RE: Simple but effective Disk Wipe Software

["dave kleiman" <dave () isecureu com>]

Here are a few:

http://sourceforge.net/projects/eraser/

http://sourceforge.net/projects/dban/


I have one that we made ourselves, will gladly e-mail it to you ( no
warranties our guaranties expressed or implied)



Here is C Code for one from: Keith Oxenrider (koxenrider () sol-biotech com)


/*******************************************
    wipeIt.c

    A program for writing random data to disk
    in an attempt to erase any preexisting data.

    It was written for Windows, but should be
    easily addapted for any UNIX variant
    (or any with an ANSI compatible C compiler).

    Written/Addapted by Keith Oxenrider (koxenrider () sol-biotech com)

    This program is hereby placed in the public domain, use as you will.

    This program has no warrentee, expressed or implied.

    Use at your own risk!

 ******************************************/

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

typedef unsigned long uint32; /* this value must be 32 bits in length! */
#define WIPENUM 1024          /* the block size for writing to disk, can be
optimized by OS */

/*
    prng adapted from http://www.math.keio.ac.jp/~matumoto/cokus.c 
    Cokus () math washington edu and matumoto () math keio ac jp
*/

#define N              (624)                 /* length of state vector */
#define M              (397)                 /* a period parameter */
#define K              (0x9908B0DFU)         /* a magic constant */
#define hiBit(u)       ((u) & 0x80000000U)   /* mask all but highest   bit
of u */
#define loBit(u)       ((u) & 0x00000001U)   /* mask all but lowest    bit
of u */
#define loBits(u)      ((u) & 0x7FFFFFFFU)   /* mask     the highest   bit
of u */
#define mixBits(u, v)  (hiBit(u)|loBits(v))  /* move hi bit of u to hi bit
of v */

static uint32   state[N+1];     /* state vector + 1 extra to not violate
ANSI C */
static uint32   *next;          /* next random value is computed from here
*/
static int      left = -1;      /* can *next++ this many times before
reloading */

void seedMT(uint32 seed){
    register uint32 x = (seed | 1U) & 0xFFFFFFFFU, *s = state;
    register int    j;

    for(left=0, *s++=x, j=N; --j;
        *s++ = (x*=69069U) & 0xFFFFFFFFU);
}

uint32 reloadMT(void){
    register uint32 *p0=state, *p2=state+2, *pM=state+M, s0, s1;
    register int    j;

    if(left < -1)
        seedMT(4357U);

    left=N-1, next=state+1;

    for(s0=state[0], s1=state[1], j=N-M+1; --j; s0=s1, s1=*p2++)
        *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);

    for(pM=state, j=M; --j; s0=s1, s1=*p2++)
        *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);

    s1=state[0], *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
    s1 ^= (s1 >> 11);
    s1 ^= (s1 <<  7) & 0x9D2C5680U;
    s1 ^= (s1 << 15) & 0xEFC60000U;
    return(s1 ^ (s1 >> 18));
}


uint32 randomMT(void){
    uint32 y;

    if(--left < 0)
        return(reloadMT());

    y  = *next++;
    y ^= (y >> 11);
    y ^= (y <<  7) & 0x9D2C5680U;
    y ^= (y << 15) & 0xEFC60000U;
    return(y ^ (y >> 18));
}

void Usage(char * argv[]){
    fprintf(stderr, "Usage: %s <drive letter (no colon!)>\n", argv[0]);
    fprintf(stderr, "\n");
    fprintf(stderr, "This program writes randomly generated data to the
root\n");
    fprintf(stderr, "directory of the drive given (this implementation is
intended\n");
    fprintf(stderr, "for Windows) until it is full (file name is 'wipe.dat',
be\n");
    fprintf(stderr, "sure that name is not in use!), then deletes the
file.\n");
    fprintf(stderr, "The purposes of this exercise is to overwrite any
deleted data.\n");
    fprintf(stderr, "\n");
    fprintf(stderr, "The prng is adapted from
http://www.math.keio.ac.jp/~matumoto/cokus.c\n";);
    fprintf(stderr, "\n");
    fprintf(stderr, "Written 2/11/2003 by Keith Oxenrider
(koxenrider () sol-biotech com)\n");
    fprintf(stderr, "\n");
    fprintf(stderr, "Press enter to quit.\n");
    getchar();
    exit(1);
}

int main(int argc, char * argv[]){
    FILE *fwipe;
    uint32 dat[WIPENUM];
    char fileName[] = "0:\\wipe.dat";
    size_t retval;
    uint32 cnt = 0;
    int i;
    time_t timeTot, elapsedTime;

    if (argc != 2)
        Usage(argv);
    if (strlen(argv[1]) != 1)
        Usage(argv);
    if (!isalpha(argv[1][0]))
        Usage(argv);

    fileName[0] = argv[1][0];

    seedMT((uint32)time(NULL));

    if ((fwipe = fopen(fileName, "r")) != NULL){
        fprintf(stderr, "\n\n\t%s already exists!\n\n\n", fileName);
        fclose(fwipe);
        Usage(argv);
    }

    if ((fwipe = fopen(fileName, "wb")) == NULL){
        fprintf(stderr, "\n\n\tCannot open %s!\n\n\n", fileName);
        Usage(argv);
    }

    fprintf(stderr, "sizeof(dat): %d, sizeof(uint32): %d, WIPENUM: %d\n",
sizeof(dat), sizeof(uint32), WIPENUM);

    time(&timeTot);

    while ((retval = fwrite(dat, sizeof(dat), 1, fwipe)) == 1){
        for (i=0;i<WIPENUM;i++){
            dat[i] = randomMT();
        }

        cnt += sizeof(dat);
        if (cnt % (sizeof(dat) * 20000) == 0){
            elapsedTime = time(NULL) - timeTot;
            fprintf(stderr, "Have written %d bytes in %d:%01d\n", cnt,
(elapsedTime / 60), (elapsedTime % 60));
        }
    }
    fclose(fwipe);
    remove(fileName);

    elapsedTime = time(NULL) - timeTot;
    fprintf(stderr, "Fini.  Wrote %d bytes in %d:%01d min\n", cnt,
(elapsedTime / 60), (elapsedTime % 60));
    fprintf(stderr, "Press enter to quit.\n");
    getchar();

    return 0;
}



 

-----Original Message-----
From: Keith Bucknall [mailto:keith.bucknall () zen co uk] 
Sent: Monday, November 08, 2004 17:26
To: security-basics () securityfocus com
Subject: Simple but effective Disk Wipe Software
Importance: High

Dear All,

I know a few weeks ago we had a post on someone putting a post up about
returning a Hard Disk to Dell.

Well at my last place of work we used Paragon Disk Wiper Pro which states it
wipes Hard Disks to DoD standard.  I am looking for a simple but effective
Boot type of wiping software for our old stock of PC's that we have just
upgraded.

My Director does not want to spend any money as he feel's a standard
"format" will suffice; therefore I guess a Linux solution is the best.  I am
wondering what people would recommend, we do not have High Classified
documents put I would like something a little more than a standard format.

Kind Regards

Keith Bucknall