3.6.1 加密工具实现源代码
下面列出按照上述操作思路编写的实现源代码
/**********************************************************************/
/*-文件名：idea.c */
/*- */
/*-功能： 利用idea加密算法实现文件的加密 */
/*- */
/*-说明： */
/*- 这是利用IDEA算法实现的文件加密工具可以在法律允许范围内以非商 */
/*-业形式自由使用,该程序的所有权利由作者吴真保留 */
/*- */
/*-版本号：1.0.0(2002.6) */
/*-AUTHOR:吴真(WUZHEN) */
/*- */
/*********************************************************************/
#include
#include
#include
#include
#include
#include "idea.h"
typedef int INT32;
typedef char INT8;
typedef unsigned char ULONG8;
typedef unsigned short ULONG16;
typedef unsigned long ULONG32;
#define SUCCESS 0
#define FAIL -1
#define WZ_COMMEND_NUM 4
#define WZUSEHELPNUM 7
#define READFILESIZE 512 /*一次从文件中读取多少字节,可以根据内存的大小调节*/
INT32 file_enc( FILE *readfile, FILE *writefile,ULONG8 *key);/*加密文件*/
INT32 file_dec( FILE *readfile, FILE *writefile,ULONG8 *key);/*解密文件*/
INT32 hextofile( ULONG8 *buf ,FILE *writefile, ULONG32 length);/*以16进制写入文件*/
INT32 encodehex(ULONG8 *tobuf,ULONG8 *frombuf,ULONG32 len);/*16进制解码*/
void wz_printhelp();/*打印帮助*/
INT8 *WZ_Commend_Help[] =
{
"基于IDEA的加密解密工具v1.0 ",/*0*/
"追求卓越,勇于创新 ",
"----著者 : 吴真--- ",
" "
};
INT8 *WZ_USE_HELP[]={
"输入5个参数:",
"\t1.可执行文件名 *.exe",
"\t2.操作类型 1:加密;2:解密;",
"\t3.读出数据的文件名*.txt",
"\t4.写入数据的文件名*.txt",
"\t5.密钥(32字节)",
"******************************"
};
void main(INT32 argc,INT8 *argv[])
{
INT8 *FILENAME1,*FILENAME2;
FILE *fp, *fp2;
ULONG8 key[33] = { 0 }; /*密钥容器*/
if ( argc != 5 )
{
wz_printhelp();
return;
}
FILENAME1 = argv[2];
FILENAME2 = argv[3];
if ((fp= fopen(FILENAME1,"r+b")) == NULL || (fp2 = fopen(FILENAME2,"w+b"))==NULL)
{
printf("Can't open file\n");
return ;
}
memcpy( key, argv[4] , strlen( argv[4]) );/*取得密钥*/
switch( atoi(argv[1] ))
{
case 1:/*加密操作*/
file_enc(fp,fp2,key);
printf("\n \t IDEA 加密完毕,密文存于%s文件\n",FILENAME2);
break;
case 2:
/*解密*/
file_dec(fp,fp2,key);
printf("\n\t IDEA解密完毕,明文存于%s文件\n",FILENAME2);
break;
default:
printf("请选择是加密|解密 plese choose encrypt|deencrypt\n");
break;
}
fclose(fp);
fclose(fp2);
}
INT32 hextofile( ULONG8 *buf ,FILE *writefile, ULONG32 length)
{
ULONG32 writelen = 0 ;
/*以16进制形式写入文件*/
while( writelen < length)
{
if(buf[writelen] == 0)
{
fprintf( writefile, "%x", 0 );
fprintf( writefile, "%x", 0 );
}
else if (buf[writelen] < 0x10)
{
fprintf( writefile, "%x", 0 );
fprintf( writefile, "%x", buf[writelen] );
}
else
{
fprintf( writefile, "%x", buf[writelen] );
}
writelen++;
}
return SUCCESS;
}
INT32 file_enc( FILE *readfile, FILE *writefile,ULONG8 *key)
{
INT32 filelen = 0,readlen = 0,writelen = 0;
ULONG32 totalfilelen = 0 ;/*统计实际的文件的长度*/
INT32 i;
ULONG8 readbuf[READFILESIZE] = { 0 };
idea_makekey( (ULONG32*)key , outkey);
filelen = fread( readbuf, sizeof( INT8 ), READFILESIZE, readfile );
while( filelen == READFILESIZE )
{
totalfilelen += READFILESIZE;
for ( i = 0 ; i < READFILESIZE ; i += 8)
{
idea_enc( (ULONG16*)&readbuf[i] );/*加密*/
}
hextofile( readbuf, writefile, READFILESIZE );/*以16进制形式写入文件*/
memset(readbuf,0,READFILESIZE);
filelen = fread( readbuf, sizeof( INT8 ), READFILESIZE, readfile );
}
/*这是从文件中读出的最后一批数据,长度可能会等于0,所以要先判断*/
if ( filelen > 0 )
{
/*如果从文件中读出的长度不等于0,那么肯定有8个字节以上的空间
文件长度存在最后8个字节中*/
totalfilelen += filelen;
memcpy( &readbuf[READFILESIZE-8], (ULONG8*)&totalfilelen,4);
for ( i = 0 ; i < READFILESIZE ; i += 8)
{
idea_enc( (ULONG16*)&readbuf[i]);/*加密*/
}
hextofile( readbuf, writefile,READFILESIZE );/*以16进制形式写入文件*/
memset(readbuf,0 ,READFILESIZE);
}
else /*filelen == 0*/
{
memcpy( &readbuf[0], (ULONG8*)&totalfilelen,4);
idea_enc( (ULONG16*)&readbuf[0] );/*加密*/
hextofile( readbuf, writefile, 8);/*以16进制形式写入文件*/
}
return SUCCESS;
}
INT32 file_dec( FILE *readfile, FILE *writefile,ULONG8 *key)
{
INT32 filelen = 0,readlen = 0,writelen = 0;
ULONG32 totalfilelen = 0 ;/*统计实际的文件的长度*/
INT32 i,num;
ULONG8 readbuf[READFILESIZE] = { 0 };
ULONG8 sendbuf[READFILESIZE*2] = { 0 };
idea_makekey( (ULONG32*)key , outkey);
key_decryExp(outkey);
fseek(readfile,-16,SEEK_END);/*最后16个字节的表示文件长度的空间*/
filelen = fread( sendbuf, sizeof( INT8 ), 16, readfile );
encodehex( readbuf,sendbuf,8);
idea_dec( (ULONG16*)&readbuf[0] );/*解密*/
memcpy((ULONG8*)&totalfilelen, &readbuf[0],4);/*得到文件总长*/
memset(readbuf,0 ,8);
memset(sendbuf,0 ,16);
num = totalfilelen/READFILESIZE;/*有几个READFILESIZE组*/
totalfilelen %= READFILESIZE;
fseek(readfile,0,SEEK_SET);/*跳到文件头*/
while(num--)
{
filelen = fread( sendbuf, sizeof( INT8 ), READFILESIZE*2, readfile );
encodehex( readbuf,sendbuf,READFILESIZE);
for ( i = 0 ; i < READFILESIZE ; i += 8)
{
idea_dec( (ULONG16*)&readbuf[i] );/*解密*/
}
writelen = fwrite(readbuf, sizeof( INT8 ), READFILESIZE, writefile);
memset(readbuf,0 ,READFILESIZE);
memset(sendbuf,0 ,READFILESIZE*2);
}
if ( totalfilelen > 0 )/*最后一块有多余的元素*/
{
filelen = fread( sendbuf, sizeof( INT8 ), READFILESIZE*2, readfile );
encodehex( readbuf,sendbuf,READFILESIZE);
for ( i = 0 ; i < READFILESIZE ; i += 8)
{
idea_dec( (ULONG16*)&readbuf[i] );/*解密*/
}
writelen = fwrite(readbuf, sizeof( INT8 ), totalfilelen, writefile);
memset(readbuf,0 ,READFILESIZE);
memset(sendbuf,0 ,READFILESIZE*2);
}
return SUCCESS;
}
INT32 encodehex(ULONG8 *tobuf,ULONG8 *frombuf,ULONG32 len)
{
ULONG8 *readfirst = frombuf ;
ULONG8 *readend = &frombuf[1] ;
INT8 *s;
ULONG8 y[2] ;
ULONG32 i;
for ( i = 0 ; i < len ; i++)
{
y[0] = *readfirst ;
y[1] = *readend ;
readfirst += 2 ;
readend += 2 ;
tobuf[i] = (ULONG8)strtol((INT8*)y, &s, 16);
}
return SUCCESS;
}
void wz_printhelp()
{
INT32 i ;
printf("\t");
for ( i = 0 ; i < 22 ; i++)
{
printf("%c ",5);
}
printf("\n");
for( i = 0 ; i < WZ_COMMEND_NUM ; i++)
{
printf("\t%c\t%s %c\n",5,WZ_Commend_Help[i],5);
}
printf("\t");
for ( i = 0 ; i < 22 ; i++)
{
printf("%c ",5);
}
printf("\n");
for( i = 0 ; i < WZUSEHELPNUM ; i++)
{
printf("\t%s\n",WZ_USE_HELP[i]);
}
return ;
}
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