/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
* COPYRIGHT (c) 2006
* The Regents of the University of Michigan
* ALL RIGHTS RESERVED
*
* Permission is granted to use, copy, create derivative works
* and redistribute this software and such derivative works
* for any purpose, so long as the name of The University of
* Michigan is not used in any advertising or publicity
* pertaining to the use of distribution of this software
* without specific, written prior authorization. If the
* above copyright notice or any other identification of the
* University of Michigan is included in any copy of any
* portion of this software, then the disclaimer below must
* also be included.
*
* THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
* FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
* PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
* MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
* WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
* REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
* FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
* CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
* OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
* IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGES.
*/
/*
* Create a key given random data. It is assumed that random_key has
* already been initialized and random_key->contents have been allocated
* with the correct length.
*/
#include "crypto_int.h"
krb5_error_code KRB5_CALLCONV
krb5_c_random_to_key(krb5_context context, krb5_enctype enctype,
krb5_data *random_data, krb5_keyblock *random_key)
{
krb5_error_code ret;
const struct krb5_keytypes *ktp;
if (random_data == NULL || random_key == NULL ||
random_key->contents == NULL)
return EINVAL;
ktp = find_enctype(enctype);
if (ktp == NULL)
return KRB5_BAD_ENCTYPE;
if (random_key->length != ktp->enc->keylength)
return KRB5_BAD_KEYSIZE;
ret = ktp->rand2key(random_data, random_key);
if (ret)
zap(random_key->contents, random_key->length);
return ret;
}
krb5_error_code
k5_rand2key_direct(const krb5_data *randombits, krb5_keyblock *keyblock)
{
if (randombits->length != keyblock->length)
return KRB5_CRYPTO_INTERNAL;
keyblock->magic = KV5M_KEYBLOCK;
memcpy(keyblock->contents, randombits->data, randombits->length);
return 0;
}
static inline void
eighth_byte(unsigned char *b)
{
b[7] = (((b[0] & 1) << 1) | ((b[1] & 1) << 2) | ((b[2] & 1) << 3) |
((b[3] & 1) << 4) | ((b[4] & 1) << 5) | ((b[5] & 1) << 6) |
((b[6] & 1) << 7));
}
krb5_error_code
k5_rand2key_des(const krb5_data *randombits, krb5_keyblock *keyblock)
{
if (randombits->length != 7)
return(KRB5_CRYPTO_INTERNAL);
keyblock->magic = KV5M_KEYBLOCK;
/* Take the seven bytes, move them around into the top 7 bits of the
* 8 key bytes, then compute the parity bits. */
memcpy(keyblock->contents, randombits->data, randombits->length);
eighth_byte(keyblock->contents);
k5_des_fixup_key_parity(keyblock->contents);
return 0;
}
krb5_error_code
k5_rand2key_des3(const krb5_data *randombits, krb5_keyblock *keyblock)
{
int i;
if (randombits->length != 21)
return KRB5_CRYPTO_INTERNAL;
keyblock->magic = KV5M_KEYBLOCK;
/* 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(&keyblock->contents[i * 8], &randombits->data[i * 7], 7);
eighth_byte(&keyblock->contents[i * 8]);
k5_des_fixup_key_parity(&keyblock->contents[i * 8]);
}
return 0;
}