java 语言与 C语言端 AES (ECB)
注：java 为no-padding 注释掉了 padding部分（byte数组初始化时 为0x00）
c 为 padding 0x00 （byte数组初始化时 为0x00）
代码出自网上
代码地址 github
https://github.com/mountwater/AES-128-ECB-java_and_c
JAVA代码
//Copyright Popa Tiberiu 2011
//free to use this in any way
package tsd.crypto.algoritm;
public class AES {
private static int Nb, Nk, Nr;
private static byte[][] w;
private static int[] sbox = { 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 };
private static int[] inv_sbox = { 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 };
private static int Rcon[] = { 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39,
0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a,
0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef,
0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc,
0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3,
0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94,
0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35,
0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f,
0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04,
0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63,
0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd,
0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb };
private static byte[] xor_func(byte[] a, byte[] b) {
byte[] out = new byte[a.length];
for (int i = 0; i < a.length; i++) {
out[i] = (byte) (a[i] ^ b[i]);
}
return out;
}
private static byte[][] generateSubkeys(byte[] key) {
byte[][] tmp = new byte[Nb * (Nr + 1)][4];
int i = 0;
while (i < Nk) {
tmp[i][0] = key[i * 4];
tmp[i][1] = key[i * 4 + 1];
tmp[i][2] = key[i * 4 + 2];
tmp[i][3] = key[i * 4 + 3];
i++;
}
i = Nk;
while (i < Nb * (Nr + 1)) {
byte[] temp = new byte[4];
for(int k = 0;k<4;k++)
temp[k] = tmp[i-1][k];
if (i % Nk == 0) {
temp = SubWord(rotateWord(temp));
temp[0] = (byte) (temp[0] ^ (Rcon[i / Nk] & 0xff));
} else if (Nk > 6 && i % Nk == 4) {
temp = SubWord(temp);
}
tmp[i] = xor_func(tmp[i - Nk], temp);
i++;
}
return tmp;
}
private static byte[] SubWord(byte[] in) {
byte[] tmp = new byte[in.length];
for (int i = 0; i < tmp.length; i++)
tmp[i] = (byte) (sbox[in[i] & 0x000000ff] & 0xff);
return tmp;
}
private static byte[] rotateWord(byte[] input) {
byte[] tmp = new byte[input.length];
tmp[0] = input[1];
tmp[1] = input[2];
tmp[2] = input[3];
tmp[3] = input[0];
return tmp;
}
private static byte[][] AddRoundKey(byte[][] state, byte[][] w, int round) {
byte[][] tmp = new byte[state.length][state[0].length];
for (int c = 0; c < Nb; c++) {
for (int l = 0; l < 4; l++)
tmp[l][c] = (byte) (state[l][c] ^ w[round * Nb + c][l]);
}
return tmp;
}
private static byte[][] SubBytes(byte[][] state) {
byte[][] tmp = new byte[state.length][state[0].length];
for (int row = 0; row < 4; row++)
for (int col = 0; col < Nb; col++)
tmp[row][col] = (byte) (sbox[(state[row][col] & 0x000000ff)] & 0xff);
return tmp;
}
private static byte[][] InvSubBytes(byte[][] state) {
for (int row = 0; row < 4; row++)
for (int col = 0; col < Nb; col++)
state[row][col] = (byte)(inv_sbox[(state[row][col] & 0x000000ff)]&0xff);
return state;
}
private static byte[][] ShiftRows(byte[][] state) {
byte[] t = new byte[4];
for (int r = 1; r < 4; r++) {
for (int c = 0; c < Nb; c++)
t[c] = state[r][(c + r) % Nb];
for (int c = 0; c < Nb; c++)
state[r][c] = t[c];
}
return state;
}
private static byte[][] InvShiftRows(byte[][] state) {
byte[] t = new byte[4];
for (int r = 1; r < 4; r++) {
for (int c = 0; c < Nb; c++)
t[(c + r)%Nb] = state[r][c];
for (int c = 0; c < Nb; c++)
state[r][c] = t[c];
}
return state;
}
private static byte[][] InvMixColumns(byte[][] s){
int[] sp = new int[4];
byte b02 = (byte)0x0e, b03 = (byte)0x0b, b04 = (byte)0x0d, b05 = (byte)0x09;
for (int c = 0; c < 4; c++) {
sp[0] = FFMul(b02, s[0][c]) ^ FFMul(b03, s[1][c]) ^ FFMul(b04,s[2][c]) ^ FFMul(b05,s[3][c]);
sp[1] = FFMul(b05, s[0][c]) ^ FFMul(b02, s[1][c]) ^ FFMul(b03,s[2][c]) ^ FFMul(b04,s[3][c]);
sp[2] = FFMul(b04, s[0][c]) ^ FFMul(b05, s[1][c]) ^ FFMul(b02,s[2][c]) ^ FFMul(b03,s[3][c]);
sp[3] = FFMul(b03, s[0][c]) ^ FFMul(b04, s[1][c]) ^ FFMul(b05,s[2][c]) ^ FFMul(b02,s[3][c]);
for (int i = 0; i < 4; i++) s[i][c] = (byte)(sp[i]);
}
return s;
}
private static byte[][] MixColumns(byte[][] s){
int[] sp = new int[4];
byte b02 = (byte)0x02, b03 = (byte)0x03;
for (int c = 0; c < 4; c++) {
sp[0] = FFMul(b02, s[0][c]) ^ FFMul(b03, s[1][c]) ^ s[2][c] ^ s[3][c];
sp[1] = s[0][c] ^ FFMul(b02, s[1][c]) ^ FFMul(b03, s[2][c]) ^ s[3][c];
sp[2] = s[0][c] ^ s[1][c] ^ FFMul(b02, s[2][c]) ^ FFMul(b03, s[3][c]);
sp[3] = FFMul(b03, s[0][c]) ^ s[1][c] ^ s[2][c] ^ FFMul(b02, s[3][c]);
for (int i = 0; i < 4; i++) s[i][c] = (byte)(sp[i]);
}
return s;
}
public static byte FFMul(byte a, byte b) {
byte aa = a, bb = b, r = 0, t;
while (aa != 0) {
if ((aa & 1) != 0)
r = (byte) (r ^ bb);
t = (byte) (bb & 0x80);
bb = (byte) (bb << 1);
if (t != 0)
bb = (byte) (bb ^ 0x1b);
aa = (byte) ((aa & 0xff) >> 1);
}
return r;
}
public static byte[] encryptBloc(byte[] in) {
byte[] tmp = new byte[in.length];
byte[][] state = new byte[4][Nb];
for (int i = 0; i < in.length; i++)
state[i / 4][i % 4] = in[i%4*4+i/4];
state = AddRoundKey(state, w, 0);
for (int round = 1; round < Nr; round++) {
state = SubBytes(state);
state = ShiftRows(state);
state = MixColumns(state);
state = AddRoundKey(state, w, round);
}
state = SubBytes(state);
state = ShiftRows(state);
state = AddRoundKey(state, w, Nr);
for (int i = 0; i < tmp.length; i++)
tmp[i%4*4+i/4] = state[i / 4][i%4];
return tmp;
}
public static byte[] decryptBloc(byte[] in) {
byte[] tmp = new byte[in.length];
byte[][] state = new byte[4][Nb];
for (int i = 0; i < in.length; i++)
state[i / 4][i % 4] = in[i%4*4+i/4];
state = AddRoundKey(state, w, Nr);
for (int round = Nr-1; round >=1; round--) {
state = InvSubBytes(state);
state = InvShiftRows(state);
state = AddRoundKey(state, w, round);
state = InvMixColumns(state);
}
state = InvSubBytes(state);
state = InvShiftRows(state);
state = AddRoundKey(state, w, 0);
for (int i = 0; i < tmp.length; i++)
tmp[i%4*4+i/4] = state[i / 4][i%4];
return tmp;
}
public static byte[] encrypt(byte[] in,byte[] key){
Nb = 4;
Nk = key.length/4;
Nr = Nk + 6;
int lenght=0;
/*byte[] padding = new byte[1];*/
int i;
/*lenght = 16 - in.length % 16;
padding = new byte[lenght];
padding[0] = (byte) 0x80;
for (i = 1; i < lenght; i++)
padding[i] = 0;*/
byte[] tmp = new byte[in.length + lenght];
byte[] bloc = new byte[16];
w = generateSubkeys(key);
int count = 0;
for (i = 0; i < in.length + lenght; i++) {
if (i > 0 && i % 16 == 0) {
bloc = encryptBloc(bloc);
System.arraycopy(bloc, 0, tmp, i - 16, bloc.length);
}
if (i < in.length)
bloc[i % 16] = in[i];
/*else{
bloc[i % 16] = padding[count % 16];
count++;
}*/
}
if(bloc.length == 16){
bloc = encryptBloc(bloc);
System.arraycopy(bloc, 0, tmp, i - 16, bloc.length);
}
return tmp;
}
public static byte[] decrypt(byte[] in,byte[] key){
int i;
byte[] tmp = new byte[in.length];
byte[] bloc = new byte[16];
Nb = 4;
Nk = key.length/4;
Nr = Nk + 6;
w = generateSubkeys(key);
for (i = 0; i < in.length; i++) {
if (i > 0 && i % 16 == 0) {
bloc = decryptBloc(bloc);
System.arraycopy(bloc, 0, tmp, i - 16, bloc.length);
}
if (i < in.length)
bloc[i % 16] = in[i];
}
bloc = decryptBloc(bloc);
System.arraycopy(bloc, 0, tmp, i - 16, bloc.length);
/*tmp = deletePadding(tmp);*/
return tmp;
}
/*private static byte[] deletePadding(byte[] input) {
int count = 0;
int i = input.length - 1;
while (input[i] == 0) {
count++;
i--;
}
byte[] tmp = new byte[input.length - count - 1];
System.arraycopy(input, 0, tmp, 0, tmp.length);
return tmp;
}*/
}
C代码
aes.c
/*
This is an implementation of the AES128 algorithm, specifically ECB mode.
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
50fe67cc996d32b6da0937e99bafec60
d9a4dada0892239f6b8b3d7680e15674
a78819583f0308e7a6bf36b1386abf23
c6d3416d29165c6fcb8e51a227ba994e
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.
*/
#ifndef _AES_C_
#define _AES_C_
/*****************************************************************************/
/* Includes: */
/*****************************************************************************/
#include <stdint.h>
#include "aes.h"
/*****************************************************************************/
/* Defines: */
/*****************************************************************************/
// The number of columns comprising a state in AES. This is a constant in AES. Value=4
#define Nb 4
// The number of 32 bit words in a key.
#define Nk 4
// Key length in bytes [128 bit]
#define keyln 16
// The number of rounds in AES Cipher.
#define Nr 10
/*****************************************************************************/
/* Private variables: */
/*****************************************************************************/
// in - pointer to the CipherText to be decrypted.
// out - pointer to buffer to hold output of the decryption.
// state - array holding the intermediate results during decryption.
static uint8_t* in, *out, state[4][4];
// The array that stores the round keys.
static uint8_t RoundKey[176];
// The Key input to the AES Program
static uint8_t* Key;
// 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 };
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 };
// The round constant word array, Rcon[i], contains the values given by
// x to th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
// Note that i starts at 1, not 0).
static const uint8_t Rcon[255] = {
0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39,
0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a,
0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef,
0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc,
0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3,
0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94,
0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35,
0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f,
0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04,
0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63,
0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd,
0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb };
/*****************************************************************************/
/* Private functions: */
/*****************************************************************************/
static uint8_t getSBoxValue(uint8_t num)
{
return sbox[num];
}
static uint8_t getSBoxInvert(uint8_t num)
{
return rsbox[num];
}
// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states.
static void KeyExpansion()
{
uint32_t 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 < (Nb * (Nr + 1))); ++i)
{
for(j = 0; j < 4; ++j)
{
tempa[j]=RoundKey[(i-1) * 4 + j];
}
if (i % Nk == 0)
{
// This function rotates the 4 bytes in a word to the left once.
// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
// Function RotWord()
{
k = tempa[0];
tempa[0] = tempa[1];
tempa[1] = tempa[2];
tempa[2] = tempa[3];
tempa[3] = k;
}
// 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];
}
else if (Nk > 6 && 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]);
}
}
RoundKey[i * 4 + 0] = RoundKey[(i - Nk) * 4 + 0] ^ tempa[0];
RoundKey[i * 4 + 1] = RoundKey[(i - Nk) * 4 + 1] ^ tempa[1];
RoundKey[i * 4 + 2] = RoundKey[(i - Nk) * 4 + 2] ^ tempa[2];
RoundKey[i * 4 + 3] = RoundKey[(i - Nk) * 4 + 3] ^ tempa[3];
}
}
// 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)
{
uint8_t i,j;
for(i=0;i<4;i++)
{
for(j = 0; j < 4; ++j)
{
state[j][i] ^= 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()
{
uint8_t i, j;
for(i = 0; i < 4; ++i)
{
for(j = 0; j < 4; ++j)
{
state[i][j] = getSBoxValue(state[i][j]);
}
}
}
// 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()
{
uint8_t temp;
// Rotate first row 1 columns to left
temp = state[1][0];
state[1][0] = state[1][1];
state[1][1] = state[1][2];
state[1][2] = state[1][3];
state[1][3] = temp;
// Rotate second row 2 columns to left
temp = state[2][0];
state[2][0] = state[2][2];
state[2][2] = temp;
temp = state[2][1];
state[2][1] = state[2][3];
state[2][3] = temp;
// Rotate third row 3 columns to left
temp = state[3][0];
state[3][0] = state[3][3];
state[3][3] = state[3][2];
state[3][2] = state[3][1];
state[3][1] = 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()
{
uint8_t i;
uint8_t Tmp,Tm,t;
for(i = 0; i < 4; ++i)
{
t = state[0][i];
Tmp = state[0][i] ^ state[1][i] ^ state[2][i] ^ state[3][i] ;
Tm = state[0][i] ^ state[1][i] ; Tm = xtime(Tm); state[0][i] ^= Tm ^ Tmp ;
Tm = state[1][i] ^ state[2][i] ; Tm = xtime(Tm); state[1][i] ^= Tm ^ Tmp ;
Tm = state[2][i] ^ state[3][i] ; Tm = xtime(Tm); state[2][i] ^= Tm ^ Tmp ;
Tm = state[3][i] ^ t ; Tm = xtime(Tm); state[3][i] ^= Tm ^ Tmp ;
}
}
// Multiplty is a macro used to multiply numbers in the field GF(2^8)
#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))))))
// 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()
{
int i;
uint8_t a,b,c,d;
for(i=0;i<4;i++)
{
a = state[0][i];
b = state[1][i];
c = state[2][i];
d = state[3][i];
state[0][i] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
state[1][i] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
state[2][i] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
state[3][i] = 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()
{
uint8_t i,j;
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
state[i][j] = getSBoxInvert(state[i][j]);
}
}
}
static void InvShiftRows()
{
uint8_t temp;
// Rotate first row 1 columns to right
temp=state[1][3];
state[1][3]=state[1][2];
state[1][2]=state[1][1];
state[1][1]=state[1][0];
state[1][0]=temp;
// Rotate second row 2 columns to right
temp=state[2][0];
state[2][0]=state[2][2];
state[2][2]=temp;
temp=state[2][1];
state[2][1]=state[2][3];
state[2][3]=temp;
// Rotate third row 3 columns to right
temp=state[3][0];
state[3][0]=state[3][1];
state[3][1]=state[3][2];
state[3][2]=state[3][3];
state[3][3]=temp;
}
// Cipher is the main function that encrypts the PlainText.
static void Cipher()
{
uint8_t i, j, round = 0;
//Copy the input PlainText to state array.
for(i = 0; i < 4; ++i)
{
for(j = 0; j < 4 ; ++j)
{
state[j][i] = in[(i * 4) + j];
}
}
// Add the First round key to the state before starting the rounds.
AddRoundKey(0);
// 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();
ShiftRows();
MixColumns();
AddRoundKey(round);
}
// The last round is given below.
// The MixColumns function is not here in the last round.
SubBytes();
ShiftRows();
AddRoundKey(Nr);
// The encryption process is over.
// Copy the state array to output array.
for(i = 0; i < 4; ++i)
{
for(j = 0; j < 4; ++j)
{
out[(i * 4) + j] = state[j][i];
}
}
}
static void InvCipher()
{
uint8_t i,j,round=0;
//Copy the input CipherText to state array.
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
state[j][i] = in[i*4 + j];
}
}
// Add the First round key to the state before starting the rounds.
AddRoundKey(Nr);
// 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();
InvSubBytes();
AddRoundKey(round);
InvMixColumns();
}
// The last round is given below.
// The MixColumns function is not here in the last round.
InvShiftRows();
InvSubBytes();
AddRoundKey(0);
// The decryption process is over.
// Copy the state array to output array.
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
out[i*4+j]=state[j][i];
}
}
}
/*****************************************************************************/
/* Public functions: */
/*****************************************************************************/
void AES128_ECB_encrypt(uint8_t* input, uint8_t* key, uint8_t *output)
{
// Copy the Key and CipherText
Key = key;
in = input;
out = output;
// The KeyExpansion routine must be called before encryption.
KeyExpansion();
// The next function call encrypts the PlainText with the Key using AES algorithm.
Cipher();
}
void AES128_ECB_decrypt(uint8_t* input, uint8_t* key, uint8_t *output)
{
Key = key;
in = input;
out = output;
KeyExpansion();
InvCipher();
}
#endif //_AES_C_
aes.h
#ifndef _AES_H_
#define _AES_H_
#include <stdint.h>
void AES128_ECB_encrypt(uint8_t* input, uint8_t* key, uint8_t *output);
void AES128_ECB_decrypt(uint8_t* input, uint8_t* key, uint8_t *output);
#endif //_AES_H_
test.c
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include "aes.h"
static void phex(uint8_t* str);
static void test_ECB(void);
static void test_decrypt(void);
int main(int argc, char** argv)
{
test_ECB();
test_decrypt();
return 0;
}
/* Helpers */
static void test_ECB(void)
{
uint8_t i, buf[64], buf2[64];
// 128bit key
uint8_t key[16] = { (uint8_t) 0x2b, (uint8_t) 0x7e, (uint8_t) 0x15, (uint8_t) 0x16, (uint8_t) 0x28, (uint8_t) 0xae, (uint8_t) 0xd2, (uint8_t) 0xa6, (uint8_t) 0xab, (uint8_t) 0xf7, (uint8_t) 0x15, (uint8_t) 0x88, (uint8_t) 0x09, (uint8_t) 0xcf, (uint8_t) 0x4f, (uint8_t) 0x3c };
// 512bit text
uint8_t plain_text[64] = { (uint8_t) 0x6b, (uint8_t) 0xc1, (uint8_t) 0xbe, (uint8_t) 0xe2, (uint8_t) 0x2e, (uint8_t) 0x40, (uint8_t) 0x9f, (uint8_t) 0x96, (uint8_t) 0xe9, (uint8_t) 0x3d, (uint8_t) 0x7e, (uint8_t) 0x11, (uint8_t) 0x73, (uint8_t) 0x93, (uint8_t) 0x17, (uint8_t) 0x2a,
(uint8_t) 0xae, (uint8_t) 0x2d, (uint8_t) 0x8a, (uint8_t) 0x57, (uint8_t) 0x1e, (uint8_t) 0x03, (uint8_t) 0xac, (uint8_t) 0x9c, (uint8_t) 0x9e, (uint8_t) 0xb7, (uint8_t) 0x6f, (uint8_t) 0xac, (uint8_t) 0x45, (uint8_t) 0xaf, (uint8_t) 0x8e, (uint8_t) 0x51,
(uint8_t) 0x30, (uint8_t) 0xc8, (uint8_t) 0x1c, (uint8_t) 0x46, (uint8_t) 0xa3, (uint8_t) 0x5c, (uint8_t) 0xe4, (uint8_t) 0x11, (uint8_t) 0xe5, (uint8_t) 0xfb, (uint8_t) 0xc1, (uint8_t) 0x19, (uint8_t) 0x1a, (uint8_t) 0x0a, (uint8_t) 0x52, (uint8_t) 0xef,
(uint8_t) 0xf6, (uint8_t) 0x9f, (uint8_t) 0x24, (uint8_t) 0x45, (uint8_t) 0xdf, (uint8_t) 0x4f, (uint8_t) 0x9b, (uint8_t) 0x17, (uint8_t) 0xad, (uint8_t) 0x2b, (uint8_t) 0x41, (uint8_t) 0x7b, (uint8_t) 0xe6, (uint8_t) 0x6c, (uint8_t) 0x37, (uint8_t) 0x10 };
memset(buf, 0, 64);
memset(buf2, 0, 64);
// print text to encrypt, key and IV
printf("plain text:\n");
for(i = (uint8_t) 0; i < (uint8_t) 4; ++i)
{
phex(plain_text + i * (uint8_t) 16);
}
printf("\n");
printf("key:\n");
phex(key);
printf("\n");
// print the resulting cipher as 4 x 16 byte strings
printf("ciphertext:\n");
for(i = 0; i < 4; ++i)
{
AES128_ECB_encrypt(plain_text + (i*16), key, buf+(i*16));
phex(buf + (i*16));
}
printf("\n");
}
// prints string as hex
static void phex(uint8_t* str)
{
unsigned char i;
for(i = 0; i < 16; ++i)
printf("%.2x", str[i]);
printf("\n");
}
static void test_decrypt(void)
{
uint8_t key[] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};
uint8_t in[] = {0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97};
uint8_t out[] = {0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a};
uint8_t buffer[16];
AES128_ECB_decrypt(in, key, buffer);
printf("decrypt: ");
if(0 == strncmp(out, buffer, 16))
{
printf("SUCCESS!\n");
}
else
{
printf("FAILURE!\n");
}
}
Makefile
#CC = avr-gcc
#CFLAGS = -Wall -mmcu=atmega16 -Os -Wl,-Map,test.map
#OBJCOPY = avr-objcopy
CC = gcc
CFLAGS = -Wall -Os -Wl,-Map,test.map
OBJCOPY = objcopy
# include path to AVR library
INCLUDE_PATH = /usr/lib/avr/include
# splint static check
SPLINT = splint test.c aes.c -I$(INCLUDE_PATH) +charindex -unrecog
.SILENT:
.PHONY: lint clean
rom.hex : test.out
# copy object-code to new image and format in hex
$(OBJCOPY) -j .text -O ihex test.out rom.hex
test.o : test.c
# compiling test.c
$(CC) $(CFLAGS) -c test.c -o test.o
aes.o : aes.h aes.c
# compiling aes.c
$(CC) $(CFLAGS) -c aes.c -o aes.o
test.out : aes.o test.o
# linking object code to binary
$(CC) $(CFLAGS) aes.o test.o -o test.out
small: test.out
$(OBJCOPY) -j .text -O ihex test.out rom.hex
clean:
rm -f *.OBJ *.LST *.o *.gch *.out *.hex *.map
lint:
$(call SPLINT)
README.md
### Tiny AES128 in C
This is a small and portable implementation of the AES128 ECB encryption algorithm implemented in C.
The API is very simple and looks like this (I am using C99 `<stdint.h>`-style annotated types):
```C
void AES128_ECB_encrypt(uint8_t* input, uint8_t* key, uint8_t *output);
void AES128_ECB_decrypt(uint8_t* input, uint8_t* key, uint8_t *output);
```
The module uses just a bit more than 200 bytes of RAM and 2.5K ROM when compiled for ARM (~2K for Thumb but YMMV).
It is the smallest implementation in C I've seen yet, but do contact me if you know of something smaller (or have improvements to the code here).
I've successfully used the code on 64bit x86, 32bit ARM and 8 bit AVR platforms.
GCC size output when compiled for ARM:
$ arm-none-eabi-gcc -Os -c aes.c
$ size aes.o
text data bss dec hex filename
2515 0 204 2719 a9f aes.o
.. and when compiling for the THUMB instruction set, we end up around 2K in code size.
$ arm-none-eabi-gcc -mthumb -Os -c aes.c
$ size aes.o
text data bss dec hex filename
1883 0 204 2087 827 aes.o
I am using Mentor Graphics free ARM toolchain:
$ arm-none-eabi-gcc --version
arm-none-eabi-gcc (GNU Tools for ARM Embedded Processors) 4.8.4 20140526 (release) [ARM/embedded-4_8-branch revision 211358]
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
This implementation is verified against the data in:
[National Institute of Standards and Technology Special Publication 800-38A 2001 ED](http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf) Appendix F: Example Vectors for Modes of Operation of the AES.
All material in this repository is in the public domain.
见github 地址
c 为 padding 0x00 （byte数组初始化时 为0x00）
代码出自网上
代码地址 github
https://github.com/mountwater/AES-128-ECB-java_and_c
JAVA代码
//Copyright Popa Tiberiu 2011
//free to use this in any way
package tsd.crypto.algoritm;
public class AES {
private static int Nb, Nk, Nr;
private static byte[][] w;
private static int[] sbox = { 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 };
private static int[] inv_sbox = { 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 };
private static int Rcon[] = { 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39,
0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a,
0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef,
0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc,
0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3,
0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94,
0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35,
0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f,
0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04,
0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63,
0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd,
0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb };
private static byte[] xor_func(byte[] a, byte[] b) {
byte[] out = new byte[a.length];
for (int i = 0; i < a.length; i++) {
out[i] = (byte) (a[i] ^ b[i]);
}
return out;
}
private static byte[][] generateSubkeys(byte[] key) {
byte[][] tmp = new byte[Nb * (Nr + 1)][4];
int i = 0;
while (i < Nk) {
tmp[i][0] = key[i * 4];
tmp[i][1] = key[i * 4 + 1];
tmp[i][2] = key[i * 4 + 2];
tmp[i][3] = key[i * 4 + 3];
i++;
}
i = Nk;
while (i < Nb * (Nr + 1)) {
byte[] temp = new byte[4];
for(int k = 0;k<4;k++)
temp[k] = tmp[i-1][k];
if (i % Nk == 0) {
temp = SubWord(rotateWord(temp));
temp[0] = (byte) (temp[0] ^ (Rcon[i / Nk] & 0xff));
} else if (Nk > 6 && i % Nk == 4) {
temp = SubWord(temp);
}
tmp[i] = xor_func(tmp[i - Nk], temp);
i++;
}
return tmp;
}
private static byte[] SubWord(byte[] in) {
byte[] tmp = new byte[in.length];
for (int i = 0; i < tmp.length; i++)
tmp[i] = (byte) (sbox[in[i] & 0x000000ff] & 0xff);
return tmp;
}
private static byte[] rotateWord(byte[] input) {
byte[] tmp = new byte[input.length];
tmp[0] = input[1];
tmp[1] = input[2];
tmp[2] = input[3];
tmp[3] = input[0];
return tmp;
}
private static byte[][] AddRoundKey(byte[][] state, byte[][] w, int round) {
byte[][] tmp = new byte[state.length][state[0].length];
for (int c = 0; c < Nb; c++) {
for (int l = 0; l < 4; l++)
tmp[l][c] = (byte) (state[l][c] ^ w[round * Nb + c][l]);
}
return tmp;
}
private static byte[][] SubBytes(byte[][] state) {
byte[][] tmp = new byte[state.length][state[0].length];
for (int row = 0; row < 4; row++)
for (int col = 0; col < Nb; col++)
tmp[row][col] = (byte) (sbox[(state[row][col] & 0x000000ff)] & 0xff);
return tmp;
}
private static byte[][] InvSubBytes(byte[][] state) {
for (int row = 0; row < 4; row++)
for (int col = 0; col < Nb; col++)
state[row][col] = (byte)(inv_sbox[(state[row][col] & 0x000000ff)]&0xff);
return state;
}
private static byte[][] ShiftRows(byte[][] state) {
byte[] t = new byte[4];
for (int r = 1; r < 4; r++) {
for (int c = 0; c < Nb; c++)
t[c] = state[r][(c + r) % Nb];
for (int c = 0; c < Nb; c++)
state[r][c] = t[c];
}
return state;
}
private static byte[][] InvShiftRows(byte[][] state) {
byte[] t = new byte[4];
for (int r = 1; r < 4; r++) {
for (int c = 0; c < Nb; c++)
t[(c + r)%Nb] = state[r][c];
for (int c = 0; c < Nb; c++)
state[r][c] = t[c];
}
return state;
}
private static byte[][] InvMixColumns(byte[][] s){
int[] sp = new int[4];
byte b02 = (byte)0x0e, b03 = (byte)0x0b, b04 = (byte)0x0d, b05 = (byte)0x09;
for (int c = 0; c < 4; c++) {
sp[0] = FFMul(b02, s[0][c]) ^ FFMul(b03, s[1][c]) ^ FFMul(b04,s[2][c]) ^ FFMul(b05,s[3][c]);
sp[1] = FFMul(b05, s[0][c]) ^ FFMul(b02, s[1][c]) ^ FFMul(b03,s[2][c]) ^ FFMul(b04,s[3][c]);
sp[2] = FFMul(b04, s[0][c]) ^ FFMul(b05, s[1][c]) ^ FFMul(b02,s[2][c]) ^ FFMul(b03,s[3][c]);
sp[3] = FFMul(b03, s[0][c]) ^ FFMul(b04, s[1][c]) ^ FFMul(b05,s[2][c]) ^ FFMul(b02,s[3][c]);
for (int i = 0; i < 4; i++) s[i][c] = (byte)(sp[i]);
}
return s;
}
private static byte[][] MixColumns(byte[][] s){
int[] sp = new int[4];
byte b02 = (byte)0x02, b03 = (byte)0x03;
for (int c = 0; c < 4; c++) {
sp[0] = FFMul(b02, s[0][c]) ^ FFMul(b03, s[1][c]) ^ s[2][c] ^ s[3][c];
sp[1] = s[0][c] ^ FFMul(b02, s[1][c]) ^ FFMul(b03, s[2][c]) ^ s[3][c];
sp[2] = s[0][c] ^ s[1][c] ^ FFMul(b02, s[2][c]) ^ FFMul(b03, s[3][c]);
sp[3] = FFMul(b03, s[0][c]) ^ s[1][c] ^ s[2][c] ^ FFMul(b02, s[3][c]);
for (int i = 0; i < 4; i++) s[i][c] = (byte)(sp[i]);
}
return s;
}
public static byte FFMul(byte a, byte b) {
byte aa = a, bb = b, r = 0, t;
while (aa != 0) {
if ((aa & 1) != 0)
r = (byte) (r ^ bb);
t = (byte) (bb & 0x80);
bb = (byte) (bb << 1);
if (t != 0)
bb = (byte) (bb ^ 0x1b);
aa = (byte) ((aa & 0xff) >> 1);
}
return r;
}
public static byte[] encryptBloc(byte[] in) {
byte[] tmp = new byte[in.length];
byte[][] state = new byte[4][Nb];
for (int i = 0; i < in.length; i++)
state[i / 4][i % 4] = in[i%4*4+i/4];
state = AddRoundKey(state, w, 0);
for (int round = 1; round < Nr; round++) {
state = SubBytes(state);
state = ShiftRows(state);
state = MixColumns(state);
state = AddRoundKey(state, w, round);
}
state = SubBytes(state);
state = ShiftRows(state);
state = AddRoundKey(state, w, Nr);
for (int i = 0; i < tmp.length; i++)
tmp[i%4*4+i/4] = state[i / 4][i%4];
return tmp;
}
public static byte[] decryptBloc(byte[] in) {
byte[] tmp = new byte[in.length];
byte[][] state = new byte[4][Nb];
for (int i = 0; i < in.length; i++)
state[i / 4][i % 4] = in[i%4*4+i/4];
state = AddRoundKey(state, w, Nr);
for (int round = Nr-1; round >=1; round--) {
state = InvSubBytes(state);
state = InvShiftRows(state);
state = AddRoundKey(state, w, round);
state = InvMixColumns(state);
}
state = InvSubBytes(state);
state = InvShiftRows(state);
state = AddRoundKey(state, w, 0);
for (int i = 0; i < tmp.length; i++)
tmp[i%4*4+i/4] = state[i / 4][i%4];
return tmp;
}
public static byte[] encrypt(byte[] in,byte[] key){
Nb = 4;
Nk = key.length/4;
Nr = Nk + 6;
int lenght=0;
/*byte[] padding = new byte[1];*/
int i;
/*lenght = 16 - in.length % 16;
padding = new byte[lenght];
padding[0] = (byte) 0x80;
for (i = 1; i < lenght; i++)
padding[i] = 0;*/
byte[] tmp = new byte[in.length + lenght];
byte[] bloc = new byte[16];
w = generateSubkeys(key);
int count = 0;
for (i = 0; i < in.length + lenght; i++) {
if (i > 0 && i % 16 == 0) {
bloc = encryptBloc(bloc);
System.arraycopy(bloc, 0, tmp, i - 16, bloc.length);
}
if (i < in.length)
bloc[i % 16] = in[i];
/*else{
bloc[i % 16] = padding[count % 16];
count++;
}*/
}
if(bloc.length == 16){
bloc = encryptBloc(bloc);
System.arraycopy(bloc, 0, tmp, i - 16, bloc.length);
}
return tmp;
}
public static byte[] decrypt(byte[] in,byte[] key){
int i;
byte[] tmp = new byte[in.length];
byte[] bloc = new byte[16];
Nb = 4;
Nk = key.length/4;
Nr = Nk + 6;
w = generateSubkeys(key);
for (i = 0; i < in.length; i++) {
if (i > 0 && i % 16 == 0) {
bloc = decryptBloc(bloc);
System.arraycopy(bloc, 0, tmp, i - 16, bloc.length);
}
if (i < in.length)
bloc[i % 16] = in[i];
}
bloc = decryptBloc(bloc);
System.arraycopy(bloc, 0, tmp, i - 16, bloc.length);
/*tmp = deletePadding(tmp);*/
return tmp;
}
/*private static byte[] deletePadding(byte[] input) {
int count = 0;
int i = input.length - 1;
while (input[i] == 0) {
count++;
i--;
}
byte[] tmp = new byte[input.length - count - 1];
System.arraycopy(input, 0, tmp, 0, tmp.length);
return tmp;
}*/
}
C代码
aes.c
/*
This is an implementation of the AES128 algorithm, specifically ECB mode.
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
50fe67cc996d32b6da0937e99bafec60
d9a4dada0892239f6b8b3d7680e15674
a78819583f0308e7a6bf36b1386abf23
c6d3416d29165c6fcb8e51a227ba994e
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.
*/
#ifndef _AES_C_
#define _AES_C_
/*****************************************************************************/
/* Includes: */
/*****************************************************************************/
#include <stdint.h>
#include "aes.h"
/*****************************************************************************/
/* Defines: */
/*****************************************************************************/
// The number of columns comprising a state in AES. This is a constant in AES. Value=4
#define Nb 4
// The number of 32 bit words in a key.
#define Nk 4
// Key length in bytes [128 bit]
#define keyln 16
// The number of rounds in AES Cipher.
#define Nr 10
/*****************************************************************************/
/* Private variables: */
/*****************************************************************************/
// in - pointer to the CipherText to be decrypted.
// out - pointer to buffer to hold output of the decryption.
// state - array holding the intermediate results during decryption.
static uint8_t* in, *out, state[4][4];
// The array that stores the round keys.
static uint8_t RoundKey[176];
// The Key input to the AES Program
static uint8_t* Key;
// 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 };
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 };
// The round constant word array, Rcon[i], contains the values given by
// x to th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
// Note that i starts at 1, not 0).
static const uint8_t Rcon[255] = {
0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39,
0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a,
0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef,
0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc,
0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3,
0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94,
0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35,
0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f,
0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04,
0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63,
0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd,
0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb };
/*****************************************************************************/
/* Private functions: */
/*****************************************************************************/
static uint8_t getSBoxValue(uint8_t num)
{
return sbox[num];
}
static uint8_t getSBoxInvert(uint8_t num)
{
return rsbox[num];
}
// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states.
static void KeyExpansion()
{
uint32_t 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 < (Nb * (Nr + 1))); ++i)
{
for(j = 0; j < 4; ++j)
{
tempa[j]=RoundKey[(i-1) * 4 + j];
}
if (i % Nk == 0)
{
// This function rotates the 4 bytes in a word to the left once.
// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
// Function RotWord()
{
k = tempa[0];
tempa[0] = tempa[1];
tempa[1] = tempa[2];
tempa[2] = tempa[3];
tempa[3] = k;
}
// 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];
}
else if (Nk > 6 && 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]);
}
}
RoundKey[i * 4 + 0] = RoundKey[(i - Nk) * 4 + 0] ^ tempa[0];
RoundKey[i * 4 + 1] = RoundKey[(i - Nk) * 4 + 1] ^ tempa[1];
RoundKey[i * 4 + 2] = RoundKey[(i - Nk) * 4 + 2] ^ tempa[2];
RoundKey[i * 4 + 3] = RoundKey[(i - Nk) * 4 + 3] ^ tempa[3];
}
}
// 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)
{
uint8_t i,j;
for(i=0;i<4;i++)
{
for(j = 0; j < 4; ++j)
{
state[j][i] ^= 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()
{
uint8_t i, j;
for(i = 0; i < 4; ++i)
{
for(j = 0; j < 4; ++j)
{
state[i][j] = getSBoxValue(state[i][j]);
}
}
}
// 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()
{
uint8_t temp;
// Rotate first row 1 columns to left
temp = state[1][0];
state[1][0] = state[1][1];
state[1][1] = state[1][2];
state[1][2] = state[1][3];
state[1][3] = temp;
// Rotate second row 2 columns to left
temp = state[2][0];
state[2][0] = state[2][2];
state[2][2] = temp;
temp = state[2][1];
state[2][1] = state[2][3];
state[2][3] = temp;
// Rotate third row 3 columns to left
temp = state[3][0];
state[3][0] = state[3][3];
state[3][3] = state[3][2];
state[3][2] = state[3][1];
state[3][1] = 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()
{
uint8_t i;
uint8_t Tmp,Tm,t;
for(i = 0; i < 4; ++i)
{
t = state[0][i];
Tmp = state[0][i] ^ state[1][i] ^ state[2][i] ^ state[3][i] ;
Tm = state[0][i] ^ state[1][i] ; Tm = xtime(Tm); state[0][i] ^= Tm ^ Tmp ;
Tm = state[1][i] ^ state[2][i] ; Tm = xtime(Tm); state[1][i] ^= Tm ^ Tmp ;
Tm = state[2][i] ^ state[3][i] ; Tm = xtime(Tm); state[2][i] ^= Tm ^ Tmp ;
Tm = state[3][i] ^ t ; Tm = xtime(Tm); state[3][i] ^= Tm ^ Tmp ;
}
}
// Multiplty is a macro used to multiply numbers in the field GF(2^8)
#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))))))
// 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()
{
int i;
uint8_t a,b,c,d;
for(i=0;i<4;i++)
{
a = state[0][i];
b = state[1][i];
c = state[2][i];
d = state[3][i];
state[0][i] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
state[1][i] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
state[2][i] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
state[3][i] = 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()
{
uint8_t i,j;
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
state[i][j] = getSBoxInvert(state[i][j]);
}
}
}
static void InvShiftRows()
{
uint8_t temp;
// Rotate first row 1 columns to right
temp=state[1][3];
state[1][3]=state[1][2];
state[1][2]=state[1][1];
state[1][1]=state[1][0];
state[1][0]=temp;
// Rotate second row 2 columns to right
temp=state[2][0];
state[2][0]=state[2][2];
state[2][2]=temp;
temp=state[2][1];
state[2][1]=state[2][3];
state[2][3]=temp;
// Rotate third row 3 columns to right
temp=state[3][0];
state[3][0]=state[3][1];
state[3][1]=state[3][2];
state[3][2]=state[3][3];
state[3][3]=temp;
}
// Cipher is the main function that encrypts the PlainText.
static void Cipher()
{
uint8_t i, j, round = 0;
//Copy the input PlainText to state array.
for(i = 0; i < 4; ++i)
{
for(j = 0; j < 4 ; ++j)
{
state[j][i] = in[(i * 4) + j];
}
}
// Add the First round key to the state before starting the rounds.
AddRoundKey(0);
// 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();
ShiftRows();
MixColumns();
AddRoundKey(round);
}
// The last round is given below.
// The MixColumns function is not here in the last round.
SubBytes();
ShiftRows();
AddRoundKey(Nr);
// The encryption process is over.
// Copy the state array to output array.
for(i = 0; i < 4; ++i)
{
for(j = 0; j < 4; ++j)
{
out[(i * 4) + j] = state[j][i];
}
}
}
static void InvCipher()
{
uint8_t i,j,round=0;
//Copy the input CipherText to state array.
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
state[j][i] = in[i*4 + j];
}
}
// Add the First round key to the state before starting the rounds.
AddRoundKey(Nr);
// 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();
InvSubBytes();
AddRoundKey(round);
InvMixColumns();
}
// The last round is given below.
// The MixColumns function is not here in the last round.
InvShiftRows();
InvSubBytes();
AddRoundKey(0);
// The decryption process is over.
// Copy the state array to output array.
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
out[i*4+j]=state[j][i];
}
}
}
/*****************************************************************************/
/* Public functions: */
/*****************************************************************************/
void AES128_ECB_encrypt(uint8_t* input, uint8_t* key, uint8_t *output)
{
// Copy the Key and CipherText
Key = key;
in = input;
out = output;
// The KeyExpansion routine must be called before encryption.
KeyExpansion();
// The next function call encrypts the PlainText with the Key using AES algorithm.
Cipher();
}
void AES128_ECB_decrypt(uint8_t* input, uint8_t* key, uint8_t *output)
{
Key = key;
in = input;
out = output;
KeyExpansion();
InvCipher();
}
#endif //_AES_C_
aes.h
#ifndef _AES_H_
#define _AES_H_
#include <stdint.h>
void AES128_ECB_encrypt(uint8_t* input, uint8_t* key, uint8_t *output);
void AES128_ECB_decrypt(uint8_t* input, uint8_t* key, uint8_t *output);
#endif //_AES_H_
test.c
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include "aes.h"
static void phex(uint8_t* str);
static void test_ECB(void);
static void test_decrypt(void);
int main(int argc, char** argv)
{
test_ECB();
test_decrypt();
return 0;
}
/* Helpers */
static void test_ECB(void)
{
uint8_t i, buf[64], buf2[64];
// 128bit key
uint8_t key[16] = { (uint8_t) 0x2b, (uint8_t) 0x7e, (uint8_t) 0x15, (uint8_t) 0x16, (uint8_t) 0x28, (uint8_t) 0xae, (uint8_t) 0xd2, (uint8_t) 0xa6, (uint8_t) 0xab, (uint8_t) 0xf7, (uint8_t) 0x15, (uint8_t) 0x88, (uint8_t) 0x09, (uint8_t) 0xcf, (uint8_t) 0x4f, (uint8_t) 0x3c };
// 512bit text
uint8_t plain_text[64] = { (uint8_t) 0x6b, (uint8_t) 0xc1, (uint8_t) 0xbe, (uint8_t) 0xe2, (uint8_t) 0x2e, (uint8_t) 0x40, (uint8_t) 0x9f, (uint8_t) 0x96, (uint8_t) 0xe9, (uint8_t) 0x3d, (uint8_t) 0x7e, (uint8_t) 0x11, (uint8_t) 0x73, (uint8_t) 0x93, (uint8_t) 0x17, (uint8_t) 0x2a,
(uint8_t) 0xae, (uint8_t) 0x2d, (uint8_t) 0x8a, (uint8_t) 0x57, (uint8_t) 0x1e, (uint8_t) 0x03, (uint8_t) 0xac, (uint8_t) 0x9c, (uint8_t) 0x9e, (uint8_t) 0xb7, (uint8_t) 0x6f, (uint8_t) 0xac, (uint8_t) 0x45, (uint8_t) 0xaf, (uint8_t) 0x8e, (uint8_t) 0x51,
(uint8_t) 0x30, (uint8_t) 0xc8, (uint8_t) 0x1c, (uint8_t) 0x46, (uint8_t) 0xa3, (uint8_t) 0x5c, (uint8_t) 0xe4, (uint8_t) 0x11, (uint8_t) 0xe5, (uint8_t) 0xfb, (uint8_t) 0xc1, (uint8_t) 0x19, (uint8_t) 0x1a, (uint8_t) 0x0a, (uint8_t) 0x52, (uint8_t) 0xef,
(uint8_t) 0xf6, (uint8_t) 0x9f, (uint8_t) 0x24, (uint8_t) 0x45, (uint8_t) 0xdf, (uint8_t) 0x4f, (uint8_t) 0x9b, (uint8_t) 0x17, (uint8_t) 0xad, (uint8_t) 0x2b, (uint8_t) 0x41, (uint8_t) 0x7b, (uint8_t) 0xe6, (uint8_t) 0x6c, (uint8_t) 0x37, (uint8_t) 0x10 };
memset(buf, 0, 64);
memset(buf2, 0, 64);
// print text to encrypt, key and IV
printf("plain text:\n");
for(i = (uint8_t) 0; i < (uint8_t) 4; ++i)
{
phex(plain_text + i * (uint8_t) 16);
}
printf("\n");
printf("key:\n");
phex(key);
printf("\n");
// print the resulting cipher as 4 x 16 byte strings
printf("ciphertext:\n");
for(i = 0; i < 4; ++i)
{
AES128_ECB_encrypt(plain_text + (i*16), key, buf+(i*16));
phex(buf + (i*16));
}
printf("\n");
}
// prints string as hex
static void phex(uint8_t* str)
{
unsigned char i;
for(i = 0; i < 16; ++i)
printf("%.2x", str[i]);
printf("\n");
}
static void test_decrypt(void)
{
uint8_t key[] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};
uint8_t in[] = {0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97};
uint8_t out[] = {0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a};
uint8_t buffer[16];
AES128_ECB_decrypt(in, key, buffer);
printf("decrypt: ");
if(0 == strncmp(out, buffer, 16))
{
printf("SUCCESS!\n");
}
else
{
printf("FAILURE!\n");
}
}
Makefile
#CC = avr-gcc
#CFLAGS = -Wall -mmcu=atmega16 -Os -Wl,-Map,test.map
#OBJCOPY = avr-objcopy
CC = gcc
CFLAGS = -Wall -Os -Wl,-Map,test.map
OBJCOPY = objcopy
# include path to AVR library
INCLUDE_PATH = /usr/lib/avr/include
# splint static check
SPLINT = splint test.c aes.c -I$(INCLUDE_PATH) +charindex -unrecog
.SILENT:
.PHONY: lint clean
rom.hex : test.out
# copy object-code to new image and format in hex
$(OBJCOPY) -j .text -O ihex test.out rom.hex
test.o : test.c
# compiling test.c
$(CC) $(CFLAGS) -c test.c -o test.o
aes.o : aes.h aes.c
# compiling aes.c
$(CC) $(CFLAGS) -c aes.c -o aes.o
test.out : aes.o test.o
# linking object code to binary
$(CC) $(CFLAGS) aes.o test.o -o test.out
small: test.out
$(OBJCOPY) -j .text -O ihex test.out rom.hex
clean:
rm -f *.OBJ *.LST *.o *.gch *.out *.hex *.map
lint:
$(call SPLINT)
README.md
### Tiny AES128 in C
This is a small and portable implementation of the AES128 ECB encryption algorithm implemented in C.
The API is very simple and looks like this (I am using C99 `<stdint.h>`-style annotated types):
```C
void AES128_ECB_encrypt(uint8_t* input, uint8_t* key, uint8_t *output);
void AES128_ECB_decrypt(uint8_t* input, uint8_t* key, uint8_t *output);
```
The module uses just a bit more than 200 bytes of RAM and 2.5K ROM when compiled for ARM (~2K for Thumb but YMMV).
It is the smallest implementation in C I've seen yet, but do contact me if you know of something smaller (or have improvements to the code here).
I've successfully used the code on 64bit x86, 32bit ARM and 8 bit AVR platforms.
GCC size output when compiled for ARM:
$ arm-none-eabi-gcc -Os -c aes.c
$ size aes.o
text data bss dec hex filename
2515 0 204 2719 a9f aes.o
.. and when compiling for the THUMB instruction set, we end up around 2K in code size.
$ arm-none-eabi-gcc -mthumb -Os -c aes.c
$ size aes.o
text data bss dec hex filename
1883 0 204 2087 827 aes.o
I am using Mentor Graphics free ARM toolchain:
$ arm-none-eabi-gcc --version
arm-none-eabi-gcc (GNU Tools for ARM Embedded Processors) 4.8.4 20140526 (release) [ARM/embedded-4_8-branch revision 211358]
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
This implementation is verified against the data in:
[National Institute of Standards and Technology Special Publication 800-38A 2001 ED](http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf) Appendix F: Example Vectors for Modes of Operation of the AES.
All material in this repository is in the public domain.
见github 地址