-/* ====================================================================
- * Copyright (c) 2014 The OpenSSL Project. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. All advertising materials mentioning features or use of this
- * software must display the following acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
- *
- * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
- * endorse or promote products derived from this software without
- * prior written permission. For written permission, please contact
- * openssl-core@openssl.org.
- *
- * 5. Products derived from this software may not be called "OpenSSL"
- * nor may "OpenSSL" appear in their names without prior written
- * permission of the OpenSSL Project.
- *
- * 6. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+/*
+ * Copyright 2014-2018 The OpenSSL Project Authors. All Rights Reserved.
*
- * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
- * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- * ====================================================================
+ * Licensed under the Apache License 2.0 (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
*/
#include <string.h>
#include <openssl/crypto.h>
-#include "modes_lcl.h"
+#include <openssl/err.h>
+#include "internal/modes_int.h"
#ifndef OPENSSL_NO_OCB
-union ublock {
- unsigned char *chrblk;
- OCB_BLOCK *ocbblk;
-};
-
/*
* Calculate the number of binary trailing zero's in any given number
*/
/*
* Shift a block of 16 bytes left by shift bits
*/
-static void ocb_block_lshift(OCB_BLOCK *in, size_t shift, OCB_BLOCK *out)
+static void ocb_block_lshift(const unsigned char *in, size_t shift,
+ unsigned char *out)
{
- unsigned char shift_mask;
int i;
- unsigned char mask[15];
- union ublock locin;
- union ublock locout;
+ unsigned char carry = 0, carry_next;
- locin.ocbblk = in;
- locout.ocbblk = out;
-
- shift_mask = 0xff;
- shift_mask <<= (8 - shift);
for (i = 15; i >= 0; i--) {
- if (i > 0) {
- mask[i - 1] = locin.chrblk[i] & shift_mask;
- mask[i - 1] >>= 8 - shift;
- }
- locout.chrblk[i] = locin.chrblk[i] << shift;
-
- if (i != 15) {
- locout.chrblk[i] ^= mask[i];
- }
+ carry_next = in[i] >> (8 - shift);
+ out[i] = (in[i] << shift) | carry;
+ carry = carry_next;
}
}
static void ocb_double(OCB_BLOCK *in, OCB_BLOCK *out)
{
unsigned char mask;
- union ublock locin;
- union ublock locout;
-
- locin.ocbblk = in;
- locout.ocbblk = out;
/*
* Calculate the mask based on the most significant bit. There are more
* efficient ways to do this - but this way is constant time
*/
- mask = locin.chrblk[0] & 0x80;
+ mask = in->c[0] & 0x80;
mask >>= 7;
- mask *= 135;
+ mask = (0 - mask) & 0x87;
- ocb_block_lshift(in, 1, out);
+ ocb_block_lshift(in->c, 1, out->c);
- locout.chrblk[15] ^= mask;
+ out->c[15] ^= mask;
}
/*
*/
static OCB_BLOCK *ocb_lookup_l(OCB128_CONTEXT *ctx, size_t idx)
{
- if (idx <= ctx->l_index) {
+ size_t l_index = ctx->l_index;
+
+ if (idx <= l_index) {
return ctx->l + idx;
}
/* We don't have it - so calculate it */
- ctx->l_index++;
- if (ctx->l_index == ctx->max_l_index) {
- ctx->max_l_index *= 2;
- ctx->l =
- OPENSSL_realloc(ctx->l, ctx->max_l_index * sizeof(OCB_BLOCK));
- if (!ctx->l)
+ if (idx >= ctx->max_l_index) {
+ void *tmp_ptr;
+ /*
+ * Each additional entry allows to process almost double as
+ * much data, so that in linear world the table will need to
+ * be expanded with smaller and smaller increments. Originally
+ * it was doubling in size, which was a waste. Growing it
+ * linearly is not formally optimal, but is simpler to implement.
+ * We grow table by minimally required 4*n that would accommodate
+ * the index.
+ */
+ ctx->max_l_index += (idx - ctx->max_l_index + 4) & ~3;
+ tmp_ptr = OPENSSL_realloc(ctx->l, ctx->max_l_index * sizeof(OCB_BLOCK));
+ if (tmp_ptr == NULL) /* prevent ctx->l from being clobbered */
return NULL;
+ ctx->l = tmp_ptr;
+ }
+ while (l_index < idx) {
+ ocb_double(ctx->l + l_index, ctx->l + l_index + 1);
+ l_index++;
}
- ocb_double(ctx->l + (idx - 1), ctx->l + idx);
+ ctx->l_index = l_index;
return ctx->l + idx;
}
-/*
- * Encrypt a block from |in| and store the result in |out|
- */
-static void ocb_encrypt(OCB128_CONTEXT *ctx, OCB_BLOCK *in, OCB_BLOCK *out,
- void *keyenc)
-{
- union ublock locin;
- union ublock locout;
-
- locin.ocbblk = in;
- locout.ocbblk = out;
-
- ctx->encrypt(locin.chrblk, locout.chrblk, keyenc);
-}
-
-/*
- * Decrypt a block from |in| and store the result in |out|
- */
-static void ocb_decrypt(OCB128_CONTEXT *ctx, OCB_BLOCK *in, OCB_BLOCK *out,
- void *keydec)
-{
- union ublock locin;
- union ublock locout;
-
- locin.ocbblk = in;
- locout.ocbblk = out;
-
- ctx->decrypt(locin.chrblk, locout.chrblk, keydec);
-}
-
/*
* Create a new OCB128_CONTEXT
*/
OCB128_CONTEXT *CRYPTO_ocb128_new(void *keyenc, void *keydec,
- block128_f encrypt, block128_f decrypt)
+ block128_f encrypt, block128_f decrypt,
+ ocb128_f stream)
{
OCB128_CONTEXT *octx;
int ret;
- if ((octx = OPENSSL_malloc(sizeof(*octx)))) {
- ret = CRYPTO_ocb128_init(octx, keyenc, keydec, encrypt, decrypt);
+ if ((octx = OPENSSL_malloc(sizeof(*octx))) != NULL) {
+ ret = CRYPTO_ocb128_init(octx, keyenc, keydec, encrypt, decrypt,
+ stream);
if (ret)
return octx;
OPENSSL_free(octx);
* Initialise an existing OCB128_CONTEXT
*/
int CRYPTO_ocb128_init(OCB128_CONTEXT *ctx, void *keyenc, void *keydec,
- block128_f encrypt, block128_f decrypt)
+ block128_f encrypt, block128_f decrypt,
+ ocb128_f stream)
{
- /* Clear everything to NULLs */
memset(ctx, 0, sizeof(*ctx));
-
ctx->l_index = 0;
- ctx->max_l_index = 1;
- ctx->l = OPENSSL_malloc(ctx->max_l_index * 16);
- if (!ctx->l)
+ ctx->max_l_index = 5;
+ if ((ctx->l = OPENSSL_malloc(ctx->max_l_index * 16)) == NULL) {
+ CRYPTOerr(CRYPTO_F_CRYPTO_OCB128_INIT, ERR_R_MALLOC_FAILURE);
return 0;
+ }
/*
* We set both the encryption and decryption key schedules - decryption
*/
ctx->encrypt = encrypt;
ctx->decrypt = decrypt;
+ ctx->stream = stream;
ctx->keyenc = keyenc;
ctx->keydec = keydec;
/* L_* = ENCIPHER(K, zeros(128)) */
- ocb_encrypt(ctx, &ctx->l_star, &ctx->l_star, ctx->keyenc);
+ ctx->encrypt(ctx->l_star.c, ctx->l_star.c, ctx->keyenc);
/* L_$ = double(L_*) */
ocb_double(&ctx->l_star, &ctx->l_dollar);
/* L_0 = double(L_$) */
ocb_double(&ctx->l_dollar, ctx->l);
+ /* L_{i} = double(L_{i-1}) */
+ ocb_double(ctx->l, ctx->l+1);
+ ocb_double(ctx->l+1, ctx->l+2);
+ ocb_double(ctx->l+2, ctx->l+3);
+ ocb_double(ctx->l+3, ctx->l+4);
+ ctx->l_index = 4; /* enough to process up to 496 bytes */
+
return 1;
}
if (keydec)
dest->keydec = keydec;
if (src->l) {
- dest->l = OPENSSL_malloc(src->max_l_index * 16);
- if (!dest->l)
+ if ((dest->l = OPENSSL_malloc(src->max_l_index * 16)) == NULL) {
+ CRYPTOerr(CRYPTO_F_CRYPTO_OCB128_COPY_CTX, ERR_R_MALLOC_FAILURE);
return 0;
+ }
memcpy(dest->l, src->l, (src->l_index + 1) * 16);
}
return 1;
unsigned char ktop[16], tmp[16], mask;
unsigned char stretch[24], nonce[16];
size_t bottom, shift;
- union ublock offset;
-
- offset.ocbblk = &ctx->offset;
/*
* Spec says IV is 120 bits or fewer - it allows non byte aligned lengths.
- * We don't support this at this stage
+ * We don't support this at this stage
*/
if ((len > 15) || (len < 1) || (taglen > 16) || (taglen < 1)) {
return -1;
}
+ /* Reset nonce-dependent variables */
+ memset(&ctx->sess, 0, sizeof(ctx->sess));
+
/* Nonce = num2str(TAGLEN mod 128,7) || zeros(120-bitlen(N)) || 1 || N */
nonce[0] = ((taglen * 8) % 128) << 1;
memset(nonce + 1, 0, 15);
/* Offset_0 = Stretch[1+bottom..128+bottom] */
shift = bottom % 8;
- ocb_block_lshift((OCB_BLOCK *)(stretch + (bottom / 8)), shift,
- &ctx->offset);
+ ocb_block_lshift(stretch + (bottom / 8), shift, ctx->sess.offset.c);
mask = 0xff;
mask <<= 8 - shift;
- offset.chrblk[15] |=
+ ctx->sess.offset.c[15] |=
(*(stretch + (bottom / 8) + 16) & mask) >> (8 - shift);
return 1;
int CRYPTO_ocb128_aad(OCB128_CONTEXT *ctx, const unsigned char *aad,
size_t len)
{
- u64 all_num_blocks, num_blocks;
- u64 i;
- OCB_BLOCK tmp1;
- OCB_BLOCK tmp2;
- int last_len;
+ u64 i, all_num_blocks;
+ size_t num_blocks, last_len;
+ OCB_BLOCK tmp;
/* Calculate the number of blocks of AAD provided now, and so far */
num_blocks = len / 16;
- all_num_blocks = num_blocks + ctx->blocks_hashed;
+ all_num_blocks = num_blocks + ctx->sess.blocks_hashed;
/* Loop through all full blocks of AAD */
- for (i = ctx->blocks_hashed + 1; i <= all_num_blocks; i++) {
+ for (i = ctx->sess.blocks_hashed + 1; i <= all_num_blocks; i++) {
OCB_BLOCK *lookup;
- OCB_BLOCK *aad_block;
/* Offset_i = Offset_{i-1} xor L_{ntz(i)} */
lookup = ocb_lookup_l(ctx, ocb_ntz(i));
- if (!lookup)
+ if (lookup == NULL)
return 0;
- ocb_block16_xor(&ctx->offset_aad, lookup, &ctx->offset_aad);
+ ocb_block16_xor(&ctx->sess.offset_aad, lookup, &ctx->sess.offset_aad);
+
+ memcpy(tmp.c, aad, 16);
+ aad += 16;
/* Sum_i = Sum_{i-1} xor ENCIPHER(K, A_i xor Offset_i) */
- aad_block = (OCB_BLOCK *)(aad + ((i - ctx->blocks_hashed - 1) * 16));
- ocb_block16_xor(&ctx->offset_aad, aad_block, &tmp1);
- ocb_encrypt(ctx, &tmp1, &tmp2, ctx->keyenc);
- ocb_block16_xor(&ctx->sum, &tmp2, &ctx->sum);
+ ocb_block16_xor(&ctx->sess.offset_aad, &tmp, &tmp);
+ ctx->encrypt(tmp.c, tmp.c, ctx->keyenc);
+ ocb_block16_xor(&tmp, &ctx->sess.sum, &ctx->sess.sum);
}
/*
if (last_len > 0) {
/* Offset_* = Offset_m xor L_* */
- ocb_block16_xor(&ctx->offset_aad, &ctx->l_star, &ctx->offset_aad);
+ ocb_block16_xor(&ctx->sess.offset_aad, &ctx->l_star,
+ &ctx->sess.offset_aad);
/* CipherInput = (A_* || 1 || zeros(127-bitlen(A_*))) xor Offset_* */
- memset((void *)&tmp1, 0, 16);
- memcpy((void *)&tmp1, aad + (num_blocks * 16), last_len);
- ((unsigned char *)&tmp1)[last_len] = 0x80;
- ocb_block16_xor(&ctx->offset_aad, &tmp1, &tmp2);
+ memset(tmp.c, 0, 16);
+ memcpy(tmp.c, aad, last_len);
+ tmp.c[last_len] = 0x80;
+ ocb_block16_xor(&ctx->sess.offset_aad, &tmp, &tmp);
/* Sum = Sum_m xor ENCIPHER(K, CipherInput) */
- ocb_encrypt(ctx, &tmp2, &tmp1, ctx->keyenc);
- ocb_block16_xor(&ctx->sum, &tmp1, &ctx->sum);
+ ctx->encrypt(tmp.c, tmp.c, ctx->keyenc);
+ ocb_block16_xor(&tmp, &ctx->sess.sum, &ctx->sess.sum);
}
- ctx->blocks_hashed = all_num_blocks;
+ ctx->sess.blocks_hashed = all_num_blocks;
return 1;
}
const unsigned char *in, unsigned char *out,
size_t len)
{
- u64 i;
- u64 all_num_blocks, num_blocks;
- OCB_BLOCK tmp1;
- OCB_BLOCK tmp2;
- OCB_BLOCK pad;
- int last_len;
+ u64 i, all_num_blocks;
+ size_t num_blocks, last_len;
/*
* Calculate the number of blocks of data to be encrypted provided now, and
* so far
*/
num_blocks = len / 16;
- all_num_blocks = num_blocks + ctx->blocks_processed;
-
- /* Loop through all full blocks to be encrypted */
- for (i = ctx->blocks_processed + 1; i <= all_num_blocks; i++) {
- OCB_BLOCK *lookup;
- OCB_BLOCK *inblock;
- OCB_BLOCK *outblock;
-
- /* Offset_i = Offset_{i-1} xor L_{ntz(i)} */
- lookup = ocb_lookup_l(ctx, ocb_ntz(i));
- if (!lookup)
+ all_num_blocks = num_blocks + ctx->sess.blocks_processed;
+
+ if (num_blocks && all_num_blocks == (size_t)all_num_blocks
+ && ctx->stream != NULL) {
+ size_t max_idx = 0, top = (size_t)all_num_blocks;
+
+ /*
+ * See how many L_{i} entries we need to process data at hand
+ * and pre-compute missing entries in the table [if any]...
+ */
+ while (top >>= 1)
+ max_idx++;
+ if (ocb_lookup_l(ctx, max_idx) == NULL)
return 0;
- ocb_block16_xor(&ctx->offset, lookup, &ctx->offset);
-
- /* C_i = Offset_i xor ENCIPHER(K, P_i xor Offset_i) */
- inblock = (OCB_BLOCK *)(in + ((i - ctx->blocks_processed - 1) * 16));
- ocb_block16_xor(&ctx->offset, inblock, &tmp1);
- ocb_encrypt(ctx, &tmp1, &tmp2, ctx->keyenc);
- outblock =
- (OCB_BLOCK *)(out + ((i - ctx->blocks_processed - 1) * 16));
- ocb_block16_xor(&ctx->offset, &tmp2, outblock);
-
- /* Checksum_i = Checksum_{i-1} xor P_i */
- ocb_block16_xor(&ctx->checksum, inblock, &ctx->checksum);
+
+ ctx->stream(in, out, num_blocks, ctx->keyenc,
+ (size_t)ctx->sess.blocks_processed + 1, ctx->sess.offset.c,
+ (const unsigned char (*)[16])ctx->l, ctx->sess.checksum.c);
+ } else {
+ /* Loop through all full blocks to be encrypted */
+ for (i = ctx->sess.blocks_processed + 1; i <= all_num_blocks; i++) {
+ OCB_BLOCK *lookup;
+ OCB_BLOCK tmp;
+
+ /* Offset_i = Offset_{i-1} xor L_{ntz(i)} */
+ lookup = ocb_lookup_l(ctx, ocb_ntz(i));
+ if (lookup == NULL)
+ return 0;
+ ocb_block16_xor(&ctx->sess.offset, lookup, &ctx->sess.offset);
+
+ memcpy(tmp.c, in, 16);
+ in += 16;
+
+ /* Checksum_i = Checksum_{i-1} xor P_i */
+ ocb_block16_xor(&tmp, &ctx->sess.checksum, &ctx->sess.checksum);
+
+ /* C_i = Offset_i xor ENCIPHER(K, P_i xor Offset_i) */
+ ocb_block16_xor(&ctx->sess.offset, &tmp, &tmp);
+ ctx->encrypt(tmp.c, tmp.c, ctx->keyenc);
+ ocb_block16_xor(&ctx->sess.offset, &tmp, &tmp);
+
+ memcpy(out, tmp.c, 16);
+ out += 16;
+ }
}
/*
last_len = len % 16;
if (last_len > 0) {
+ OCB_BLOCK pad;
+
/* Offset_* = Offset_m xor L_* */
- ocb_block16_xor(&ctx->offset, &ctx->l_star, &ctx->offset);
+ ocb_block16_xor(&ctx->sess.offset, &ctx->l_star, &ctx->sess.offset);
/* Pad = ENCIPHER(K, Offset_*) */
- ocb_encrypt(ctx, &ctx->offset, &pad, ctx->keyenc);
+ ctx->encrypt(ctx->sess.offset.c, pad.c, ctx->keyenc);
/* C_* = P_* xor Pad[1..bitlen(P_*)] */
- ocb_block_xor(in + (len / 16) * 16, (unsigned char *)&pad, last_len,
- out + (num_blocks * 16));
+ ocb_block_xor(in, pad.c, last_len, out);
/* Checksum_* = Checksum_m xor (P_* || 1 || zeros(127-bitlen(P_*))) */
- memset((void *)&tmp1, 0, 16);
- memcpy((void *)&tmp1, in + (len / 16) * 16, last_len);
- ((unsigned char *)(&tmp1))[last_len] = 0x80;
- ocb_block16_xor(&ctx->checksum, &tmp1, &ctx->checksum);
+ memset(pad.c, 0, 16); /* borrow pad */
+ memcpy(pad.c, in, last_len);
+ pad.c[last_len] = 0x80;
+ ocb_block16_xor(&pad, &ctx->sess.checksum, &ctx->sess.checksum);
}
- ctx->blocks_processed = all_num_blocks;
+ ctx->sess.blocks_processed = all_num_blocks;
return 1;
}
const unsigned char *in, unsigned char *out,
size_t len)
{
- u64 i;
- u64 all_num_blocks, num_blocks;
- OCB_BLOCK tmp1;
- OCB_BLOCK tmp2;
- OCB_BLOCK pad;
- int last_len;
+ u64 i, all_num_blocks;
+ size_t num_blocks, last_len;
+
/*
* Calculate the number of blocks of data to be decrypted provided now, and
* so far
*/
num_blocks = len / 16;
- all_num_blocks = num_blocks + ctx->blocks_processed;
+ all_num_blocks = num_blocks + ctx->sess.blocks_processed;
+
+ if (num_blocks && all_num_blocks == (size_t)all_num_blocks
+ && ctx->stream != NULL) {
+ size_t max_idx = 0, top = (size_t)all_num_blocks;
+
+ /*
+ * See how many L_{i} entries we need to process data at hand
+ * and pre-compute missing entries in the table [if any]...
+ */
+ while (top >>= 1)
+ max_idx++;
+ if (ocb_lookup_l(ctx, max_idx) == NULL)
+ return 0;
- /* Loop through all full blocks to be decrypted */
- for (i = ctx->blocks_processed + 1; i <= all_num_blocks; i++) {
- OCB_BLOCK *inblock;
- OCB_BLOCK *outblock;
+ ctx->stream(in, out, num_blocks, ctx->keydec,
+ (size_t)ctx->sess.blocks_processed + 1, ctx->sess.offset.c,
+ (const unsigned char (*)[16])ctx->l, ctx->sess.checksum.c);
+ } else {
+ OCB_BLOCK tmp;
- /* Offset_i = Offset_{i-1} xor L_{ntz(i)} */
- OCB_BLOCK *lookup = ocb_lookup_l(ctx, ocb_ntz(i));
- if (!lookup)
- return 0;
- ocb_block16_xor(&ctx->offset, lookup, &ctx->offset);
-
- /* P_i = Offset_i xor DECIPHER(K, C_i xor Offset_i) */
- inblock = (OCB_BLOCK *)(in + ((i - ctx->blocks_processed - 1) * 16));
- ocb_block16_xor(&ctx->offset, inblock, &tmp1);
- ocb_decrypt(ctx, &tmp1, &tmp2, ctx->keydec);
- outblock =
- (OCB_BLOCK *)(out + ((i - ctx->blocks_processed - 1) * 16));
- ocb_block16_xor(&ctx->offset, &tmp2, outblock);
-
- /* Checksum_i = Checksum_{i-1} xor P_i */
- ocb_block16_xor(&ctx->checksum, outblock, &ctx->checksum);
+ /* Loop through all full blocks to be decrypted */
+ for (i = ctx->sess.blocks_processed + 1; i <= all_num_blocks; i++) {
+
+ /* Offset_i = Offset_{i-1} xor L_{ntz(i)} */
+ OCB_BLOCK *lookup = ocb_lookup_l(ctx, ocb_ntz(i));
+ if (lookup == NULL)
+ return 0;
+ ocb_block16_xor(&ctx->sess.offset, lookup, &ctx->sess.offset);
+
+ memcpy(tmp.c, in, 16);
+ in += 16;
+
+ /* P_i = Offset_i xor DECIPHER(K, C_i xor Offset_i) */
+ ocb_block16_xor(&ctx->sess.offset, &tmp, &tmp);
+ ctx->decrypt(tmp.c, tmp.c, ctx->keydec);
+ ocb_block16_xor(&ctx->sess.offset, &tmp, &tmp);
+
+ /* Checksum_i = Checksum_{i-1} xor P_i */
+ ocb_block16_xor(&tmp, &ctx->sess.checksum, &ctx->sess.checksum);
+
+ memcpy(out, tmp.c, 16);
+ out += 16;
+ }
}
/*
last_len = len % 16;
if (last_len > 0) {
+ OCB_BLOCK pad;
+
/* Offset_* = Offset_m xor L_* */
- ocb_block16_xor(&ctx->offset, &ctx->l_star, &ctx->offset);
+ ocb_block16_xor(&ctx->sess.offset, &ctx->l_star, &ctx->sess.offset);
/* Pad = ENCIPHER(K, Offset_*) */
- ocb_encrypt(ctx, &ctx->offset, &pad, ctx->keyenc);
+ ctx->encrypt(ctx->sess.offset.c, pad.c, ctx->keyenc);
/* P_* = C_* xor Pad[1..bitlen(C_*)] */
- ocb_block_xor(in + (len / 16) * 16, (unsigned char *)&pad, last_len,
- out + (num_blocks * 16));
+ ocb_block_xor(in, pad.c, last_len, out);
/* Checksum_* = Checksum_m xor (P_* || 1 || zeros(127-bitlen(P_*))) */
- memset((void *)&tmp1, 0, 16);
- memcpy((void *)&tmp1, out + (len / 16) * 16, last_len);
- ((unsigned char *)(&tmp1))[last_len] = 0x80;
- ocb_block16_xor(&ctx->checksum, &tmp1, &ctx->checksum);
+ memset(pad.c, 0, 16); /* borrow pad */
+ memcpy(pad.c, out, last_len);
+ pad.c[last_len] = 0x80;
+ ocb_block16_xor(&pad, &ctx->sess.checksum, &ctx->sess.checksum);
}
- ctx->blocks_processed = all_num_blocks;
+ ctx->sess.blocks_processed = all_num_blocks;
return 1;
}
-/*
- * Calculate the tag and verify it against the supplied tag
- */
-int CRYPTO_ocb128_finish(OCB128_CONTEXT *ctx, const unsigned char *tag,
- size_t len)
+static int ocb_finish(OCB128_CONTEXT *ctx, unsigned char *tag, size_t len,
+ int write)
{
- OCB_BLOCK tmp1, tmp2;
+ OCB_BLOCK tmp;
+
+ if (len > 16 || len < 1) {
+ return -1;
+ }
/*
* Tag = ENCIPHER(K, Checksum_* xor Offset_* xor L_$) xor HASH(K,A)
*/
- ocb_block16_xor(&ctx->checksum, &ctx->offset, &tmp1);
- ocb_block16_xor(&tmp1, &ctx->l_dollar, &tmp2);
- ocb_encrypt(ctx, &tmp2, &tmp1, ctx->keyenc);
- ocb_block16_xor(&tmp1, &ctx->sum, &ctx->tag);
-
- if (len > 16 || len < 1) {
- return -1;
+ ocb_block16_xor(&ctx->sess.checksum, &ctx->sess.offset, &tmp);
+ ocb_block16_xor(&ctx->l_dollar, &tmp, &tmp);
+ ctx->encrypt(tmp.c, tmp.c, ctx->keyenc);
+ ocb_block16_xor(&tmp, &ctx->sess.sum, &tmp);
+
+ if (write) {
+ memcpy(tag, &tmp, len);
+ return 1;
+ } else {
+ return CRYPTO_memcmp(&tmp, tag, len);
}
+}
- /* Compare the tag if we've been given one */
- if (tag)
- return CRYPTO_memcmp(&ctx->tag, tag, len);
- else
- return -1;
+/*
+ * Calculate the tag and verify it against the supplied tag
+ */
+int CRYPTO_ocb128_finish(OCB128_CONTEXT *ctx, const unsigned char *tag,
+ size_t len)
+{
+ return ocb_finish(ctx, (unsigned char*)tag, len, 0);
}
/*
*/
int CRYPTO_ocb128_tag(OCB128_CONTEXT *ctx, unsigned char *tag, size_t len)
{
- if (len > 16 || len < 1) {
- return -1;
- }
-
- /* Calculate the tag */
- CRYPTO_ocb128_finish(ctx, NULL, 0);
-
- /* Copy the tag into the supplied buffer */
- memcpy(tag, &ctx->tag, len);
-
- return 1;
+ return ocb_finish(ctx, tag, len, 1);
}
/*
projects / openssl.git / blobdiff