mit_stringtokey.c

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#ifdef M_KERB
/*
 * $Id: mit_stringtokey.c,v 1.1.1.1 2001/08/10 20:49:28 bonze Exp $
 *
 * Copyright 1985, 1986, 1987, 1988, 1989 by the Massachusetts Institute
 * of Technology.
 *
 * For copying and distribution information, please see the file
 * <mit-copyright.h>.
 *
 * These routines perform encryption and decryption using the DES
 * private key algorithm, or else a subset of it-- fewer inner loops.
 * (AUTH_DES_ITER defaults to 16, may be less.)
 *
 * Under U.S. law, this software may not be exported outside the US
 * without license from the U.S. Commerce department.
 *
 * The key schedule is passed as an arg, as well as the cleartext or
 * ciphertext.  The cleartext and ciphertext should be in host order.
 *
 * These routines form the library interface to the DES facilities.
 *
 *	spm	8/85	MIT project athena
 */

#ifndef	lint
static char     rcsid_string_to_key_c[] =
"$Id: mit_stringtokey.c,v 1.1.1.1 2001/08/10 20:49:28 bonze Exp $";

#endif	/* lint */

#include <mit-copyright.h>
#include <stdio.h>
#include <memory.h>
#include <des.h>
/*#include "des_internal.h"*/

#if 1
#include <krb.h>
#endif

extern int      des_debug;
extern int      des_debug_print ();
extern void     des_fixup_key_parity ();

/*
 * convert an arbitrary length string to a DES key
 */
int
mit_string_to_key (str, key)

char           *str;
register des_cblock *key;

{
	register char  *in_str;
	register unsigned temp,
	                i;
	register int    j;
	register long   length;
	static unsigned char *k_p;
	static int      forward;
	register char  *p_char;
	static char     k_char[64];
	static des_key_schedule key_sked;
	extern unsigned long des_cbc_cksum ();

	in_str = str;
	forward = 1;
	p_char = k_char;
	length = strlen (str);

	/* init key array for bits */
	memset (k_char, '\0', sizeof (k_char));

	/* get next 8 bytes, strip parity, xor */
	for (i = 1; i <= length; i++)
	{
		/* get next input key byte */
		temp = (unsigned int) *str++;
		/* loop through bits within byte, ignore parity */
		for (j = 0; j <= 6; j++)
		{
			if (forward)
				*p_char++ ^= (int) temp & 01;
			else
				*--p_char ^= (int) temp & 01;
			temp = temp >> 1;
		} while (--j > 0);

		/* check and flip direction */
		if ((i % 8) == 0)
			forward = !forward;
	}

	/* now stuff into the key des_cblock, and force odd parity */
	p_char = k_char;
	k_p = (unsigned char *) key;

	for (i = 0; i <= 7; i++)
	{
		temp = 0;
		for (j = 0; j <= 6; j++)
			temp |= *p_char++ << (1 + j);
		*k_p++ = (unsigned char) temp;
	}

	/* fix key parity */
	des_fixup_key_parity (key);

	/* Now one-way encrypt it with the folded key */
	(void) des_key_sched (key, key_sked);
	(void) des_cbc_cksum ((des_cblock *) in_str, key, length, key_sked, key);
	/* erase key_sked */
	memset ((char *) key_sked, '\0', sizeof (key_sked));

	/* now fix up key parity again */
	des_fixup_key_parity (key);

}

int 
mit_passwd_to_key (user, instance, realm, passwd, key)

char           *user;
char           *instance;
char           *realm;
char           *passwd;
C_Block         key;

{
	mit_string_to_key (passwd, key);
	return (0);
}
#endif	/* #ifdef M_KERB */