AES加密演算法C++實現
阿新 • • 發佈:2018-12-20
(1)aes.h
#ifndef aes_h__ #define aes_h__ class AES { public: AES(unsigned char* key); virtual ~AES(); unsigned char* Cipher(unsigned char* input); // 加密,傳入的陣列大小必須是16位元組 unsigned char* InvCipher(unsigned char* input); // 解密,傳入的陣列也必須是16位元組 void* Cipher(void* input, int length=0); // 可以傳入陣列,大小必須是16的整數倍,如果不是將會越界操作;如果不傳length而預設為0,那麼將按照字串處理,遇'\0'結束 void* InvCipher(void* input, int length); // 必須傳入陣列和大小,必須是16的整數倍 private: unsigned char Sbox[256]; unsigned char InvSbox[256]; unsigned char w[11][4][4]; void KeyExpansion(unsigned char* key, unsigned char w[][4][4]); unsigned char FFmul(unsigned char a, unsigned char b); void SubBytes(unsigned char state[][4]); void ShiftRows(unsigned char state[][4]); void MixColumns(unsigned char state[][4]); void AddRoundKey(unsigned char state[][4], unsigned char k[][4]); void InvSubBytes(unsigned char state[][4]); void InvShiftRows(unsigned char state[][4]); void InvMixColumns(unsigned char state[][4]); }; #endif // aes_h__
(2)aes.cpp
#include "aes.h" #include "string.h" AES::AES(unsigned char* key) { unsigned char sBox[] = { /* 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, /*0*/ 0xca,0x82,0xc9,0x7d,0xfa,0x59,0x47,0xf0,0xad,0xd4,0xa2,0xaf,0x9c,0xa4,0x72,0xc0, /*1*/ 0xb7,0xfd,0x93,0x26,0x36,0x3f,0xf7,0xcc,0x34,0xa5,0xe5,0xf1,0x71,0xd8,0x31,0x15, /*2*/ 0x04,0xc7,0x23,0xc3,0x18,0x96,0x05,0x9a,0x07,0x12,0x80,0xe2,0xeb,0x27,0xb2,0x75, /*3*/ 0x09,0x83,0x2c,0x1a,0x1b,0x6e,0x5a,0xa0,0x52,0x3b,0xd6,0xb3,0x29,0xe3,0x2f,0x84, /*4*/ 0x53,0xd1,0x00,0xed,0x20,0xfc,0xb1,0x5b,0x6a,0xcb,0xbe,0x39,0x4a,0x4c,0x58,0xcf, /*5*/ 0xd0,0xef,0xaa,0xfb,0x43,0x4d,0x33,0x85,0x45,0xf9,0x02,0x7f,0x50,0x3c,0x9f,0xa8, /*6*/ 0x51,0xa3,0x40,0x8f,0x92,0x9d,0x38,0xf5,0xbc,0xb6,0xda,0x21,0x10,0xff,0xf3,0xd2, /*7*/ 0xcd,0x0c,0x13,0xec,0x5f,0x97,0x44,0x17,0xc4,0xa7,0x7e,0x3d,0x64,0x5d,0x19,0x73, /*8*/ 0x60,0x81,0x4f,0xdc,0x22,0x2a,0x90,0x88,0x46,0xee,0xb8,0x14,0xde,0x5e,0x0b,0xdb, /*9*/ 0xe0,0x32,0x3a,0x0a,0x49,0x06,0x24,0x5c,0xc2,0xd3,0xac,0x62,0x91,0x95,0xe4,0x79, /*a*/ 0xe7,0xc8,0x37,0x6d,0x8d,0xd5,0x4e,0xa9,0x6c,0x56,0xf4,0xea,0x65,0x7a,0xae,0x08, /*b*/ 0xba,0x78,0x25,0x2e,0x1c,0xa6,0xb4,0xc6,0xe8,0xdd,0x74,0x1f,0x4b,0xbd,0x8b,0x8a, /*c*/ 0x70,0x3e,0xb5,0x66,0x48,0x03,0xf6,0x0e,0x61,0x35,0x57,0xb9,0x86,0xc1,0x1d,0x9e, /*d*/ 0xe1,0xf8,0x98,0x11,0x69,0xd9,0x8e,0x94,0x9b,0x1e,0x87,0xe9,0xce,0x55,0x28,0xdf, /*e*/ 0x8c,0xa1,0x89,0x0d,0xbf,0xe6,0x42,0x68,0x41,0x99,0x2d,0x0f,0xb0,0x54,0xbb,0x16 /*f*/ }; unsigned char invsBox[256] = { /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ 0x52,0x09,0x6a,0xd5,0x30,0x36,0xa5,0x38,0xbf,0x40,0xa3,0x9e,0x81,0xf3,0xd7,0xfb, /*0*/ 0x7c,0xe3,0x39,0x82,0x9b,0x2f,0xff,0x87,0x34,0x8e,0x43,0x44,0xc4,0xde,0xe9,0xcb, /*1*/ 0x54,0x7b,0x94,0x32,0xa6,0xc2,0x23,0x3d,0xee,0x4c,0x95,0x0b,0x42,0xfa,0xc3,0x4e, /*2*/ 0x08,0x2e,0xa1,0x66,0x28,0xd9,0x24,0xb2,0x76,0x5b,0xa2,0x49,0x6d,0x8b,0xd1,0x25, /*3*/ 0x72,0xf8,0xf6,0x64,0x86,0x68,0x98,0x16,0xd4,0xa4,0x5c,0xcc,0x5d,0x65,0xb6,0x92, /*4*/ 0x6c,0x70,0x48,0x50,0xfd,0xed,0xb9,0xda,0x5e,0x15,0x46,0x57,0xa7,0x8d,0x9d,0x84, /*5*/ 0x90,0xd8,0xab,0x00,0x8c,0xbc,0xd3,0x0a,0xf7,0xe4,0x58,0x05,0xb8,0xb3,0x45,0x06, /*6*/ 0xd0,0x2c,0x1e,0x8f,0xca,0x3f,0x0f,0x02,0xc1,0xaf,0xbd,0x03,0x01,0x13,0x8a,0x6b, /*7*/ 0x3a,0x91,0x11,0x41,0x4f,0x67,0xdc,0xea,0x97,0xf2,0xcf,0xce,0xf0,0xb4,0xe6,0x73, /*8*/ 0x96,0xac,0x74,0x22,0xe7,0xad,0x35,0x85,0xe2,0xf9,0x37,0xe8,0x1c,0x75,0xdf,0x6e, /*9*/ 0x47,0xf1,0x1a,0x71,0x1d,0x29,0xc5,0x89,0x6f,0xb7,0x62,0x0e,0xaa,0x18,0xbe,0x1b, /*a*/ 0xfc,0x56,0x3e,0x4b,0xc6,0xd2,0x79,0x20,0x9a,0xdb,0xc0,0xfe,0x78,0xcd,0x5a,0xf4, /*b*/ 0x1f,0xdd,0xa8,0x33,0x88,0x07,0xc7,0x31,0xb1,0x12,0x10,0x59,0x27,0x80,0xec,0x5f, /*c*/ 0x60,0x51,0x7f,0xa9,0x19,0xb5,0x4a,0x0d,0x2d,0xe5,0x7a,0x9f,0x93,0xc9,0x9c,0xef, /*d*/ 0xa0,0xe0,0x3b,0x4d,0xae,0x2a,0xf5,0xb0,0xc8,0xeb,0xbb,0x3c,0x83,0x53,0x99,0x61, /*e*/ 0x17,0x2b,0x04,0x7e,0xba,0x77,0xd6,0x26,0xe1,0x69,0x14,0x63,0x55,0x21,0x0c,0x7d /*f*/ }; memcpy(Sbox, sBox, 256); memcpy(InvSbox, invsBox, 256); KeyExpansion(key, w); } AES::~AES() { } unsigned char* AES::Cipher(unsigned char* input) { unsigned char state[4][4]; int i,r,c; for(r=0; r<4; r++) { for(c=0; c<4 ;c++) { state[r][c] = input[c*4+r]; } } AddRoundKey(state,w[0]); for(i=1; i<=10; i++) { SubBytes(state); ShiftRows(state); if(i!=10)MixColumns(state); AddRoundKey(state,w[i]); } for(r=0; r<4; r++) { for(c=0; c<4 ;c++) { input[c*4+r] = state[r][c]; } } return input; } unsigned char* AES::InvCipher(unsigned char* input) { unsigned char state[4][4]; int i,r,c; for(r=0; r<4; r++) { for(c=0; c<4 ;c++) { state[r][c] = input[c*4+r]; } } AddRoundKey(state, w[10]); for(i=9; i>=0; i--) { InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, w[i]); if(i) { InvMixColumns(state); } } for(r=0; r<4; r++) { for(c=0; c<4 ;c++) { input[c*4+r] = state[r][c]; } } return input; } void* AES::Cipher(void* input, int length) { unsigned char* in = (unsigned char*) input; int i; if(!length) // 如果是0則當做字串處理 { while(*(in+length++)); in = (unsigned char*) input; } for(i=0; i<length; i+=16) { Cipher(in+i); } return input; } void* AES::InvCipher(void* input, int length) { unsigned char* in = (unsigned char*) input; int i; for(i=0; i<length; i+=16) { InvCipher(in+i); } return input; } void AES::KeyExpansion(unsigned char* key, unsigned char w[][4][4]) { int i,j,r,c; unsigned char rc[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36}; for(r=0; r<4; r++) { for(c=0; c<4; c++) { w[0][r][c] = key[r+c*4]; } } for(i=1; i<=10; i++) { for(j=0; j<4; j++) { unsigned char t[4]; for(r=0; r<4; r++) { t[r] = j ? w[i][r][j-1] : w[i-1][r][3]; } if(j == 0) { unsigned char temp = t[0]; for(r=0; r<3; r++) { t[r] = Sbox[t[(r+1)%4]]; } t[3] = Sbox[temp]; t[0] ^= rc[i-1]; } for(r=0; r<4; r++) { w[i][r][j] = w[i-1][r][j] ^ t[r]; } } } } unsigned char AES::FFmul(unsigned char a, unsigned char b) { unsigned char bw[4]; unsigned char res=0; int i; bw[0] = b; for(i=1; i<4; i++) { bw[i] = bw[i-1]<<1; if(bw[i-1]&0x80) { bw[i]^=0x1b; } } for(i=0; i<4; i++) { if((a>>i)&0x01) { res ^= bw[i]; } } return res; } void AES::SubBytes(unsigned char state[][4]) { int r,c; for(r=0; r<4; r++) { for(c=0; c<4; c++) { state[r][c] = Sbox[state[r][c]]; } } } void AES::ShiftRows(unsigned char state[][4]) { unsigned char t[4]; int r,c; for(r=1; r<4; r++) { for(c=0; c<4; c++) { t[c] = state[r][(c+r)%4]; } for(c=0; c<4; c++) { state[r][c] = t[c]; } } } void AES::MixColumns(unsigned char state[][4]) { unsigned char t[4]; int r,c; for(c=0; c< 4; c++) { for(r=0; r<4; r++) { t[r] = state[r][c]; } for(r=0; r<4; r++) { state[r][c] = FFmul(0x02, t[r]) ^ FFmul(0x03, t[(r+1)%4]) ^ FFmul(0x01, t[(r+2)%4]) ^ FFmul(0x01, t[(r+3)%4]); } } } void AES::AddRoundKey(unsigned char state[][4], unsigned char k[][4]) { int r,c; for(c=0; c<4; c++) { for(r=0; r<4; r++) { state[r][c] ^= k[r][c]; } } } void AES::InvSubBytes(unsigned char state[][4]) { int r,c; for(r=0; r<4; r++) { for(c=0; c<4; c++) { state[r][c] = InvSbox[state[r][c]]; } } } void AES::InvShiftRows(unsigned char state[][4]) { unsigned char t[4]; int r,c; for(r=1; r<4; r++) { for(c=0; c<4; c++) { t[c] = state[r][(c-r+4)%4]; } for(c=0; c<4; c++) { state[r][c] = t[c]; } } } void AES::InvMixColumns(unsigned char state[][4]) { unsigned char t[4]; int r,c; for(c=0; c< 4; c++) { for(r=0; r<4; r++) { t[r] = state[r][c]; } for(r=0; r<4; r++) { state[r][c] = FFmul(0x0e, t[r]) ^ FFmul(0x0b, t[(r+1)%4]) ^ FFmul(0x0d, t[(r+2)%4]) ^ FFmul(0x09, t[(r+3)%4]); } } }
上面的加密演算法是沒問題的,但是介面有兩個需要注意的地方,也就是在標頭檔案中備註的地方:
1、陣列的大小必須是16位元組或者16的整數倍。
2、不能直接使用字串輸出,因為加密後的陣列內容可能有'\0',字串會被截斷。
為了更方便的使用此加密演算法,封裝了一個介面類,宣告如下:
(3)AESEncryptor.h
(4)AESEncryptor.cpp#ifndef AES_Encryptor_h__ #define AES_Encryptor_h__ #include <string> class AES; class AesEncryptor { public: AesEncryptor(unsigned char* key); ~AesEncryptor(void); std::string EncryptString(std::string strInfor); std::string DecryptString(std::string strMessage); void EncryptTxtFile(const char* inputFileName, const char* outputFileName); void DecryptTxtFile(const char* inputFileName, const char* outputFileName); private: void Byte2Hex(const unsigned char* src, int len, char* dest); void Hex2Byte(const char* src, int len, unsigned char* dest); int Char2Int(char c); private: AES* m_pEncryptor; }; #endif // AES_Encryptor_h__
#include "aes.h"
#include "AESEncryptor.h"
//#include "log.h"
#include <fstream>
using namespace std;
AesEncryptor::AesEncryptor(unsigned char* key)
{
m_pEncryptor = new AES(key);
}
AesEncryptor::~AesEncryptor(void)
{
delete m_pEncryptor;
}
void AesEncryptor::Byte2Hex(const unsigned char* src, int len, char* dest) {
for (int i=0; i<len; ++i) {
sprintf_s(dest + i * 2, 3, "%02X", src[i]);
}
}
void AesEncryptor::Hex2Byte(const char* src, int len, unsigned char* dest) {
int length = len / 2;
for (int i=0; i<length; ++i) {
dest[i] = Char2Int(src[i * 2]) * 16 + Char2Int(src[i * 2 + 1]);
}
}
int AesEncryptor::Char2Int(char c) {
if ('0' <= c && c <= '9') {
return (c - '0');
}
else if ('a' <= c && c<= 'f') {
return (c - 'a' + 10);
}
else if ('A' <= c && c<= 'F') {
return (c - 'A' + 10);
}
return -1;
}
string AesEncryptor::EncryptString(string strInfor)
{
int nLength = strInfor.length();
int spaceLength = 16 - (nLength % 16);
unsigned char* pBuffer = new unsigned char[nLength + spaceLength];
memset(pBuffer, '\0', nLength + spaceLength);
memcpy_s(pBuffer, nLength + spaceLength, strInfor.c_str(), nLength);
m_pEncryptor->Cipher(pBuffer, nLength + spaceLength);
// 這裡需要把得到的字元陣列轉換成十六進位制字串
char* pOut = new char[2 * (nLength + spaceLength)];
memset(pOut, '\0', 2 * (nLength + spaceLength));
Byte2Hex(pBuffer, nLength + spaceLength, pOut);
string retValue(pOut);
delete[] pBuffer;
//delete[] pOut;
return retValue;
}
string AesEncryptor::DecryptString(string strMessage) {
int nLength = strMessage.length() / 2;
unsigned char* pBuffer = new unsigned char[nLength];
memset(pBuffer, '\0', nLength);
Hex2Byte(strMessage.c_str(), strMessage.length(), pBuffer);
m_pEncryptor->InvCipher(pBuffer, nLength);
string retValue((char*)pBuffer);
delete[] pBuffer;
return retValue;
}
void AesEncryptor::EncryptTxtFile(const char* inputFileName, const char* outputFileName) {
ifstream ifs;
// Open file:
ifs.open(inputFileName);
if (!ifs) {
//UNILOGW("AesEncryptor::EncryptTxtFile() - Open input file failed!");
return ;
}
// Read config data:
string strInfor;
string strLine;
while (!ifs.eof()) {
char temp[1024];
memset(temp, '\0', 1024);
ifs.read(temp, 1000);
strInfor += temp;
}
ifs.close();
// Encrypt
strLine = EncryptString(strInfor);
// Writefile
ofstream ofs;
ofs.open(outputFileName);
if (!ofs) {
//UNILOGW("AesEncryptor::EncryptTxtFile() - Open output file failed!");
return ;
}
ofs << strLine;
ofs.close();
}
void AesEncryptor::DecryptTxtFile(const char* inputFile, const char* outputFile) {
ifstream ifs;
// Open file:
ifs.open(inputFile);
if (!ifs) {
//UNILOGW("AesEncryptor::DecryptTxtFile() - Open input file failed!");
return ;
}
// Read config data:
string strInfor;
string strLine;
while (!ifs.eof()) {
char temp[1024];
memset(temp, '\0', 1024);
ifs.read(temp, 1000);
strInfor += temp;
}
ifs.close();
// Encrypt
strLine = DecryptString(strInfor);
// Writefile
ofstream ofs;
ofs.open(outputFile);
if (!ofs) {
//UNILOGW("AesEncryptor::DecryptTxtFile() - Open output file failed!");
return ;
}
ofs << strLine;
ofs.close();
}
從程式碼中可以看到增加了以下特性:
1、支援對std::string 字串型別的加密,並返回相應的字串,這個字串是將加密後的內容轉換成十六進位制表示的,所以不存在截斷的問題。當然了,解密的時候也需要轉換成真正的unsigned char陣列;
2、支援直接對文字檔案進行加密,指定輸入和輸出的檔名即可。
(5)main.cpp#include <iostream>
#include <string>
#include "AESEncryptor.h"
int main()
{
unsigned char src[4] = {0x28, 0x7e, 0x88, 0x16};
AesEncryptor aesE(src);
std::string strInfor = "你好";
std::string encryptS = aesE.EncryptString(strInfor);
std::string decryptS = aesE.DecryptString(encryptS);
system("pause");
return 0;
}