f75d43bb19
* Added AES and AES-CTR modules. AES-CTR conforms to the same counter mode used with AES in *OpenSSL*. * All algorithms now work on Big-Endian architectures. * Now uses CMake for building rather than make files and Visual Studio projects. CMake will generate whatever system is required. * Input function parameters are now marked `const` * File names have been changed to have the prefix `CryptLib_` rather than `Lib`. * Various formatting changes to the files.
578 lines
23 KiB
C
578 lines
23 KiB
C
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// CryptLib_Aes
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//
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// Implementation of AES block cipher. Originally written by Kokke (https://github.com/kokke). Modified by WaterJuice
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// retaining Public Domain license.
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//
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// AES is a block cipher that operates on 128 bit blocks. Encryption an Decryption routines use an AesContext which
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// must be initialised with the key. An AesContext can be initialised with a 128, 192, or 256 bit key. Use the
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// AesInitialise[n] functions to initialise the context with the key. Once an AES context is initialised its contents
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// are not changed by the encrypting and decrypting functions. A context only needs to be initialised once for any
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// given key and the context may be used by the encrypt/decrypt functions in simultaneous threads.
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// All operations are performed byte wise and this implementation works in both little and endian processors.
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// There are no alignment requirements with the keys and data blocks.
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//
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// This is free and unencumbered software released into the public domain - November 2017 waterjuice.org
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// IMPORTS
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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#include "CryptLib_Aes.h"
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#include <stdint.h>
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#include <memory.h>
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// DEFINES
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// Array holding the intermediate results during decryption.
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typedef struct
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{
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uint8_t state[4][4];
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} AesState;
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// CONSTANTS
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// AES lookup values
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static const uint8_t SBOX[256] =
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{
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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_t RSBOX[256] =
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{
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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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// 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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static const uint8_t RCON[11] = { 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 };
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// INTERNAL FUNCTIONS
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// KeyExpansion
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//
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// This function produces Nb(Nr+1) round keys. The round keys are used in each 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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(
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uint8_t const* Key, // [in]
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AesContext* Context // [in out]
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)
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{
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uint32_t i;
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uint8_t k;
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uint8_t temp [4]; // Used for the column/row operations
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// The first round key is the key itself.
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for( i=0; i<Context->KeySizeInWords; i++ )
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{
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Context->RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];
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Context->RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];
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Context->RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];
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Context->RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];
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}
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// All other round keys are found from the previous round keys.
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for( i=Context->KeySizeInWords; i<4*(Context->NumberOfRounds+1); i++ )
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{
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#ifdef _MSC_VER
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// Visual Studio code analysis complains about the following code that the index into Context->RoundKey
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// may be -4. This is because it is concerned that 'i' may be zero. However we know that 'i' will not
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// be zero as it starts at Context->KeySizeInWords which is never going to be zero when this function
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// is called (It will have one of 3 values assigned to it by the initialise functions). So we need to
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// just suppress the warning here to stop Visual Studio complaining.
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#pragma warning( suppress : 6385 )
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#endif
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temp[0] = Context->RoundKey[(i-1) * 4 + 0];
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temp[1] = Context->RoundKey[(i-1) * 4 + 1];
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temp[2] = Context->RoundKey[(i-1) * 4 + 2];
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temp[3] = Context->RoundKey[(i-1) * 4 + 3];
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if( 0 == i % Context->KeySizeInWords )
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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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k = temp[0];
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temp[0] = temp[1];
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temp[1] = temp[2];
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temp[2] = temp[3];
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temp[3] = k;
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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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temp[0] = SBOX[temp[0]];
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temp[1] = SBOX[temp[1]];
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temp[2] = SBOX[temp[2]];
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temp[3] = SBOX[temp[3]];
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temp[0] = temp[0] ^ RCON[i/Context->KeySizeInWords];
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}
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if( AES_KEY_SIZE_256/4 == Context->KeySizeInWords )
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{
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// Only performed with 256 bit sized keys
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if( 4 == i % Context->KeySizeInWords )
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{
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// Function Subword()
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temp[0] = SBOX[temp[0]];
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temp[1] = SBOX[temp[1]];
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temp[2] = SBOX[temp[2]];
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temp[3] = SBOX[temp[3]];
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}
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}
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Context->RoundKey[i*4 + 0] = Context->RoundKey[(i-Context->KeySizeInWords)*4 + 0] ^ temp[0];
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Context->RoundKey[i*4 + 1] = Context->RoundKey[(i-Context->KeySizeInWords)*4 + 1] ^ temp[1];
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Context->RoundKey[i*4 + 2] = Context->RoundKey[(i-Context->KeySizeInWords)*4 + 2] ^ temp[2];
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Context->RoundKey[i*4 + 3] = Context->RoundKey[(i-Context->KeySizeInWords)*4 + 3] ^ temp[3];
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}
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}
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// AddRoundKey
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//
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// This function adds the round key to state. 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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(
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uint32_t Round, // [in]
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AesContext const* Context, // [in]
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AesState* State // [in out]
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)
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{
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uint32_t i;
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uint32_t j;
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for( i=0; i<4; i++ )
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{
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for( j=0; j<4; j++ )
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{
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State->state[i][j] ^= Context->RoundKey[(Round*4*4) + (i*4) + j];
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}
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}
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}
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// SubBytes
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//
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// The SubBytes Function Substitutes the values in the 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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(
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AesState* State // [in out]
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)
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{
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uint32_t i;
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uint32_t j;
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for( i=0; i<4; i++ )
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{
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for( j=0; j<4; j++ )
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{
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State->state[j][i] = SBOX[ State->state[j][i] ];
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}
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}
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}
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// ShiftRows
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//
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// The ShiftRows() function shifts the rows in the state to the left. 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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(
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AesState* State // [in out]
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)
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{
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uint8_t temp;
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// Rotate first row 1 columns to left
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temp = State->state[0][1];
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State->state[0][1] = State->state[1][1];
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State->state[1][1] = State->state[2][1];
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State->state[2][1] = State->state[3][1];
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State->state[3][1] = temp;
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// Rotate second row 2 columns to left
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temp = State->state[0][2];
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State->state[0][2] = State->state[2][2];
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State->state[2][2] = temp;
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temp = State->state[1][2];
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State->state[1][2] = State->state[3][2];
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State->state[3][2] = temp;
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// Rotate third row 3 columns to left
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temp = State->state[0][3];
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State->state[0][3] = State->state[3][3];
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State->state[3][3] = State->state[2][3];
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State->state[2][3] = State->state[1][3];
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State->state[1][3] = temp;
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}
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// xtime
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//
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// Performs a calculation
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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static
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uint8_t
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xtime
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(
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uint8_t x // [in]
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)
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{
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return (x<<1) ^ ( ((x>>7) & 1) * 0x1b );
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}
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// MixColumns
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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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(
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AesState* State // [in out]
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)
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{
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uint32_t i;
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uint8_t Tmp;
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uint8_t Tm;
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uint8_t t;
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for( i=0; i<4; i++ )
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{
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t = State->state[i][0];
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Tmp = State->state[i][0] ^ State->state[i][1] ^ State->state[i][2] ^ State->state[i][3] ;
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Tm = State->state[i][0] ^ State->state[i][1] ; Tm = xtime(Tm); State->state[i][0] ^= Tm ^ Tmp ;
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Tm = State->state[i][1] ^ State->state[i][2] ; Tm = xtime(Tm); State->state[i][1] ^= Tm ^ Tmp ;
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Tm = State->state[i][2] ^ State->state[i][3] ; Tm = xtime(Tm); State->state[i][2] ^= Tm ^ Tmp ;
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Tm = State->state[i][3] ^ t ; Tm = xtime(Tm); State->state[i][3] ^= Tm ^ Tmp ;
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}
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}
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// Multiply
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//
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// Multiply is used to multiply numbers in the field GF(2^8). This is defined as a macro.
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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#define Multiply(x, y) \
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( ((y & 1) * x) ^ \
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((y>>1 & 1) * xtime(x)) ^ \
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((y>>2 & 1) * xtime(xtime(x))) ^ \
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((y>>3 & 1) * xtime(xtime(xtime(x)))) ^ \
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((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))) \
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// InvMixColumns
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//
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// InvMixColumns 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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InvMixColumns
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(
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AesState* State // [in out]
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)
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{
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uint32_t i;
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uint8_t a;
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uint8_t b;
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uint8_t c;
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uint8_t d;
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for( i=0; i<4; i++ )
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{
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a = State->state[i][0];
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b = State->state[i][1];
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c = State->state[i][2];
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d = State->state[i][3];
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State->state[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
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State->state[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
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State->state[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
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State->state[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e);
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}
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}
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// InvSubBytes
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//
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// The InvSubBytes Function Substitutes the values in the 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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InvSubBytes
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(
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AesState* State // [in out]
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)
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{
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uint32_t i;
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uint32_t j;
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for( i=0; i<4; i++ )
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{
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for( j=0; j<4; j++ )
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{
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State->state[j][i] = RSBOX[ State->state[j][i] ];
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}
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}
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}
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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// InvShiftRows
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//
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// Inverse of ShiftRows
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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static
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void
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InvShiftRows
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(
|
|
AesState* State // [in out]
|
|
)
|
|
{
|
|
uint8_t temp;
|
|
|
|
// Rotate first row 1 columns to right
|
|
temp = State->state[3][1];
|
|
State->state[3][1] = State->state[2][1];
|
|
State->state[2][1] = State->state[1][1];
|
|
State->state[1][1] = State->state[0][1];
|
|
State->state[0][1] = temp;
|
|
|
|
// Rotate second row 2 columns to right
|
|
temp = State->state[0][2];
|
|
State->state[0][2] = State->state[2][2];
|
|
State->state[2][2] = temp;
|
|
|
|
temp = State->state[1][2];
|
|
State->state[1][2] = State->state[3][2];
|
|
State->state[3][2] = temp;
|
|
|
|
// Rotate third row 3 columns to right
|
|
temp = State->state[0][3];
|
|
State->state[0][3] = State->state[1][3];
|
|
State->state[1][3] = State->state[2][3];
|
|
State->state[2][3] = State->state[3][3];
|
|
State->state[3][3] = temp;
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// EXPORTED FUNCTIONS
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// AesInitialise128
|
|
//
|
|
// Initialises an AesContext with a 128 bit key.
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
void
|
|
AesInitialise128
|
|
(
|
|
uint8_t const Key [AES_KEY_SIZE_128], // [in]
|
|
AesContext* Context // [out]
|
|
)
|
|
{
|
|
memset( Context, 0, sizeof(*Context) );
|
|
|
|
Context->KeySizeInWords = AES_KEY_SIZE_128 / sizeof(uint32_t);
|
|
Context->NumberOfRounds = 10;
|
|
|
|
KeyExpansion( Key, Context );
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// AesInitialise192
|
|
//
|
|
// Initialises an AesContext with a 192 bit key.
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
void
|
|
AesInitialise192
|
|
(
|
|
uint8_t const Key [AES_KEY_SIZE_192], // [in]
|
|
AesContext* Context // [out]
|
|
)
|
|
{
|
|
memset( Context, 0, sizeof(*Context) );
|
|
|
|
Context->KeySizeInWords = AES_KEY_SIZE_192 / sizeof(uint32_t);
|
|
Context->NumberOfRounds = 12;
|
|
|
|
KeyExpansion( Key, Context );
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// AesInitialise256
|
|
//
|
|
// Initialises an AesContext with a 256 bit key.
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
void
|
|
AesInitialise256
|
|
(
|
|
uint8_t const Key [AES_KEY_SIZE_256], // [in]
|
|
AesContext* Context // [out]
|
|
)
|
|
{
|
|
memset( Context, 0, sizeof(*Context) );
|
|
|
|
Context->KeySizeInWords = AES_KEY_SIZE_256 / sizeof(uint32_t);
|
|
Context->NumberOfRounds = 14;
|
|
|
|
KeyExpansion( Key, Context );
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// AesEncrypt
|
|
//
|
|
// Performs an AES encryption of one block (128 bits) with the AesContext initialised with one of the functions
|
|
// AesInitialise[n]. Input and Output can point to same memory location, however it is more efficient to use
|
|
// AesEncryptInPlace in this situation.
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
void
|
|
AesEncrypt
|
|
(
|
|
AesContext const* Context, // [in]
|
|
uint8_t const Input [AES_BLOCK_SIZE], // [in]
|
|
uint8_t Output [AES_BLOCK_SIZE] // [out]
|
|
)
|
|
{
|
|
memcpy( Output, Input, AES_BLOCK_SIZE );
|
|
AesEncryptInPlace( Context, Output );
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// AesDecrypt
|
|
//
|
|
// Performs an AES decryption of one block (128 bits) with the AesContext initialised with one of the functions
|
|
// AesInitialise[n]. Input and Output can point to same memory location, however it is more efficient to use
|
|
// AesDecryptInPlace in this situation.
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
void
|
|
AesDecrypt
|
|
(
|
|
AesContext const* Context, // [in]
|
|
uint8_t const Input [AES_BLOCK_SIZE], // [in]
|
|
uint8_t Output [AES_BLOCK_SIZE] // [out]
|
|
)
|
|
{
|
|
memcpy( Output, Input, AES_BLOCK_SIZE);
|
|
AesDecryptInPlace(Context, Output );
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// AesEncryptInPlace
|
|
//
|
|
// Performs an AES encryption of one block (128 bits) with the AesContext initialised with one of the functions
|
|
// AesInitialise[n]. The encryption is performed in place.
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
void
|
|
AesEncryptInPlace
|
|
(
|
|
AesContext const* Context, // [in]
|
|
uint8_t Block [AES_BLOCK_SIZE] // [in out]
|
|
)
|
|
{
|
|
uint32_t round = 0;
|
|
|
|
// Add the First round key to the state before starting the rounds.
|
|
AddRoundKey( 0, Context, (AesState*)Block );
|
|
|
|
// 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<Context->NumberOfRounds; round++ )
|
|
{
|
|
SubBytes( (AesState*)Block );
|
|
ShiftRows( (AesState*)Block );
|
|
MixColumns( (AesState*)Block );
|
|
AddRoundKey( round, Context, (AesState*)Block );
|
|
}
|
|
|
|
// The last round is given below.
|
|
// The MixColumns function is not here in the last round.
|
|
SubBytes( (AesState*)Block);
|
|
ShiftRows( (AesState*)Block);
|
|
AddRoundKey( Context->NumberOfRounds, Context, (AesState*)Block );
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// AesDecryptInPlace
|
|
//
|
|
// Performs an AES decryption of one block (128 bits) with the AesContext initialised with one of the functions
|
|
// AesInitialise[n]. The decryption is performed in place.
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
void
|
|
AesDecryptInPlace
|
|
(
|
|
AesContext const* Context, // [in]
|
|
uint8_t Block [AES_BLOCK_SIZE] // [in out]
|
|
)
|
|
{
|
|
uint32_t round = 0;
|
|
|
|
// Add the First round key to the state before starting the rounds.
|
|
AddRoundKey( Context->NumberOfRounds, Context, (AesState*)Block );
|
|
|
|
// The first NumberOfRounds-1 rounds are identical.
|
|
for( round=(Context->NumberOfRounds-1); round>0; round-- )
|
|
{
|
|
InvShiftRows( (AesState*)Block );
|
|
InvSubBytes( (AesState*)Block );
|
|
AddRoundKey( round, Context, (AesState*)Block );
|
|
InvMixColumns( (AesState*)Block );
|
|
}
|
|
|
|
// The MixColumns function is not here in the last round.
|
|
InvShiftRows( (AesState*)Block );
|
|
InvSubBytes( (AesState*)Block );
|
|
AddRoundKey( 0, Context, (AesState*)Block );
|
|
}
|