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 <openssl/crypto.h>
52#include "modes_lcl.h"
53#include <string.h>
54
55#ifndef MODES_DEBUG
56# ifndef NDEBUG
57#  define NDEBUG
58# endif
59#endif
60#include <assert.h>
61
62#ifndef STRICT_ALIGNMENT
63#  define STRICT_ALIGNMENT 0
64#endif
65
66void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
67			size_t len, const void *key,
68			unsigned char ivec[16], block128_f block)
69{
70	size_t n;
71	const unsigned char *iv = ivec;
72
73	assert(in && out && key && ivec);
74
75#if !defined(OPENSSL_SMALL_FOOTPRINT)
76	if (STRICT_ALIGNMENT &&
77	    ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
78		while (len>=16) {
79			for(n=0; n<16; ++n)
80				out[n] = in[n] ^ iv[n];
81			(*block)(out, out, key);
82			iv = out;
83			len -= 16;
84			in  += 16;
85			out += 16;
86		}
87	} else {
88		while (len>=16) {
89			for(n=0; n<16; n+=sizeof(size_t))
90				*(size_t*)(out+n) =
91				*(size_t*)(in+n) ^ *(size_t*)(iv+n);
92			(*block)(out, out, key);
93			iv = out;
94			len -= 16;
95			in  += 16;
96			out += 16;
97		}
98	}
99#endif
100	while (len) {
101		for(n=0; n<16 && n<len; ++n)
102			out[n] = in[n] ^ iv[n];
103		for(; n<16; ++n)
104			out[n] = iv[n];
105		(*block)(out, out, key);
106		iv = out;
107		if (len<=16) break;
108		len -= 16;
109		in  += 16;
110		out += 16;
111	}
112	memcpy(ivec,iv,16);
113}
114
115void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
116			size_t len, const void *key,
117			unsigned char ivec[16], block128_f block)
118{
119	size_t n;
120	union { size_t t[16/sizeof(size_t)]; unsigned char c[16]; } tmp;
121
122	assert(in && out && key && ivec);
123
124#if !defined(OPENSSL_SMALL_FOOTPRINT)
125	if (in != out) {
126		const unsigned char *iv = ivec;
127
128		if (STRICT_ALIGNMENT &&
129		    ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
130			while (len>=16) {
131				(*block)(in, out, key);
132				for(n=0; n<16; ++n)
133					out[n] ^= iv[n];
134				iv = in;
135				len -= 16;
136				in  += 16;
137				out += 16;
138			}
139		}
140		else  if (16%sizeof(size_t) == 0) { /* always true */
141			while (len>=16) {
142				size_t *out_t=(size_t *)out, *iv_t=(size_t *)iv;
143
144				(*block)(in, out, key);
145				for(n=0; n<16/sizeof(size_t); n++)
146					out_t[n] ^= iv_t[n];
147				iv = in;
148				len -= 16;
149				in  += 16;
150				out += 16;
151			}
152		}
153		memcpy(ivec,iv,16);
154	} else {
155		if (STRICT_ALIGNMENT &&
156		    ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
157			unsigned char c;
158			while (len>=16) {
159				(*block)(in, tmp.c, key);
160				for(n=0; n<16; ++n) {
161					c = in[n];
162					out[n] = tmp.c[n] ^ ivec[n];
163					ivec[n] = c;
164				}
165				len -= 16;
166				in  += 16;
167				out += 16;
168			}
169		}
170		else if (16%sizeof(size_t) == 0) { /* always true */
171			while (len>=16) {
172				size_t c, *out_t=(size_t *)out, *ivec_t=(size_t *)ivec;
173				const size_t *in_t=(const size_t *)in;
174
175				(*block)(in, tmp.c, key);
176				for(n=0; n<16/sizeof(size_t); n++) {
177					c = in_t[n];
178					out_t[n] = tmp.t[n] ^ ivec_t[n];
179					ivec_t[n] = c;
180				}
181				len -= 16;
182				in  += 16;
183				out += 16;
184			}
185		}
186	}
187#endif
188	while (len) {
189		unsigned char c;
190		(*block)(in, tmp.c, key);
191		for(n=0; n<16 && n<len; ++n) {
192			c = in[n];
193			out[n] = tmp.c[n] ^ ivec[n];
194			ivec[n] = c;
195		}
196		if (len<=16) {
197			for (; n<16; ++n)
198				ivec[n] = in[n];
199			break;
200		}
201		len -= 16;
202		in  += 16;
203		out += 16;
204	}
205}
206