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#include <ctype.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

void hexdump(void *pdata, int size) {

const uint8_t *p = (const uint8_t *)pdata;

int count = size / 16;

int rem = size % 16;

for (int r = 0; r <= count; r++) {

int k = (r == count) ? rem : 16;

if (r)

printf("\n");

for (int i = 0; i < 16; i++) {

if (i < k)

printf("%02X ", p[i]);

else

printf("   ");

}

printf(" ");

for (int i = 0; i < k; i++) {

printf("%c", isprint(p[i]) ? p[i] : '.');

}

p += 0x10;

}

printf("\n");

}

/*

This is an implementation of the AES algorithm, specifically ECB, CTR and CBC

mode. Block size can be chosen in aes.h - available choices are AES128, AES192,

AES256.

The implementation is verified against the test vectors in:

National Institute of Standards and Technology Special Publication 800-38A

2001 ED

ECB-AES128

----------

plain-text:

6bc1bee22e409f96e93d7e117393172a

ae2d8a571e03ac9c9eb76fac45af8e51

30c81c46a35ce411e5fbc1191a0a52ef

f69f2445df4f9b17ad2b417be66c3710

key:

2b7e151628aed2a6abf7158809cf4f3c

resulting cipher

3ad77bb40d7a3660a89ecaf32466ef97

f5d3d58503b9699de785895a96fdbaaf

43b1cd7f598ece23881b00e3ed030688

7b0c785e27e8ad3f8223207104725dd4

NOTE:   String length must be evenly divisible by 16byte (str_len % 16 == 0)

You should pad the end of the string with zeros if this is not the case.

For AES192/256 the key size is proportionally larger.

*/

/*****************************************************************************/

/* Includes:                                                                 */

/*****************************************************************************/

#include "aes.h"

#include <string.h> // CBC mode, for memset

/*****************************************************************************/

/* Defines:                                                                  */

/*****************************************************************************/

// The number of columns comprising a state in AES. This is a constant in AES.

// Value=4

#define Nb 4

#if defined(AES256) && (AES256 == 1)

#define Nk 8

#define Nr 14

#elif defined(AES192) && (AES192 == 1)

#define Nk 6

#define Nr 12

#else

#define Nk 4  // The number of 32 bit words in a key.

#define Nr 10 // The number of rounds in AES Cipher.

#endif

// [email protected] points out that declaring Multiply as a function

// reduces code size considerably with the Keil ARM compiler.

// See this link for more information:

// https://github.com/kokke/tiny-AES-C/pull/3

#ifndef MULTIPLY_AS_A_FUNCTION

#define MULTIPLY_AS_A_FUNCTION 0

#endif

/*****************************************************************************/

/* Private variables:                                                        */

/*****************************************************************************/

// state - array holding the intermediate results during decryption.

typedef uint8_t state_t[4][4];

// The lookup-tables are marked const so they can be placed in read-only storage

// instead of RAM The numbers below can be computed dynamically trading ROM for

// RAM - This can be useful in (embedded) bootloader applications, where ROM is

// often limited.

static const uint8_t sbox[256] = {

// 0     1    2      3     4    5     6     7      8    9     A      B    C

// D     E     F

0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b,

0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0,

0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93, 0x26,

0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,

0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2,

0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0,

0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed,

0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,

0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f,

0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5,

0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec,

0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,

0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14,

0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c,

0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d,

0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,

0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f,

0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e,

0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11,

0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,

0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f,

0xb0, 0x54, 0xbb, 0x16};

#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)

static const uint8_t rsbox[256] = {

0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e,

0x81, 0xf3, 0xd7, 0xfb, 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87,

0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, 0x54, 0x7b, 0x94, 0x32,

0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,

0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49,

0x6d, 0x8b, 0xd1, 0x25, 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16,

0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, 0x6c, 0x70, 0x48, 0x50,

0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,

0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05,

0xb8, 0xb3, 0x45, 0x06, 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02,

0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b, 0x3a, 0x91, 0x11, 0x41,

0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,

0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8,

0x1c, 0x75, 0xdf, 0x6e, 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89,

0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, 0xfc, 0x56, 0x3e, 0x4b,

0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,

0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59,

0x27, 0x80, 0xec, 0x5f, 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d,

0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, 0xa0, 0xe0, 0x3b, 0x4d,

0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,

0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63,

0x55, 0x21, 0x0c, 0x7d};

#endif

// The round constant word array, Rcon[i], contains the values given by

// x to the power (i-1) being powers of x (x is denoted as {02}) in the field

// GF(2^8)

static const uint8_t Rcon[11] = {0x8d, 0x01, 0x02, 0x04, 0x08, 0x10,

0x20, 0x40, 0x80, 0x1b, 0x36};

/*

* Jordan Goulder points out in PR #12

* (https://github.com/kokke/tiny-AES-C/pull/12), that you can remove most of

* the elements in the Rcon array, because they are unused.

*

* From Wikipedia's article on the Rijndael key schedule @

* https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon

*

* "Only the first some of these constants are actually used – up to rcon[10]

* for AES-128 (as 11 round keys are needed), up to rcon[8] for AES-192, up to

* rcon[7] for AES-256. rcon[0] is not used in AES algorithm."

*/

/*****************************************************************************/

/* Private functions:                                                        */

/*****************************************************************************/

/*

static uint8_t getSBoxValue(uint8_t num)

{

return sbox[num];

}

*/

#define getSBoxValue(num) (sbox[(num)])

// This function produces Nb(Nr+1) round keys. The round keys are used in each

// round to decrypt the states.

static void KeyExpansion(uint8_t *RoundKey, const uint8_t *Key) {

unsigned i, j, k;

uint8_t tempa[4]; // Used for the column/row operations

// The first round key is the key itself.

for (i = 0; i < Nk; ++i) {

RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];

RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];

RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];

RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];

}

// All other round keys are found from the previous round keys.

for (i = Nk; i < Nb * (Nr + 1); ++i) {

{

k = (i - 1) * 4;

tempa[0] = RoundKey[k + 0];

tempa[1] = RoundKey[k + 1];

tempa[2] = RoundKey[k + 2];

tempa[3] = RoundKey[k + 3];

}

if (i % Nk == 0) {

// This function shifts the 4 bytes in a word to the left once.

// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]

// Function RotWord()

{

const uint8_t u8tmp = tempa[0];

tempa[0] = tempa[1];

tempa[1] = tempa[2];

tempa[2] = tempa[3];

tempa[3] = u8tmp;

}

// SubWord() is a function that takes a four-byte input word and

// applies the S-box to each of the four bytes to produce an output word.

// Function Subword()

{

tempa[0] = getSBoxValue(tempa[0]);

tempa[1] = getSBoxValue(tempa[1]);

tempa[2] = getSBoxValue(tempa[2]);

tempa[3] = getSBoxValue(tempa[3]);

}

tempa[0] = tempa[0] ^ Rcon[i / Nk];

}

#if defined(AES256) && (AES256 == 1)

if (i % Nk == 4) {

// Function Subword()

{

tempa[0] = getSBoxValue(tempa[0]);

tempa[1] = getSBoxValue(tempa[1]);

tempa[2] = getSBoxValue(tempa[2]);

tempa[3] = getSBoxValue(tempa[3]);

}

}

#endif

j = i * 4;

k = (i - Nk) * 4;

RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0];

RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1];

RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2];

RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3];

}

}

void AES_init_ctx(struct AES_ctx *ctx, const uint8_t *key) {

KeyExpansion(ctx->RoundKey, key);

}

#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))

void AES_init_ctx_iv(struct AES_ctx *ctx, const uint8_t *key,

const uint8_t *iv) {

KeyExpansion(ctx->RoundKey, key);

memcpy(ctx->Iv, iv, AES_BLOCKLEN);

}

void AES_ctx_set_iv(struct AES_ctx *ctx, const uint8_t *iv) {

memcpy(ctx->Iv, iv, AES_BLOCKLEN);

}

#endif

// This function adds the round key to state.

// The round key is added to the state by an XOR function.

static void AddRoundKey(uint8_t round, state_t *state,

const uint8_t *RoundKey) {

uint8_t i, j;

for (i = 0; i < 4; ++i) {

for (j = 0; j < 4; ++j) {

(*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j];

}

}

}

// The SubBytes Function Substitutes the values in the

// state matrix with values in an S-box.

static void SubBytes(state_t *state) {

uint8_t i, j;

for (i = 0; i < 4; ++i) {

for (j = 0; j < 4; ++j) {

(*state)[j][i] = getSBoxValue((*state)[j][i]);

}

}

}

// The ShiftRows() function shifts the rows in the state to the left.

// Each row is shifted with different offset.

// Offset = Row number. So the first row is not shifted.

static void ShiftRows(state_t *state) {

uint8_t temp;

// Rotate first row 1 columns to left

temp = (*state)[0][1];

(*state)[0][1] = (*state)[1][1];

(*state)[1][1] = (*state)[2][1];

(*state)[2][1] = (*state)[3][1];

(*state)[3][1] = temp;

// Rotate second row 2 columns to left

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 left

temp = (*state)[0][3];

(*state)[0][3] = (*state)[3][3];

(*state)[3][3] = (*state)[2][3];

(*state)[2][3] = (*state)[1][3];

(*state)[1][3] = temp;

}

static uint8_t xtime(uint8_t x) { return ((x << 1) ^ (((x >> 7) & 1) * 0x1b)); }

// MixColumns function mixes the columns of the state matrix

static void MixColumns(state_t *state) {

uint8_t i;

uint8_t Tmp, Tm, t;

for (i = 0; i < 4; ++i) {

t = (*state)[i][0];

Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3];

Tm = (*state)[i][0] ^ (*state)[i][1];

Tm = xtime(Tm);

(*state)[i][0] ^= Tm ^ Tmp;

Tm = (*state)[i][1] ^ (*state)[i][2];

Tm = xtime(Tm);

(*state)[i][1] ^= Tm ^ Tmp;

Tm = (*state)[i][2] ^ (*state)[i][3];

Tm = xtime(Tm);

(*state)[i][2] ^= Tm ^ Tmp;

Tm = (*state)[i][3] ^ t;

Tm = xtime(Tm);

(*state)[i][3] ^= Tm ^ Tmp;

}

}

// Multiply is used to multiply numbers in the field GF(2^8)

// Note: The last call to xtime() is unneeded, but often ends up generating a

// smaller binary

//       The compiler seems to be able to vectorize the operation better this

//       way. See https://github.com/kokke/tiny-AES-c/pull/34

#if MULTIPLY_AS_A_FUNCTION

static uint8_t Multiply(uint8_t x, uint8_t y) {

return (((y & 1) * x) ^ ((y >> 1 & 1) * xtime(x)) ^

((y >> 2 & 1) * xtime(xtime(x))) ^

((y >> 3 & 1) * xtime(xtime(xtime(x)))) ^

((y >> 4 & 1) *

xtime(xtime(xtime(

xtime(x)))))); /* this last call to xtime() can be omitted */

}

#else

#define Multiply(x, y)                                                         \

(((y & 1) * x) ^ ((y >> 1 & 1) * xtime(x)) ^                                 \

((y >> 2 & 1) * xtime(xtime(x))) ^                                          \

((y >> 3 & 1) * xtime(xtime(xtime(x)))) ^                                   \

((y >> 4 & 1) * xtime(xtime(xtime(xtime(x))))))

#endif

#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)

/*

static uint8_t getSBoxInvert(uint8_t num)

{

return rsbox[num];

}

*/

#define getSBoxInvert(num) (rsbox[(num)])

// 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(state_t *state) {

int i;

uint8_t 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] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^

Multiply(d, 0x09);

(*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^

Multiply(d, 0x0d);

(*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^

Multiply(d, 0x0b);

(*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^

Multiply(d, 0x0e);

}

}

// The SubBytes Function Substitutes the values in the

// state matrix with values in an S-box.

static void InvSubBytes(state_t *state) {

uint8_t i, j;

for (i = 0; i < 4; ++i) {

for (j = 0; j < 4; ++j) {

(*state)[j][i] = getSBoxInvert((*state)[j][i]);

}

}

}

static void InvShiftRows(state_t *state) {

uint8_t 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;

}

#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)

void swap_xxx(state_t *state) {

for (int j = 0; j < 4; j++) {

uint8_t a = (*state)[j][0];

uint8_t b = (*state)[j][1];

uint8_t c = (*state)[j][2];

uint8_t d = (*state)[j][3];

(*state)[j][3] = a;

(*state)[j][2] = b;

(*state)[j][1] = c;

(*state)[j][0] = d;

}

}

// Cipher is the main function that encrypts the PlainText.

static void Cipher(state_t *state, const uint8_t *RoundKey) {

uint8_t round = 0;

// 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 rounds are executed in the loop below.

// Last one without MixColumns()

for (round = 1;; ++round) {

if (round != Nr) {

swap_xxx(state);

}

if (round == Nr) {

uint32_t a = *(uint32_t *)(*state)[3];

uint32_t b = *(uint32_t *)(*state)[2];

uint32_t c = *(uint32_t *)(*state)[1];

uint32_t d = *(uint32_t *)(*state)[0];

*(uint32_t *)(*state)[0] = a;

*(uint32_t *)(*state)[1] = b;

*(uint32_t *)(*state)[2] = c;

*(uint32_t *)(*state)[3] = d;

}

SubBytes(state);

ShiftRows(state);

if (round == Nr) {

uint32_t a = *(uint32_t *)(*state)[0];

uint32_t b = *(uint32_t *)(*state)[1];

uint32_t c = *(uint32_t *)(*state)[2];

uint32_t d = *(uint32_t *)(*state)[3];

*(uint32_t *)(*state)[0] = a;

*(uint32_t *)(*state)[3] = b;

*(uint32_t *)(*state)[2] = c;

*(uint32_t *)(*state)[1] = d;

break;

}

MixColumns(state);

swap_xxx(state);

AddRoundKey(round, state, RoundKey);

hexdump((*state), sizeof(*state));

}

hexdump(*state, sizeof(*state));

// Add round key to last round

AddRoundKey(Nr, state, RoundKey);

swap_xxx(state);

}

#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)

static void InvCipher(state_t *state, const uint8_t *RoundKey) {

uint8_t round = 0;

swap_xxx(state);

// 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 rounds are executed in the loop below.

// Last one without InvMixColumn()

for (round = (Nr - 1);; --round) {

if (round == (Nr - 1)) {

uint32_t a = *(uint32_t *)(*state)[0];

uint32_t b = *(uint32_t *)(*state)[1];

uint32_t c = *(uint32_t *)(*state)[2];

uint32_t d = *(uint32_t *)(*state)[3];

*(uint32_t *)(*state)[0] = a;

*(uint32_t *)(*state)[3] = b;

*(uint32_t *)(*state)[2] = c;

*(uint32_t *)(*state)[1] = d;

}

InvShiftRows(state);

InvSubBytes(state);

if (round == (Nr - 1)) {

uint32_t a = *(uint32_t *)(*state)[3];

uint32_t b = *(uint32_t *)(*state)[2];

uint32_t c = *(uint32_t *)(*state)[1];

uint32_t d = *(uint32_t *)(*state)[0];

*(uint32_t *)(*state)[0] = a;

*(uint32_t *)(*state)[1] = b;

*(uint32_t *)(*state)[2] = c;

*(uint32_t *)(*state)[3] = d;

}

if (round != (Nr - 1)) {

swap_xxx(state);

}

AddRoundKey(round, state, RoundKey);

if (round == 0) {

break;

}

swap_xxx(state);

InvMixColumns(state);

}

}

#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)

/*****************************************************************************/

/* Public functions:                                                         */

/*****************************************************************************/

#if defined(ECB) && (ECB == 1)

void AES_ECB_encrypt(const struct AES_ctx *ctx, uint8_t *buf) {

// The next function call encrypts the PlainText with the Key using AES

// algorithm.

Cipher((state_t *)buf, ctx->RoundKey);

}

void AES_ECB_decrypt(const struct AES_ctx *ctx, uint8_t *buf) {

// The next function call decrypts the PlainText with the Key using AES

// algorithm.

InvCipher((state_t *)buf, ctx->RoundKey);

}

#endif // #if defined(ECB) && (ECB == 1)

#if defined(CBC) && (CBC == 1)

static void XorWithIv(uint8_t *buf, const uint8_t *Iv) {

uint8_t i;

for (i = 0; i < AES_BLOCKLEN;

++i) // The block in AES is always 128bit no matter the key size

{

buf[i] ^= Iv[i];

}

}

void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t *buf, size_t length) {

size_t i;

uint8_t *Iv = ctx->Iv;

for (i = 0; i < length; i += AES_BLOCKLEN) {

XorWithIv(buf, Iv);

Cipher((state_t *)buf, ctx->RoundKey);

Iv = buf;

buf += AES_BLOCKLEN;

}

/* store Iv in ctx for next call */

memcpy(ctx->Iv, Iv, AES_BLOCKLEN);

}

void AES_CBC_decrypt_buffer(struct AES_ctx *ctx, uint8_t *buf, size_t length) {

size_t i;

uint8_t storeNextIv[AES_BLOCKLEN];

for (i = 0; i < length; i += AES_BLOCKLEN) {

memcpy(storeNextIv, buf, AES_BLOCKLEN);

InvCipher((state_t *)buf, ctx->RoundKey);

XorWithIv(buf, ctx->Iv);

memcpy(ctx->Iv, storeNextIv, AES_BLOCKLEN);

buf += AES_BLOCKLEN;

}

}

#endif // #if defined(CBC) && (CBC == 1)

#if defined(CTR) && (CTR == 1)

/* Symmetrical operation: same function for encrypting as for decrypting. Note

* any IV/nonce should never be reused with the same key */

void AES_CTR_xcrypt_buffer(struct AES_ctx *ctx, uint8_t *buf, size_t length) {

uint8_t buffer[AES_BLOCKLEN];

size_t i;

int bi;

for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi) {

if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */

{

memcpy(buffer, ctx->Iv, AES_BLOCKLEN);

Cipher((state_t *)buffer, ctx->RoundKey);

/* Increment Iv and handle overflow */

for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi) {

/* inc will overflow */

if (ctx->Iv[bi] == 255) {

ctx->Iv[bi] = 0;

continue;

}

ctx->Iv[bi] += 1;

break;

}

bi = 0;

}

buf[i] = (buf[i] ^ buffer[bi]);

}

}

#endif // #if defined(CTR) && (CTR == 1)

unsigned char hexData2[176] = {

0x39, 0xBA, 0x3A, 0x0B, 0x1C, 0x27, 0x64, 0xA2, 0x80, 0x98, 0x31, 0x36,

0xEB, 0x9E, 0x77, 0x9E, 0x32, 0x53, 0x31, 0xFF, 0x2E, 0x74, 0x55, 0x5D,

0xAE, 0xEC, 0x64, 0x6B, 0x45, 0x72, 0x13, 0xF5, 0xD4, 0x3D, 0x71, 0x80,

0xFA, 0x49, 0x24, 0xDD, 0x54, 0xA5, 0x40, 0xB6, 0x11, 0xD7, 0x53, 0x43,

0xCE, 0xBF, 0x7F, 0x69, 0x34, 0xF6, 0x5B, 0xB4, 0x60, 0x53, 0x1B, 0x02,

0x71, 0x84, 0x48, 0x41, 0x4D, 0x1C, 0x20, 0x33, 0x79, 0xEA, 0x7B, 0x87,

0x19, 0xB9, 0x60, 0x85, 0x68, 0x3D, 0x28, 0xC4, 0x51, 0x59, 0x07, 0x17,

0x28, 0xB3, 0x7C, 0x90, 0x31, 0x0A, 0x1C, 0x15, 0x59, 0x37, 0x34, 0xD1,

0x6F, 0x92, 0x9D, 0x2F, 0x47, 0x21, 0xE1, 0xBF, 0x76, 0x2B, 0xFD, 0xAA,

0x2F, 0x1C, 0xC9, 0x7B, 0x4E, 0x87, 0x01, 0xB2, 0x09, 0xA6, 0xE0, 0x0D,

0x7F, 0x8D, 0x1D, 0xA7, 0x50, 0x91, 0xD4, 0xDC, 0xC8, 0xD4, 0x80, 0x7A,

0xC1, 0x72, 0x60, 0x77, 0xBE, 0xFF, 0x7D, 0xD0, 0xEE, 0x6E, 0xA9, 0x0C,

0x36, 0xFC, 0x1F, 0xB2, 0xF7, 0x8E, 0x7F, 0xC5, 0x49, 0x71, 0x02, 0x15,

0xA7, 0x1F, 0xAB, 0x19, 0xE2, 0xA0, 0xDF, 0xE6, 0x15, 0x2E, 0xA0, 0x23,

0x5C, 0x5F, 0xA2, 0x36, 0xFB, 0x40, 0x09, 0x2F};

int main() {

struct AES_ctx ctx;

uint8_t key[] =

"\x39\xba\x3a\x0b\x1c\x27\x64\xa2\x80\x98\x31\x36\xeb\x9e\x77\x9e";

uint8_t buf[16] = "FFFFFFFFFFFFFFFF";

AES_init_ctx(&ctx, key);

memcpy(ctx.RoundKey, hexData2, sizeof(hexData2));

hexdump(ctx.RoundKey, sizeof(ctx.RoundKey));

AES_ECB_encrypt(&ctx, buf);

hexdump(buf, sizeof(buf));

uint8_t bufx[16] =

"\xAA\xFE\xE4\xE0\xC3\xB3\x24\x16\x4E\x5B\xF7\x13\x9E\xE1\xCA\xA0";

AES_ECB_decrypt(&ctx, bufx);

hexdump(bufx, sizeof(bufx));

return 0;

}