1 /* crypto/camellia/camellia_ctr.c -*- mode:C; c-file-style: "eay" -*- */
2 /* ====================================================================
3 * Copyright (c) 2006 The OpenSSL Project. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
17 * 3. All advertising materials mentioning features or use of this
18 * software must display the following acknowledgment:
19 * "This product includes software developed by the OpenSSL Project
20 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For written permission, please contact
25 * openssl-core@openssl.org.
27 * 5. Products derived from this software may not be called "OpenSSL"
28 * nor may "OpenSSL" appear in their names without prior written
29 * permission of the OpenSSL Project.
31 * 6. Redistributions of any form whatsoever must retain the following
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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48 * ====================================================================
52 #ifndef CAMELLIA_DEBUG
59 #include <openssl/camellia.h>
60 #include <openssl/crypto.h>
61 #include "cmll_locl.h"
63 /* NOTE: the IV/counter CTR mode is big-endian. The rest of the Camellia code
64 * is endian-neutral. */
65 /* increment counter (128-bit int) by 1 */
66 static void Camellia_ctr128_inc(unsigned char *counter)
70 /* Grab bottom dword of counter and increment */
71 c = GETU32(counter + 12);
73 PUTU32(counter + 12, c);
75 /* if no overflow, we're done */
79 /* Grab 1st dword of counter and increment */
80 c = GETU32(counter + 8);
82 PUTU32(counter + 8, c);
84 /* if no overflow, we're done */
88 /* Grab 2nd dword of counter and increment */
89 c = GETU32(counter + 4);
91 PUTU32(counter + 4, c);
93 /* if no overflow, we're done */
97 /* Grab top dword of counter and increment */
98 c = GETU32(counter + 0);
100 PUTU32(counter + 0, c);
103 /* The input encrypted as though 128bit counter mode is being
104 * used. The extra state information to record how much of the
105 * 128bit block we have used is contained in *num, and the
106 * encrypted counter is kept in ecount_buf. Both *num and
107 * ecount_buf must be initialised with zeros before the first
108 * call to Camellia_ctr128_encrypt().
110 * This algorithm assumes that the counter is in the x lower bits
111 * of the IV (ivec), and that the application has full control over
112 * overflow and the rest of the IV. This implementation takes NO
113 * responsability for checking that the counter doesn't overflow
114 * into the rest of the IV when incremented.
116 void Camellia_ctr128_encrypt(const unsigned char *in, unsigned char *out,
117 size_t length, const CAMELLIA_KEY *key,
118 unsigned char ivec[CAMELLIA_BLOCK_SIZE],
119 unsigned char ecount_buf[CAMELLIA_BLOCK_SIZE],
125 OPENSSL_assert(in && out && key && ecount_buf && num);
126 OPENSSL_assert(*num < CAMELLIA_BLOCK_SIZE);
134 Camellia_encrypt(ivec, ecount_buf, key);
135 Camellia_ctr128_inc(ivec);
137 *(out++) = *(in++) ^ ecount_buf[n];
138 n = (n+1) % CAMELLIA_BLOCK_SIZE;