Line data    Source code

       1             : /**
       2             :  * The MIT License (MIT)
       3             :  *
       4             :  * Copyright (c) 2021 RSK Labs Ltd
       5             :  *
       6             :  * Permission is hereby granted, free of charge, to any person obtaining a copy
       7             :  * of this software and associated documentation files (the "Software"), to
       8             :  * deal in the Software without restriction, including without limitation the
       9             :  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
      10             :  * sell copies of the Software, and to permit persons to whom the Software is
      11             :  * furnished to do so, subject to the following conditions:
      12             :  *
      13             :  * The above copyright notice and this permission notice shall be included in
      14             :  * all copies or substantial portions of the Software.
      15             :  *
      16             :  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      17             :  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      18             :  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      19             :  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      20             :  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
      21             :  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
      22             :  * IN THE SOFTWARE.
      23             :  */
      24             : 
      25             : #include "bc.h"
      26             : #include "bc_hash.h"
      27             : 
      28             : /*
      29             :  * Compute a double sha256 and a final reversal.
      30             :  *
      31             :  * @arg[in]  ctx  sha256 context
      32             :  * @arg[in]  data pointer tobytes to double hash and reverse
      33             :  * @arg[in]  len  length of data to hash in bytes
      34             :  * @arg[out] hash 32-byte buffer where hash will be stored
      35             :  */
      36         295 : void double_sha256_rev(sha256_ctx_t* ctx,
      37             :                        uint8_t* data,
      38             :                        size_t len,
      39             :                        uint8_t* hash) {
      40         295 :     SHA256_INIT(ctx);
      41         295 :     SHA256_UPDATE(ctx, data, len);
      42         295 :     SHA256_FINAL(ctx, hash);
      43         295 :     SHA256_INIT(ctx);
      44         295 :     SHA256_UPDATE(ctx, hash, HASH_SIZE);
      45         295 :     SHA256_FINAL(ctx, hash);
      46        5015 :     REV_HASH(hash);
      47         295 : }
      48             : 
      49             : /*
      50             :  * Perform one step of the Merkle proof validation. The result
      51             :  * of the hash step will be stored in `left`, thus clobbering
      52             :  * `left`'s input value.
      53             :  *
      54             :  * @arg[in]     ctx s ha256 context
      55             :  * @arg[in/out] left  pointer to left hash, result will be stored here
      56             :  * @arg[in]     right pointer to right hash
      57             :  */
      58          79 : void fold_left(sha256_ctx_t* ctx, uint8_t* left, uint8_t* right) {
      59        1343 :     REV_HASH(left);
      60        1343 :     REV_HASH(right);
      61          79 :     SHA256_INIT(ctx);
      62          79 :     SHA256_UPDATE(ctx, left, HASH_SIZE);
      63          79 :     SHA256_UPDATE(ctx, right, HASH_SIZE);
      64          79 :     SHA256_FINAL(ctx, left);
      65          79 :     SHA256_INIT(ctx);
      66          79 :     SHA256_UPDATE(ctx, left, HASH_SIZE);
      67          79 :     SHA256_FINAL(ctx, left);
      68        1343 :     REV_HASH(left);
      69          79 : }