des.h

这是毕业设计的程序主要是图书管理功能,希望大家给给意见

/* ==================================================== */
/*                                                      */
/* 学生宿舍管理系统Ver 1.00.1 源代码                    */
/* 文件名: DES.h                                        */
/* 作用: DES加密和解密模块，实现对数据的加密解密        */
/* 接口函数:                                            */
/*                                                      */
/*      加密:                                           */
/*      void DESEncrypt(pvoid pMem,pvoid pKey,int size) */
/*                                                      */
/*      解密:                                           */
/*      void DESDecrypt(pvoid pMem,pvoid pKey,int size) */
/*                                                      */
/* 版权所有 (c) 2007  张元龙 保留所有权利               */
/*                                                      */
/* ==================================================== */

#include <stdio.h>
#include <string.h>

#ifndef DES_INCLUDE

#define DES_INCLUDE

typedef void *pvoid,*PVOID;
typedef char *pchar;

const char MoveStep[16]={
        1, 1, 2, 2,
        2, 2, 2, 2,
        1, 2, 2, 2,
        2, 2, 2, 1
};

char P1_Rule[]={
        58, 50, 42, 34, 26, 18, 10,  2,
        60, 52, 44, 36, 28, 20, 12,  4,
        62, 54, 46, 38, 30, 22, 14,  6,
        64, 56, 48, 40, 32, 24, 16,  8,
        57, 49, 41, 33, 25, 17,  9,  1,
        59, 51, 43, 35, 27, 19, 11,  3,
        61, 53, 45, 37, 29, 21, 13,  5,
        63, 55, 47, 39, 31, 23, 15,  7
};

char P2_Rule[]={
        40,  8, 48, 16, 56, 24, 64, 32,
        39,  7, 47, 15, 55, 23, 63, 31,
        38,  6, 46, 14, 54, 22, 62, 30,
        37,  5, 45, 13, 53, 21, 61, 29,
        36,  4, 44, 12, 52, 20, 60, 28,
        35,  3, 43, 11, 51, 19, 59, 27,
        34,  2, 42, 10, 50, 18, 58, 26,
        33,  1, 41,  9, 49, 17, 57, 25
};

char PC1_Rule[56]={
        57, 49, 41, 33, 25, 17,  9,
         1, 58, 50, 42, 34, 26, 18,
        10,  2, 59, 51, 43, 35, 27,
        19, 11,  3, 60, 52, 44, 36,
        63, 55, 47, 39, 31, 23, 15,
         7, 62, 54, 46, 38, 30, 22,
        14,  6, 61, 53, 45, 37, 29,
        21, 13,  5, 28, 20, 12,  4
    };

char PC2_Rule[]={
        14, 17, 11, 24,  1,  5,
         3, 28, 15,  6, 21, 10,
        23, 19, 12,  4, 26,  8,
        16,  7, 27, 20, 13,  2,
        41, 52, 31, 37, 47, 55,
        30, 40, 51, 45, 33, 48,
        44, 49, 39, 56, 34, 53,
        46, 42, 50, 36, 29, 32
};

char E_Rule[48]={
        32, 1, 2, 3, 4, 5,
         4, 5, 6, 7, 8, 9,
         8, 9,10,11,12,13,
        12,13,14,15,16,17,
        16,17,18,19,20,21,
        20,21,22,23,24,25,
        24,25,26,27,28,29,
        28,29,30,31,32, 1
};

char si[8][64]={
        14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7,
         0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8,
         4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0,
        15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13,

        15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10,
         3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5,
         0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15,
        13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9,

        10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8,
        13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1,
        13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7,
         1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12,

         7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15,
        13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9,
        10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4,
         3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14,

         2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9,
        14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6,
         4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14,
        11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3,

        12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11,
        10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8,
         9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6,
         4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13,

         4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1,
        13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6,
         1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2,
         6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12,

        13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7,
         1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2,
         7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8,
         2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11
};

char P_Rule[32]={
        16,  7, 20, 21,
        29, 12, 28, 17,
         1, 15, 23, 26,
         5, 18, 31, 10,
         2,  8, 24, 14,
        32, 27,  3,  9,
        19, 13, 30,  6,
        22, 11,  4, 25
};

void fillbit(pvoid pMem,long data,int length){              /*将数据转换成二进制数组*/
    char *p=(char *)pMem;
    while (length && data){
        *p=data & 1;
        p++;
        length--;
        data>>=1;
    }
    if (length){
        memset(p,0,length);
    }
}

void ConversionBit(pchar bit,pchar rule,int length){        /*换位操作*/
    char p[128];
    int i;
    for (i=1;i<=length;i++){
        p[i-1]=bit[rule[i-1]-1];
    }
    memcpy(bit,p,length);
}

void S_BOX_Conversion(pchar bit){                           /*S-盒变换48 bits->32 bits*/
    int i;
    char buf[48];
    pchar p=bit;
    for (i=0;i<8;i++){
        fillbit(buf+i*4,si[i][ p[0]<<1 | p[1]<<2 | p[2]<<3 | p[3]<<4 | p[4]<<5 | p[5] ],4);
        p+=6;
    }
    memcpy(bit,buf,32);
}

void DESF(pchar bit,pchar Key){                             /*DES算法的F函数，参数分别为32位数据以及48位密钥*/
    char data[50];
    memcpy(data,bit,32);
    ConversionBit(data,E_Rule,sizeof E_Rule);               /*进行一次E-盒扩展置换*/
    int i;
    for (i=0;i<48;i++)                                      /*与48位密钥逐位异或*/
        data[i]^=Key[i];
    S_BOX_Conversion(data);                                 /*进行一次S-盒变换*/
    ConversionBit(data,P_Rule,sizeof P_Rule);               /*进行一次P-盒变换*/
    memcpy(bit,data,32);
}

void SHL(pchar bit,char step){                              /*对数据进行循环左移操作*/
    char buf[32];
    memcpy(buf,bit+28-step,step);
    memcpy(buf+step,bit,28-step);
    memcpy(bit,buf,28);
}

void MakeData(pvoid pMem,pvoid pKey,bool IsEncrypt){        /*对数据进行加密和解密*/
    char Key[70];
    static char keys[16][56];
    char Data[70];
    char C[30],D[30];
    char L[40],R[40];
    char buf[32];
    int i,j;
    unsigned long left,right;
    for (i=0;i<8;i++){                                      /*将64位密钥和原文按位转换成字节形式*/
        fillbit(Key+i*8,((char *)pKey)[i],8);
        fillbit(Data+i*8,((char *)pMem)[i],8);
    }
    ConversionBit(Key,PC1_Rule,sizeof PC1_Rule);            /*密钥进行PC1变换*/
    ConversionBit(Data,P1_Rule,sizeof P1_Rule);             /*数据进行初始换位*/
    memcpy(C,Key,28);
    memcpy(D,Key+28,28);
    memcpy(L,Data,32);
    memcpy(R,Data+32,32);
    for (i=0;i<16;i++){                                     /*生成16组子密钥*/
        SHL(C,MoveStep[i]);
        SHL(D,MoveStep[i]);
        memcpy(keys[i],C,28);
        memcpy(keys[i]+28,D,28);
        ConversionBit(keys[i],PC2_Rule,sizeof PC2_Rule);    /*密钥进行PC2变换*/
    }
    
    for (i=0;i<16;i++){                                     /*进行16轮叠代加密操作*/

        memcpy(buf,R,32);
        if (IsEncrypt)
            DESF(R,keys[i]);
        else
            DESF(R,keys[15-i]);
        for (j=0;j<32;j++)
            R[j]^=L[j];
        memcpy(L,buf,32);
    }
    memcpy(Data+32,L,32);
    memcpy(Data,R,32);
    ConversionBit(Data,P2_Rule,sizeof P2_Rule);             /*数据进行初始换位*/
    right=left=0;
    for (i=0;i<32;i++){
        left=left<<1 | Data[31-i];
        right=right<<1 | Data[31-i+32];
    }
    memcpy(pMem,&left,4);
    memcpy(((pchar)pMem)+4,&right,4);
}
    
void Encrypt64(pvoid pMem,pvoid pKey){                      /*对64位数据进行DES加密*/
    MakeData(pMem,pKey,true);
}

void Decrypt64(pvoid pMem,pvoid pKey){                      /*对64位数据进行DES加密*/
    MakeData(pMem,pKey,false);
}


void DESEncrypt(pvoid pMem,pvoid pKey,int size){            /*对数据进行DES加密*/
    pchar p=(pchar)pMem;
    while (size>0){
        Encrypt64(p,pKey);                                  /*对数据进行64位分组*/
        size-=8;
        p+=8;
    }
}

void DESDecrypt(pvoid pMem,pvoid pKey,int size){            /*对数据进行DES解密*/
    pchar p=(pchar)pMem;
    while (size>0){
        Decrypt64(p,pKey);                                  /*对数据进行64位分组*/
        size-=8;
        p+=8;
    }
}

#endif