1 /*
2 * Copyright 2006-2020 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /*
11 * AES_encrypt/AES_decrypt are deprecated - but we need to use them to implement
12 * these functions
13 */
14 #include "internal/deprecated.h"
15
16 #include "internal/cryptlib.h"
17
18 #include <openssl/aes.h>
19 #include "aes_local.h"
20
21 /* XXX: probably some better way to do this */
22 #if defined(__i386__) || defined(__x86_64__)
23 # define UNALIGNED_MEMOPS_ARE_FAST 1
24 #else
25 # define UNALIGNED_MEMOPS_ARE_FAST 0
26 #endif
27
28 #define N_WORDS (AES_BLOCK_SIZE / sizeof(unsigned long))
29 typedef struct {
30 unsigned long data[N_WORDS];
31 #if defined(__GNUC__) && UNALIGNED_MEMOPS_ARE_FAST
32 } aes_block_t __attribute((__aligned__(1)));
33 #else
34 } aes_block_t;
35 #endif
36
37 #if UNALIGNED_MEMOPS_ARE_FAST
38 # define load_block(d, s) (d) = *(const aes_block_t *)(s)
39 # define store_block(d, s) *(aes_block_t *)(d) = (s)
40 #else
41 # define load_block(d, s) memcpy((d).data, (s), AES_BLOCK_SIZE)
42 # define store_block(d, s) memcpy((d), (s).data, AES_BLOCK_SIZE)
43 #endif
44
45 /* N.B. The IV for this mode is _twice_ the block size */
46
47 /* Use of this function is deprecated. */
AES_ige_encrypt(const unsigned char * in,unsigned char * out,size_t length,const AES_KEY * key,unsigned char * ivec,const int enc)48 void AES_ige_encrypt(const unsigned char *in, unsigned char *out,
49 size_t length, const AES_KEY *key,
50 unsigned char *ivec, const int enc)
51 {
52 size_t n;
53 size_t len = length / AES_BLOCK_SIZE;
54
55 if (length == 0)
56 return;
57
58 OPENSSL_assert(in && out && key && ivec);
59 OPENSSL_assert((AES_ENCRYPT == enc) || (AES_DECRYPT == enc));
60 OPENSSL_assert((length % AES_BLOCK_SIZE) == 0);
61
62 if (AES_ENCRYPT == enc) {
63 if (in != out &&
64 (UNALIGNED_MEMOPS_ARE_FAST
65 || ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(long) ==
66 0)) {
67 aes_block_t *ivp = (aes_block_t *) ivec;
68 aes_block_t *iv2p = (aes_block_t *) (ivec + AES_BLOCK_SIZE);
69
70 while (len) {
71 aes_block_t *inp = (aes_block_t *) in;
72 aes_block_t *outp = (aes_block_t *) out;
73
74 for (n = 0; n < N_WORDS; ++n)
75 outp->data[n] = inp->data[n] ^ ivp->data[n];
76 AES_encrypt((unsigned char *)outp->data,
77 (unsigned char *)outp->data, key);
78 for (n = 0; n < N_WORDS; ++n)
79 outp->data[n] ^= iv2p->data[n];
80 ivp = outp;
81 iv2p = inp;
82 --len;
83 in += AES_BLOCK_SIZE;
84 out += AES_BLOCK_SIZE;
85 }
86 memcpy(ivec, ivp->data, AES_BLOCK_SIZE);
87 memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
88 } else {
89 aes_block_t tmp, tmp2;
90 aes_block_t iv;
91 aes_block_t iv2;
92
93 load_block(iv, ivec);
94 load_block(iv2, ivec + AES_BLOCK_SIZE);
95
96 while (len) {
97 load_block(tmp, in);
98 for (n = 0; n < N_WORDS; ++n)
99 tmp2.data[n] = tmp.data[n] ^ iv.data[n];
100 AES_encrypt((unsigned char *)tmp2.data,
101 (unsigned char *)tmp2.data, key);
102 for (n = 0; n < N_WORDS; ++n)
103 tmp2.data[n] ^= iv2.data[n];
104 store_block(out, tmp2);
105 iv = tmp2;
106 iv2 = tmp;
107 --len;
108 in += AES_BLOCK_SIZE;
109 out += AES_BLOCK_SIZE;
110 }
111 memcpy(ivec, iv.data, AES_BLOCK_SIZE);
112 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
113 }
114 } else {
115 if (in != out &&
116 (UNALIGNED_MEMOPS_ARE_FAST
117 || ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(long) ==
118 0)) {
119 aes_block_t *ivp = (aes_block_t *) ivec;
120 aes_block_t *iv2p = (aes_block_t *) (ivec + AES_BLOCK_SIZE);
121
122 while (len) {
123 aes_block_t tmp;
124 aes_block_t *inp = (aes_block_t *) in;
125 aes_block_t *outp = (aes_block_t *) out;
126
127 for (n = 0; n < N_WORDS; ++n)
128 tmp.data[n] = inp->data[n] ^ iv2p->data[n];
129 AES_decrypt((unsigned char *)tmp.data,
130 (unsigned char *)outp->data, key);
131 for (n = 0; n < N_WORDS; ++n)
132 outp->data[n] ^= ivp->data[n];
133 ivp = inp;
134 iv2p = outp;
135 --len;
136 in += AES_BLOCK_SIZE;
137 out += AES_BLOCK_SIZE;
138 }
139 memcpy(ivec, ivp->data, AES_BLOCK_SIZE);
140 memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
141 } else {
142 aes_block_t tmp, tmp2;
143 aes_block_t iv;
144 aes_block_t iv2;
145
146 load_block(iv, ivec);
147 load_block(iv2, ivec + AES_BLOCK_SIZE);
148
149 while (len) {
150 load_block(tmp, in);
151 tmp2 = tmp;
152 for (n = 0; n < N_WORDS; ++n)
153 tmp.data[n] ^= iv2.data[n];
154 AES_decrypt((unsigned char *)tmp.data,
155 (unsigned char *)tmp.data, key);
156 for (n = 0; n < N_WORDS; ++n)
157 tmp.data[n] ^= iv.data[n];
158 store_block(out, tmp);
159 iv = tmp2;
160 iv2 = tmp;
161 --len;
162 in += AES_BLOCK_SIZE;
163 out += AES_BLOCK_SIZE;
164 }
165 memcpy(ivec, iv.data, AES_BLOCK_SIZE);
166 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
167 }
168 }
169 }
170
171 /*
172 * Note that its effectively impossible to do biIGE in anything other
173 * than a single pass, so no provision is made for chaining.
174 *
175 * NB: The implementation of AES_bi_ige_encrypt has a bug. It is supposed to use
176 * 2 AES keys, but in fact only one is ever used. This bug has been present
177 * since this code was first implemented. It is believed to have minimal
178 * security impact in practice and has therefore not been fixed for backwards
179 * compatibility reasons.
180 *
181 * Use of this function is deprecated.
182 */
183
184 /* N.B. The IV for this mode is _four times_ the block size */
185
AES_bi_ige_encrypt(const unsigned char * in,unsigned char * out,size_t length,const AES_KEY * key,const AES_KEY * key2,const unsigned char * ivec,const int enc)186 void AES_bi_ige_encrypt(const unsigned char *in, unsigned char *out,
187 size_t length, const AES_KEY *key,
188 const AES_KEY *key2, const unsigned char *ivec,
189 const int enc)
190 {
191 size_t n;
192 size_t len = length;
193 unsigned char tmp[AES_BLOCK_SIZE];
194 unsigned char tmp2[AES_BLOCK_SIZE];
195 unsigned char tmp3[AES_BLOCK_SIZE];
196 unsigned char prev[AES_BLOCK_SIZE];
197 const unsigned char *iv;
198 const unsigned char *iv2;
199
200 OPENSSL_assert(in && out && key && ivec);
201 OPENSSL_assert((AES_ENCRYPT == enc) || (AES_DECRYPT == enc));
202 OPENSSL_assert((length % AES_BLOCK_SIZE) == 0);
203
204 if (AES_ENCRYPT == enc) {
205 /*
206 * XXX: Do a separate case for when in != out (strictly should check
207 * for overlap, too)
208 */
209
210 /* First the forward pass */
211 iv = ivec;
212 iv2 = ivec + AES_BLOCK_SIZE;
213 while (len >= AES_BLOCK_SIZE) {
214 for (n = 0; n < AES_BLOCK_SIZE; ++n)
215 out[n] = in[n] ^ iv[n];
216 AES_encrypt(out, out, key);
217 for (n = 0; n < AES_BLOCK_SIZE; ++n)
218 out[n] ^= iv2[n];
219 iv = out;
220 memcpy(prev, in, AES_BLOCK_SIZE);
221 iv2 = prev;
222 len -= AES_BLOCK_SIZE;
223 in += AES_BLOCK_SIZE;
224 out += AES_BLOCK_SIZE;
225 }
226
227 /* And now backwards */
228 iv = ivec + AES_BLOCK_SIZE * 2;
229 iv2 = ivec + AES_BLOCK_SIZE * 3;
230 len = length;
231 while (len >= AES_BLOCK_SIZE) {
232 out -= AES_BLOCK_SIZE;
233 /*
234 * XXX: reduce copies by alternating between buffers
235 */
236 memcpy(tmp, out, AES_BLOCK_SIZE);
237 for (n = 0; n < AES_BLOCK_SIZE; ++n)
238 out[n] ^= iv[n];
239 /*
240 * hexdump(stdout, "out ^ iv", out, AES_BLOCK_SIZE);
241 */
242 AES_encrypt(out, out, key);
243 /*
244 * hexdump(stdout,"enc", out, AES_BLOCK_SIZE);
245 */
246 /*
247 * hexdump(stdout,"iv2", iv2, AES_BLOCK_SIZE);
248 */
249 for (n = 0; n < AES_BLOCK_SIZE; ++n)
250 out[n] ^= iv2[n];
251 /*
252 * hexdump(stdout,"out", out, AES_BLOCK_SIZE);
253 */
254 iv = out;
255 memcpy(prev, tmp, AES_BLOCK_SIZE);
256 iv2 = prev;
257 len -= AES_BLOCK_SIZE;
258 }
259 } else {
260 /* First backwards */
261 iv = ivec + AES_BLOCK_SIZE * 2;
262 iv2 = ivec + AES_BLOCK_SIZE * 3;
263 in += length;
264 out += length;
265 while (len >= AES_BLOCK_SIZE) {
266 in -= AES_BLOCK_SIZE;
267 out -= AES_BLOCK_SIZE;
268 memcpy(tmp, in, AES_BLOCK_SIZE);
269 memcpy(tmp2, in, AES_BLOCK_SIZE);
270 for (n = 0; n < AES_BLOCK_SIZE; ++n)
271 tmp[n] ^= iv2[n];
272 AES_decrypt(tmp, out, key);
273 for (n = 0; n < AES_BLOCK_SIZE; ++n)
274 out[n] ^= iv[n];
275 memcpy(tmp3, tmp2, AES_BLOCK_SIZE);
276 iv = tmp3;
277 iv2 = out;
278 len -= AES_BLOCK_SIZE;
279 }
280
281 /* And now forwards */
282 iv = ivec;
283 iv2 = ivec + AES_BLOCK_SIZE;
284 len = length;
285 while (len >= AES_BLOCK_SIZE) {
286 memcpy(tmp, out, AES_BLOCK_SIZE);
287 memcpy(tmp2, out, AES_BLOCK_SIZE);
288 for (n = 0; n < AES_BLOCK_SIZE; ++n)
289 tmp[n] ^= iv2[n];
290 AES_decrypt(tmp, out, key);
291 for (n = 0; n < AES_BLOCK_SIZE; ++n)
292 out[n] ^= iv[n];
293 memcpy(tmp3, tmp2, AES_BLOCK_SIZE);
294 iv = tmp3;
295 iv2 = out;
296 len -= AES_BLOCK_SIZE;
297 in += AES_BLOCK_SIZE;
298 out += AES_BLOCK_SIZE;
299 }
300 }
301 }
302
