common.c

采用非对称密钥加密方式的应用系统认证系统

#include "common.h"

int SetNonblock(int fd)
{
  int flags;
  if((flags=fcntl(fd,F_GETFL,0))==-1) {
      CommonShow("SetNonBlock Get error!");
      return(-abs(errno));
  }
  flags|=O_NONBLOCK;

  if(fcntl(fd,F_SETFL,flags)==-1) {
      CommonShow("SetNonBlock Set error!");
      return(-abs(errno));
  }
  return(0);
}
/*******************************************************************************/
int SetBlock(int fd)
{
  int flags;
  if((flags=fcntl(fd,F_GETFL,0))==-1) {
      CommonShow("SetBlock Get error!");
      return(-abs(errno));
  }
  flags&=~O_NONBLOCK;

  if(fcntl(fd,F_SETFL,flags)==-1) {
      CommonShow("SetBlock Set error!");
      return(-abs(errno));
  }
  return(0);
}
/**/
int Readn(int Fd,char *Buf,int n)
{
  int m;
  int ReadNum;
  char *p;
  p=Buf;
  m=n;
ReadnAgain:
	if((ReadNum=read(Fd,p,m))<0)
	{
	    if(errno==EINTR || errno==EAGAIN)
                goto ReadnAgain;
            else if(errno==ECONNRESET)
                 return(0);
            CommonShow("Readn");
            return(-abs(errno));
	}
	else if (ReadNum==0)
                return(0);
             else {
                p+=ReadNum;
                m-=ReadNum;
		if(m==0)
		{
		    *p=0;
		    return(n);
		}
		else if(m>0) {
                         goto ReadnAgain;
                     }
                     else {
                         CommonShow("Unexpected fatal error");
                         *p=0;
                         return(-10000);
                          }
                }
}

/*将十六进制转化为十进制*/
int HexToInt(char *h,int n)
{
	int s;
	int i;
	int a[10];
	if(n==0) n=strlen(h);
    for(i=0;i<n;i++)
        if((h[i]>='0')&&(h[i]<='9'))
            a[i]=h[i]-48;
        else if((h[i]>='A')&&(h[i]<='F'))
            a[i]=h[i]-55;
        else if((h[i]>='a')&&(h[i]<='f'))
            a[i]=h[i]-87;
        else 
        {
            CommonShow("Error,The string is not a hex string:HexToDeci");
            return(-10000);
        }
   	s=a[0];
	for(i=1;i<n;i++)
		s=s*16+a[i];
	return(s);
}

int IntToHex(char *bufback, int iValue)
{
  sprintf(bufback, "%4X", iValue);
}

/*取系统时间*/
void SysTime(int *year,int *mon,int *day,int *hour,int *min,int *sec)
{
    struct tm *tt;
    time_t secs;
    time(&secs);
    tt=localtime(&secs);
    *year=tt->tm_year+1900;
    *mon=tt->tm_mon+1;
    *day=tt->tm_mday;
    *hour=tt->tm_hour;
    *min=tt->tm_min;
    *sec=tt->tm_sec;
}
/*************************************************************/
/*取系统时间*/
void GetSysTime(char *t)
{
	int year,mon,day,hour,min,sec;
	SysTime(&year,&mon,&day,&hour,&min,&sec);
	sprintf(t,"%04d%02d%02d%02d%02d%02d",year,mon,day,hour,min,sec);
}
/******************************************************************************/
void CommonShow(char *w)
{
    char message[200];
    GetSysTime(message);
    sprintf(message+14," :%8d: %s\n",getpid(),w);
    printf("%s", message);      
}

/*************************************************/
/**  解密函数                                   **/
/*************************************************/
void decodekey(char *source,char *dest)   
{
    char *s;
    char highchar[4] = {0x41,0x01,0x40,0x00};
    int i,len,cnt,li_loop;
    char cc,c1,c2,c3,c4;
    len = strlen(source);
    cnt = len / 4;
    for (li_loop = 0;li_loop < cnt;li_loop ++)
    {
    	s = source;
    	cc = c1 = c2 = 0x00;
    	for(i=3;i>=0;)
    	{
	c2 <<= 2;
	cc = s[li_loop*4 + i];
	c4 = cc & 0x41;
	switch (c4)
	{
	    case 65:
		c1 = 0;
		break;
            case 1:
		c1 = 1;
                break;
            case 0x40:
		c1 = 0x02;
		break;
            case 0:
		c1 = 0x03;
		break;
            default:
		break;
          }
	  c2 = c1 | c2;
	  i--;
      }
      c3 = ~c2;
      dest[li_loop] = c3; 
      dest[li_loop + 1] = 0x00;
      }
}
/*************************************************/