aes.c 23 KB

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  1. /**
  2. * @file aes.c
  3. * @brief AES (Advanced Encryption Standard)
  4. *
  5. * @section License
  6. *
  7. * SPDX-License-Identifier: GPL-2.0-or-later
  8. *
  9. * Copyright (C) 2010-2023 Oryx Embedded SARL. All rights reserved.
  10. *
  11. * This file is part of CycloneCRYPTO Open.
  12. *
  13. * This program is free software; you can redistribute it and/or
  14. * modify it under the terms of the GNU General Public License
  15. * as published by the Free Software Foundation; either version 2
  16. * of the License, or (at your option) any later version.
  17. *
  18. * This program is distributed in the hope that it will be useful,
  19. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  21. * GNU General Public License for more details.
  22. *
  23. * You should have received a copy of the GNU General Public License
  24. * along with this program; if not, write to the Free Software Foundation,
  25. * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  26. *
  27. * @section Description
  28. *
  29. * AES is an encryption standard based on Rijndael algorithm, a symmetric block
  30. * cipher that can process data blocks of 128 bits, using cipher keys with
  31. * lengths of 128, 192, and 256 bits. Refer to FIPS 197 for more details
  32. *
  33. * @author Oryx Embedded SARL (www.oryx-embedded.com)
  34. * @version 2.2.4
  35. **/
  36. //Switch to the appropriate trace level
  37. #define TRACE_LEVEL CRYPTO_TRACE_LEVEL
  38. //Dependencies
  39. #include "core/crypto.h"
  40. #include "cipher/aes.h"
  41. //Check crypto library configuration
  42. #if (AES_SUPPORT == ENABLED)
  43. //Substitution table used by encryption algorithm (S-box)
  44. static const uint8_t sbox[256] =
  45. {
  46. 0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
  47. 0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
  48. 0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
  49. 0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
  50. 0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
  51. 0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
  52. 0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
  53. 0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
  54. 0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
  55. 0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
  56. 0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
  57. 0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
  58. 0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
  59. 0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
  60. 0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
  61. 0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16
  62. };
  63. //Substitution table used by decryption algorithm (inverse S-box)
  64. static const uint8_t isbox[256] =
  65. {
  66. 0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
  67. 0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
  68. 0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
  69. 0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
  70. 0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
  71. 0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
  72. 0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
  73. 0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
  74. 0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
  75. 0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
  76. 0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
  77. 0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
  78. 0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
  79. 0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
  80. 0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
  81. 0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D
  82. };
  83. //Precalculated table (encryption)
  84. static const uint32_t te[256] =
  85. {
  86. 0xA56363C6, 0x847C7CF8, 0x997777EE, 0x8D7B7BF6, 0x0DF2F2FF, 0xBD6B6BD6, 0xB16F6FDE, 0x54C5C591,
  87. 0x50303060, 0x03010102, 0xA96767CE, 0x7D2B2B56, 0x19FEFEE7, 0x62D7D7B5, 0xE6ABAB4D, 0x9A7676EC,
  88. 0x45CACA8F, 0x9D82821F, 0x40C9C989, 0x877D7DFA, 0x15FAFAEF, 0xEB5959B2, 0xC947478E, 0x0BF0F0FB,
  89. 0xECADAD41, 0x67D4D4B3, 0xFDA2A25F, 0xEAAFAF45, 0xBF9C9C23, 0xF7A4A453, 0x967272E4, 0x5BC0C09B,
  90. 0xC2B7B775, 0x1CFDFDE1, 0xAE93933D, 0x6A26264C, 0x5A36366C, 0x413F3F7E, 0x02F7F7F5, 0x4FCCCC83,
  91. 0x5C343468, 0xF4A5A551, 0x34E5E5D1, 0x08F1F1F9, 0x937171E2, 0x73D8D8AB, 0x53313162, 0x3F15152A,
  92. 0x0C040408, 0x52C7C795, 0x65232346, 0x5EC3C39D, 0x28181830, 0xA1969637, 0x0F05050A, 0xB59A9A2F,
  93. 0x0907070E, 0x36121224, 0x9B80801B, 0x3DE2E2DF, 0x26EBEBCD, 0x6927274E, 0xCDB2B27F, 0x9F7575EA,
  94. 0x1B090912, 0x9E83831D, 0x742C2C58, 0x2E1A1A34, 0x2D1B1B36, 0xB26E6EDC, 0xEE5A5AB4, 0xFBA0A05B,
  95. 0xF65252A4, 0x4D3B3B76, 0x61D6D6B7, 0xCEB3B37D, 0x7B292952, 0x3EE3E3DD, 0x712F2F5E, 0x97848413,
  96. 0xF55353A6, 0x68D1D1B9, 0x00000000, 0x2CEDEDC1, 0x60202040, 0x1FFCFCE3, 0xC8B1B179, 0xED5B5BB6,
  97. 0xBE6A6AD4, 0x46CBCB8D, 0xD9BEBE67, 0x4B393972, 0xDE4A4A94, 0xD44C4C98, 0xE85858B0, 0x4ACFCF85,
  98. 0x6BD0D0BB, 0x2AEFEFC5, 0xE5AAAA4F, 0x16FBFBED, 0xC5434386, 0xD74D4D9A, 0x55333366, 0x94858511,
  99. 0xCF45458A, 0x10F9F9E9, 0x06020204, 0x817F7FFE, 0xF05050A0, 0x443C3C78, 0xBA9F9F25, 0xE3A8A84B,
  100. 0xF35151A2, 0xFEA3A35D, 0xC0404080, 0x8A8F8F05, 0xAD92923F, 0xBC9D9D21, 0x48383870, 0x04F5F5F1,
  101. 0xDFBCBC63, 0xC1B6B677, 0x75DADAAF, 0x63212142, 0x30101020, 0x1AFFFFE5, 0x0EF3F3FD, 0x6DD2D2BF,
  102. 0x4CCDCD81, 0x140C0C18, 0x35131326, 0x2FECECC3, 0xE15F5FBE, 0xA2979735, 0xCC444488, 0x3917172E,
  103. 0x57C4C493, 0xF2A7A755, 0x827E7EFC, 0x473D3D7A, 0xAC6464C8, 0xE75D5DBA, 0x2B191932, 0x957373E6,
  104. 0xA06060C0, 0x98818119, 0xD14F4F9E, 0x7FDCDCA3, 0x66222244, 0x7E2A2A54, 0xAB90903B, 0x8388880B,
  105. 0xCA46468C, 0x29EEEEC7, 0xD3B8B86B, 0x3C141428, 0x79DEDEA7, 0xE25E5EBC, 0x1D0B0B16, 0x76DBDBAD,
  106. 0x3BE0E0DB, 0x56323264, 0x4E3A3A74, 0x1E0A0A14, 0xDB494992, 0x0A06060C, 0x6C242448, 0xE45C5CB8,
  107. 0x5DC2C29F, 0x6ED3D3BD, 0xEFACAC43, 0xA66262C4, 0xA8919139, 0xA4959531, 0x37E4E4D3, 0x8B7979F2,
  108. 0x32E7E7D5, 0x43C8C88B, 0x5937376E, 0xB76D6DDA, 0x8C8D8D01, 0x64D5D5B1, 0xD24E4E9C, 0xE0A9A949,
  109. 0xB46C6CD8, 0xFA5656AC, 0x07F4F4F3, 0x25EAEACF, 0xAF6565CA, 0x8E7A7AF4, 0xE9AEAE47, 0x18080810,
  110. 0xD5BABA6F, 0x887878F0, 0x6F25254A, 0x722E2E5C, 0x241C1C38, 0xF1A6A657, 0xC7B4B473, 0x51C6C697,
  111. 0x23E8E8CB, 0x7CDDDDA1, 0x9C7474E8, 0x211F1F3E, 0xDD4B4B96, 0xDCBDBD61, 0x868B8B0D, 0x858A8A0F,
  112. 0x907070E0, 0x423E3E7C, 0xC4B5B571, 0xAA6666CC, 0xD8484890, 0x05030306, 0x01F6F6F7, 0x120E0E1C,
  113. 0xA36161C2, 0x5F35356A, 0xF95757AE, 0xD0B9B969, 0x91868617, 0x58C1C199, 0x271D1D3A, 0xB99E9E27,
  114. 0x38E1E1D9, 0x13F8F8EB, 0xB398982B, 0x33111122, 0xBB6969D2, 0x70D9D9A9, 0x898E8E07, 0xA7949433,
  115. 0xB69B9B2D, 0x221E1E3C, 0x92878715, 0x20E9E9C9, 0x49CECE87, 0xFF5555AA, 0x78282850, 0x7ADFDFA5,
  116. 0x8F8C8C03, 0xF8A1A159, 0x80898909, 0x170D0D1A, 0xDABFBF65, 0x31E6E6D7, 0xC6424284, 0xB86868D0,
  117. 0xC3414182, 0xB0999929, 0x772D2D5A, 0x110F0F1E, 0xCBB0B07B, 0xFC5454A8, 0xD6BBBB6D, 0x3A16162C
  118. };
  119. //Precalculated table (decryption)
  120. static const uint32_t td[256] =
  121. {
  122. 0x50A7F451, 0x5365417E, 0xC3A4171A, 0x965E273A, 0xCB6BAB3B, 0xF1459D1F, 0xAB58FAAC, 0x9303E34B,
  123. 0x55FA3020, 0xF66D76AD, 0x9176CC88, 0x254C02F5, 0xFCD7E54F, 0xD7CB2AC5, 0x80443526, 0x8FA362B5,
  124. 0x495AB1DE, 0x671BBA25, 0x980EEA45, 0xE1C0FE5D, 0x02752FC3, 0x12F04C81, 0xA397468D, 0xC6F9D36B,
  125. 0xE75F8F03, 0x959C9215, 0xEB7A6DBF, 0xDA595295, 0x2D83BED4, 0xD3217458, 0x2969E049, 0x44C8C98E,
  126. 0x6A89C275, 0x78798EF4, 0x6B3E5899, 0xDD71B927, 0xB64FE1BE, 0x17AD88F0, 0x66AC20C9, 0xB43ACE7D,
  127. 0x184ADF63, 0x82311AE5, 0x60335197, 0x457F5362, 0xE07764B1, 0x84AE6BBB, 0x1CA081FE, 0x942B08F9,
  128. 0x58684870, 0x19FD458F, 0x876CDE94, 0xB7F87B52, 0x23D373AB, 0xE2024B72, 0x578F1FE3, 0x2AAB5566,
  129. 0x0728EBB2, 0x03C2B52F, 0x9A7BC586, 0xA50837D3, 0xF2872830, 0xB2A5BF23, 0xBA6A0302, 0x5C8216ED,
  130. 0x2B1CCF8A, 0x92B479A7, 0xF0F207F3, 0xA1E2694E, 0xCDF4DA65, 0xD5BE0506, 0x1F6234D1, 0x8AFEA6C4,
  131. 0x9D532E34, 0xA055F3A2, 0x32E18A05, 0x75EBF6A4, 0x39EC830B, 0xAAEF6040, 0x069F715E, 0x51106EBD,
  132. 0xF98A213E, 0x3D06DD96, 0xAE053EDD, 0x46BDE64D, 0xB58D5491, 0x055DC471, 0x6FD40604, 0xFF155060,
  133. 0x24FB9819, 0x97E9BDD6, 0xCC434089, 0x779ED967, 0xBD42E8B0, 0x888B8907, 0x385B19E7, 0xDBEEC879,
  134. 0x470A7CA1, 0xE90F427C, 0xC91E84F8, 0x00000000, 0x83868009, 0x48ED2B32, 0xAC70111E, 0x4E725A6C,
  135. 0xFBFF0EFD, 0x5638850F, 0x1ED5AE3D, 0x27392D36, 0x64D90F0A, 0x21A65C68, 0xD1545B9B, 0x3A2E3624,
  136. 0xB1670A0C, 0x0FE75793, 0xD296EEB4, 0x9E919B1B, 0x4FC5C080, 0xA220DC61, 0x694B775A, 0x161A121C,
  137. 0x0ABA93E2, 0xE52AA0C0, 0x43E0223C, 0x1D171B12, 0x0B0D090E, 0xADC78BF2, 0xB9A8B62D, 0xC8A91E14,
  138. 0x8519F157, 0x4C0775AF, 0xBBDD99EE, 0xFD607FA3, 0x9F2601F7, 0xBCF5725C, 0xC53B6644, 0x347EFB5B,
  139. 0x7629438B, 0xDCC623CB, 0x68FCEDB6, 0x63F1E4B8, 0xCADC31D7, 0x10856342, 0x40229713, 0x2011C684,
  140. 0x7D244A85, 0xF83DBBD2, 0x1132F9AE, 0x6DA129C7, 0x4B2F9E1D, 0xF330B2DC, 0xEC52860D, 0xD0E3C177,
  141. 0x6C16B32B, 0x99B970A9, 0xFA489411, 0x2264E947, 0xC48CFCA8, 0x1A3FF0A0, 0xD82C7D56, 0xEF903322,
  142. 0xC74E4987, 0xC1D138D9, 0xFEA2CA8C, 0x360BD498, 0xCF81F5A6, 0x28DE7AA5, 0x268EB7DA, 0xA4BFAD3F,
  143. 0xE49D3A2C, 0x0D927850, 0x9BCC5F6A, 0x62467E54, 0xC2138DF6, 0xE8B8D890, 0x5EF7392E, 0xF5AFC382,
  144. 0xBE805D9F, 0x7C93D069, 0xA92DD56F, 0xB31225CF, 0x3B99ACC8, 0xA77D1810, 0x6E639CE8, 0x7BBB3BDB,
  145. 0x097826CD, 0xF418596E, 0x01B79AEC, 0xA89A4F83, 0x656E95E6, 0x7EE6FFAA, 0x08CFBC21, 0xE6E815EF,
  146. 0xD99BE7BA, 0xCE366F4A, 0xD4099FEA, 0xD67CB029, 0xAFB2A431, 0x31233F2A, 0x3094A5C6, 0xC066A235,
  147. 0x37BC4E74, 0xA6CA82FC, 0xB0D090E0, 0x15D8A733, 0x4A9804F1, 0xF7DAEC41, 0x0E50CD7F, 0x2FF69117,
  148. 0x8DD64D76, 0x4DB0EF43, 0x544DAACC, 0xDF0496E4, 0xE3B5D19E, 0x1B886A4C, 0xB81F2CC1, 0x7F516546,
  149. 0x04EA5E9D, 0x5D358C01, 0x737487FA, 0x2E410BFB, 0x5A1D67B3, 0x52D2DB92, 0x335610E9, 0x1347D66D,
  150. 0x8C61D79A, 0x7A0CA137, 0x8E14F859, 0x893C13EB, 0xEE27A9CE, 0x35C961B7, 0xEDE51CE1, 0x3CB1477A,
  151. 0x59DFD29C, 0x3F73F255, 0x79CE1418, 0xBF37C773, 0xEACDF753, 0x5BAAFD5F, 0x146F3DDF, 0x86DB4478,
  152. 0x81F3AFCA, 0x3EC468B9, 0x2C342438, 0x5F40A3C2, 0x72C31D16, 0x0C25E2BC, 0x8B493C28, 0x41950DFF,
  153. 0x7101A839, 0xDEB30C08, 0x9CE4B4D8, 0x90C15664, 0x6184CB7B, 0x70B632D5, 0x745C6C48, 0x4257B8D0
  154. };
  155. //Round constant word array
  156. static const uint32_t rcon[11] =
  157. {
  158. 0x00000000,
  159. 0x00000001,
  160. 0x00000002,
  161. 0x00000004,
  162. 0x00000008,
  163. 0x00000010,
  164. 0x00000020,
  165. 0x00000040,
  166. 0x00000080,
  167. 0x0000001B,
  168. 0x00000036
  169. };
  170. //Common interface for encryption algorithms
  171. const CipherAlgo aesCipherAlgo =
  172. {
  173. "AES",
  174. sizeof(AesContext),
  175. CIPHER_ALGO_TYPE_BLOCK,
  176. AES_BLOCK_SIZE,
  177. (CipherAlgoInit) aesInit,
  178. NULL,
  179. NULL,
  180. (CipherAlgoEncryptBlock) aesEncryptBlock,
  181. (CipherAlgoDecryptBlock) aesDecryptBlock,
  182. (CipherAlgoDeinit) aesDeinit
  183. };
  184. /**
  185. * @brief Key expansion
  186. * @param[in] context Pointer to the AES context to initialize
  187. * @param[in] key Pointer to the key
  188. * @param[in] keyLen Length of the key
  189. * @return Error code
  190. **/
  191. error_t aesInit(AesContext *context, const uint8_t *key,
  192. size_t keyLen)
  193. {
  194. uint_t i;
  195. uint32_t temp;
  196. size_t keyScheduleSize;
  197. //Check parameters
  198. if(context == NULL || key == NULL)
  199. return WINDOWS_ERROR_INVALID_PARAMETER;
  200. //Check the length of the key
  201. if(keyLen == 16)
  202. {
  203. //10 rounds are required for 128-bit key
  204. context->nr = 10;
  205. }
  206. else if(keyLen == 24)
  207. {
  208. //12 rounds are required for 192-bit key
  209. context->nr = 12;
  210. }
  211. else if(keyLen == 32)
  212. {
  213. //14 rounds are required for 256-bit key
  214. context->nr = 14;
  215. }
  216. else
  217. {
  218. //Report an error
  219. return ERROR_INVALID_KEY_LENGTH;
  220. }
  221. //Determine the number of 32-bit words in the key
  222. keyLen /= 4;
  223. //Copy the original key
  224. for(i = 0; i < keyLen; i++)
  225. {
  226. context->ek[i] = LOAD32LE(key + (i * 4));
  227. }
  228. //The size of the key schedule depends on the number of rounds
  229. keyScheduleSize = 4 * (context->nr + 1);
  230. //Generate the key schedule (encryption)
  231. for(i = keyLen; i < keyScheduleSize; i++)
  232. {
  233. //Save previous word
  234. temp = context->ek[i - 1];
  235. //Apply transformation
  236. if((i % keyLen) == 0)
  237. {
  238. context->ek[i] = sbox[(temp >> 8) & 0xFF];
  239. context->ek[i] |= (sbox[(temp >> 16) & 0xFF] << 8);
  240. context->ek[i] |= (sbox[(temp >> 24) & 0xFF] << 16);
  241. context->ek[i] |= (sbox[temp & 0xFF] << 24);
  242. context->ek[i] ^= rcon[i / keyLen];
  243. }
  244. else if(keyLen > 6 && (i % keyLen) == 4)
  245. {
  246. context->ek[i] = sbox[temp & 0xFF];
  247. context->ek[i] |= (sbox[(temp >> 8) & 0xFF] << 8);
  248. context->ek[i] |= (sbox[(temp >> 16) & 0xFF] << 16);
  249. context->ek[i] |= (sbox[(temp >> 24) & 0xFF] << 24);
  250. }
  251. else
  252. {
  253. context->ek[i] = temp;
  254. }
  255. //Update the key schedule
  256. context->ek[i] ^= context->ek[i - keyLen];
  257. }
  258. //Generate the key schedule (decryption)
  259. for(i = 0; i < keyScheduleSize; i++)
  260. {
  261. //Apply the InvMixColumns transformation to all round keys but the first
  262. //and the last
  263. if(i < 4 || i >= (keyScheduleSize - 4))
  264. {
  265. context->dk[i] = context->ek[i];
  266. }
  267. else
  268. {
  269. context->dk[i] = td[sbox[context->ek[i] & 0xFF]];
  270. temp = td[sbox[(context->ek[i] >> 8) & 0xFF]];
  271. context->dk[i] ^= ROL32(temp, 8);
  272. temp = td[sbox[(context->ek[i] >> 16) & 0xFF]];
  273. context->dk[i] ^= ROL32(temp, 16);
  274. temp = td[sbox[(context->ek[i] >> 24) & 0xFF]];
  275. context->dk[i] ^= ROL32(temp, 24);
  276. }
  277. }
  278. //No error to report
  279. return WINDOWS_NO_ERROR;
  280. }
  281. /**
  282. * @brief Encrypt a 16-byte block using AES algorithm
  283. * @param[in] context Pointer to the AES context
  284. * @param[in] input Plaintext block to encrypt
  285. * @param[out] output Ciphertext block resulting from encryption
  286. **/
  287. void aesEncryptBlock(AesContext *context, const uint8_t *input,
  288. uint8_t *output)
  289. {
  290. uint_t i;
  291. uint32_t s0;
  292. uint32_t s1;
  293. uint32_t s2;
  294. uint32_t s3;
  295. uint32_t t0;
  296. uint32_t t1;
  297. uint32_t t2;
  298. uint32_t t3;
  299. uint32_t temp;
  300. //Copy the plaintext to the state array
  301. s0 = LOAD32LE(input + 0);
  302. s1 = LOAD32LE(input + 4);
  303. s2 = LOAD32LE(input + 8);
  304. s3 = LOAD32LE(input + 12);
  305. //Initial round key addition
  306. s0 ^= context->ek[0];
  307. s1 ^= context->ek[1];
  308. s2 ^= context->ek[2];
  309. s3 ^= context->ek[3];
  310. //The number of rounds depends on the key length
  311. for(i = 1; i < context->nr; i++)
  312. {
  313. //Apply round function
  314. t0 = te[s0 & 0xFF];
  315. temp = te[(s1 >> 8) & 0xFF];
  316. t0 ^= ROL32(temp, 8);
  317. temp = te[(s2 >> 16) & 0xFF];
  318. t0 ^= ROL32(temp, 16);
  319. temp = te[(s3 >> 24) & 0xFF];
  320. t0 ^= ROL32(temp, 24);
  321. t1 = te[s1 & 0xFF];
  322. temp = te[(s2 >> 8) & 0xFF];
  323. t1 ^= ROL32(temp, 8);
  324. temp = te[(s3 >> 16) & 0xFF];
  325. t1 ^= ROL32(temp, 16);
  326. temp = te[(s0 >> 24) & 0xFF];
  327. t1 ^= ROL32(temp, 24);
  328. t2 = te[s2 & 0xFF];
  329. temp = te[(s3 >> 8) & 0xFF];
  330. t2 ^= ROL32(temp, 8);
  331. temp = te[(s0 >> 16) & 0xFF];
  332. t2 ^= ROL32(temp, 16);
  333. temp = te[(s1 >> 24) & 0xFF];
  334. t2 ^= ROL32(temp, 24);
  335. t3 = te[s3 & 0xFF];
  336. temp = te[(s0 >> 8) & 0xFF];
  337. t3 ^= ROL32(temp, 8);
  338. temp = te[(s1 >> 16) & 0xFF];
  339. t3 ^= ROL32(temp, 16);
  340. temp = te[(s2 >> 24) & 0xFF];
  341. t3 ^= ROL32(temp, 24);
  342. //Round key addition
  343. s0 = t0 ^ context->ek[i * 4];
  344. s1 = t1 ^ context->ek[i * 4 + 1];
  345. s2 = t2 ^ context->ek[i * 4 + 2];
  346. s3 = t3 ^ context->ek[i * 4 + 3];
  347. }
  348. //The last round differs slightly from the first rounds
  349. t0 = sbox[s0 & 0xFF];
  350. t0 |= sbox[(s1 >> 8) & 0xFF] << 8;
  351. t0 |= sbox[(s2 >> 16) & 0xFF] << 16;
  352. t0 |= sbox[(s3 >> 24) & 0xFF] << 24;
  353. t1 = sbox[s1 & 0xFF];
  354. t1 |= sbox[(s2 >> 8) & 0xFF] << 8;
  355. t1 |= sbox[(s3 >> 16) & 0xFF] << 16;
  356. t1 |= sbox[(s0 >> 24) & 0xFF] << 24;
  357. t2 = sbox[s2 & 0xFF];
  358. t2 |= sbox[(s3 >> 8) & 0xFF] << 8;
  359. t2 |= sbox[(s0 >> 16) & 0xFF] << 16;
  360. t2 |= sbox[(s1 >> 24) & 0xFF] << 24;
  361. t3 = sbox[s3 & 0xFF];
  362. t3 |= sbox[(s0 >> 8) & 0xFF] << 8;
  363. t3 |= sbox[(s1 >> 16) & 0xFF] << 16;
  364. t3 |= sbox[(s2 >> 24) & 0xFF] << 24;
  365. //Last round key addition
  366. s0 = t0 ^ context->ek[context->nr * 4];
  367. s1 = t1 ^ context->ek[context->nr * 4 + 1];
  368. s2 = t2 ^ context->ek[context->nr * 4 + 2];
  369. s3 = t3 ^ context->ek[context->nr * 4 + 3];
  370. //The final state is then copied to the output
  371. STORE32LE(s0, output + 0);
  372. STORE32LE(s1, output + 4);
  373. STORE32LE(s2, output + 8);
  374. STORE32LE(s3, output + 12);
  375. }
  376. /**
  377. * @brief Decrypt a 16-byte block using AES algorithm
  378. * @param[in] context Pointer to the AES context
  379. * @param[in] input Ciphertext block to decrypt
  380. * @param[out] output Plaintext block resulting from decryption
  381. **/
  382. void aesDecryptBlock(AesContext *context, const uint8_t *input,
  383. uint8_t *output)
  384. {
  385. uint_t i;
  386. uint32_t s0;
  387. uint32_t s1;
  388. uint32_t s2;
  389. uint32_t s3;
  390. uint32_t t0;
  391. uint32_t t1;
  392. uint32_t t2;
  393. uint32_t t3;
  394. uint32_t temp;
  395. //Copy the ciphertext to the state array
  396. s0 = LOAD32LE(input + 0);
  397. s1 = LOAD32LE(input + 4);
  398. s2 = LOAD32LE(input + 8);
  399. s3 = LOAD32LE(input + 12);
  400. //Initial round key addition
  401. s0 ^= context->dk[context->nr * 4];
  402. s1 ^= context->dk[context->nr * 4 + 1];
  403. s2 ^= context->dk[context->nr * 4 + 2];
  404. s3 ^= context->dk[context->nr * 4 + 3];
  405. //The number of rounds depends on the key length
  406. for(i = context->nr - 1; i >= 1; i--)
  407. {
  408. //Apply round function
  409. t0 = td[s0 & 0xFF];
  410. temp = td[(s3 >> 8) & 0xFF];
  411. t0 ^= ROL32(temp, 8);
  412. temp = td[(s2 >> 16) & 0xFF];
  413. t0 ^= ROL32(temp, 16);
  414. temp = td[(s1 >> 24) & 0xFF];
  415. t0 ^= ROL32(temp, 24);
  416. t1 = td[s1 & 0xFF];
  417. temp = td[(s0 >> 8) & 0xFF];
  418. t1 ^= ROL32(temp, 8);
  419. temp = td[(s3 >> 16) & 0xFF];
  420. t1 ^= ROL32(temp, 16);
  421. temp = td[(s2 >> 24) & 0xFF];
  422. t1 ^= ROL32(temp, 24);
  423. t2 = td[s2 & 0xFF];
  424. temp = td[(s1 >> 8) & 0xFF];
  425. t2 ^= ROL32(temp, 8);
  426. temp = td[(s0 >> 16) & 0xFF];
  427. t2 ^= ROL32(temp, 16);
  428. temp = td[(s3 >> 24) & 0xFF];
  429. t2 ^= ROL32(temp, 24);
  430. t3 = td[s3 & 0xFF];
  431. temp = td[(s2 >> 8) & 0xFF];
  432. t3 ^= ROL32(temp, 8);
  433. temp = td[(s1 >> 16) & 0xFF];
  434. t3 ^= ROL32(temp, 16);
  435. temp = td[(s0 >> 24) & 0xFF];
  436. t3 ^= ROL32(temp, 24);
  437. //Round key addition
  438. s0 = t0 ^ context->dk[i * 4];
  439. s1 = t1 ^ context->dk[i * 4 + 1];
  440. s2 = t2 ^ context->dk[i * 4 + 2];
  441. s3 = t3 ^ context->dk[i * 4 + 3];
  442. }
  443. //The last round differs slightly from the first rounds
  444. t0 = isbox[s0 & 0xFF];
  445. t0 |= isbox[(s3 >> 8) & 0xFF] << 8;
  446. t0 |= isbox[(s2 >> 16) & 0xFF] << 16;
  447. t0 |= isbox[(s1 >> 24) & 0xFF] << 24;
  448. t1 = isbox[s1 & 0xFF];
  449. t1 |= isbox[(s0 >> 8) & 0xFF] << 8;
  450. t1 |= isbox[(s3 >> 16) & 0xFF] << 16;
  451. t1 |= isbox[(s2 >> 24) & 0xFF] << 24;
  452. t2 = isbox[s2 & 0xFF];
  453. t2 |= isbox[(s1 >> 8) & 0xFF] << 8;
  454. t2 |= isbox[(s0 >> 16) & 0xFF] << 16;
  455. t2 |= isbox[(s3 >> 24) & 0xFF] << 24;
  456. t3 = isbox[s3 & 0xFF];
  457. t3 |= isbox[(s2 >> 8) & 0xFF] << 8;
  458. t3 |= isbox[(s1 >> 16) & 0xFF] << 16;
  459. t3 |= isbox[(s0 >> 24) & 0xFF] << 24;
  460. //Last round key addition
  461. s0 = t0 ^ context->dk[0];
  462. s1 = t1 ^ context->dk[1];
  463. s2 = t2 ^ context->dk[2];
  464. s3 = t3 ^ context->dk[3];
  465. //The final state is then copied to the output
  466. STORE32LE(s0, output + 0);
  467. STORE32LE(s1, output + 4);
  468. STORE32LE(s2, output + 8);
  469. STORE32LE(s3, output + 12);
  470. }
  471. /**
  472. * @brief Release AES context
  473. * @param[in] context Pointer to the AES context
  474. **/
  475. __weak_func void aesDeinit(AesContext *context)
  476. {
  477. //Clear AES context
  478. osMemset(context, 0, sizeof(AesContext));
  479. }
  480. #endif