :             :                       uint8_t *dst_buf, uint8_t *src_buf, unsigned int nbytes)
      50                 :             : {
      51                 :           0 :         uint8_t iv[16];
      52                 :           0 :         int dstlen;
      53                 :           0 :         xts_aes_plain_iv_generate(iv, 16, sector);
      54                 :             : 
      55         [ #  # ]:           0 :         if (!EVP_CipherInit_ex(xts_tfm->en_ctx, NULL, NULL, NULL, iv, -1))
      56                 :           0 :                 return -1;
      57         [ #  # ]:           0 :         if (!EVP_CipherUpdate(xts_tfm->en_ctx, dst_buf, &dstlen, src_buf, nbytes))
      58                 :           0 :                 return -2;
      59                 :             :         /* no need to finalize with XTS when multiple of blocksize */
      60                 :             :         return 0;
      61                 :             : }
      62                 :             : 
      63                 :             : static inline int
      64                 :           0 : xts_aes_plain_decrypt(struct crypto_blkcipher *xts_tfm, sector_t sector,
      65                 :             :                       uint8_t *dst_buf, uint8_t *src_buf, unsigned int nbytes)
      66                 :             : {
      67                 :           0 :         uint8_t iv[16];
      68                 :           0 :         int dstlen;
      69                 :           0 :         xts_aes_plain_iv_generate(iv, 16, sector);
      70                 :             : 
      71         [ #  # ]:           0 :         if (!EVP_CipherInit_ex(xts_tfm->de_ctx, NULL, NULL, NULL, iv, -1))
      72                 :           0 :                 return -1;
      73         [ #  # ]:           0 :         if (!EVP_CipherUpdate(xts_tfm->de_ctx, dst_buf, &dstlen, src_buf, nbytes))
      74                 :           0 :                 return -2;
      75                 :             :         /* no need to finalize with XTS when multiple of blocksize */
      76                 :             :         return 0;
      77                 :             : }