| /* ==================================================================== |
| * 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 <openssl/opensslconf.h> |
| #if !defined(OPENSSL_SYS_STARBOARD) |
| #include <assert.h> |
| #include <string.h> |
| #endif // !defined(OPENSSL_SYS_STARBOARD) |
| |
| #ifndef MODES_DEBUG |
| # ifndef NDEBUG |
| # define NDEBUG |
| # endif |
| #endif |
| |
| /* |
| * 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; |
| u8 c; |
| |
| do { |
| --n; |
| c = counter[n]; |
| ++c; |
| counter[n] = c; |
| if (c) |
| return; |
| } while (n); |
| } |
| |
| #if !defined(OPENSSL_SMALL_FOOTPRINT) |
| static void ctr128_inc_aligned(unsigned char *counter) |
| { |
| size_t *data, c, n; |
| const union { |
| long one; |
| char little; |
| } is_endian = { |
| 1 |
| }; |
| |
| if (is_endian.little) { |
| ctr128_inc(counter); |
| return; |
| } |
| |
| data = (size_t *)counter; |
| n = 16 / sizeof(size_t); |
| do { |
| --n; |
| c = data[n]; |
| ++c; |
| data[n] = c; |
| if (c) |
| return; |
| } 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; |
| |
| OPENSSL_port_assert(in && out && key && ecount_buf && num); |
| OPENSSL_port_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)ivec) % sizeof(size_t) != |
| 0) |
| break; |
| # endif |
| while (len >= 16) { |
| (*block) (ivec, ecount_buf, key); |
| ctr128_inc_aligned(ivec); |
| for (; 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; |
| u8 c; |
| |
| do { |
| --n; |
| c = counter[n]; |
| ++c; |
| counter[n] = c; |
| if (c) |
| return; |
| } 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; |
| |
| OPENSSL_port_assert(in && out && key && ecount_buf && num); |
| OPENSSL_port_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) { |
| OPENSSL_port_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; |
| } |
