passwords.c

/* passwords.c */

#include "wand_head.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define PASS "poppycrash"

/***************************************************
*                      scrn_passwd                 *
*            reads password num into passwd        *
****************************************************/
int scrn_passwd(int num, char *passwd)
{
    long position;
    FILE *fp;

    position = PASSWD;
    if (position < 0)
        position = -position;
    while (position > 200000)
        position -= 200000;
    if (position > 198500)
        position -= 198500;
    if ((fp = fopen(DICTIONARY, "r")) == NULL)
        return 0;
    fseek(fp, position, ftell(fp));
    while (fgetc(fp) != '\n');
    if (fscanf(fp, "%s\n", passwd) == EOF && errno != 0)
    {
        fprintf(stderr, "fscanf error\n");
        exit(EXIT_FAILURE);
    }
    /* read a word into passwd */
    fclose(fp);
    return (1);
}

/************************************************
*                    main                       *
*************************************************/
int main(int argc, char **argv)
{
    int scr, position, mpw = 0;
    char pass[20];
    char pw[100];
    if (argc < 2)
    {
        printf("Usage: %s screen1 screen2 ...\n", argv[0]);
        exit(-1);
    }
    position = 0;
    while (++position < argc)
    {
        if (atoi(argv[position]) < 1)
        {
            printf("Option not known: %s.\n", argv[position]);
            continue;
        }
        scr = atoi(argv[position]);
        if ((scr < 100) && (mpw == 0))
        {
            printf("You need clearance to see passwords below 100.\n");
            printf("Enter master password:");
            if (scanf("%s", pw) == EOF && errno != 0)
            {
                fprintf(stderr, "scanf error\n");
                exit(EXIT_FAILURE);
            }
            if (strncmp(pw, PASS, strlen(PASS)))
            {
                printf("Foo, charlatan!\n");
                exit(-1);
            }
            mpw = 1;
        }
        if (!scrn_passwd((scr - 1), pass))
        {
            printf("%s: Cannot access %s.\n", argv[0], DICTIONARY);
            exit(-1);
        }
        printf("Screen %d password is '%s'.\n", scr, pass);
    }
}