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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <sys/zfs_context.h>
#include <modes/modes.h>
#include <sys/crypto/common.h>
#include <sys/crypto/impl.h>
#include <sys/byteorder.h>
/*
* Encrypt and decrypt multiple blocks of data in counter mode.
*/
int
ctr_mode_contiguous_blocks(ctr_ctx_t *ctx, char *data, size_t length,
crypto_data_t *out, size_t block_size,
int (*cipher)(const void *ks, const uint8_t *pt, uint8_t *ct),
void (*xor_block)(uint8_t *, uint8_t *))
{
size_t remainder = length;
size_t need = 0;
uint8_t *datap = (uint8_t *)data;
uint8_t *blockp;
uint8_t *lastp;
void *iov_or_mp;
offset_t offset;
uint8_t *out_data_1;
uint8_t *out_data_2;
size_t out_data_1_len;
uint64_t lower_counter, upper_counter;
if (length + ctx->ctr_remainder_len < block_size) {
/* accumulate bytes here and return */
memcpy((uint8_t *)ctx->ctr_remainder + ctx->ctr_remainder_len,
datap,
length);
ctx->ctr_remainder_len += length;
ctx->ctr_copy_to = datap;
return (CRYPTO_SUCCESS);
}
lastp = (uint8_t *)ctx->ctr_cb;
crypto_init_ptrs(out, &iov_or_mp, &offset);
do {
/* Unprocessed data from last call. */
if (ctx->ctr_remainder_len > 0) {
need = block_size - ctx->ctr_remainder_len;
if (need > remainder)
return (CRYPTO_DATA_LEN_RANGE);
memcpy(&((uint8_t *)ctx->ctr_remainder)
[ctx->ctr_remainder_len], datap, need);
blockp = (uint8_t *)ctx->ctr_remainder;
} else {
blockp = datap;
}
/* ctr_cb is the counter block */
cipher(ctx->ctr_keysched, (uint8_t *)ctx->ctr_cb,
(uint8_t *)ctx->ctr_tmp);
lastp = (uint8_t *)ctx->ctr_tmp;
/*
* Increment Counter.
*/
lower_counter = ntohll(ctx->ctr_cb[1] & ctx->ctr_lower_mask);
lower_counter = htonll(lower_counter + 1);
lower_counter &= ctx->ctr_lower_mask;
ctx->ctr_cb[1] = (ctx->ctr_cb[1] & ~(ctx->ctr_lower_mask)) |
lower_counter;
/* wrap around */
if (lower_counter == 0) {
upper_counter =
ntohll(ctx->ctr_cb[0] & ctx->ctr_upper_mask);
upper_counter = htonll(upper_counter + 1);
upper_counter &= ctx->ctr_upper_mask;
ctx->ctr_cb[0] =
(ctx->ctr_cb[0] & ~(ctx->ctr_upper_mask)) |
upper_counter;
}
/*
* XOR encrypted counter block with the current clear block.
*/
xor_block(blockp, lastp);
crypto_get_ptrs(out, &iov_or_mp, &offset, &out_data_1,
&out_data_1_len, &out_data_2, block_size);
/* copy block to where it belongs */
memcpy(out_data_1, lastp, out_data_1_len);
if (out_data_2 != NULL) {
memcpy(out_data_2, lastp + out_data_1_len,
block_size - out_data_1_len);
}
/* update offset */
out->cd_offset += block_size;
/* Update pointer to next block of data to be processed. */
if (ctx->ctr_remainder_len != 0) {
datap += need;
ctx->ctr_remainder_len = 0;
} else {
datap += block_size;
}
remainder = (size_t)&data[length] - (size_t)datap;
/* Incomplete last block. */
if (remainder > 0 && remainder < block_size) {
memcpy(ctx->ctr_remainder, datap, remainder);
ctx->ctr_remainder_len = remainder;
ctx->ctr_copy_to = datap;
goto out;
}
ctx->ctr_copy_to = NULL;
} while (remainder > 0);
out:
return (CRYPTO_SUCCESS);
}
int
ctr_mode_final(ctr_ctx_t *ctx, crypto_data_t *out,
int (*encrypt_block)(const void *, const uint8_t *, uint8_t *))
{
uint8_t *lastp;
void *iov_or_mp;
offset_t offset;
uint8_t *out_data_1;
uint8_t *out_data_2;
size_t out_data_1_len;
uint8_t *p;
int i;
if (out->cd_length < ctx->ctr_remainder_len)
return (CRYPTO_DATA_LEN_RANGE);
encrypt_block(ctx->ctr_keysched, (uint8_t *)ctx->ctr_cb,
(uint8_t *)ctx->ctr_tmp);
lastp = (uint8_t *)ctx->ctr_tmp;
p = (uint8_t *)ctx->ctr_remainder;
for (i = 0; i < ctx->ctr_remainder_len; i++) {
p[i] ^= lastp[i];
}
crypto_init_ptrs(out, &iov_or_mp, &offset);
crypto_get_ptrs(out, &iov_or_mp, &offset, &out_data_1,
&out_data_1_len, &out_data_2, ctx->ctr_remainder_len);
memcpy(out_data_1, p, out_data_1_len);
if (out_data_2 != NULL) {
memcpy(out_data_2,
(uint8_t *)p + out_data_1_len,
ctx->ctr_remainder_len - out_data_1_len);
}
out->cd_offset += ctx->ctr_remainder_len;
ctx->ctr_remainder_len = 0;
return (CRYPTO_SUCCESS);
}
int
ctr_init_ctx(ctr_ctx_t *ctr_ctx, ulong_t count, uint8_t *cb,
void (*copy_block)(uint8_t *, uint8_t *))
{
uint64_t upper_mask = 0;
uint64_t lower_mask = 0;
if (count == 0 || count > 128) {
return (CRYPTO_MECHANISM_PARAM_INVALID);
}
/* upper 64 bits of the mask */
if (count >= 64) {
count -= 64;
upper_mask = (count == 64) ? UINT64_MAX : (1ULL << count) - 1;
lower_mask = UINT64_MAX;
} else {
/* now the lower 63 bits */
lower_mask = (1ULL << count) - 1;
}
ctr_ctx->ctr_lower_mask = htonll(lower_mask);
ctr_ctx->ctr_upper_mask = htonll(upper_mask);
copy_block(cb, (uchar_t *)ctr_ctx->ctr_cb);
ctr_ctx->ctr_lastp = (uint8_t *)&ctr_ctx->ctr_cb[0];
ctr_ctx->ctr_flags |= CTR_MODE;
return (CRYPTO_SUCCESS);
}
void *
ctr_alloc_ctx(int kmflag)
{
ctr_ctx_t *ctr_ctx;
if ((ctr_ctx = kmem_zalloc(sizeof (ctr_ctx_t), kmflag)) == NULL)
return (NULL);
ctr_ctx->ctr_flags = CTR_MODE;
return (ctr_ctx);
}
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