CryptoPkg/Library/BaseCryptLib/Hash/CryptXkcp.c

   1 /** @file
   2   Encode realted functions from Xkcp.
   3
   4 Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 Copyright 2022 The eXtended Keccak Code Package (XKCP)
   8 https://github.com/XKCP/XKCP
   9 Keccak, designed by Guido Bertoni, Joan Daemen, Michael Peeters and Gilles Van Assche.
  10 Implementation by the designers, hereby denoted as "the implementer".
  11 For more information, feedback or questions, please refer to the Keccak Team website:
  12 https://keccak.team/
  13 To the extent possible under law, the implementer has waived all copyright
  14 and related or neighboring rights to the source code in this file.
  15 http://creativecommons.org/publicdomain/zero/1.0/
  16
  17 **/
  18
  19 #include "CryptParallelHash.h"
  20
  21 /**
  22   Encode function from XKCP.
  23
  24   Encodes the input as a byte string in a way that can be unambiguously parsed
  25   from the beginning of the string by inserting the length of the byte string
  26   before the byte string representation of input.
  27
  28   @param[out] EncBuf  Result of left encode.
  29   @param[in]  Value   Input of left encode.
  30
  31   @retval EncLen  Size of encode result in bytes.
  32 **/
  33 UINTN
  34 EFIAPI
  35 LeftEncode (
  36   OUT UINT8  *EncBuf,
  37   IN  UINTN  Value
  38   )
  39 {
  40   UINT32  BlockNum;
  41   UINT32  EncLen;
  42   UINT32  Index;
  43   UINTN   ValueCopy;
  44
  45   for ( ValueCopy = Value, BlockNum = 0; ValueCopy && (BlockNum < sizeof (UINTN)); ++BlockNum, ValueCopy >>= 8 ) {
  46     //
  47     // Empty
  48     //
  49   }
  50
  51   if (BlockNum == 0) {
  52     BlockNum = 1;
  53   }
  54
  55   for (Index = 1; Index <= BlockNum; ++Index) {
  56     EncBuf[Index] = (UINT8)(Value >> (8 * (BlockNum - Index)));
  57   }
  58
  59   EncBuf[0] = (UINT8)BlockNum;
  60   EncLen    = BlockNum + 1;
  61
  62   return EncLen;
  63 }
  64
  65 /**
  66   Encode function from XKCP.
  67
  68   Encodes the input as a byte string in a way that can be unambiguously parsed
  69   from the end of the string by inserting the length of the byte string after
  70   the byte string representation of input.
  71
  72   @param[out] EncBuf  Result of right encode.
  73   @param[in]  Value   Input of right encode.
  74
  75   @retval EncLen  Size of encode result in bytes.
  76 **/
  77 UINTN
  78 EFIAPI
  79 RightEncode (
  80   OUT UINT8  *EncBuf,
  81   IN  UINTN  Value
  82   )
  83 {
  84   UINT32  BlockNum;
  85   UINT32  EncLen;
  86   UINT32  Index;
  87   UINTN   ValueCopy;
  88
  89   for (ValueCopy = Value, BlockNum = 0; ValueCopy && (BlockNum < sizeof (UINTN)); ++BlockNum, ValueCopy >>= 8) {
  90     //
  91     // Empty
  92     //
  93   }
  94
  95   if (BlockNum == 0) {
  96     BlockNum = 1;
  97   }
  98
  99   for (Index = 1; Index <= BlockNum; ++Index) {
 100     EncBuf[Index-1] = (UINT8)(Value >> (8 * (BlockNum-Index)));
 101   }
 102
 103   EncBuf[BlockNum] = (UINT8)BlockNum;
 104   EncLen           = BlockNum + 1;
 105
 106   return EncLen;
 107 }