1 /* crypto/camellia/camellia_ctr.c -*- mode:C; c-file-style: "eay" -*- */
2 /* ====================================================================
3 * Copyright (c) 2006 The OpenSSL Project. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
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
15 * distribution.
16 *
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/)"
21 *
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.
26 *
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.
30 *
31 * 6. Redistributions of any form whatsoever must retain the following
32 * acknowledgment:
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 *
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;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
49 *
50 */
51
52 #ifndef CAMELLIA_DEBUG
53 # ifndef NDEBUG
54 # define NDEBUG
55 # endif
56 #endif
57 #include <assert.h>
58
59 #include <openssl/camellia.h>
60 #include "cmll_locl.h"
61
62 /* NOTE: the IV/counter CTR mode is big-endian. The rest of the Camellia code
63 * is endian-neutral. */
64 /* increment counter (128-bit int) by 1 */
Camellia_ctr128_inc(unsigned char * counter)65 static void Camellia_ctr128_inc(unsigned char *counter)
66 {
67 unsigned long c;
68
69 /* Grab bottom dword of counter and increment */
70 c = GETU32(counter + 12);
71 c++; c &= 0xFFFFFFFF;
72 PUTU32(counter + 12, c);
73
74 /* if no overflow, we're done */
75 if (c)
76 return;
77
78 /* Grab 1st dword of counter and increment */
79 c = GETU32(counter + 8);
80 c++; c &= 0xFFFFFFFF;
81 PUTU32(counter + 8, c);
82
83 /* if no overflow, we're done */
84 if (c)
85 return;
86
87 /* Grab 2nd dword of counter and increment */
88 c = GETU32(counter + 4);
89 c++; c &= 0xFFFFFFFF;
90 PUTU32(counter + 4, c);
91
92 /* if no overflow, we're done */
93 if (c)
94 return;
95
96 /* Grab top dword of counter and increment */
97 c = GETU32(counter + 0);
98 c++; c &= 0xFFFFFFFF;
99 PUTU32(counter + 0, c);
100 }
101
102 /* The input encrypted as though 128bit counter mode is being
103 * used. The extra state information to record how much of the
104 * 128bit block we have used is contained in *num, and the
105 * encrypted counter is kept in ecount_buf. Both *num and
106 * ecount_buf must be initialised with zeros before the first
107 * call to Camellia_ctr128_encrypt().
108 *
109 * This algorithm assumes that the counter is in the x lower bits
110 * of the IV (ivec), and that the application has full control over
111 * overflow and the rest of the IV. This implementation takes NO
112 * responsability for checking that the counter doesn't overflow
113 * into the rest of the IV when incremented.
114 */
Camellia_ctr128_encrypt(const unsigned char * in,unsigned char * out,const unsigned long length,const CAMELLIA_KEY * key,unsigned char ivec[CAMELLIA_BLOCK_SIZE],unsigned char ecount_buf[CAMELLIA_BLOCK_SIZE],unsigned int * num)115 void Camellia_ctr128_encrypt(const unsigned char *in, unsigned char *out,
116 const unsigned long length, const CAMELLIA_KEY *key,
117 unsigned char ivec[CAMELLIA_BLOCK_SIZE],
118 unsigned char ecount_buf[CAMELLIA_BLOCK_SIZE],
119 unsigned int *num)
120 {
121
122 unsigned int n;
123 unsigned long l=length;
124
125 assert(in && out && key && counter && num);
126 assert(*num < CAMELLIA_BLOCK_SIZE);
127
128 n = *num;
129
130 while (l--)
131 {
132 if (n == 0)
133 {
134 Camellia_encrypt(ivec, ecount_buf, key);
135 Camellia_ctr128_inc(ivec);
136 }
137 *(out++) = *(in++) ^ ecount_buf[n];
138 n = (n+1) % CAMELLIA_BLOCK_SIZE;
139 }
140
141 *num=n;
142 }
143
144