1/* ====================================================================
2 * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *
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
14 *    distribution.
15 *
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/)"
20 *
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.
25 *
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.
29 *
30 * 6. Redistributions of any form whatsoever must retain the following
31 *    acknowledgment:
32 *    "This product includes software developed by the OpenSSL Project
33 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
34 *
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 * ====================================================================
48 *
49 */
50
51#include "modes.h"
52#include <string.h>
53
54#ifndef MODES_DEBUG
55# ifndef NDEBUG
56#  define NDEBUG
57# endif
58#endif
59#include <assert.h>
60
61#define STRICT_ALIGNMENT 1
62#if defined(__i386) || defined(__i386__) || \
63    defined(__x86_64) || defined(__x86_64__) || \
64    defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || \
65    defined(__s390__) || defined(__s390x__)
66#  undef STRICT_ALIGNMENT
67#  define STRICT_ALIGNMENT 0
68#endif
69
70void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
71			size_t len, const void *key,
72			unsigned char ivec[16], block128_f block)
73{
74	size_t n;
75	const unsigned char *iv = ivec;
76
77	assert(in && out && key && ivec);
78
79#if !defined(OPENSSL_SMALL_FOOTPRINT)
80	if (STRICT_ALIGNMENT &&
81	    ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
82		while (len>=16) {
83			for(n=0; n<16; ++n)
84				out[n] = in[n] ^ iv[n];
85			(*block)(out, out, key);
86			iv = out;
87			len -= 16;
88			in  += 16;
89			out += 16;
90		}
91	} else {
92		while (len>=16) {
93			for(n=0; n<16; n+=sizeof(size_t))
94				*(size_t*)(out+n) =
95				*(size_t*)(in+n) ^ *(size_t*)(iv+n);
96			(*block)(out, out, key);
97			iv = out;
98			len -= 16;
99			in  += 16;
100			out += 16;
101		}
102	}
103#endif
104	while (len) {
105		for(n=0; n<16 && n<len; ++n)
106			out[n] = in[n] ^ iv[n];
107		for(; n<16; ++n)
108			out[n] = iv[n];
109		(*block)(out, out, key);
110		iv = out;
111		if (len<=16) break;
112		len -= 16;
113		in  += 16;
114		out += 16;
115	}
116	memcpy(ivec,iv,16);
117}
118
119void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
120			size_t len, const void *key,
121			unsigned char ivec[16], block128_f block)
122{
123	size_t n;
124	union { size_t align; unsigned char c[16]; } tmp;
125
126	assert(in && out && key && ivec);
127
128#if !defined(OPENSSL_SMALL_FOOTPRINT)
129	if (in != out) {
130		const unsigned char *iv = ivec;
131
132		if (STRICT_ALIGNMENT &&
133		    ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
134			while (len>=16) {
135				(*block)(in, out, key);
136				for(n=0; n<16; ++n)
137					out[n] ^= iv[n];
138				iv = in;
139				len -= 16;
140				in  += 16;
141				out += 16;
142			}
143		}
144		else {
145			while (len>=16) {
146				(*block)(in, out, key);
147				for(n=0; n<16; n+=sizeof(size_t))
148					*(size_t *)(out+n) ^= *(size_t *)(iv+n);
149				iv = in;
150				len -= 16;
151				in  += 16;
152				out += 16;
153			}
154		}
155		memcpy(ivec,iv,16);
156	} else {
157		if (STRICT_ALIGNMENT &&
158		    ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
159			unsigned char c;
160			while (len>=16) {
161				(*block)(in, tmp.c, key);
162				for(n=0; n<16; ++n) {
163					c = in[n];
164					out[n] = tmp.c[n] ^ ivec[n];
165					ivec[n] = c;
166				}
167				len -= 16;
168				in  += 16;
169				out += 16;
170			}
171		}
172		else {
173			size_t c;
174			while (len>=16) {
175				(*block)(in, tmp.c, key);
176				for(n=0; n<16; n+=sizeof(size_t)) {
177					c = *(size_t *)(in+n);
178					*(size_t *)(out+n) =
179					*(size_t *)(tmp.c+n) ^ *(size_t *)(ivec+n);
180					*(size_t *)(ivec+n) = c;
181				}
182				len -= 16;
183				in  += 16;
184				out += 16;
185			}
186		}
187	}
188#endif
189	while (len) {
190		unsigned char c;
191		(*block)(in, tmp.c, key);
192		for(n=0; n<16 && n<len; ++n) {
193			c = in[n];
194			out[n] = tmp.c[n] ^ ivec[n];
195			ivec[n] = c;
196		}
197		if (len<=16) {
198			for (; n<16; ++n)
199				ivec[n] = in[n];
200			break;
201		}
202		len -= 16;
203		in  += 16;
204		out += 16;
205	}
206}
207