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674 lines
18 KiB
C
Executable File
674 lines
18 KiB
C
Executable File
/** @file
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OcCryptoLib
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Copyright (c) 2018, savvas
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All rights reserved.
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This program and the accompanying materials
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are licensed and made available under the terms and conditions of the BSD License
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which accompanies this distribution. The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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/**
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Copyright (c) 2014-2018, kokke
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This is free and unencumbered software released into the public domain.
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Anyone is free to copy, modify, publish, use, compile, sell, or
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distribute this software, either in source code form or as a compiled
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binary, for any purpose, commercial or non-commercial, and by any
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means.
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In jurisdictions that recognize copyright laws, the author or authors
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of this software dedicate any and all copyright interest in the
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software to the public domain. We make this dedication for the benefit
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of the public at large and to the detriment of our heirs and
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successors. We intend this dedication to be an overt act of
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relinquishment in perpetuity of all present and future rights to this
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software under copyright law.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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OTHER DEALINGS IN THE SOFTWARE.
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For more information, please refer to <http://unlicense.org/>
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**/
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/**
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This is an implementation of the AES algorithm, specifically CTR and CBC mode.
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Block size can be chosen in OcCryptoLib.h.
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The implementation is verified against the test vectors in:
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National Institute of Standards and Technology Special Publication 800-38A 2001 ED
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NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0)
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You should pad the end of the string with zeros if this is not the case.
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For AES192/256 the key size is proportionally larger.
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**/
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#include <Library/BaseMemoryLib.h>
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#include <Library/OcCryptoLib.h>
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//
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// The number of columns comprising a state in AES (Nb). This is a CONSTant in AES. Value=4
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// The number of 32 bit words in a key (Nk).
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// The number of rounds in AES Cipher (Nr).
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//
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#define Nb 4
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#if CONFIG_AES_KEY_SIZE == 32
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#define Nk 8
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#define Nr 14
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#elif CONFIG_AES_KEY_SIZE == 24
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#define Nk 6
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#define Nr 12
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#elif CONFIG_AES_KEY_SIZE == 16
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#define Nk 4
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#define Nr 10
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#endif
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//
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// state - array holding the intermediate results during decryption.
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//
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typedef UINT8 AES_INTERNAL_STATE[4][4];
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//
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// The lookup-tables are marked CONST so they can be placed in read-only storage instead of RAM
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// The numbers below can be computed dynamically trading ROM for RAM -
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// This can be useful in (embedded) bootloader applications, where ROM is often limited.
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//
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STATIC CONST UINT8 Sbox[256] = {
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//0 1 2 3 4 5 6 7 8 9 A B C D E F
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0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
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0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
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0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
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0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
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0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
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0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
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0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
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0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
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0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
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0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
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0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
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0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
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0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
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0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
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0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
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0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16
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};
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STATIC CONST UINT8 RsBox[256] = {
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0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
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0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
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0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
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0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
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0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
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0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
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0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
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0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
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0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
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0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
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0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
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0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
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0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
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0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
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0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
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0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
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};
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//
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// The round CONSTant word array, Rcon[i], contains the values given by
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// x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
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//
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STATIC CONST UINT8 Rcon[11] = {
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0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36
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};
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/*
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* Jordan Goulder points out in PR #12 (https://github.com/kokke/tiny-AES-C/pull/12),
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* that you can remove most of the elements in the Rcon array, because they are unused.
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*
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* From Wikipedia's article on the Rijndael key schedule @ https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon
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*
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* "Only the first some of these CONSTants are actually used – up to rcon[10] for AES-128 (as 11 round keys are needed),
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* up to rcon[8] for AES-192, up to rcon[7] for AES-256. rcon[0] is not used in AES algorithm."
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*/
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//
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// Private functions:
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//
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#define GetSboxValue(num) (Sbox[(num)])
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#define GetSBoxInvert(num) (RsBox[(num)])
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//
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// This function produces Nb(Nr+1) round keys. The round keys are used in each
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// round to decrypt the states.
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//
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STATIC
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VOID
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KeyExpansion (
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OUT UINT8 *RoundKey,
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IN CONST UINT8 *Key
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)
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{
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UINT32 Index, J, K;
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//
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// Used for the column/row operations
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//
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UINT8 TempA[4];
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//
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// The first round key is the key itself.
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//
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for (Index = 0; Index < Nk; ++Index) {
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RoundKey[(Index * 4) + 0] = Key[(Index * 4) + 0];
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RoundKey[(Index * 4) + 1] = Key[(Index * 4) + 1];
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RoundKey[(Index * 4) + 2] = Key[(Index * 4) + 2];
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RoundKey[(Index * 4) + 3] = Key[(Index * 4) + 3];
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}
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//
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// All other round keys are found from the previous round keys.
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//
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for (Index = Nk; Index < Nb * (Nr + 1); ++Index) {
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K = (Index - 1) * 4;
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TempA[0] = RoundKey[K + 0];
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TempA[1] = RoundKey[K + 1];
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TempA[2] = RoundKey[K + 2];
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TempA[3] = RoundKey[K + 3];
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if (Index % Nk == 0) {
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//
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// This function shifts the 4 bytes in a word to the left once.
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// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
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//
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//
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// Function RotWord()
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//
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K = TempA[0];
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TempA[0] = TempA[1];
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TempA[1] = TempA[2];
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TempA[2] = TempA[3];
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TempA[3] = (UINT8) K;
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//
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// SubWord() is a function that takes a four-byte input word and
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// applies the S-box to each of the four bytes to produce an output word.
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//
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//
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// Function Subword()
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//
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TempA[0] = GetSboxValue (TempA[0]);
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TempA[1] = GetSboxValue (TempA[1]);
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TempA[2] = GetSboxValue (TempA[2]);
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TempA[3] = GetSboxValue (TempA[3]);
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TempA[0] = TempA[0] ^ Rcon[Index / Nk];
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}
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#if CONFIG_AES_KEY_SIZE == 32
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if (Index % Nk == 4) {
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//
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// Function Subword()
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//
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TempA[0] = GetSboxValue (TempA[0]);
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TempA[1] = GetSboxValue (TempA[1]);
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TempA[2] = GetSboxValue (TempA[2]);
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TempA[3] = GetSboxValue (TempA[3]);
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}
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#endif
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J = Index * 4; K = (Index - Nk) * 4;
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RoundKey[J + 0] = RoundKey[K + 0] ^ TempA[0];
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RoundKey[J + 1] = RoundKey[K + 1] ^ TempA[1];
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RoundKey[J + 2] = RoundKey[K + 2] ^ TempA[2];
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RoundKey[J + 3] = RoundKey[K + 3] ^ TempA[3];
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}
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}
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VOID
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AesInitCtxIv (
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OUT AES_CONTEXT *Context,
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IN CONST UINT8 *Key,
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IN CONST UINT8 *Iv
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)
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{
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KeyExpansion (Context->RoundKey, Key);
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CopyMem (Context->Iv, Iv, AES_BLOCK_SIZE);
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}
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VOID
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AesSetCtxIv (
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OUT AES_CONTEXT *Context,
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IN CONST UINT8 *Iv
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)
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{
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CopyMem (Context->Iv, Iv, AES_BLOCK_SIZE);
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}
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//
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// This function adds the round key to state.
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// The round key is added to the state by an XOR function.
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//
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STATIC
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VOID
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AddRoundKey (
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IN UINT8 Round,
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IN OUT AES_INTERNAL_STATE *State,
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IN CONST UINT8 *RoundKey
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)
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{
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UINT8 I, J;
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for (I = 0; I < 4; ++I) {
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for (J = 0; J < 4; ++J) {
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(*State)[I][J] ^= RoundKey[(Round * Nb * 4) + (I * Nb) + J];
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}
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}
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}
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//
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// The SubBytes Function Substitutes the values in the
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// state matrix with values in an S-box.
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//
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STATIC
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VOID
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SubBytes (
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IN OUT AES_INTERNAL_STATE *State
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)
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{
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UINT8 I, J;
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for (I = 0; I < 4; ++I) {
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for (J = 0; J < 4; ++J) {
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(*State)[J][I] = GetSboxValue((*State)[J][I]);
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}
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}
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}
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//
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// The ShiftRows() function shifts the rows in the state to the left.
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// Each row is shifted with different offset.
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// Offset = Row number. So the first row is not shifted.
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//
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STATIC
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VOID
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ShiftRows (
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IN OUT AES_INTERNAL_STATE *State
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)
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{
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UINT8 Temp;
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//
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// Rotate first row 1 columns to left
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//
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Temp = (*State)[0][1];
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(*State)[0][1] = (*State)[1][1];
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(*State)[1][1] = (*State)[2][1];
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(*State)[2][1] = (*State)[3][1];
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(*State)[3][1] = Temp;
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//
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// Rotate second row 2 columns to left
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//
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Temp = (*State)[0][2];
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(*State)[0][2] = (*State)[2][2];
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(*State)[2][2] = Temp;
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Temp = (*State)[1][2];
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(*State)[1][2] = (*State)[3][2];
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(*State)[3][2] = Temp;
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//
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// Rotate third row 3 columns to left
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//
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Temp = (*State)[0][3];
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(*State)[0][3] = (*State)[3][3];
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(*State)[3][3] = (*State)[2][3];
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(*State)[2][3] = (*State)[1][3];
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(*State)[1][3] = Temp;
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}
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STATIC
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UINT8
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XTime (
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IN UINT8 X
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)
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{
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return (UINT8) (((UINT32) X << 1u) ^ ((((UINT32) X >> 7u) & 1u) * 0x1bu));
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}
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//
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// MixColumns function mixes the columns of the state matrix
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//
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STATIC
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VOID
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MixColumns (
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IN OUT AES_INTERNAL_STATE *State
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)
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{
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UINT8 I, Tmp, Tm, T;
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for (I = 0; I < 4; ++I) {
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T = (*State)[I][0];
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Tmp = (UINT8) ((UINT32) ((*State) [I][0]) ^ (UINT32) ((*State) [I][1])
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^ (UINT32) ((*State) [I][2]) ^ (UINT32) ((*State) [I][3]));
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Tm = (*State) [I][0] ^ (*State) [I][1];
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Tm = XTime (Tm);
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(*State) [I][0] ^= Tm ^ Tmp;
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Tm = (*State)[I][1] ^ (*State)[I][2];
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Tm = XTime (Tm);
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(*State) [I][1] ^= Tm ^ Tmp;
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Tm = (*State) [I][2] ^ (*State) [I][3];
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Tm = XTime (Tm);
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(*State) [I][2] ^= Tm ^ Tmp;
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Tm = (*State)[I][3] ^ T ;
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Tm = XTime (Tm);
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(*State) [I][3] ^= Tm ^ Tmp ;
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}
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}
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//
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// Multiply is used to multiply numbers in the field GF(2^8)
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// Note: The last call to XTime() is unneeded, but often ends up generating a smaller binary
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// The compiler seems to be able to vectorize the operation better this way.
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// See https://github.com/kokke/tiny-AES-c/pull/34
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//
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#define Multiply(x, y) \
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( (((y) & 1u) * (x)) ^ \
|
||
(((y)>>1u & 1u) * XTime(x)) ^ \
|
||
(((y)>>2u & 1u) * XTime(XTime(x))) ^ \
|
||
(((y)>>3u & 1u) * XTime(XTime(XTime(x)))) ^ \
|
||
(((y)>>4u & 1u) * XTime(XTime(XTime(XTime(x)))))) \
|
||
|
||
//
|
||
// MixColumns function mixes the columns of the state matrix.
|
||
// The method used to multiply may be difficult to understand for the inexperienced.
|
||
// Please use the references to gain more information.
|
||
//
|
||
STATIC
|
||
VOID
|
||
InvMixColumns (
|
||
IN OUT AES_INTERNAL_STATE *State
|
||
)
|
||
{
|
||
UINT8 I, A, B, C, D;
|
||
|
||
for (I = 0; I < 4; ++I) {
|
||
A = (*State) [I][0];
|
||
B = (*State) [I][1];
|
||
C = (*State) [I][2];
|
||
D = (*State) [I][3];
|
||
|
||
(*State)[I][0] = (UINT8) ((UINT32) Multiply(A, 0x0eu) ^ (UINT32) Multiply(B, 0x0bu)
|
||
^ (UINT32) Multiply(C, 0x0du) ^ (UINT32) Multiply(D, 0x09u));
|
||
(*State)[I][1] = (UINT8) ((UINT32) Multiply(A, 0x09u) ^ (UINT32) Multiply(B, 0x0eu)
|
||
^ (UINT32) Multiply(C, 0x0bu) ^ (UINT32) Multiply(D, 0x0du));
|
||
(*State)[I][2] = (UINT8) ((UINT32) Multiply(A, 0x0du) ^ (UINT32) Multiply(B, 0x09u)
|
||
^ (UINT32) Multiply(C, 0x0eu) ^ (UINT32) Multiply(D, 0x0bu));
|
||
(*State)[I][3] = (UINT8) ((UINT32) Multiply(A, 0x0bu) ^ (UINT32) Multiply(B, 0x0du)
|
||
^ (UINT32) Multiply(C, 0x09u) ^ (UINT32) Multiply(D, 0x0eu));
|
||
}
|
||
}
|
||
|
||
//
|
||
// The SubBytes Function Substitutes the values in the
|
||
// state matrix with values in an S-box.
|
||
//
|
||
STATIC
|
||
VOID
|
||
InvSubBytes (
|
||
IN OUT AES_INTERNAL_STATE *State
|
||
)
|
||
{
|
||
UINT8 I, J;
|
||
|
||
for (I = 0; I < 4; ++I) {
|
||
for (J = 0; J < 4; ++J) {
|
||
(*State)[J][I] = GetSBoxInvert ((*State)[J][I]);
|
||
}
|
||
}
|
||
}
|
||
|
||
STATIC
|
||
VOID
|
||
InvShiftRows (
|
||
IN OUT AES_INTERNAL_STATE *State
|
||
)
|
||
{
|
||
UINT8 Temp;
|
||
|
||
//
|
||
// Rotate first row 1 columns to right
|
||
//
|
||
Temp = (*State)[3][1];
|
||
(*State)[3][1] = (*State)[2][1];
|
||
(*State)[2][1] = (*State)[1][1];
|
||
(*State)[1][1] = (*State)[0][1];
|
||
(*State)[0][1] = Temp;
|
||
|
||
//
|
||
// Rotate second row 2 columns to right
|
||
//
|
||
Temp = (*State)[0][2];
|
||
(*State)[0][2] = (*State)[2][2];
|
||
(*State)[2][2] = Temp;
|
||
|
||
Temp = (*State)[1][2];
|
||
(*State)[1][2] = (*State)[3][2];
|
||
(*State)[3][2] = Temp;
|
||
|
||
//
|
||
// Rotate third row 3 columns to right
|
||
//
|
||
Temp = (*State)[0][3];
|
||
(*State)[0][3] = (*State)[1][3];
|
||
(*State)[1][3] = (*State)[2][3];
|
||
(*State)[2][3] = (*State)[3][3];
|
||
(*State)[3][3] = Temp;
|
||
}
|
||
|
||
//
|
||
// Cipher is the main function that encrypts the PlainText.
|
||
//
|
||
STATIC
|
||
VOID
|
||
Cipher (
|
||
IN OUT AES_INTERNAL_STATE *State,
|
||
IN CONST UINT8 *RoundKey
|
||
)
|
||
{
|
||
UINT8 Round;
|
||
|
||
//
|
||
// Add the First round key to the state before starting the rounds.
|
||
//
|
||
AddRoundKey(0, State, RoundKey);
|
||
|
||
//
|
||
// There will be Nr rounds.
|
||
// The first Nr-1 rounds are identical.
|
||
// These Nr-1 rounds are executed in the loop below.
|
||
//
|
||
for (Round = 1; Round < Nr; ++Round) {
|
||
SubBytes (State);
|
||
ShiftRows (State);
|
||
MixColumns (State);
|
||
AddRoundKey (Round, State, RoundKey);
|
||
}
|
||
|
||
//
|
||
// The last round is given below.
|
||
// The MixColumns function is not here in the last round.
|
||
//
|
||
SubBytes (State);
|
||
ShiftRows (State);
|
||
AddRoundKey (Nr, State, RoundKey);
|
||
}
|
||
|
||
STATIC
|
||
VOID
|
||
InvCipher (
|
||
IN OUT AES_INTERNAL_STATE *State,
|
||
IN CONST UINT8 *RoundKey
|
||
)
|
||
{
|
||
UINT8 Round;
|
||
|
||
//
|
||
// Add the First round key to the state before starting the rounds.
|
||
//
|
||
AddRoundKey (Nr, State, RoundKey);
|
||
|
||
//
|
||
// There will be Nr rounds.
|
||
// The first Nr-1 rounds are identical.
|
||
// These Nr-1 rounds are executed in the loop below.
|
||
//
|
||
for (Round = (Nr - 1); Round > 0; --Round) {
|
||
InvShiftRows (State);
|
||
InvSubBytes (State);
|
||
AddRoundKey (Round, State, RoundKey);
|
||
InvMixColumns (State);
|
||
}
|
||
|
||
//
|
||
// The last round is given below.
|
||
// The MixColumns function is not here in the last round.
|
||
//
|
||
InvShiftRows (State);
|
||
InvSubBytes (State);
|
||
AddRoundKey (0, State, RoundKey);
|
||
}
|
||
|
||
STATIC
|
||
VOID
|
||
XorWithIv (
|
||
IN OUT UINT8 *Buf,
|
||
IN CONST UINT8 *Iv
|
||
)
|
||
{
|
||
UINT8 I;
|
||
|
||
//
|
||
// The block in AES is always 128bit no matter the key size
|
||
//
|
||
for (I = 0; I < AES_BLOCK_SIZE; ++I) {
|
||
Buf[I] ^= Iv[I];
|
||
}
|
||
}
|
||
|
||
//
|
||
// Public functions
|
||
//
|
||
|
||
VOID
|
||
AesCbcEncryptBuffer (
|
||
IN OUT AES_CONTEXT *Context,
|
||
IN OUT UINT8 *Data,
|
||
IN UINT32 Len
|
||
)
|
||
{
|
||
UINT32 I;
|
||
UINT8 *Iv;
|
||
|
||
Iv = Context->Iv;
|
||
|
||
for (I = 0; I < Len; I += AES_BLOCK_SIZE) {
|
||
XorWithIv (Data, Iv);
|
||
Cipher ((AES_INTERNAL_STATE *) Data, Context->RoundKey);
|
||
Iv = Data;
|
||
Data += AES_BLOCK_SIZE;
|
||
}
|
||
|
||
//
|
||
// Store Iv in Context for next call
|
||
//
|
||
CopyMem (Context->Iv, Iv, AES_BLOCK_SIZE);
|
||
}
|
||
|
||
VOID
|
||
AesCbcDecryptBuffer (
|
||
IN OUT AES_CONTEXT *Context,
|
||
IN OUT UINT8 *Data,
|
||
IN UINT32 Len
|
||
)
|
||
{
|
||
UINT32 I;
|
||
UINT8 StoreNextIv[AES_BLOCK_SIZE];
|
||
|
||
for (I = 0; I < Len; I += AES_BLOCK_SIZE) {
|
||
CopyMem (StoreNextIv, Data, AES_BLOCK_SIZE);
|
||
InvCipher ((AES_INTERNAL_STATE *) Data, Context->RoundKey);
|
||
XorWithIv (Data, Context->Iv);
|
||
CopyMem (Context->Iv, StoreNextIv, AES_BLOCK_SIZE);
|
||
Data += AES_BLOCK_SIZE;
|
||
}
|
||
}
|
||
|
||
//
|
||
// Symmetrical operation: same function for encrypting as for decrypting.
|
||
// Note any IV/nonce should never be reused with the same key
|
||
//
|
||
VOID
|
||
AesCtrXcryptBuffer (
|
||
IN OUT AES_CONTEXT *Context,
|
||
IN OUT UINT8 *Data,
|
||
IN UINT32 Len
|
||
)
|
||
{
|
||
UINT8 Buffer[AES_BLOCK_SIZE];
|
||
UINT32 I;
|
||
INT32 Bi;
|
||
|
||
for (I = 0, Bi = AES_BLOCK_SIZE; I < Len; ++I, ++Bi) {
|
||
//
|
||
// We need to regen xor compliment in buffer
|
||
//
|
||
if (Bi == AES_BLOCK_SIZE) {
|
||
CopyMem (Buffer, Context->Iv, AES_BLOCK_SIZE);
|
||
Cipher ((AES_INTERNAL_STATE *) Buffer, Context->RoundKey);
|
||
|
||
//
|
||
// Increment Iv and handle overflow
|
||
//
|
||
for (Bi = (AES_BLOCK_SIZE - 1); Bi >= 0; --Bi) {
|
||
//
|
||
// Inc will owerflow
|
||
//
|
||
if (Context->Iv[Bi] == 255) {
|
||
Context->Iv[Bi] = 0;
|
||
continue;
|
||
}
|
||
|
||
Context->Iv[Bi] += 1;
|
||
break;
|
||
}
|
||
|
||
Bi = 0;
|
||
}
|
||
|
||
Data[I] = (Data[I] ^ Buffer[Bi]);
|
||
}
|
||
}
|