_ Git - BearSSL/blob - src/symcipher/aes_ct64_cbcenc.c

   1 /*
   2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 #include "inner.h"
  26
  27 /* see bearssl_block.h */
  28 void
  29 br_aes_ct64_cbcenc_init(br_aes_ct64_cbcenc_keys *ctx,
  30         const void *key, size_t len)
  31 {
  32         ctx->vtable = &br_aes_ct64_cbcenc_vtable;
  33         ctx->num_rounds = br_aes_ct64_keysched(ctx->skey, key, len);
  34 }
  35
  36 /* see bearssl_block.h */
  37 void
  38 br_aes_ct64_cbcenc_run(const br_aes_ct64_cbcenc_keys *ctx,
  39         void *iv, void *data, size_t len)
  40 {
  41         unsigned char *buf;
  42         uint64_t sk_exp[120];
  43         uint32_t ivw[4];
  44
  45         br_aes_ct64_skey_expand(sk_exp, ctx->num_rounds, ctx->skey);
  46         br_range_dec32le(ivw, 4, iv);
  47         buf = data;
  48         while (len > 0) {
  49                 uint32_t w[4];
  50                 uint64_t q[8];
  51
  52                 w[0] = ivw[0] ^ br_dec32le(buf);
  53                 w[1] = ivw[1] ^ br_dec32le(buf + 4);
  54                 w[2] = ivw[2] ^ br_dec32le(buf + 8);
  55                 w[3] = ivw[3] ^ br_dec32le(buf + 12);
  56                 br_aes_ct64_interleave_in(&q[0], &q[4], w);
  57                 br_aes_ct64_ortho(q);
  58                 br_aes_ct64_bitslice_encrypt(ctx->num_rounds, sk_exp, q);
  59                 br_aes_ct64_ortho(q);
  60                 br_aes_ct64_interleave_out(w, q[0], q[4]);
  61                 memcpy(ivw, w, sizeof w);
  62                 br_enc32le(buf, w[0]);
  63                 br_enc32le(buf + 4, w[1]);
  64                 br_enc32le(buf + 8, w[2]);
  65                 br_enc32le(buf + 12, w[3]);
  66                 buf += 16;
  67                 len -= 16;
  68         }
  69         br_range_enc32le(iv, ivw, 4);
  70 }
  71
  72 /* see bearssl_block.h */
  73 const br_block_cbcenc_class br_aes_ct64_cbcenc_vtable = {
  74         sizeof(br_aes_ct64_cbcenc_keys),
  75         16,
  76         4,
  77         (void (*)(const br_block_cbcenc_class **, const void *, size_t))
  78                 &br_aes_ct64_cbcenc_init,
  79         (void (*)(const br_block_cbcenc_class *const *, void *, void *, size_t))
  80                 &br_aes_ct64_cbcenc_run
  81 };