C语言AES加解密代码实现

#include
#include
#include
#include
#include
#include
using namespace std;
#define Max 1024

int S[16][16] =   ///s盒
{
    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
};

int S2[16][16] =    ///逆s盒
{
    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
};


///文件存储区
void getString(char *str,int len) ///判断文件内容的结尾的位置
{
    int slen = read(0,str,len);
    for(int i=0; i= Max)
    {
        cout<<"解密文件过大！"<> 24;
    array[0] = one & 0x000000ff;
    int two = num >> 16;
    array[1] = two & 0x000000ff;
    int three = num >> 8;
    array[2] = three & 0x000000ff;
    array[3] = num & 0x000000ff;
}
int mergeArrayToInt(int array[4]) ///把数组中的第一、二、三和四元素分别作为4字节整型的第一、二、三和四字节，合并成一个4字节整型
{
    int one = array[0] << 24;
    int two = array[1] << 16;
    int three = array[2] << 8;
    int four = array[3];
    return one | two | three | four;
}

void leftLoop4int(int array[4], int step) ///将数组中的元素循环左移step位
{
    int temp[4];
    for(int i = 0; i < 4; i++)
        temp[i] = array[i];

    int index = step % 4 == 0 ? 0 : step % 4;
    for(int i = 0; i < 4; i++)
    {
        array[i] = temp[index];
        index++;
        index = index % 4;
    }
}
void rightLoop4int(int array[4], int step) ///将数组循环右移step位
{
    int temp[4];
    for(int i = 0; i < 4; i++)
        temp[i] = array[i];

    int index = step % 4 == 0 ? 0 : step % 4;
    index = 3 - index;
    for(int i = 3; i >= 0; i--)
    {
        array[i] = temp[index];
        index--;
        index = index == -1 ? 3 : index;
    }
}

int getLeft4Bit(int num) ///获取八比特的前四位，并化为十六进制
{
    int left = num & 0x000000f0;
    return left >> 4;
}
int getRight4Bit(int num) ///获取八比特的后四位，并化为十六进制
{
    return num & 0x0000000f;
}

int getNumFromSBox(int index) ///从s盒获取元素
{
    int row = getLeft4Bit(index);
    int col = getRight4Bit(index);
    return S[row][col];
}
int getNumFromS1Box(int index) ///从逆s盒获取元素
{
    int row = getLeft4Bit(index);
    int col = getRight4Bit(index);
    return S2[row][col];
}

int Rcon[10] =            ///常量轮值表
{
    0x01000000, 0x02000000,
    0x04000000, 0x08000000,
    0x10000000, 0x20000000,
    0x40000000, 0x80000000,
    0x1b000000, 0x36000000
};

int T(int num, int round) ///密钥扩展的T函数
{
    int numArray[4];
    splitIntToArray(num, numArray);
    leftLoop4int(numArray, 1);//字循环

    //字节代换
    for(int i = 0; i < 4; i++)
        numArray[i] = getNumFromSBox(numArray[i]);

    int result = mergeArrayToInt(numArray);
    return result ^ Rcon[round];
}

int w[45];

void extendKey(char *key) ///扩展密钥长度
{
    for(int i = 0; i < 4; i++)
        w[i] = getWordFromStr(key + i * 4);

    for(int i = 4, j = 0; i < 44; i++)
    {
        if( i % 4 == 0)
        {
            w[i] = w[i - 4] ^ T(w[i - 1], j);
            j++;//下一轮
        }
        else
        {
            w[i] = w[i - 4] ^ w[i - 1];
        }
    }
}

void convertToIntArray(char *str, int pa[4][4]) ///把字符转化为字节并按矩阵排列，中字节排序，先上后下，在左后右
{
    int k = 0;
    for(int i = 0; i < 4; i++)
        for(int j = 0; j < 4; j++)
        {
            pa[j][i] = getIntFromChar(str[k]);
            k++;
        }
}

void convertArrayToStr(int array[4][4], char *str) ///把字节转换为字符
{
    for(int i = 0; i < 4; i++)
        for(int j = 0; j < 4; j++)
            *str++ = (char)array[j][i];
}

int colM[4][4] =     ///列混合所用到的矩阵
{
    2, 3, 1, 1,
    1, 2, 3, 1,
    1, 1, 2, 3,
    3, 1, 1, 2
};
int deColM[4][4] =   ///逆列混合所用到的矩阵
{
    0xe, 0xb, 0xd, 0x9,
    0x9, 0xe, 0xb, 0xd,
    0xd, 0x9, 0xe, 0xb,
    0xb, 0xd, 0x9, 0xe
};

int GFMul2(int s) ///GF上对应的值
{
    int result = s << 1;
    int a7 = result & 0x00000100;

    if(a7 != 0)
    {
        result = result & 0x000000ff;
        result = result ^ 0x1b;
    }

    return result;
}
int GFMul3(int s)
{
    return GFMul2(s) ^ s;
}
int GFMul4(int s)
{
    return GFMul2(GFMul2(s));
}
int GFMul8(int s)
{
    return GFMul2(GFMul4(s));
}
int GFMul9(int s)
{
    return GFMul8(s) ^ s;
}
int GFMul11(int s)
{
    return GFMul9(s) ^ GFMul2(s);
}
int GFMul12(int s)
{
    return GFMul8(s) ^ GFMul4(s);
}
int GFMul13(int s)
{
    return GFMul12(s) ^ s;
}
int GFMul14(int s)
{
    return GFMul12(s) ^ GFMul2(s);
}

int GFMul(int n, int s) ///GF上的二元运算
{
    int result;

    if(n == 1)
        result = s;
    else if(n == 2)
        result = GFMul2(s);
    else if(n == 3)
        result = GFMul3(s);
    else if(n == 0x9)
        result = GFMul9(s);
    else if(n == 0xb)//11
        result = GFMul11(s);
    else if(n == 0xd)//13
        result = GFMul13(s);
    else if(n == 0xe)//14
        result = GFMul14(s);

    return result;
}


///1.加密
void addRoundKey(int array[4][4], int round) ///轮密钥加
{
    int warray[4];
    for(int i = 0; i < 4; i++)
    {

        splitIntToArray(w[ round * 4 + i], warray);

        for(int j = 0; j < 4; j++)
        {
            array[j][i] = array[j][i] ^ warray[j];
        }
    }
}

void subBytes(int array[4][4]) ///字节代换
{
    for(int i = 0; i < 4; i++)
        for(int j = 0; j < 4; j++)
            array[i][j] = getNumFromSBox(array[i][j]);
}

void shiftRows(int array[4][4]) ///行移位
{
    int rowTwo[4], rowThree[4], rowFour[4];
    //复制状态矩阵的第2,3,4行
    for(int i = 0; i < 4; i++)
    {
        rowTwo[i] = array[1][i];
        rowThree[i] = array[2][i];
        rowFour[i] = array[3][i];
    }
    //循环左移相应的位数
    leftLoop4int(rowTwo, 1);
    leftLoop4int(rowThree, 2);
    leftLoop4int(rowFour, 3);

    //把左移后的行复制回状态矩阵中
    for(int i = 0; i < 4; i++)
    {
        array[1][i] = rowTwo[i];
        array[2][i] = rowThree[i];
        array[3][i] = rowFour[i];
    }
}

void mixColumns(int array[4][4]) ///列混合
{

    int tempArray[4][4];

    for(int i = 0; i < 4; i++)
        for(int j = 0; j < 4; j++)
            tempArray[i][j] = array[i][j];

    for(int i = 0; i < 4; i++)
        for(int j = 0; j < 4; j++)
        {
            array[i][j] = GFMul(colM[i][0],tempArray[0][j]) ^ GFMul(colM[i][1],tempArray[1][j])
                          ^ GFMul(colM[i][2],tempArray[2][j]) ^ GFMul(colM[i][3], tempArray[3][j]);
        }
}


///2.解密
void deSubBytes(int array[4][4]) ///逆字节变换
{
    for(int i = 0; i < 4; i++)
        for(int j = 0; j < 4; j++)
            array[i][j] = getNumFromS1Box(array[i][j]);
}

void deShiftRows(int array[4][4]) ///逆行移位
{
    int rowTwo[4], rowThree[4], rowFour[4];
    for(int i = 0; i < 4; i++)
    {
        rowTwo[i] = array[1][i];
        rowThree[i] = array[2][i];
        rowFour[i] = array[3][i];
    }

    rightLoop4int(rowTwo, 1);
    rightLoop4int(rowThree, 2);
    rightLoop4int(rowFour, 3);

    for(int i = 0; i < 4; i++)
    {
        array[1][i] = rowTwo[i];
        array[2][i] = rowThree[i];
        array[3][i] = rowFour[i];
    }
}

void deMixColumns(int array[4][4]) ///逆列混合
{

    int tempArray[4][4];
    for(int i = 0; i < 4; i++)
        for(int j = 0; j < 4; j++)
            tempArray[i][j] = array[i][j];

    for(int i = 0; i < 4; i++)
        for(int j = 0; j < 4; j++)
        {
            array[i][j] = GFMul(deColM[i][0],tempArray[0][j]) ^ GFMul(deColM[i][1],tempArray[1][j])
                          ^ GFMul(deColM[i][2],tempArray[2][j]) ^ GFMul(deColM[i][3], tempArray[3][j]);
        }
}

void getArrayFrom4W(int i, int array[4][4]) ///从4个32位的密钥字中获得4X4数组，用于进行逆列混合
{
    int index = i * 4;
    int colOne[4], colTwo[4], colThree[4], colFour[4];
    splitIntToArray(w[index], colOne);
    splitIntToArray(w[index + 1], colTwo);
    splitIntToArray(w[index + 2], colThree);
    splitIntToArray(w[index + 3], colFour);

    for(int i = 0; i < 4; i++)
    {
        array[i][0] = colOne[i];
        array[i][1] = colTwo[i];
        array[i][2] = colThree[i];
        array[i][3] = colFour[i];
    }

}

void addRoundTowArray(int aArray[4][4],int bArray[4][4]) ///逆轮密钥加
{
    for(int i = 0; i < 4; i++)
        for(int j = 0; j < 4; j++)
            aArray[i][j] = aArray[i][j] ^ bArray[i][j];
}



void aes(char *p, int plen, char *key)///AES加密
{

    int keylen=strlen(key);
    if(plen == 0 || plen % 16 != 0)
    {
        printf("明文字符长度必须为16的倍数！\n");
        exit(0);
    }

    if(!checkKeyLen(keylen))
    {
        printf("密钥字符长度错误！长度必须为16、24和32。当前长度为%d\n",keylen);
        exit(0);
    }

    extendKey(key);//扩展密钥
    int pArray[4][4];

    for(int k = 0; k < plen; k += 16)
    {
        convertToIntArray(p + k, pArray);//变成矩阵

        addRoundKey(pArray, 0);//一开始的轮密钥加

        for(int i = 1; i < 10; i++) //前9轮
        {

            subBytes(pArray);//字节代换

            shiftRows(pArray);//行移位

            mixColumns(pArray);//列混合

            addRoundKey(pArray, i);//轮密钥加

        }

        //第10轮
        subBytes(pArray);//字节代换

        shiftRows(pArray);//行移位

        addRoundKey(pArray, 10);//轮密钥加

        convertArrayToStr(pArray, p + k);
    }
}

void deAes(char *c, int clen, char *key) ///AES解密
{

    int keylen = strlen(key);
    if(clen == 0 || clen % 16 != 0)
    {
        printf("密文字符长度必须为16的倍数！现在的长度为%d\n",clen);
        exit(0);
    }

    if(!checkKeyLen(keylen))
    {
        printf("密钥字符长度错误！长度必须为16、24和32。当前长度为%d\n",keylen);
        exit(0);
    }

    extendKey(key);//扩展密钥
    int cArray[4][4];
    for(int k = 0; k < clen; k += 16)
    {

        convertToIntArray(c + k, cArray);  //字符转化为字节，并以矩阵形式排列
        addRoundKey(cArray, 10);   //轮密钥加

        int wArray[4][4];
        for(int i = 9; i >= 1; i--)
        {
            deSubBytes(cArray); //逆字节替换
            deShiftRows(cArray);//逆行移位

            deMixColumns(cArray); //逆列混合
            getArrayFrom4W(i, wArray);
            deMixColumns(wArray);//逆列混合

            addRoundTowArray(cArray, wArray);//逆轮密钥加
        }

        deSubBytes(cArray);//逆字节替换

        deShiftRows(cArray);//逆行移位

        addRoundKey(cArray, 0);//逆密钥加

        convertArrayToStr(cArray, c + k);

    }
}

void aesStrToFile(char *key) ///s操作，输入明文，并加密后保存在文件里
{

    char p[Max];
    int plen;

    printf("请输入你的明文，明文字符长度必须为16的倍数\n");
    readPlainText(p,&plen);
    printf("进行AES加密..................\n");

    aes(p, plen, key);//AES加密

    printf("加密完后的明文的ASCCI为：\n");
    printASCCI(p, plen);
    char fileName[64];
    printf("请输入你想要写进的文件名，比如'test.txt':\n");
    if(scanf("%s", fileName) == 1)
    {
        writeStrToFile(p, plen, fileName);
        printf("已经将密文写进%s中了,可以在运行该程序的当前目录中找到它。\n", fileName);
    }
}

void deAesFile(char *key) ///p操作，将存有密文的文件进行解密，并保存在文件里
{
    char fileName[64];
    char c[Max];//密文字符串
    printf("请输入要解密的文件名，该文件必须和本程序在同一个目录\n");
    if(scanf("%s", fileName) == 1)
    {
        int clen = readStrFromFile(fileName,c);
        printf("开始解密.........\n");
        deAes(c, clen, key);
        printf("解密后的明文ASCII为：\n");
        printASCCI(c, clen);
        printf("明文为：%s\n", c);
        writeStrToFile(c,clen,fileName);
        printf("现在可以打开%s来查看解密后的密文了！\n",fileName);
    }
}

void aesFile(char *key)  ///f操作，将某文件里的内容进行加密
{
    char fileName[64];
    char fileP[Max];

    printf("请输入要加密的文件名，该文件必须和本程序在同一个目录\n");
    if(scanf("%s", fileName) == 1)
    {
        readStrFromFile(fileName,fileP);
        int plen = strlen(fileP);
        printf("开始加密.........\n");
        printf("加密前文件中字符的ASCII为：\n");
        printASCCI(fileP, plen);

        aes(fileP, plen, key);//开始加密

        printf("加密后的密文ASCII为：\n");
        printASCCI(fileP, plen);
        writeStrToFile(fileP,plen,fileName);
        printf("已经将加密后的密文写进%s中了\n",fileName);
    }
}

int main()
{

    char key[17];
    printf("请输入16个字符的密钥：\n");

    int klen;
    while(1)
    {
        getString(key,17);
        klen = strlen(key);
        if(klen != 16)
        {
            printf("请输入16个字符的密钥,当前密钥的长度为%d\n",klen);
        }
        else
        {
            printf("你输入的密钥为：%s\n",key);
            break;
        }
    }
    printf("输入's'表示要加密输入的字符串,并将加密后的内容写入到文件\n");
    printf("请输入要功能选项并按回车，输入'f'表示要加密文件\n");
    printf("输入'p'表示要解密文件\n");
    char c;
    if(scanf("%c",&c) == 1)
    {
        if(c == 's')
            aesStrToFile(key);//用AES加密字符串，并将字符串写进文件中
        else if(c == 'p')
            deAesFile(key);//把文件中的密文解密，并写回文件中
        else if(c == 'f')//用AES加密文件
            aesFile(key);
    }
    return 0;
}