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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 "dk.h"
krb5_error_code
krb5_derive_key(const struct krb5_enc_provider *enc,
const krb5_keyblock *inkey, krb5_keyblock *outkey,
const krb5_data *in_constant)
{
size_t blocksize, keybytes, n;
unsigned char *inblockdata = NULL, *outblockdata = NULL, *rawkey = NULL;
krb5_data inblock, outblock;
krb5_error_code ret;
blocksize = enc->block_size;
keybytes = enc->keybytes;
if (inkey->length != enc->keylength || outkey->length != enc->keylength)
return KRB5_CRYPTO_INTERNAL;
/* Allocate and set up buffers. */
inblockdata = k5alloc(blocksize, &ret);
if (ret)
goto cleanup;
outblockdata = k5alloc(blocksize, &ret);
if (ret)
goto cleanup;
rawkey = k5alloc(keybytes, &ret);
if (ret)
goto cleanup;
inblock.data = (char *) inblockdata;
inblock.length = blocksize;
outblock.data = (char *) outblockdata;
outblock.length = blocksize;
/* Initialize the input block. */
if (in_constant->length == inblock.length) {
memcpy(inblock.data, in_constant->data, inblock.length);
} else {
krb5_nfold(in_constant->length*8, (unsigned char *) in_constant->data,
inblock.length*8, (unsigned char *) inblock.data);
}
/* Loop encrypting the blocks until enough key bytes are generated */
n = 0;
while (n < keybytes) {
ret = (*enc->encrypt)(inkey, 0, &inblock, &outblock);
if (ret)
goto cleanup;
if ((keybytes - n) <= outblock.length) {
memcpy(rawkey + n, outblock.data, (keybytes - n));
break;
}
memcpy(rawkey+n, outblock.data, outblock.length);
memcpy(inblock.data, outblock.data, outblock.length);
n += outblock.length;
}
/* postprocess the key */
inblock.data = (char *) rawkey;
inblock.length = keybytes;
ret = (*enc->make_key)(&inblock, outkey);
if (ret)
goto cleanup;
cleanup:
zapfree(inblockdata, blocksize);
zapfree(outblockdata, blocksize);
zapfree(rawkey, keybytes);
return ret;
}
krb5_error_code
krb5_derive_random(const struct krb5_enc_provider *enc,
const krb5_keyblock *inkey, krb5_data *outrnd,
const krb5_data *in_constant)
{
size_t blocksize, keybytes, n;
unsigned char *inblockdata = NULL, *outblockdata = NULL, *rawkey = NULL;
krb5_data inblock, outblock;
krb5_error_code ret;
blocksize = enc->block_size;
keybytes = enc->keybytes;
if (inkey->length != enc->keylength || outrnd->length != keybytes)
return KRB5_CRYPTO_INTERNAL;
/* Allocate and set up buffers. */
inblockdata = k5alloc(blocksize, &ret);
if (ret)
goto cleanup;
outblockdata = k5alloc(blocksize, &ret);
if (ret)
goto cleanup;
rawkey = k5alloc(keybytes, &ret);
if (ret)
goto cleanup;
inblock.data = (char *) inblockdata;
inblock.length = blocksize;
outblock.data = (char *) outblockdata;
outblock.length = blocksize;
/* Initialize the input block. */
if (in_constant->length == inblock.length) {
memcpy(inblock.data, in_constant->data, inblock.length);
} else {
krb5_nfold(in_constant->length*8, (unsigned char *) in_constant->data,
inblock.length*8, (unsigned char *) inblock.data);
}
/* Loop encrypting the blocks until enough key bytes are generated. */
n = 0;
while (n < keybytes) {
ret = (*enc->encrypt)(inkey, 0, &inblock, &outblock);
if (ret)
goto cleanup;
if ((keybytes - n) <= outblock.length) {
memcpy(rawkey + n, outblock.data, (keybytes - n));
break;
}
memcpy(rawkey+n, outblock.data, outblock.length);
memcpy(inblock.data, outblock.data, outblock.length);
n += outblock.length;
}
/* Postprocess the key. */
memcpy(outrnd->data, rawkey, keybytes);
cleanup:
zapfree(inblockdata, blocksize);
zapfree(outblockdata, blocksize);
zapfree(rawkey, keybytes);
return ret;
}
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