AES加密
要求
- 明文、密鑰和向量都是通過文件輸入,密文通過文件輸出
- 可以通過選擇加密模式:CBC和EBC
- 計算程序運行時間
- 對於長度的不夠的情況,在最后填充0來補足
- 輸出最后一塊的加密結果
分析
- 對於文件的輸入輸出,主要就是用到了C語言的文件讀入和讀出
ofstream is1(argv[3],ios::app);
if (!is1)
{
cerr << "InputFileNotFoundException" << endl;
return 2;
}
is1.write((char*)zero, 16);
is1.close();
ifstream is(argv[3], ios::in | ios::binary|ios::app);
if (!is)
{
cerr << "InputFileNotFoundException" << endl;
return 2;
}
ifstream ks(argv[4], ios::in | ios::binary);
if (!ks)
{
cerr << "KeyFileNotFoundException" << endl;
return 2;
}
- 在程序中供模式選擇,並且根據選擇來進行不同的處理
cout << "please choose mode: " << endl;
cin >> mode;</pre>
- 為了方便處理不同工作模式下的要求,我在處理的時候把初始化向量和密鑰分開放置在兩個不同的文件內:key.txt和iv.txt
這樣的話,在EBC模式下就可以少讀取一個文件。同時分開存放也比較方便。 - 補0
對於補0的情況,為了方便處理,在文件讀取之前,先在文件末尾寫入16個字節的0,在處理的時候,如果讀到全零的情況就直接跳出。
這樣處理比較簡單方便 - 時間計算
為了得到比較精准的結果,通過兩種不同的時間函數來進行計算
//定義變量
clock_t start, finish;
DWORD startt, finisht;
//調用函數
start = clock();
startt = GetTickCount();</pre>
//結果
cout << "\nTime: " << ( finish - start ) << endl;
cout << "\nTime: " << (finisht - startt) << endl;</pre>
設計
- 使用方式
明文、密鑰、初始化向量都寫在文件中,文件名稱通過命令行輸入,對於命令行輸入的參數有要求
const string USAGE = "Usage: AES [-E | -D] destinationfile sourcefile keyfile ";
if (argc != 5)
{
cout << USAGE << endl;
return 1;
}
- 對於補0的情況
通過在文件中補0來完成,避免過多的對數組的操作
const string USAGE = "Usage: AES [-E | -D] destinationfile sourcefile keyfile ";
結果
默認參數設置
- ECB模式
上面命令行中顯示的是最后一塊的加密結果,完整 的加密結果如下:
- CBC模式
備注一下:
我這里用到的是debug模式的結果,所以時間特別長。
在實際用release在cmd中運行的時候,時間大概在3秒左右。
和教員給的數據進行比較
教員給的是Cipher.txt
自己得到的是result.txt
得到的結果完全相同,說明我的程序是正確的。
補充說明
當加密文件很短的時候,整個程序運行的時間很短,所以在程序中使用了兩種方式來進行計時,但是還是會遇到兩者相減為0的情況
不過這個只是在加密明文很短的情況下,就是教員給的第一個樣例是這樣的,但是第二份樣例中不是這樣的。
不過,當需要加密的內容很長的時候,需要的時間也是很長的,比如教員給的第二份樣例,處理時間就很長,大概有
代碼
使用方法
參數:
-E result.txt message.txt key.txt
(命令行輸入)
程序在release文件夾中
程序在選擇CBC模式的時候讀取iv.txt(程序內寫死的)
輸出文件在release文件夾的result里面
注意:
在cmd中運行的時候,要進入當前文件夾,不然可能文件不能打開
主文件
#include <fstream>
#include <iostream>
#include <iomanip>
#include "AES.h"
#include <time.h>
#include <windows.h>
using namespace std;
int main(int argc, char* argv[])
{
clock_t start, finish;
DWORD startt, finisht;
//命令行參數輸入提醒
const string USAGE = "Usage: AES [-E | -D] destinationfile sourcefile keyfile ";
//參數個數判斷,並給出相應提示
if (argc != 5)
{
cout << USAGE << endl;
return 1;
}
const unsigned char zero[16] = { 0 };
//在明文文件末尾加上16個0
ofstream is1(argv[3],ios::app);
if (!is1)
{
cerr << "InputFileNotFoundException" << endl;
return 2;
}
is1.write((char*)zero, 16);
is1.close();
ifstream is(argv[3], ios::in | ios::binary|ios::app);
if (!is)
{
cerr << "InputFileNotFoundException" << endl;
return 2;
}
ifstream ks(argv[4], ios::in | ios::binary);
if (!ks)
{
cerr << "KeyFileNotFoundException" << endl;
return 2;
}
//創建類
AES aes;
//讀密鑰
const unsigned char *key = new unsigned char[16];
ks.read((char*)key, 16);
//讀明文
ofstream os;
os.open(argv[2], ios::out | ios::binary|ios::trunc);
//模式選擇
int mode = 0;
cout << "please choose mode: " << endl;
cin >> mode;
const unsigned char* cipherText = new unsigned char[16];
unsigned char * lastcipher = new unsigned char[16];
if (strcmp(argv[1], "-E") == 0 || strcmp(argv[1], "-e") == 0)
{
//ECB加密過程
if (mode == 1) //ECB
{
const unsigned char* plainText = new unsigned char[16];
// memset((unsigned char*)plainText, 0, sizeof(plainText));
//開始計時
start = clock();
startt = GetTickCount();
while (is.read((char*)plainText, 16))
{
//按塊讀取,並且判斷是否是有效數據
if (!strcmp((char*)plainText, (char*)zero))
{
break;
}
//加密,將當前組的密文暫時存起來
cipherText = aes.Cipher(plainText, key, 16);
//將每一塊的密文寫入文件
os.write((char*)cipherText, 16);
if (!os.is_open())
{
cout << "Error" << endl;
}
memset((unsigned char*)plainText, 0, sizeof(plainText));
}
//計時結束
finish = clock();
finisht = GetTickCount();
}
//CBC模式
else if (mode == 2)
{
//需要判斷是不是以第一組加密,用first變量判斷
//
const unsigned char* plainText = new unsigned char[16];
const unsigned char* iv = new unsigned char[16];
unsigned char *temp = new unsigned char[16];
bool first = true;
ifstream ivstream;
//讀取初始化向量
ivstream.open("iv.txt", ios::in);
ivstream.read((char*)iv, 16);
memset((unsigned char*)plainText, 0, sizeof(plainText));
//計時開始
start = clock();
startt = GetTickCount();
//對於每一塊進行加密
while (is.read((char*)temp, 16))
{
//判斷是否是有效數據
if (!strcmp((char*)temp, (char*)zero))
{
break;
}
//第一組加密,要異或上初始化向量
if (first)
{
for (int i = 0; i < 16; i++)
{
temp[i] = temp[i] ^ iv[i];
}
first = false;
}
else
{
//以后每一組異或上一組得到的密文
for (int i = 0; i < 16; i++)
{
temp[i] = temp[i] ^ lastcipher[i];
}
}
plainText = temp;
cipherText = aes.Cipher(plainText, key, 16);
lastcipher = (unsigned char *)cipherText;
os.write((char*)cipherText,16);
if (!os.is_open())
{
cout << "Error" << endl;
}
//計時結束
finish = clock();
finisht = GetTickCount();
}
}
}
delete[] key;
//輸出最后一組的密文
for (int i = 0; i < 16; i++)
{
cout << cipherText[i];
}
cout << endl;
//文件關閉
is.close();
ks.close();
os.close();
//計算時間
cout << "\nTime: " << ( finish - start ) << endl;
cout << "\nTime: " << (finisht - startt) << endl;
system("pause");
return 0;
}
頭文件
#ifndef AES_H_
#define AES_H_
#include <bitset>
#include <utility>
using namespace std;
class AES
{
public:
typedef unsigned char byte;
static const int KEY_SIZE = 16; // 密鑰長度為位
static const int N_ROUND = 11;
byte plainText[16]; // 明文
byte state[16]; // 當前分組。
byte cipherKey[16]; // 密鑰
byte roundKey[N_ROUND][16]; //輪密鑰
byte cipherText[16]; //密文
byte SBox[16][16]; // S盒
byte InvSBox[16][16]; // 逆S盒
void EncryptionProcess();
void DecryptionProcess();
void Round(const int& round);
void InvRound(const int& round);
void FinalRound();
void InvFinalRound();
void KeyExpansion();
void AddRoundKey(const int& round);
void SubBytes();
void InvSubBytes();
void ShiftRows();
void InvShiftRows();
void MixColumns();
void InvMixColumns();
void BuildSBox();
void BuildInvSBox();
void InitialState(const byte* text);
void InitialCipherText();
void InitialplainText();
byte GFMultplyByte(const byte& left, const byte& right);
const byte* GFMultplyBytesMatrix(const byte* left, const byte* right);
public:
AES();
const byte* Cipher(const byte* text, const byte* key, const int& keySize);
const byte* InvCipher(const byte* text, const byte* key, const int& keySize);
};
void AES::EncryptionProcess()
{ // 加密過程
InitialState(plainText);
KeyExpansion(); // 密鑰擴展
AddRoundKey(0); // 輪密鑰加
for (int i = 1; i < N_ROUND - 1; ++i)
{
Round(i);
}
FinalRound();
InitialCipherText();
}
void AES::DecryptionProcess()
{ // 解密過程
InitialState(cipherText);
KeyExpansion();
InvFinalRound();
for (int i = N_ROUND - 2; i > 0; --i)
{
InvRound(i);
}
AddRoundKey(0);
InitialplainText();
}
void AES::Round(const int& round)
{ // 正常輪
SubBytes();
ShiftRows();
MixColumns();
AddRoundKey(round);
}
void AES::InvRound(const int& round)
{ // 正常輪的逆
AddRoundKey(round);
InvMixColumns();
InvShiftRows();
InvSubBytes();
}
void AES::FinalRound()
{ // 最后輪
SubBytes();
ShiftRows();
AddRoundKey(N_ROUND - 1);
}
void AES::InvFinalRound()
{ // 最后輪的逆
AddRoundKey(N_ROUND - 1);
InvShiftRows();
InvSubBytes();
}
void AES::KeyExpansion()
{ // 密鑰擴展
const byte rcon[N_ROUND][4] = {
{ 0x00, 0x00, 0x00, 0x00 },
{ 0x01, 0x00, 0x00, 0x00 },
{ 0x02, 0x00, 0x00, 0x00 },
{ 0x04, 0x00, 0x00, 0x00 },
{ 0x08, 0x00, 0x00, 0x00 },
{ 0x10, 0x00, 0x00, 0x00 },
{ 0x20, 0x00, 0x00, 0x00 },
{ 0x40, 0x00, 0x00, 0x00 },
{ 0x80, 0x00, 0x00, 0x00 },
{ 0x1b, 0x00, 0x00, 0x00 },
{ 0x36, 0x00, 0x00, 0x00 } };
for (int i = 0; i < 16; ++i)
{
roundKey[0][i] = cipherKey[i];
}
for (int i = 0; i < 4; ++i)
{ // roundKey[0][16]為cipherKey的轉置矩陣
for (int j = 0; j < 4; ++j)
{
roundKey[0][4 * i + j] = cipherKey[4 * j + i];
}
}
for (int roundIndex = 1; roundIndex < N_ROUND; ++roundIndex)
{
byte rotWord[4] = { 0x00 };
rotWord[0] = roundKey[roundIndex - 1][3];
rotWord[1] = roundKey[roundIndex - 1][7];
rotWord[2] = roundKey[roundIndex - 1][11];
rotWord[3] = roundKey[roundIndex - 1][15];
std::swap<byte>(rotWord[0], rotWord[1]);
std::swap<byte>(rotWord[1], rotWord[2]);
std::swap<byte>(rotWord[2], rotWord[3]);
for (int i = 0; i < 4; ++i)
{
rotWord[i] = SBox[rotWord[i] >> 4][rotWord[i] & 0x0f];
roundKey[roundIndex][4 * i] = roundKey[roundIndex - 1][4 * i] ^ rotWord[i] ^ rcon[roundIndex][i];
}
for (int j = 1; j < 4; ++j)
{
for (int i = 0; i < 4; ++i)
{
roundKey[roundIndex][4 * i + j] = roundKey[roundIndex - 1][4 * i + j] ^ roundKey[roundIndex][4 * i + j - 1];
}
}
}
}
void AES::AddRoundKey(const int& round)
{ // 輪密鑰加
for (int i = 0; i < 16; ++i)
{ // 利用當前分組state和第round組擴展密鑰進行按位異或
state[i] ^= roundKey[round][i];
}
}
void AES::SubBytes()
{ // 字節代換
for (int i = 0; i < 16; ++i)
{
state[i] = SBox[state[i] >> 4][state[i] & 0x0f];
}
}
void AES::InvSubBytes()
{ // 逆字節代換
for (int i = 0; i < 16; ++i)
{
state[i] = InvSBox[state[i] >> 4][state[i] & 0x0f];
}
}
void AES::ShiftRows()
{ // 行變換
//state第一行保持不變
// Do nothing.
//state第二行循環左移一個字節
std::swap<byte>(state[4], state[5]);
std::swap<byte>(state[5], state[6]);
std::swap<byte>(state[6], state[7]);
//state第三行循環左移兩個字節
std::swap<byte>(state[8], state[10]);
std::swap<byte>(state[9], state[11]);
//state第三行循環左移三個字節
std::swap<byte>(state[14], state[15]);
std::swap<byte>(state[13], state[14]);
std::swap<byte>(state[12], state[13]);
}
void AES::InvShiftRows()
{ // 行變換反演
//state第一行保持不變
// Do nothing.
//state第二行循環右移一個字節
std::swap<byte>(state[6], state[7]);
std::swap<byte>(state[5], state[6]);
std::swap<byte>(state[4], state[5]);
//state第三行循環右移兩個字節
std::swap<byte>(state[9], state[11]);
std::swap<byte>(state[8], state[10]);
//state第三行循環右移三個字節
std::swap<byte>(state[12], state[13]);
std::swap<byte>(state[13], state[14]);
std::swap<byte>(state[14], state[15]);
}
void AES::MixColumns()
{ // 列混淆
byte matrix[4][4] = {
{ 0x02, 0x03, 0x01, 0x01 },
{ 0x01, 0x02, 0x03, 0x01 },
{ 0x01, 0x01, 0x02, 0x03 },
{ 0x03, 0x01, 0x01, 0x02 } };
const byte* temp = GFMultplyBytesMatrix((byte*)matrix, state);
for (int i = 0; i < 16; ++i)
{
state[i] = temp[i];
}
delete[] temp;
}
void AES::InvMixColumns()
{ // 列混淆反演
byte matrix[4][4] = {
{ 0x0e, 0x0b, 0x0d, 0x09 },
{ 0x09, 0x0e, 0x0b, 0x0d },
{ 0x0d, 0x09, 0x0e, 0x0b },
{ 0x0b, 0x0d, 0x09, 0x0e } };
const byte* temp = GFMultplyBytesMatrix((byte*)matrix, state);
for (int i = 0; i < 16; ++i)
{
state[i] = temp[i];
}
delete[] temp;
}
void AES::BuildSBox()
{ // 構建S盒
byte box[16][16] =
{
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
/*0*/{ 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76 },
/*1*/{ 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0 },
/*2*/{ 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15 },
/*3*/{ 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75 },
/*4*/{ 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84 },
/*5*/{ 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf },
/*6*/{ 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8 },
/*7*/{ 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2 },
/*8*/{ 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73 },
/*9*/{ 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb },
/*a*/{ 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79 },
/*b*/{ 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08 },
/*c*/{ 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a },
/*d*/{ 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e },
/*e*/{ 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf },
/*f*/{ 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 }
};
for (int i = 0; i < 16; ++i)
{
for (int j = 0; j < 16; ++j)
{
SBox[i][j] = box[i][j];
}
}
}
void AES::BuildInvSBox()
{ // 構建逆S盒
byte box[16][16] =
{
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
/*0*/{ 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb },
/*1*/{ 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb },
/*2*/{ 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e },
/*3*/{ 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25 },
/*4*/{ 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92 },
/*5*/{ 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84 },
/*6*/{ 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06 },
/*7*/{ 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b },
/*8*/{ 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73 },
/*9*/{ 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e },
/*a*/{ 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b },
/*b*/{ 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4 },
/*c*/{ 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f },
/*d*/{ 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef },
/*e*/{ 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61 },
/*f*/{ 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d }
};
for (int i = 0; i < 16; ++i)
{
for (int j = 0; j < 16; ++j)
{
InvSBox[i][j] = box[i][j];
}
}
}
void AES::InitialState(const byte* text)
{ // state初始時候為明(密)文矩陣的轉置矩陣
for (int i = 0; i < 4; ++i)
{ //轉置text存放在state中
for (int j = 0; j < 4; ++j)
{
state[4 * i + j] = text[4 * j + i];
}
}
}
void AES::InitialCipherText()
{ // state被復制到輸出矩陣中
for (int i = 0; i < 4; ++i)
{ //轉置state存放在cipherText中
for (int j = 0; j < 4; ++j)
{
cipherText[4 * i + j] = state[4 * j + i];
}
}
}
void AES::InitialplainText()
{ // state被復制到輸入矩陣中
for (int i = 0; i < 4; ++i)
{ //轉置state存放在plainText中
for (int j = 0; j < 4; ++j)
{
plainText[4 * i + j] = state[4 * j + i];
}
}
}
AES::byte AES::GFMultplyByte(const byte& left, const byte& right)
{ //有限域GF(2^8)上的乘法
byte temp[8];
bitset<8> bits((unsigned long)right); //把right化為個二進制位存放在bits中
temp[0] = left;
for (int i = 1; i < 8; ++i)
{
if (temp[i - 1] >= 0x80) //若(temp[i-1] 首位為"1"
{
temp[i] = temp[i - 1] << 1;
temp[i] = temp[i] ^ 0x1b; //與(00011011)異或
}
else
{
temp[i] = temp[i - 1] << 1;
}
}
byte result = 0x00;
for (int i = 0; i < 8; ++i)
{
if (bits[i] == 1)
{
result ^= temp[i];
}
}
return result;
}
const AES::byte* AES::GFMultplyBytesMatrix(const byte* left, const byte* right)
{ //有限域GF(2^8)上的矩陣(4*4)乘法
AES::byte* result = new AES::byte[16];
for (int i = 0; i < 4; ++i)
{
for (int j = 0; j < 4; ++j)
{
result[4 * i + j] = GFMultplyByte(left[4 * i], right[j]);
for (int k = 1; k < 4; ++k)
{
result[4 * i + j] ^= GFMultplyByte(left[4 * i + k], right[4 * k + j]);
}
}
}
return result;
}
AES::AES()
{
BuildSBox();
BuildInvSBox();
}
const AES::byte* AES::Cipher(const byte* text, const byte* key, const int& keySize)
{ // 用key給text加密
for (int i = 0; i < 16; ++i)
{
plainText[i] = text[i];
}
for (int i = 0; i < keySize; ++i)
{
cipherKey[i] = key[i];
}
EncryptionProcess();
return cipherText;
}
const AES::byte* AES::InvCipher(const byte* text, const byte* key, const int& keySize)
{ // 用key給text解密
for (int i = 0; i < 16; ++i)
{
cipherText[i] = text[i];
}
for (int i = 0; i < keySize; ++i)
{
cipherKey[i] = key[i];
}
DecryptionProcess();
return plainText;
}
#endif /* AES_H_ */