1 /* ====================================================================
2 * Copyright (c) 2008 The OpenSSL Project. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in
13 * the documentation and/or other materials provided with the
16 * 3. All advertising materials mentioning features or use of this
17 * software must display the following acknowledgment:
18 * "This product includes software developed by the OpenSSL Project
19 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22 * endorse or promote products derived from this software without
23 * prior written permission. For written permission, please contact
24 * openssl-core@openssl.org.
26 * 5. Products derived from this software may not be called "OpenSSL"
27 * nor may "OpenSSL" appear in their names without prior written
28 * permission of the OpenSSL Project.
30 * 6. Redistributions of any form whatsoever must retain the following
32 * "This product includes software developed by the OpenSSL Project
33 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 * ====================================================================
61 typedef unsigned int u32;
62 typedef unsigned char u8;
64 #define STRICT_ALIGNMENT
65 #if defined(__i386) || defined(__i386__) || \
66 defined(__x86_64) || defined(__x86_64__) || \
67 defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || \
68 defined(__s390__) || defined(__s390x__)
69 # undef STRICT_ALIGNMENT
73 * NOTE: the IV/counter CTR mode is big-endian. The code itself is
77 /* increment counter (128-bit int) by 1 */
78 static void ctr128_inc(unsigned char *counter)
93 #if !defined(OPENSSL_SMALL_FOOTPRINT)
94 static void ctr128_inc_aligned(unsigned char *counter)
104 if (is_endian.little) {
109 data = (size_t *)counter;
110 n = 16 / sizeof(size_t);
123 * The input encrypted as though 128bit counter mode is being used. The
124 * extra state information to record how much of the 128bit block we have
125 * used is contained in *num, and the encrypted counter is kept in
126 * ecount_buf. Both *num and ecount_buf must be initialised with zeros
127 * before the first call to CRYPTO_ctr128_encrypt(). This algorithm assumes
128 * that the counter is in the x lower bits of the IV (ivec), and that the
129 * application has full control over overflow and the rest of the IV. This
130 * implementation takes NO responsability for checking that the counter
131 * doesn't overflow into the rest of the IV when incremented.
133 void CRYPTO_ctr128_encrypt(const unsigned char *in, unsigned char *out,
134 size_t len, const void *key,
135 unsigned char ivec[16],
136 unsigned char ecount_buf[16], unsigned int *num,
142 assert(in && out && key && ecount_buf && num);
147 #if !defined(OPENSSL_SMALL_FOOTPRINT)
148 if (16 % sizeof(size_t) == 0) { /* always true actually */
151 *(out++) = *(in++) ^ ecount_buf[n];
156 # if defined(STRICT_ALIGNMENT)
157 if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) !=
162 (*block) (ivec, ecount_buf, key);
163 ctr128_inc_aligned(ivec);
164 for (; n < 16; n += sizeof(size_t))
165 *(size_t *)(out + n) =
166 *(size_t *)(in + n) ^ *(size_t *)(ecount_buf + n);
173 (*block) (ivec, ecount_buf, key);
174 ctr128_inc_aligned(ivec);
176 out[n] = in[n] ^ ecount_buf[n];
184 /* the rest would be commonly eliminated by x86* compiler */
188 (*block) (ivec, ecount_buf, key);
191 out[l] = in[l] ^ ecount_buf[n];