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/*
* Copyright (C) 1998 by the FundsXpress, INC.
*
* All rights reserved.
*
* Export of this software from the United States of America may require
* a specific license from the United States Government. It is the
* responsibility of any person or organization contemplating export to
* obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of FundsXpress. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. FundsXpress makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#include "k5-int.h"
#include "des_int.h"
static const mit_des_cblock mit_des_zeroblock[8] /* = all zero */;
static void
k5_des3_block_size(size_t *blocksize)
{
*blocksize = 8;
}
static void
k5_des3_keysize(size_t *keybytes, size_t *keylength)
{
*keybytes = 21;
*keylength = 24;
}
static krb5_error_code
k5_des3_docrypt(const krb5_keyblock *key, const krb5_data *ivec,
const krb5_data *input, krb5_data *output, int encrypt)
{
mit_des3_key_schedule schedule;
/* key->enctype was checked by the caller */
if (key->length != 24)
return(KRB5_BAD_KEYSIZE);
if ((input->length%8) != 0)
return(KRB5_BAD_MSIZE);
if (ivec && (ivec->length != 8))
return(KRB5_BAD_MSIZE);
if (input->length != output->length)
return(KRB5_BAD_MSIZE);
switch (mit_des3_key_sched(*(mit_des3_cblock *)key->contents,
schedule)) {
case -1:
return(KRB5DES_BAD_KEYPAR);
case -2:
return(KRB5DES_WEAK_KEY);
}
/* this has a return value, but the code always returns zero */
mit_des3_cbc_encrypt((krb5_pointer) input->data,
(krb5_pointer) output->data, input->length,
schedule[0], schedule[1], schedule[2],
ivec?ivec->data:(char *)mit_des_zeroblock,
encrypt);
memset(schedule, 0, sizeof(schedule));
return(0);
}
static krb5_error_code
k5_des3_encrypt(const krb5_keyblock *key, const krb5_data *ivec,
const krb5_data *input, krb5_data *output)
{
return(k5_des3_docrypt(key, ivec, input, output, 1));
}
static krb5_error_code
k5_des3_decrypt(const krb5_keyblock *key, const krb5_data *ivec,
const krb5_data *input, krb5_data *output)
{
return(k5_des3_docrypt(key, ivec, input, output, 0));
}
static krb5_error_code
k5_des3_make_key(const krb5_data *randombits, krb5_keyblock *key)
{
int i;
if (key->length != 24)
return(KRB5_BAD_KEYSIZE);
if (randombits->length != 21)
return(KRB5_CRYPTO_INTERNAL);
key->magic = KV5M_KEYBLOCK;
key->length = 24;
/* take the seven bytes, move them around into the top 7 bits of the
8 key bytes, then compute the parity bits. Do this three times. */
for (i=0; i<3; i++) {
memcpy(key->contents+i*8, randombits->data+i*7, 7);
key->contents[i*8+7] = (((key->contents[i*8]&1)<<1) |
((key->contents[i*8+1]&1)<<2) |
((key->contents[i*8+2]&1)<<3) |
((key->contents[i*8+3]&1)<<4) |
((key->contents[i*8+4]&1)<<5) |
((key->contents[i*8+5]&1)<<6) |
((key->contents[i*8+6]&1)<<7));
mit_des_fixup_key_parity(key->contents+i*8);
}
return(0);
}
const struct krb5_enc_provider krb5_enc_des3 = {
k5_des3_block_size,
k5_des3_keysize,
k5_des3_encrypt,
k5_des3_decrypt,
k5_des3_make_key
};
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