zfs-builds-mm/zfs-0.8.1/module/icp/algs/modes/ccm.c

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2019-07-06 23:40:11 +02:00
/*
* 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>
#ifdef HAVE_EFFICIENT_UNALIGNED_ACCESS
#include <sys/byteorder.h>
#define UNALIGNED_POINTERS_PERMITTED
#endif
/*
* Encrypt multiple blocks of data in CCM mode. Decrypt for CCM mode
* is done in another function.
*/
int
ccm_mode_encrypt_contiguous_blocks(ccm_ctx_t *ctx, char *data, size_t length,
crypto_data_t *out, size_t block_size,
int (*encrypt_block)(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;
uint64_t counter;
uint8_t *mac_buf;
if (length + ctx->ccm_remainder_len < block_size) {
/* accumulate bytes here and return */
bcopy(datap,
(uint8_t *)ctx->ccm_remainder + ctx->ccm_remainder_len,
length);
ctx->ccm_remainder_len += length;
ctx->ccm_copy_to = datap;
return (CRYPTO_SUCCESS);
}
lastp = (uint8_t *)ctx->ccm_cb;
if (out != NULL)
crypto_init_ptrs(out, &iov_or_mp, &offset);
mac_buf = (uint8_t *)ctx->ccm_mac_buf;
do {
/* Unprocessed data from last call. */
if (ctx->ccm_remainder_len > 0) {
need = block_size - ctx->ccm_remainder_len;
if (need > remainder)
return (CRYPTO_DATA_LEN_RANGE);
bcopy(datap, &((uint8_t *)ctx->ccm_remainder)
[ctx->ccm_remainder_len], need);
blockp = (uint8_t *)ctx->ccm_remainder;
} else {
blockp = datap;
}
/*
* do CBC MAC
*
* XOR the previous cipher block current clear block.
* mac_buf always contain previous cipher block.
*/
xor_block(blockp, mac_buf);
encrypt_block(ctx->ccm_keysched, mac_buf, mac_buf);
/* ccm_cb is the counter block */
encrypt_block(ctx->ccm_keysched, (uint8_t *)ctx->ccm_cb,
(uint8_t *)ctx->ccm_tmp);
lastp = (uint8_t *)ctx->ccm_tmp;
/*
* Increment counter. Counter bits are confined
* to the bottom 64 bits of the counter block.
*/
#ifdef _LITTLE_ENDIAN
counter = ntohll(ctx->ccm_cb[1] & ctx->ccm_counter_mask);
counter = htonll(counter + 1);
#else
counter = ctx->ccm_cb[1] & ctx->ccm_counter_mask;
counter++;
#endif /* _LITTLE_ENDIAN */
counter &= ctx->ccm_counter_mask;
ctx->ccm_cb[1] =
(ctx->ccm_cb[1] & ~(ctx->ccm_counter_mask)) | counter;
/*
* XOR encrypted counter block with the current clear block.
*/
xor_block(blockp, lastp);
ctx->ccm_processed_data_len += block_size;
if (out == NULL) {
if (ctx->ccm_remainder_len > 0) {
bcopy(blockp, ctx->ccm_copy_to,
ctx->ccm_remainder_len);
bcopy(blockp + ctx->ccm_remainder_len, datap,
need);
}
} else {
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->ccm_remainder_len != 0) {
datap += need;
ctx->ccm_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->ccm_remainder, remainder);
ctx->ccm_remainder_len = remainder;
ctx->ccm_copy_to = datap;
goto out;
}
ctx->ccm_copy_to = NULL;
} while (remainder > 0);
out:
return (CRYPTO_SUCCESS);
}
void
calculate_ccm_mac(ccm_ctx_t *ctx, uint8_t *ccm_mac,
int (*encrypt_block)(const void *, const uint8_t *, uint8_t *))
{
uint64_t counter;
uint8_t *counterp, *mac_buf;
int i;
mac_buf = (uint8_t *)ctx->ccm_mac_buf;
/* first counter block start with index 0 */
counter = 0;
ctx->ccm_cb[1] = (ctx->ccm_cb[1] & ~(ctx->ccm_counter_mask)) | counter;
counterp = (uint8_t *)ctx->ccm_tmp;
encrypt_block(ctx->ccm_keysched, (uint8_t *)ctx->ccm_cb, counterp);
/* calculate XOR of MAC with first counter block */
for (i = 0; i < ctx->ccm_mac_len; i++) {
ccm_mac[i] = mac_buf[i] ^ counterp[i];
}
}
/* ARGSUSED */
int
ccm_encrypt_final(ccm_ctx_t *ctx, crypto_data_t *out, size_t block_size,
int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
void (*xor_block)(uint8_t *, uint8_t *))
{
uint8_t *lastp, *mac_buf, *ccm_mac_p, *macp = NULL;
void *iov_or_mp;
offset_t offset;
uint8_t *out_data_1;
uint8_t *out_data_2;
size_t out_data_1_len;
int i;
if (out->cd_length < (ctx->ccm_remainder_len + ctx->ccm_mac_len)) {
return (CRYPTO_DATA_LEN_RANGE);
}
/*
* When we get here, the number of bytes of payload processed
* plus whatever data remains, if any,
* should be the same as the number of bytes that's being
* passed in the argument during init time.
*/
if ((ctx->ccm_processed_data_len + ctx->ccm_remainder_len)
!= (ctx->ccm_data_len)) {
return (CRYPTO_DATA_LEN_RANGE);
}
mac_buf = (uint8_t *)ctx->ccm_mac_buf;
if (ctx->ccm_remainder_len > 0) {
/* ccm_mac_input_buf is not used for encryption */
macp = (uint8_t *)ctx->ccm_mac_input_buf;
bzero(macp, block_size);
/* copy remainder to temporary buffer */
bcopy(ctx->ccm_remainder, macp, ctx->ccm_remainder_len);
/* calculate the CBC MAC */
xor_block(macp, mac_buf);
encrypt_block(ctx->ccm_keysched, mac_buf, mac_buf);
/* calculate the counter mode */
lastp = (uint8_t *)ctx->ccm_tmp;
encrypt_block(ctx->ccm_keysched, (uint8_t *)ctx->ccm_cb, lastp);
/* XOR with counter block */
for (i = 0; i < ctx->ccm_remainder_len; i++) {
macp[i] ^= lastp[i];
}
ctx->ccm_processed_data_len += ctx->ccm_remainder_len;
}
/* Calculate the CCM MAC */
ccm_mac_p = (uint8_t *)ctx->ccm_tmp;
calculate_ccm_mac(ctx, ccm_mac_p, encrypt_block);
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->ccm_remainder_len + ctx->ccm_mac_len);
if (ctx->ccm_remainder_len > 0) {
/* copy temporary block to where it belongs */
if (out_data_2 == NULL) {
/* everything will fit in out_data_1 */
bcopy(macp, out_data_1, ctx->ccm_remainder_len);
bcopy(ccm_mac_p, out_data_1 + ctx->ccm_remainder_len,
ctx->ccm_mac_len);
} else {
if (out_data_1_len < ctx->ccm_remainder_len) {
size_t data_2_len_used;
bcopy(macp, out_data_1, out_data_1_len);
data_2_len_used = ctx->ccm_remainder_len
- out_data_1_len;
bcopy((uint8_t *)macp + out_data_1_len,
out_data_2, data_2_len_used);
bcopy(ccm_mac_p, out_data_2 + data_2_len_used,
ctx->ccm_mac_len);
} else {
bcopy(macp, out_data_1, out_data_1_len);
if (out_data_1_len == ctx->ccm_remainder_len) {
/* mac will be in out_data_2 */
bcopy(ccm_mac_p, out_data_2,
ctx->ccm_mac_len);
} else {
size_t len_not_used = out_data_1_len -
ctx->ccm_remainder_len;
/*
* part of mac in will be in
* out_data_1, part of the mac will be
* in out_data_2
*/
bcopy(ccm_mac_p,
out_data_1 + ctx->ccm_remainder_len,
len_not_used);
bcopy(ccm_mac_p + len_not_used,
out_data_2,
ctx->ccm_mac_len - len_not_used);
}
}
}
} else {
/* copy block to where it belongs */
bcopy(ccm_mac_p, out_data_1, out_data_1_len);
if (out_data_2 != NULL) {
bcopy(ccm_mac_p + out_data_1_len, out_data_2,
block_size - out_data_1_len);
}
}
out->cd_offset += ctx->ccm_remainder_len + ctx->ccm_mac_len;
ctx->ccm_remainder_len = 0;
return (CRYPTO_SUCCESS);
}
/*
* This will only deal with decrypting the last block of the input that
* might not be a multiple of block length.
*/
void
ccm_decrypt_incomplete_block(ccm_ctx_t *ctx,
int (*encrypt_block)(const void *, const uint8_t *, uint8_t *))
{
uint8_t *datap, *outp, *counterp;
int i;
datap = (uint8_t *)ctx->ccm_remainder;
outp = &((ctx->ccm_pt_buf)[ctx->ccm_processed_data_len]);
counterp = (uint8_t *)ctx->ccm_tmp;
encrypt_block(ctx->ccm_keysched, (uint8_t *)ctx->ccm_cb, counterp);
/* XOR with counter block */
for (i = 0; i < ctx->ccm_remainder_len; i++) {
outp[i] = datap[i] ^ counterp[i];
}
}
/*
* This will decrypt the cipher text. However, the plaintext won't be
* returned to the caller. It will be returned when decrypt_final() is
* called if the MAC matches
*/
/* ARGSUSED */
int
ccm_mode_decrypt_contiguous_blocks(ccm_ctx_t *ctx, char *data, size_t length,
crypto_data_t *out, size_t block_size,
int (*encrypt_block)(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 *cbp;
uint64_t counter;
size_t pt_len, total_decrypted_len, mac_len, pm_len, pd_len;
uint8_t *resultp;
pm_len = ctx->ccm_processed_mac_len;
if (pm_len > 0) {
uint8_t *tmp;
/*
* all ciphertext has been processed, just waiting for
* part of the value of the mac
*/
if ((pm_len + length) > ctx->ccm_mac_len) {
return (CRYPTO_ENCRYPTED_DATA_LEN_RANGE);
}
tmp = (uint8_t *)ctx->ccm_mac_input_buf;
bcopy(datap, tmp + pm_len, length);
ctx->ccm_processed_mac_len += length;
return (CRYPTO_SUCCESS);
}
/*
* If we decrypt the given data, what total amount of data would
* have been decrypted?
*/
pd_len = ctx->ccm_processed_data_len;
total_decrypted_len = pd_len + length + ctx->ccm_remainder_len;
if (total_decrypted_len >
(ctx->ccm_data_len + ctx->ccm_mac_len)) {
return (CRYPTO_ENCRYPTED_DATA_LEN_RANGE);
}
pt_len = ctx->ccm_data_len;
if (total_decrypted_len > pt_len) {
/*
* part of the input will be the MAC, need to isolate that
* to be dealt with later. The left-over data in
* ccm_remainder_len from last time will not be part of the
* MAC. Otherwise, it would have already been taken out
* when this call is made last time.
*/
size_t pt_part = pt_len - pd_len - ctx->ccm_remainder_len;
mac_len = length - pt_part;
ctx->ccm_processed_mac_len = mac_len;
bcopy(data + pt_part, ctx->ccm_mac_input_buf, mac_len);
if (pt_part + ctx->ccm_remainder_len < block_size) {
/*
* since this is last of the ciphertext, will
* just decrypt with it here
*/
bcopy(datap, &((uint8_t *)ctx->ccm_remainder)
[ctx->ccm_remainder_len], pt_part);
ctx->ccm_remainder_len += pt_part;
ccm_decrypt_incomplete_block(ctx, encrypt_block);
ctx->ccm_processed_data_len += ctx->ccm_remainder_len;
ctx->ccm_remainder_len = 0;
return (CRYPTO_SUCCESS);
} else {
/* let rest of the code handle this */
length = pt_part;
}
} else if (length + ctx->ccm_remainder_len < block_size) {
/* accumulate bytes here and return */
bcopy(datap,
(uint8_t *)ctx->ccm_remainder + ctx->ccm_remainder_len,
length);
ctx->ccm_remainder_len += length;
ctx->ccm_copy_to = datap;
return (CRYPTO_SUCCESS);
}
do {
/* Unprocessed data from last call. */
if (ctx->ccm_remainder_len > 0) {
need = block_size - ctx->ccm_remainder_len;
if (need > remainder)
return (CRYPTO_ENCRYPTED_DATA_LEN_RANGE);
bcopy(datap, &((uint8_t *)ctx->ccm_remainder)
[ctx->ccm_remainder_len], need);
blockp = (uint8_t *)ctx->ccm_remainder;
} else {
blockp = datap;
}
/* Calculate the counter mode, ccm_cb is the counter block */
cbp = (uint8_t *)ctx->ccm_tmp;
encrypt_block(ctx->ccm_keysched, (uint8_t *)ctx->ccm_cb, cbp);
/*
* Increment counter.
* Counter bits are confined to the bottom 64 bits
*/
#ifdef _LITTLE_ENDIAN
counter = ntohll(ctx->ccm_cb[1] & ctx->ccm_counter_mask);
counter = htonll(counter + 1);
#else
counter = ctx->ccm_cb[1] & ctx->ccm_counter_mask;
counter++;
#endif /* _LITTLE_ENDIAN */
counter &= ctx->ccm_counter_mask;
ctx->ccm_cb[1] =
(ctx->ccm_cb[1] & ~(ctx->ccm_counter_mask)) | counter;
/* XOR with the ciphertext */
xor_block(blockp, cbp);
/* Copy the plaintext to the "holding buffer" */
resultp = (uint8_t *)ctx->ccm_pt_buf +
ctx->ccm_processed_data_len;
copy_block(cbp, resultp);
ctx->ccm_processed_data_len += block_size;
ctx->ccm_lastp = blockp;
/* Update pointer to next block of data to be processed. */
if (ctx->ccm_remainder_len != 0) {
datap += need;
ctx->ccm_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->ccm_remainder, remainder);
ctx->ccm_remainder_len = remainder;
ctx->ccm_copy_to = datap;
if (ctx->ccm_processed_mac_len > 0) {
/*
* not expecting anymore ciphertext, just
* compute plaintext for the remaining input
*/
ccm_decrypt_incomplete_block(ctx,
encrypt_block);
ctx->ccm_processed_data_len += remainder;
ctx->ccm_remainder_len = 0;
}
goto out;
}
ctx->ccm_copy_to = NULL;
} while (remainder > 0);
out:
return (CRYPTO_SUCCESS);
}
int
ccm_decrypt_final(ccm_ctx_t *ctx, crypto_data_t *out, size_t block_size,
int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
void (*copy_block)(uint8_t *, uint8_t *),
void (*xor_block)(uint8_t *, uint8_t *))
{
size_t mac_remain, pt_len;
uint8_t *pt, *mac_buf, *macp, *ccm_mac_p;
int rv;
pt_len = ctx->ccm_data_len;
/* Make sure output buffer can fit all of the plaintext */
if (out->cd_length < pt_len) {
return (CRYPTO_DATA_LEN_RANGE);
}
pt = ctx->ccm_pt_buf;
mac_remain = ctx->ccm_processed_data_len;
mac_buf = (uint8_t *)ctx->ccm_mac_buf;
macp = (uint8_t *)ctx->ccm_tmp;
while (mac_remain > 0) {
if (mac_remain < block_size) {
bzero(macp, block_size);
bcopy(pt, macp, mac_remain);
mac_remain = 0;
} else {
copy_block(pt, macp);
mac_remain -= block_size;
pt += block_size;
}
/* calculate the CBC MAC */
xor_block(macp, mac_buf);
encrypt_block(ctx->ccm_keysched, mac_buf, mac_buf);
}
/* Calculate the CCM MAC */
ccm_mac_p = (uint8_t *)ctx->ccm_tmp;
calculate_ccm_mac((ccm_ctx_t *)ctx, ccm_mac_p, encrypt_block);
/* compare the input CCM MAC value with what we calculated */
if (bcmp(ctx->ccm_mac_input_buf, ccm_mac_p, ctx->ccm_mac_len)) {
/* They don't match */
return (CRYPTO_INVALID_MAC);
} else {
rv = crypto_put_output_data(ctx->ccm_pt_buf, out, pt_len);
if (rv != CRYPTO_SUCCESS)
return (rv);
out->cd_offset += pt_len;
}
return (CRYPTO_SUCCESS);
}
int
ccm_validate_args(CK_AES_CCM_PARAMS *ccm_param, boolean_t is_encrypt_init)
{
size_t macSize, nonceSize;
uint8_t q;
uint64_t maxValue;
/*
* Check the length of the MAC. The only valid
* lengths for the MAC are: 4, 6, 8, 10, 12, 14, 16
*/
macSize = ccm_param->ulMACSize;
if ((macSize < 4) || (macSize > 16) || ((macSize % 2) != 0)) {
return (CRYPTO_MECHANISM_PARAM_INVALID);
}
/* Check the nonce length. Valid values are 7, 8, 9, 10, 11, 12, 13 */
nonceSize = ccm_param->ulNonceSize;
if ((nonceSize < 7) || (nonceSize > 13)) {
return (CRYPTO_MECHANISM_PARAM_INVALID);
}
/* q is the length of the field storing the length, in bytes */
q = (uint8_t)((15 - nonceSize) & 0xFF);
/*
* If it is decrypt, need to make sure size of ciphertext is at least
* bigger than MAC len
*/
if ((!is_encrypt_init) && (ccm_param->ulDataSize < macSize)) {
return (CRYPTO_MECHANISM_PARAM_INVALID);
}
/*
* Check to make sure the length of the payload is within the
* range of values allowed by q
*/
if (q < 8) {
maxValue = (1ULL << (q * 8)) - 1;
} else {
maxValue = ULONG_MAX;
}
if (ccm_param->ulDataSize > maxValue) {
return (CRYPTO_MECHANISM_PARAM_INVALID);
}
return (CRYPTO_SUCCESS);
}
/*
* Format the first block used in CBC-MAC (B0) and the initial counter
* block based on formatting functions and counter generation functions
* specified in RFC 3610 and NIST publication 800-38C, appendix A
*
* b0 is the first block used in CBC-MAC
* cb0 is the first counter block
*
* It's assumed that the arguments b0 and cb0 are preallocated AES blocks
*
*/
static void
ccm_format_initial_blocks(uchar_t *nonce, ulong_t nonceSize,
ulong_t authDataSize, uint8_t *b0, ccm_ctx_t *aes_ctx)
{
uint64_t payloadSize;
uint8_t t, q, have_adata = 0;
size_t limit;
int i, j, k;
uint64_t mask = 0;
uint8_t *cb;
q = (uint8_t)((15 - nonceSize) & 0xFF);
t = (uint8_t)((aes_ctx->ccm_mac_len) & 0xFF);
/* Construct the first octet of b0 */
if (authDataSize > 0) {
have_adata = 1;
}
b0[0] = (have_adata << 6) | (((t - 2) / 2) << 3) | (q - 1);
/* copy the nonce value into b0 */
bcopy(nonce, &(b0[1]), nonceSize);
/* store the length of the payload into b0 */
bzero(&(b0[1+nonceSize]), q);
payloadSize = aes_ctx->ccm_data_len;
limit = 8 < q ? 8 : q;
for (i = 0, j = 0, k = 15; i < limit; i++, j += 8, k--) {
b0[k] = (uint8_t)((payloadSize >> j) & 0xFF);
}
/* format the counter block */
cb = (uint8_t *)aes_ctx->ccm_cb;
cb[0] = 0x07 & (q-1); /* first byte */
/* copy the nonce value into the counter block */
bcopy(nonce, &(cb[1]), nonceSize);
bzero(&(cb[1+nonceSize]), q);
/* Create the mask for the counter field based on the size of nonce */
q <<= 3;
while (q-- > 0) {
mask |= (1ULL << q);
}
#ifdef _LITTLE_ENDIAN
mask = htonll(mask);
#endif
aes_ctx->ccm_counter_mask = mask;
/*
* During calculation, we start using counter block 1, we will
* set it up right here.
* We can just set the last byte to have the value 1, because
* even with the biggest nonce of 13, the last byte of the
* counter block will be used for the counter value.
*/
cb[15] = 0x01;
}
/*
* Encode the length of the associated data as
* specified in RFC 3610 and NIST publication 800-38C, appendix A
*/
static void
encode_adata_len(ulong_t auth_data_len, uint8_t *encoded, size_t *encoded_len)
{
#ifdef UNALIGNED_POINTERS_PERMITTED
uint32_t *lencoded_ptr;
#ifdef _LP64
uint64_t *llencoded_ptr;
#endif
#endif /* UNALIGNED_POINTERS_PERMITTED */
if (auth_data_len < ((1ULL<<16) - (1ULL<<8))) {
/* 0 < a < (2^16-2^8) */
*encoded_len = 2;
encoded[0] = (auth_data_len & 0xff00) >> 8;
encoded[1] = auth_data_len & 0xff;
} else if ((auth_data_len >= ((1ULL<<16) - (1ULL<<8))) &&
(auth_data_len < (1ULL << 31))) {
/* (2^16-2^8) <= a < 2^32 */
*encoded_len = 6;
encoded[0] = 0xff;
encoded[1] = 0xfe;
#ifdef UNALIGNED_POINTERS_PERMITTED
lencoded_ptr = (uint32_t *)&encoded[2];
*lencoded_ptr = htonl(auth_data_len);
#else
encoded[2] = (auth_data_len & 0xff000000) >> 24;
encoded[3] = (auth_data_len & 0xff0000) >> 16;
encoded[4] = (auth_data_len & 0xff00) >> 8;
encoded[5] = auth_data_len & 0xff;
#endif /* UNALIGNED_POINTERS_PERMITTED */
#ifdef _LP64
} else {
/* 2^32 <= a < 2^64 */
*encoded_len = 10;
encoded[0] = 0xff;
encoded[1] = 0xff;
#ifdef UNALIGNED_POINTERS_PERMITTED
llencoded_ptr = (uint64_t *)&encoded[2];
*llencoded_ptr = htonl(auth_data_len);
#else
encoded[2] = (auth_data_len & 0xff00000000000000) >> 56;
encoded[3] = (auth_data_len & 0xff000000000000) >> 48;
encoded[4] = (auth_data_len & 0xff0000000000) >> 40;
encoded[5] = (auth_data_len & 0xff00000000) >> 32;
encoded[6] = (auth_data_len & 0xff000000) >> 24;
encoded[7] = (auth_data_len & 0xff0000) >> 16;
encoded[8] = (auth_data_len & 0xff00) >> 8;
encoded[9] = auth_data_len & 0xff;
#endif /* UNALIGNED_POINTERS_PERMITTED */
#endif /* _LP64 */
}
}
/*
* The following function should be call at encrypt or decrypt init time
* for AES CCM mode.
*/
int
ccm_init(ccm_ctx_t *ctx, unsigned char *nonce, size_t nonce_len,
unsigned char *auth_data, size_t auth_data_len, size_t block_size,
int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
void (*xor_block)(uint8_t *, uint8_t *))
{
uint8_t *mac_buf, *datap, *ivp, *authp;
size_t remainder, processed;
uint8_t encoded_a[10]; /* max encoded auth data length is 10 octets */
size_t encoded_a_len = 0;
mac_buf = (uint8_t *)&(ctx->ccm_mac_buf);
/*
* Format the 1st block for CBC-MAC and construct the
* 1st counter block.
*
* aes_ctx->ccm_iv is used for storing the counter block
* mac_buf will store b0 at this time.
*/
ccm_format_initial_blocks(nonce, nonce_len,
auth_data_len, mac_buf, ctx);
/* The IV for CBC MAC for AES CCM mode is always zero */
ivp = (uint8_t *)ctx->ccm_tmp;
bzero(ivp, block_size);
xor_block(ivp, mac_buf);
/* encrypt the nonce */
encrypt_block(ctx->ccm_keysched, mac_buf, mac_buf);
/* take care of the associated data, if any */
if (auth_data_len == 0) {
return (CRYPTO_SUCCESS);
}
encode_adata_len(auth_data_len, encoded_a, &encoded_a_len);
remainder = auth_data_len;
/* 1st block: it contains encoded associated data, and some data */
authp = (uint8_t *)ctx->ccm_tmp;
bzero(authp, block_size);
bcopy(encoded_a, authp, encoded_a_len);
processed = block_size - encoded_a_len;
if (processed > auth_data_len) {
/* in case auth_data is very small */
processed = auth_data_len;
}
bcopy(auth_data, authp+encoded_a_len, processed);
/* xor with previous buffer */
xor_block(authp, mac_buf);
encrypt_block(ctx->ccm_keysched, mac_buf, mac_buf);
remainder -= processed;
if (remainder == 0) {
/* a small amount of associated data, it's all done now */
return (CRYPTO_SUCCESS);
}
do {
if (remainder < block_size) {
/*
* There's not a block full of data, pad rest of
* buffer with zero
*/
bzero(authp, block_size);
bcopy(&(auth_data[processed]), authp, remainder);
datap = (uint8_t *)authp;
remainder = 0;
} else {
datap = (uint8_t *)(&(auth_data[processed]));
processed += block_size;
remainder -= block_size;
}
xor_block(datap, mac_buf);
encrypt_block(ctx->ccm_keysched, mac_buf, mac_buf);
} while (remainder > 0);
return (CRYPTO_SUCCESS);
}
int
ccm_init_ctx(ccm_ctx_t *ccm_ctx, char *param, int kmflag,
boolean_t is_encrypt_init, size_t block_size,
int (*encrypt_block)(const void *, const uint8_t *, uint8_t *),
void (*xor_block)(uint8_t *, uint8_t *))
{
int rv;
CK_AES_CCM_PARAMS *ccm_param;
if (param != NULL) {
ccm_param = (CK_AES_CCM_PARAMS *)param;
if ((rv = ccm_validate_args(ccm_param,
is_encrypt_init)) != 0) {
return (rv);
}
ccm_ctx->ccm_mac_len = ccm_param->ulMACSize;
if (is_encrypt_init) {
ccm_ctx->ccm_data_len = ccm_param->ulDataSize;
} else {
ccm_ctx->ccm_data_len =
ccm_param->ulDataSize - ccm_ctx->ccm_mac_len;
ccm_ctx->ccm_processed_mac_len = 0;
}
ccm_ctx->ccm_processed_data_len = 0;
ccm_ctx->ccm_flags |= CCM_MODE;
} else {
rv = CRYPTO_MECHANISM_PARAM_INVALID;
goto out;
}
if (ccm_init(ccm_ctx, ccm_param->nonce, ccm_param->ulNonceSize,
ccm_param->authData, ccm_param->ulAuthDataSize, block_size,
encrypt_block, xor_block) != 0) {
rv = CRYPTO_MECHANISM_PARAM_INVALID;
goto out;
}
if (!is_encrypt_init) {
/* allocate buffer for storing decrypted plaintext */
ccm_ctx->ccm_pt_buf = vmem_alloc(ccm_ctx->ccm_data_len,
kmflag);
if (ccm_ctx->ccm_pt_buf == NULL) {
rv = CRYPTO_HOST_MEMORY;
}
}
out:
return (rv);
}
void *
ccm_alloc_ctx(int kmflag)
{
ccm_ctx_t *ccm_ctx;
if ((ccm_ctx = kmem_zalloc(sizeof (ccm_ctx_t), kmflag)) == NULL)
return (NULL);
ccm_ctx->ccm_flags = CCM_MODE;
return (ccm_ctx);
}