You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
263 lines
8.1 KiB
263 lines
8.1 KiB
/* ==================================================================== |
|
* Copyright (c) 2008 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/)" |
|
* |
|
* 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. |
|
* ==================================================================== |
|
* |
|
*/ |
|
|
|
#include <openssl/crypto.h> |
|
#include "modes_lcl.h" |
|
#include <string.h> |
|
|
|
#ifndef MODES_DEBUG |
|
# ifndef NDEBUG |
|
# define NDEBUG |
|
# endif |
|
#endif |
|
#include <assert.h> |
|
|
|
/* |
|
* NOTE: the IV/counter CTR mode is big-endian. The code itself is |
|
* endian-neutral. |
|
*/ |
|
|
|
/* increment counter (128-bit int) by 1 */ |
|
static void ctr128_inc(unsigned char *counter) |
|
{ |
|
u32 n = 16, c = 1; |
|
|
|
do { |
|
--n; |
|
c += counter[n]; |
|
counter[n] = (u8)c; |
|
c >>= 8; |
|
} while (n); |
|
} |
|
|
|
#if !defined(OPENSSL_SMALL_FOOTPRINT) |
|
static void ctr128_inc_aligned(unsigned char *counter) |
|
{ |
|
size_t *data, c, d, n; |
|
const union { |
|
long one; |
|
char little; |
|
} is_endian = { |
|
1 |
|
}; |
|
|
|
if (is_endian.little || ((size_t)counter % sizeof(size_t)) != 0) { |
|
ctr128_inc(counter); |
|
return; |
|
} |
|
|
|
data = (size_t *)counter; |
|
c = 1; |
|
n = 16 / sizeof(size_t); |
|
do { |
|
--n; |
|
d = data[n] += c; |
|
/* did addition carry? */ |
|
c = ((d - c) & ~d) >> (sizeof(size_t) * 8 - 1); |
|
} while (n); |
|
} |
|
#endif |
|
|
|
/* |
|
* The input encrypted as though 128bit counter mode is being used. The |
|
* extra state information to record how much of the 128bit block we have |
|
* used is contained in *num, and the encrypted counter is kept in |
|
* ecount_buf. Both *num and ecount_buf must be initialised with zeros |
|
* before the first call to CRYPTO_ctr128_encrypt(). This algorithm assumes |
|
* that the counter is in the x lower bits of the IV (ivec), and that the |
|
* application has full control over overflow and the rest of the IV. This |
|
* implementation takes NO responsability for checking that the counter |
|
* doesn't overflow into the rest of the IV when incremented. |
|
*/ |
|
void CRYPTO_ctr128_encrypt(const unsigned char *in, unsigned char *out, |
|
size_t len, const void *key, |
|
unsigned char ivec[16], |
|
unsigned char ecount_buf[16], unsigned int *num, |
|
block128_f block) |
|
{ |
|
unsigned int n; |
|
size_t l = 0; |
|
|
|
assert(in && out && key && ecount_buf && num); |
|
assert(*num < 16); |
|
|
|
n = *num; |
|
|
|
#if !defined(OPENSSL_SMALL_FOOTPRINT) |
|
if (16 % sizeof(size_t) == 0) { /* always true actually */ |
|
do { |
|
while (n && len) { |
|
*(out++) = *(in++) ^ ecount_buf[n]; |
|
--len; |
|
n = (n + 1) % 16; |
|
} |
|
|
|
# if defined(STRICT_ALIGNMENT) |
|
if (((size_t)in | (size_t)out | (size_t)ecount_buf) |
|
% sizeof(size_t) != 0) |
|
break; |
|
# endif |
|
while (len >= 16) { |
|
(*block) (ivec, ecount_buf, key); |
|
ctr128_inc_aligned(ivec); |
|
for (n = 0; n < 16; n += sizeof(size_t)) |
|
*(size_t *)(out + n) = |
|
*(size_t *)(in + n) ^ *(size_t *)(ecount_buf + n); |
|
len -= 16; |
|
out += 16; |
|
in += 16; |
|
n = 0; |
|
} |
|
if (len) { |
|
(*block) (ivec, ecount_buf, key); |
|
ctr128_inc_aligned(ivec); |
|
while (len--) { |
|
out[n] = in[n] ^ ecount_buf[n]; |
|
++n; |
|
} |
|
} |
|
*num = n; |
|
return; |
|
} while (0); |
|
} |
|
/* the rest would be commonly eliminated by x86* compiler */ |
|
#endif |
|
while (l < len) { |
|
if (n == 0) { |
|
(*block) (ivec, ecount_buf, key); |
|
ctr128_inc(ivec); |
|
} |
|
out[l] = in[l] ^ ecount_buf[n]; |
|
++l; |
|
n = (n + 1) % 16; |
|
} |
|
|
|
*num = n; |
|
} |
|
|
|
/* increment upper 96 bits of 128-bit counter by 1 */ |
|
static void ctr96_inc(unsigned char *counter) |
|
{ |
|
u32 n = 12, c = 1; |
|
|
|
do { |
|
--n; |
|
c += counter[n]; |
|
counter[n] = (u8)c; |
|
c >>= 8; |
|
} while (n); |
|
} |
|
|
|
void CRYPTO_ctr128_encrypt_ctr32(const unsigned char *in, unsigned char *out, |
|
size_t len, const void *key, |
|
unsigned char ivec[16], |
|
unsigned char ecount_buf[16], |
|
unsigned int *num, ctr128_f func) |
|
{ |
|
unsigned int n, ctr32; |
|
|
|
assert(in && out && key && ecount_buf && num); |
|
assert(*num < 16); |
|
|
|
n = *num; |
|
|
|
while (n && len) { |
|
*(out++) = *(in++) ^ ecount_buf[n]; |
|
--len; |
|
n = (n + 1) % 16; |
|
} |
|
|
|
ctr32 = GETU32(ivec + 12); |
|
while (len >= 16) { |
|
size_t blocks = len / 16; |
|
/* |
|
* 1<<28 is just a not-so-small yet not-so-large number... |
|
* Below condition is practically never met, but it has to |
|
* be checked for code correctness. |
|
*/ |
|
if (sizeof(size_t) > sizeof(unsigned int) && blocks > (1U << 28)) |
|
blocks = (1U << 28); |
|
/* |
|
* As (*func) operates on 32-bit counter, caller |
|
* has to handle overflow. 'if' below detects the |
|
* overflow, which is then handled by limiting the |
|
* amount of blocks to the exact overflow point... |
|
*/ |
|
ctr32 += (u32)blocks; |
|
if (ctr32 < blocks) { |
|
blocks -= ctr32; |
|
ctr32 = 0; |
|
} |
|
(*func) (in, out, blocks, key, ivec); |
|
/* (*ctr) does not update ivec, caller does: */ |
|
PUTU32(ivec + 12, ctr32); |
|
/* ... overflow was detected, propogate carry. */ |
|
if (ctr32 == 0) |
|
ctr96_inc(ivec); |
|
blocks *= 16; |
|
len -= blocks; |
|
out += blocks; |
|
in += blocks; |
|
} |
|
if (len) { |
|
memset(ecount_buf, 0, 16); |
|
(*func) (ecount_buf, ecount_buf, 1, key, ivec); |
|
++ctr32; |
|
PUTU32(ivec + 12, ctr32); |
|
if (ctr32 == 0) |
|
ctr96_inc(ivec); |
|
while (len--) { |
|
out[n] = in[n] ^ ecount_buf[n]; |
|
++n; |
|
} |
|
} |
|
|
|
*num = n; |
|
}
|
|
|