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发表于 2009-04-28 16:19 |只看该作者 |倒序浏览

cpasswd.rar (1.31 KB, 下载次数: 56)

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/select.h>
#include <sys/time.h>

#define CP_OK 0
#define CP_ERR_PARAMETER 1
#define CP_ERR_NO_OLDPASSWD 2
#define CP_ERR_NO_NEWPASSWD 3
#define CP_ERR_PIPE 3
#define CP_ERR_FORK 4
#define CP_ERR_DUP 5
#define CP_ERR_WRONG_PASSWD 6
#define CP_ERR_SIMPLE_CHK 7
#define CP_ERR_NO_MATCH 8
#define CP_ERR_OTHER 9

int main(int argc, char *argv[])
{

int fd_w[2],fd_r[2],ret;
char buf[256];
char prompt_1[]="New password:";
char prompt_2[]="Retype new password:";
char prompt_3[]="(current) UNIX password:";
char prompt_4[]="passwd: Authentication token manipulation error";
char prompt_5[]="BAD PASSWORD";
char prompt_6[]="Sorry, passwords do not match";

int i=0;
pid_t pid;
fd_set readset;

uid_t userid;
char new_password[256]={0};
char old_password[256]={0};
char user_name[256]={0};
struct timeval tv;

int ch;
while((ch = getopt(argc,argv,"n

:u:h"))!= -1)
{
      switch(ch)
      {
         case 'n':
            strncpy(new_password,optarg,30);
            strncat(new_password,"\n",1);
            break;
         case 'o':
            strncpy(old_password,optarg,30);
            strncat(old_password,"\n",1);
            break;
         case 'u':
            strncpy(user_name,optarg,30);
            break;
         default:
            printf("usage:%s -n new_password [ -o old_password :is needs if not root ] [ -u username :can use only root ]\n",argv[0]);
            return CP_ERR_PARAMETER;
      }
}

if(strlen(new_password) == 0)
{
      printf("you must specify a new password by parameter -n\n");
      printf("usage:%s -n new_password [ -o old_password :is needs if not root ] [ -u username :can use only root ]\n",argv[0]);
      return CP_ERR_NO_NEWPASSWD;
}

userid = getuid();
if(userid != 0)/*not root*/
{
      if(strlen(old_password) == 0)
      {
         printf("the current password is needs\n");
         return CP_ERR_NO_OLDPASSWD;
      }
}

FD_ZERO(&readset);
if(pipe(fd_w) != 0)
{
      perror("pipe");
      return CP_ERR_PIPE;
}

if(pipe(fd_r) != 0)
{
      perror("pipe");
      return CP_ERR_PIPE;
}

FD_SET(fd_w[0],&readset);
pid=fork();
if(pid < 0)
{
      perror("fork");
      return CP_ERR_FORK;
}
else if(pid==0)/*child*/
{

      if(dup2(fd_r[0], STDIN_FILENO) != STDIN_FILENO)
      {
         perror("dup2");
         return CP_ERR_DUP;
      }

      if(dup2(fd_w[1], STDERR_FILENO) != STDERR_FILENO)
      {
         perror("dup2");
         return CP_ERR_DUP;
      }

      close(fd_r[1]);
      close(fd_w[0]);
      close(STDOUT_FILENO);
      if(strlen(user_name))
      {
         execl("/usr/bin/passwd","passwd",user_name,(char *)0);
      }
      else
      {
         execl("/usr/bin/passwd","passwd",(char *)0);
      }
}
else/*parent*/
{

      close(fd_r[0]);
      close(fd_w[1]);
      /* Wait up to 3 seconds. */
      tv.tv_sec = 3;
      tv.tv_usec = 0;
      for(;;)
      {
         memset(buf,0,256);
         ret=select(fd_w[0]+1,&readset,NULL,NULL,&tv);
         if(ret < 0)
         {
            return CP_ERR_OTHER;
         }

         if(FD_ISSET(fd_w[0],&readset))
         {
            read(fd_w[0],buf,256);
         }
         else
         {
            return CP_ERR_OTHER;
         }

         if(strlen(buf))
         {
            if(userid != 0)
            {

                  if (strstr(buf,prompt_3))
                  {
                     write(fd_r[1],old_password,strlen(old_password));
                  }
                  if(strstr(buf,prompt_4))
                  {
                     return CP_ERR_WRONG_PASSWD;
                  }
                  if( strstr(buf,prompt_5))
                  {
                     return CP_ERR_SIMPLE_CHK;
                  }
                  if(strstr(buf,prompt_6))
                  {
                     return CP_ERR_NO_MATCH;
                  }

            }
            if(strstr(buf,prompt_1) || strstr(buf,prompt_2))
            {
                  write(fd_r[1],new_password,strlen(new_password));
                  i++;
                  if(i==2)
                  {
                     return CP_OK;
                  }
            }
         }
      }
}
}