c++实现aes加密算法，对字符串进行加密

 我的blog中，已经写过一篇关于aes加密算法的调用。不过使用的参数必须时unsigned char类型。我们在
编程中使用最多的char类型，我从网上下载了一个代码，追加了一部分代码。
    其主要功能进行实现unsigned char类型数据到char类型转化，将unsigned char结果与16进制字符串串之间的转化。代码如下：

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 #ifndef AES_H
 #define AES_H

 #include <string.h>

 class AES
 {
 public:
   AES(unsigned char* key);
   virtual ~AES();
   unsigned char* Cipher(unsigned char* input);
   unsigned char* InvCipher(unsigned char* input);
   void* Cipher(void* input, int length=0);
   void* InvCipher(void* input, int length);

   void Cipher(char *input, char *output);
   void InvCipher(char *inut, char *output);

 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]);

   int strToHex(const char *ch, char *hex);
   int hexToStr(const char *hex, char *ch);
   int ascillToValue(const char ch);
   char valueToHexCh(const int value);
   int getUCharLen(const unsigned char *uch);
   int strToUChar(const char *ch, unsigned char *uch);
   int ucharToStr(const unsigned char *uch, char *ch);
   int ucharToHex(const unsigned char *uch, char *hex);
   int hexToUChar(const char *hex, unsigned char *uch);
 };

 #endif // AES_H

对应的cpp文件如下：

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 #include "aes.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()
 {

 }

 void AES::Cipher(char *input, char *output)
 {
   unsigned char uch_input[1024];
   strToUChar(input, uch_input);
   Cipher(uch_input);
   ucharToHex(uch_input,output);
 }

 void AES::InvCipher(char *input, char *output)
 {
   unsigned char uch_input[1024];
   hexToUChar(input, uch_input);
   InvCipher(uch_input);
   ucharToStr(uch_input, output);
 }

 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)
   {
     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]);
     }
   }
 }

 int AES::getUCharLen(const unsigned char *uch)
 {
   int len = 0;
   while(*uch++)
     ++len;

   return len;
 }

 int AES::ucharToHex(const unsigned char *uch, char *hex)
 {
   int high,low;
   int tmp = 0;
   if(uch == NULL || hex == NULL){
     return -1;
   }

   if(getUCharLen(uch) == 0){
     return -2;
   }

   while(*uch){
     tmp = (int)*uch;
     high = tmp >> 4;
     low = tmp & 15;
     *hex++ = valueToHexCh(high); //先写高字节
     *hex++ = valueToHexCh(low); //其次写低字节
     uch++;
   }
   *hex = '\0';
   return 0;
 }

 int AES::hexToUChar(const char *hex, unsigned char *uch)
 {
   int high,low;
   int tmp = 0;
   if(hex == NULL || uch == NULL){
     return -1;
   }

   if(strlen(hex) %2 == 1){
     return -2;
   }

   while(*hex){
     high = ascillToValue(*hex);
     if(high < 0){
       *uch = '\0';
       return -3;
     }
     hex++; //指针移动到下一个字符上
     low = ascillToValue(*hex);
     if(low < 0){
       *uch = '\0';
       return -3;
     }
     tmp = (high << 4) + low;
     *uch++ = tmp;
     hex++;
   }
   *uch = (int)'\0';
   return 0;
 }

 int AES::strToUChar(const char *ch, unsigned char *uch)
 {
   int tmp = 0;
   if(ch == NULL || uch == NULL)
     return -1;
   if(strlen(ch) == 0)
     return -2;

   while(*ch){
     tmp = (int)*ch;
     *uch++ = tmp;
     ch++;
   }
   *uch = (int)'\0';
   return 0;
 }

 int AES::ucharToStr(const unsigned char *uch, char *ch)
 {
   int tmp = 0;
   if(uch == NULL || ch == NULL)
     return -1;

   while(*uch){
     tmp = (int)*uch;
     *ch++ = (char)tmp;
     uch++;
   }
   *ch = '\0';

   return 0;
 }

 int AES::strToHex(const char *ch, char *hex)
 {
   int high,low;
   int tmp = 0;
   if(ch == NULL || hex == NULL){
     return -1;
   }

   if(strlen(ch) == 0){
     return -2;
   }

   while(*ch){
     tmp = (int)*ch;
     high = tmp >> 4;
     low = tmp & 15;
     *hex++ = valueToHexCh(high); //先写高字节
     *hex++ = valueToHexCh(low); //其次写低字节
     ch++;
   }
   *hex = '\0';
   return 0;
 }

 int AES::hexToStr(const char *hex, char *ch)
 {
   int high,low;
   int tmp = 0;
   if(hex == NULL || ch == NULL){
     return -1;
   }

   if(strlen(hex) %2 == 1){
     return -2;
   }

   while(*hex){
     high = ascillToValue(*hex);
     if(high < 0){
       *ch = '\0';
       return -3;
     }
     hex++; //指针移动到下一个字符上
     low = ascillToValue(*hex);
     if(low < 0){
       *ch = '\0';
       return -3;
     }
     tmp = (high << 4) + low;
     *ch++ = (char)tmp;
     hex++;
   }
   *ch = '\0';
   return 0;
 }

 int AES::ascillToValue(const char ch){
   int result = 0;
   //获取16进制的高字节位数据
   if(ch >= '0' && ch <= '9'){
     result = (int)(ch - '0');
   }
   else if(ch >= 'a' && ch <= 'z'){
     result = (int)(ch - 'a') + 10;
   }
   else if(ch >= 'A' && ch <= 'Z'){
     result = (int)(ch - 'A') + 10;
   }
   else{
     result = -1;
   }
   return result;
 }

 char AES::valueToHexCh(const int value)
 {
   char result = '\0';
   if(value >= 0 && value <= 9){
     result = (char)(value + 48); //48为ascii编码的‘0’字符编码值
   }
   else if(value >= 10 && value <= 15){
     result = (char)(value - 10 + 65); //减去10则找出其在16进制的偏移量，65为ascii的'A'的字符编码值
   }
   else{
     ;
   }

   return result;
 }

     经过对代码的补充，这样我们在调用加密，解密时，就非常方便了，不用再考虑unsigned char类型字符串了。
直接使用char类型字符串，就好了。调用如下：

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 #include <QString>

 #include <stdio.h>
 #include "aes.h"

 int main(int argc, char *argv[])
 {
     char mingwen[] = "http://www.baidu.com";
     char miwen_hex[1024];
     //char miwen_hex[] = "8FEEEFE524F8B68DC1FCA2899AC1A6B82E636F6D";
     char result[1024];
     unsigned char key[] = "xcysoft123";
     AES aes(key);
     aes.Cipher(mingwen, miwen_hex);
     printf("%s\n",miwen_hex);
     aes.InvCipher(miwen_hex, result);
     printf("%s\n",result);
     getchar();
     return 0;
 }

附件为使用qt creator开发工具，加载对aes加密算法的测试。
 AES.rar    

补充：在QT开发环境中，我们经常使用的QString类型进行字符串的加密，解密。因此编写一个类。
来进行方便的操作，代码如下：
AesHelper.h的源代码

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 #ifndef AESHELPER_H
 #define AESHELPER_H

 #include <QString>
 #include <QTextCodec>

 #include <string.h>

 #include "aes.h"

 class AesHelper
 {
 public:
     AesHelper();
     ~AesHelper();
     QString aesEncrypt(QString mingwen);

     QString aesUncrypt(QString miwen);

 private:
     AES *aes;
 };

 #endif // AESHELPER_H

AesHelper.cpp的代码如下：

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 #include "AesHelper.h"

 AesHelper::AesHelper()
 {
   unsigned char key[] = "1p2w3e4r";
   aes = new AES(key);
 }

 AesHelper::~AesHelper()
 {
   delete aes;
   aes = 0;
 }

 QString AesHelper::aesEncrypt(QString mingwen)
 {
   QString result = QString("");
   char ch_mingwen[10240];
   char ch_miwen[10240];
   strcpy(ch_mingwen, mingwen.toUtf8().data());
   aes->Cipher(ch_mingwen, ch_miwen);
   result = QString(ch_miwen);
   return result;
 }

 QString AesHelper::aesUncrypt(QString miwen)
 {
   QString result = QString("");
   char ch_mingwen[10240];
   char ch_miwen[10240];
   strcpy(ch_miwen, miwen.toUtf8().data());
   aes->InvCipher(ch_miwen, ch_mingwen);
   result = QString(ch_mingwen);

   return result;
 }