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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>
/*
* Algorithm independent CBC functions.
*/
int
cbc_encrypt_contiguous_blocks(cbc_ctx_t *ctx, char *data, size_t length,
crypto_data_t *out, size_t block_size,
int (*encrypt)(const void *, const uint8_t *, uint8_t *),
void (*copy_block)(uint8_t *, uint8_t *),
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;
if (length + ctx->cbc_remainder_len < block_size) {
/* accumulate bytes here and return */
bcopy(datap,
(uint8_t *)ctx->cbc_remainder + ctx->cbc_remainder_len,
length);
ctx->cbc_remainder_len += length;
ctx->cbc_copy_to = datap;
return (CRYPTO_SUCCESS);
}
lastp = (uint8_t *)ctx->cbc_iv;
crypto_init_ptrs(out, &iov_or_mp, &offset);
do {
/* Unprocessed data from last call. */
if (ctx->cbc_remainder_len > 0) {
need = block_size - ctx->cbc_remainder_len;
if (need > remainder)
return (CRYPTO_DATA_LEN_RANGE);
bcopy(datap, &((uint8_t *)ctx->cbc_remainder)
[ctx->cbc_remainder_len], need);
blockp = (uint8_t *)ctx->cbc_remainder;
} else {
blockp = datap;
}
/*
* XOR the previous cipher block or IV with the
* current clear block.
*/
xor_block(blockp, lastp);
encrypt(ctx->cbc_keysched, lastp, 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 */
if (out_data_1_len == block_size) {
copy_block(lastp, out_data_1);
} else {
bcopy(lastp, out_data_1, out_data_1_len);
if (out_data_2 != NULL) {
bcopy(lastp + out_data_1_len,
out_data_2,
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->cbc_remainder_len != 0) {
datap += need;
ctx->cbc_remainder_len = 0;
} else {
datap += block_size;
}
remainder = (size_t)&data[length] - (size_t)datap;
/* Incomplete last block. */
if (remainder > 0 && remainder < block_size) {
bcopy(datap, ctx->cbc_remainder, remainder);
ctx->cbc_remainder_len = remainder;
ctx->cbc_copy_to = datap;
goto out;
}
ctx->cbc_copy_to = NULL;
} while (remainder > 0);
out:
/*
* Save the last encrypted block in the context.
*/
if (ctx->cbc_lastp != NULL) {
copy_block((uint8_t *)ctx->cbc_lastp, (uint8_t *)ctx->cbc_iv);
ctx->cbc_lastp = (uint8_t *)ctx->cbc_iv;
}
return (CRYPTO_SUCCESS);
}
#define OTHER(a, ctx) \
(((a) == (ctx)->cbc_lastblock) ? (ctx)->cbc_iv : (ctx)->cbc_lastblock)
/* ARGSUSED */
int
cbc_decrypt_contiguous_blocks(cbc_ctx_t *ctx, char *data, size_t length,
crypto_data_t *out, size_t block_size,
int (*decrypt)(const void *, const uint8_t *, uint8_t *),
void (*copy_block)(uint8_t *, uint8_t *),
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;
if (length + ctx->cbc_remainder_len < block_size) {
/* accumulate bytes here and return */
bcopy(datap,
(uint8_t *)ctx->cbc_remainder + ctx->cbc_remainder_len,
length);
ctx->cbc_remainder_len += length;
ctx->cbc_copy_to = datap;
return (CRYPTO_SUCCESS);
}
lastp = ctx->cbc_lastp;
crypto_init_ptrs(out, &iov_or_mp, &offset);
do {
/* Unprocessed data from last call. */
if (ctx->cbc_remainder_len > 0) {
need = block_size - ctx->cbc_remainder_len;
if (need > remainder)
return (CRYPTO_ENCRYPTED_DATA_LEN_RANGE);
bcopy(datap, &((uint8_t *)ctx->cbc_remainder)
[ctx->cbc_remainder_len], need);
blockp = (uint8_t *)ctx->cbc_remainder;
} else {
blockp = datap;
}
/* LINTED: pointer alignment */
copy_block(blockp, (uint8_t *)OTHER((uint64_t *)lastp, ctx));
decrypt(ctx->cbc_keysched, blockp,
(uint8_t *)ctx->cbc_remainder);
blockp = (uint8_t *)ctx->cbc_remainder;
/*
* XOR the previous cipher block or IV with the
* currently decrypted block.
*/
xor_block(lastp, blockp);
/* LINTED: pointer alignment */
lastp = (uint8_t *)OTHER((uint64_t *)lastp, ctx);
crypto_get_ptrs(out, &iov_or_mp, &offset, &out_data_1,
&out_data_1_len, &out_data_2, block_size);
bcopy(blockp, out_data_1, out_data_1_len);
if (out_data_2 != NULL) {
bcopy(blockp + out_data_1_len, out_data_2,
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->cbc_remainder_len != 0) {
datap += need;
ctx->cbc_remainder_len = 0;
} else {
datap += block_size;
}
remainder = (size_t)&data[length] - (size_t)datap;
/* Incomplete last block. */
if (remainder > 0 && remainder < block_size) {
bcopy(datap, ctx->cbc_remainder, remainder);
ctx->cbc_remainder_len = remainder;
ctx->cbc_lastp = lastp;
ctx->cbc_copy_to = datap;
return (CRYPTO_SUCCESS);
}
ctx->cbc_copy_to = NULL;
} while (remainder > 0);
ctx->cbc_lastp = lastp;
return (CRYPTO_SUCCESS);
}
int
cbc_init_ctx(cbc_ctx_t *cbc_ctx, char *param, size_t param_len,
size_t block_size, void (*copy_block)(uint8_t *, uint64_t *))
{
/*
* Copy IV into context.
*
* If cm_param == NULL then the IV comes from the
* cd_miscdata field in the crypto_data structure.
*/
if (param != NULL) {
ASSERT(param_len == block_size);
copy_block((uchar_t *)param, cbc_ctx->cbc_iv);
}
cbc_ctx->cbc_lastp = (uint8_t *)&cbc_ctx->cbc_iv[0];
cbc_ctx->cbc_flags |= CBC_MODE;
return (CRYPTO_SUCCESS);
}
/* ARGSUSED */
void *
cbc_alloc_ctx(int kmflag)
{
cbc_ctx_t *cbc_ctx;
if ((cbc_ctx = kmem_zalloc(sizeof (cbc_ctx_t), kmflag)) == NULL)
return (NULL);
cbc_ctx->cbc_flags = CBC_MODE;
return (cbc_ctx);
}
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