1/* crypto/aes/aes_ige.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#include "cryptlib.h"
53
54#include <openssl/aes.h>
55#include "aes_locl.h"
56
57#define N_WORDS (AES_BLOCK_SIZE / sizeof(unsigned long))
58typedef struct {
59        unsigned long data[N_WORDS];
60} aes_block_t;
61
62/* XXX: probably some better way to do this */
63#if defined(__i386__) || defined(__x86_64__)
64#define UNALIGNED_MEMOPS_ARE_FAST 1
65#else
66#define UNALIGNED_MEMOPS_ARE_FAST 0
67#endif
68
69#if UNALIGNED_MEMOPS_ARE_FAST
70#define load_block(d, s)        (d) = *(const aes_block_t *)(s)
71#define store_block(d, s)       *(aes_block_t *)(d) = (s)
72#else
73#define load_block(d, s)        memcpy((d).data, (s), AES_BLOCK_SIZE)
74#define store_block(d, s)       memcpy((d), (s).data, AES_BLOCK_SIZE)
75#endif
76
77/* N.B. The IV for this mode is _twice_ the block size */
78
79void AES_ige_encrypt(const unsigned char *in, unsigned char *out,
80					 size_t length, const AES_KEY *key,
81					 unsigned char *ivec, const int enc)
82	{
83	size_t n;
84	size_t len = length;
85
86	OPENSSL_assert(in && out && key && ivec);
87	OPENSSL_assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));
88	OPENSSL_assert((length%AES_BLOCK_SIZE) == 0);
89
90	len = length / AES_BLOCK_SIZE;
91
92	if (AES_ENCRYPT == enc)
93		{
94		if (in != out &&
95		    (UNALIGNED_MEMOPS_ARE_FAST || ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(long)==0))
96			{
97			aes_block_t *ivp = (aes_block_t *)ivec;
98			aes_block_t *iv2p = (aes_block_t *)(ivec + AES_BLOCK_SIZE);
99
100			while (len)
101				{
102				aes_block_t *inp = (aes_block_t *)in;
103				aes_block_t *outp = (aes_block_t *)out;
104
105				for(n=0 ; n < N_WORDS; ++n)
106					outp->data[n] = inp->data[n] ^ ivp->data[n];
107				AES_encrypt((unsigned char *)outp->data, (unsigned char *)outp->data, key);
108				for(n=0 ; n < N_WORDS; ++n)
109					outp->data[n] ^= iv2p->data[n];
110				ivp = outp;
111				iv2p = inp;
112				--len;
113				in += AES_BLOCK_SIZE;
114				out += AES_BLOCK_SIZE;
115				}
116			memcpy(ivec, ivp->data, AES_BLOCK_SIZE);
117			memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
118			}
119		else
120			{
121			aes_block_t tmp, tmp2;
122			aes_block_t iv;
123			aes_block_t iv2;
124
125			load_block(iv, ivec);
126			load_block(iv2, ivec + AES_BLOCK_SIZE);
127
128			while (len)
129				{
130				load_block(tmp, in);
131				for(n=0 ; n < N_WORDS; ++n)
132					tmp2.data[n] = tmp.data[n] ^ iv.data[n];
133				AES_encrypt((unsigned char *)tmp2.data, (unsigned char *)tmp2.data, key);
134				for(n=0 ; n < N_WORDS; ++n)
135					tmp2.data[n] ^= iv2.data[n];
136				store_block(out, tmp2);
137				iv = tmp2;
138				iv2 = tmp;
139				--len;
140				in += AES_BLOCK_SIZE;
141				out += AES_BLOCK_SIZE;
142				}
143			memcpy(ivec, iv.data, AES_BLOCK_SIZE);
144			memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
145			}
146		}
147	else
148		{
149		if (in != out &&
150		    (UNALIGNED_MEMOPS_ARE_FAST || ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(long)==0))
151			{
152			aes_block_t *ivp = (aes_block_t *)ivec;
153			aes_block_t *iv2p = (aes_block_t *)(ivec + AES_BLOCK_SIZE);
154
155			while (len)
156				{
157				aes_block_t tmp;
158				aes_block_t *inp = (aes_block_t *)in;
159				aes_block_t *outp = (aes_block_t *)out;
160
161				for(n=0 ; n < N_WORDS; ++n)
162					tmp.data[n] = inp->data[n] ^ iv2p->data[n];
163				AES_decrypt((unsigned char *)tmp.data, (unsigned char *)outp->data, key);
164				for(n=0 ; n < N_WORDS; ++n)
165					outp->data[n] ^= ivp->data[n];
166				ivp = inp;
167				iv2p = outp;
168				--len;
169				in += AES_BLOCK_SIZE;
170				out += AES_BLOCK_SIZE;
171				}
172			memcpy(ivec, ivp->data, AES_BLOCK_SIZE);
173			memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
174			}
175		else
176			{
177			aes_block_t tmp, tmp2;
178			aes_block_t iv;
179			aes_block_t iv2;
180
181			load_block(iv, ivec);
182			load_block(iv2, ivec + AES_BLOCK_SIZE);
183
184			while (len)
185				{
186				load_block(tmp, in);
187				tmp2 = tmp;
188				for(n=0 ; n < N_WORDS; ++n)
189					tmp.data[n] ^= iv2.data[n];
190				AES_decrypt((unsigned char *)tmp.data, (unsigned char *)tmp.data, key);
191				for(n=0 ; n < N_WORDS; ++n)
192					tmp.data[n] ^= iv.data[n];
193				store_block(out, tmp);
194				iv = tmp2;
195				iv2 = tmp;
196				--len;
197				in += AES_BLOCK_SIZE;
198				out += AES_BLOCK_SIZE;
199				}
200			memcpy(ivec, iv.data, AES_BLOCK_SIZE);
201			memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
202			}
203		}
204	}
205
206/*
207 * Note that its effectively impossible to do biIGE in anything other
208 * than a single pass, so no provision is made for chaining.
209 */
210
211/* N.B. The IV for this mode is _four times_ the block size */
212
213void AES_bi_ige_encrypt(const unsigned char *in, unsigned char *out,
214						size_t length, const AES_KEY *key,
215						const AES_KEY *key2, const unsigned char *ivec,
216						const int enc)
217	{
218	size_t n;
219	size_t len = length;
220	unsigned char tmp[AES_BLOCK_SIZE];
221	unsigned char tmp2[AES_BLOCK_SIZE];
222	unsigned char tmp3[AES_BLOCK_SIZE];
223	unsigned char prev[AES_BLOCK_SIZE];
224	const unsigned char *iv;
225	const unsigned char *iv2;
226
227	OPENSSL_assert(in && out && key && ivec);
228	OPENSSL_assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));
229	OPENSSL_assert((length%AES_BLOCK_SIZE) == 0);
230
231	if (AES_ENCRYPT == enc)
232		{
233		/* XXX: Do a separate case for when in != out (strictly should
234		   check for overlap, too) */
235
236		/* First the forward pass */
237		iv = ivec;
238		iv2 = ivec + AES_BLOCK_SIZE;
239		while (len >= AES_BLOCK_SIZE)
240			{
241			for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
242				out[n] = in[n] ^ iv[n];
243			AES_encrypt(out, out, key);
244			for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
245				out[n] ^= iv2[n];
246			iv = out;
247			memcpy(prev, in, AES_BLOCK_SIZE);
248			iv2 = prev;
249			len -= AES_BLOCK_SIZE;
250			in += AES_BLOCK_SIZE;
251			out += AES_BLOCK_SIZE;
252			}
253
254		/* And now backwards */
255		iv = ivec + AES_BLOCK_SIZE*2;
256		iv2 = ivec + AES_BLOCK_SIZE*3;
257		len = length;
258		while(len >= AES_BLOCK_SIZE)
259			{
260			out -= AES_BLOCK_SIZE;
261			/* XXX: reduce copies by alternating between buffers */
262			memcpy(tmp, out, AES_BLOCK_SIZE);
263			for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
264				out[n] ^= iv[n];
265			/*			hexdump(stdout, "out ^ iv", out, AES_BLOCK_SIZE); */
266			AES_encrypt(out, out, key);
267			/*			hexdump(stdout,"enc", out, AES_BLOCK_SIZE); */
268			/*			hexdump(stdout,"iv2", iv2, AES_BLOCK_SIZE); */
269			for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
270				out[n] ^= iv2[n];
271			/*			hexdump(stdout,"out", out, AES_BLOCK_SIZE); */
272			iv = out;
273			memcpy(prev, tmp, AES_BLOCK_SIZE);
274			iv2 = prev;
275			len -= AES_BLOCK_SIZE;
276			}
277		}
278	else
279		{
280		/* First backwards */
281		iv = ivec + AES_BLOCK_SIZE*2;
282		iv2 = ivec + AES_BLOCK_SIZE*3;
283		in += length;
284		out += length;
285		while (len >= AES_BLOCK_SIZE)
286			{
287			in -= AES_BLOCK_SIZE;
288			out -= AES_BLOCK_SIZE;
289			memcpy(tmp, in, AES_BLOCK_SIZE);
290			memcpy(tmp2, in, AES_BLOCK_SIZE);
291			for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
292				tmp[n] ^= iv2[n];
293			AES_decrypt(tmp, out, key);
294			for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
295				out[n] ^= iv[n];
296			memcpy(tmp3, tmp2, AES_BLOCK_SIZE);
297			iv = tmp3;
298			iv2 = out;
299			len -= AES_BLOCK_SIZE;
300			}
301
302		/* And now forwards */
303		iv = ivec;
304		iv2 = ivec + AES_BLOCK_SIZE;
305		len = length;
306		while (len >= AES_BLOCK_SIZE)
307			{
308			memcpy(tmp, out, AES_BLOCK_SIZE);
309			memcpy(tmp2, out, AES_BLOCK_SIZE);
310			for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
311				tmp[n] ^= iv2[n];
312			AES_decrypt(tmp, out, key);
313			for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
314				out[n] ^= iv[n];
315			memcpy(tmp3, tmp2, AES_BLOCK_SIZE);
316			iv = tmp3;
317			iv2 = out;
318			len -= AES_BLOCK_SIZE;
319			in += AES_BLOCK_SIZE;
320			out += AES_BLOCK_SIZE;
321			}
322		}
323	}
324