[CRYPTO] Ensure cit_iv is aligned correctly
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / crypto / cipher.c
CommitLineData
1da177e4
LT
1/*
2 * Cryptographic API.
3 *
4 * Cipher operations.
5 *
6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
c774e93e 7 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
1da177e4
LT
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 *
14 */
15#include <linux/compiler.h>
16#include <linux/kernel.h>
17#include <linux/crypto.h>
18#include <linux/errno.h>
19#include <linux/mm.h>
20#include <linux/slab.h>
21#include <linux/string.h>
22#include <asm/scatterlist.h>
23#include "internal.h"
24#include "scatterwalk.h"
25
1da177e4
LT
26static inline void xor_64(u8 *a, const u8 *b)
27{
28 ((u32 *)a)[0] ^= ((u32 *)b)[0];
29 ((u32 *)a)[1] ^= ((u32 *)b)[1];
30}
31
32static inline void xor_128(u8 *a, const u8 *b)
33{
34 ((u32 *)a)[0] ^= ((u32 *)b)[0];
35 ((u32 *)a)[1] ^= ((u32 *)b)[1];
36 ((u32 *)a)[2] ^= ((u32 *)b)[2];
37 ((u32 *)a)[3] ^= ((u32 *)b)[3];
38}
c774e93e
HX
39
40static unsigned int crypt_slow(const struct cipher_desc *desc,
41 struct scatter_walk *in,
42 struct scatter_walk *out, unsigned int bsize)
1da177e4 43{
fbdae9f3 44 unsigned int alignmask = crypto_tfm_alg_alignmask(desc->tfm);
95477377
HX
45 u8 buffer[bsize * 2 + alignmask];
46 u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
47 u8 *dst = src + bsize;
c774e93e 48 unsigned int n;
1da177e4 49
c774e93e
HX
50 n = scatterwalk_copychunks(src, in, bsize, 0);
51 scatterwalk_advance(in, n);
1da177e4 52
c774e93e 53 desc->prfn(desc, dst, src, bsize);
1da177e4 54
c774e93e
HX
55 n = scatterwalk_copychunks(dst, out, bsize, 1);
56 scatterwalk_advance(out, n);
1da177e4 57
c774e93e 58 return bsize;
1da177e4
LT
59}
60
c774e93e
HX
61static inline unsigned int crypt_fast(const struct cipher_desc *desc,
62 struct scatter_walk *in,
63 struct scatter_walk *out,
95477377 64 unsigned int nbytes, u8 *tmp)
1da177e4 65{
c774e93e
HX
66 u8 *src, *dst;
67
68 src = in->data;
69 dst = scatterwalk_samebuf(in, out) ? src : out->data;
70
95477377
HX
71 if (tmp) {
72 memcpy(tmp, in->data, nbytes);
73 src = tmp;
74 dst = tmp;
75 }
76
c774e93e
HX
77 nbytes = desc->prfn(desc, dst, src, nbytes);
78
95477377
HX
79 if (tmp)
80 memcpy(out->data, tmp, nbytes);
81
c774e93e
HX
82 scatterwalk_advance(in, nbytes);
83 scatterwalk_advance(out, nbytes);
1da177e4 84
c774e93e 85 return nbytes;
1da177e4
LT
86}
87
88/*
89 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
90 * multiple page boundaries by using temporary blocks. In user context,
c774e93e 91 * the kernel is given a chance to schedule us once per page.
1da177e4 92 */
c774e93e 93static int crypt(const struct cipher_desc *desc,
1da177e4
LT
94 struct scatterlist *dst,
95 struct scatterlist *src,
c774e93e 96 unsigned int nbytes)
1da177e4
LT
97{
98 struct scatter_walk walk_in, walk_out;
c774e93e 99 struct crypto_tfm *tfm = desc->tfm;
1da177e4 100 const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
fbdae9f3 101 unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
95477377 102 unsigned long buffer = 0;
1da177e4
LT
103
104 if (!nbytes)
105 return 0;
106
107 if (nbytes % bsize) {
108 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
109 return -EINVAL;
110 }
111
112 scatterwalk_start(&walk_in, src);
113 scatterwalk_start(&walk_out, dst);
114
115 for(;;) {
95477377
HX
116 unsigned int n = nbytes;
117 u8 *tmp = NULL;
118
119 if (!scatterwalk_aligned(&walk_in, alignmask) ||
120 !scatterwalk_aligned(&walk_out, alignmask)) {
121 if (!buffer) {
122 buffer = __get_free_page(GFP_ATOMIC);
123 if (!buffer)
124 n = 0;
125 }
126 tmp = (u8 *)buffer;
127 }
1da177e4
LT
128
129 scatterwalk_map(&walk_in, 0);
130 scatterwalk_map(&walk_out, 1);
131
95477377 132 n = scatterwalk_clamp(&walk_in, n);
c774e93e 133 n = scatterwalk_clamp(&walk_out, n);
1da177e4 134
c774e93e 135 if (likely(n >= bsize))
95477377 136 n = crypt_fast(desc, &walk_in, &walk_out, n, tmp);
c774e93e
HX
137 else
138 n = crypt_slow(desc, &walk_in, &walk_out, bsize);
1da177e4 139
c774e93e 140 nbytes -= n;
1da177e4
LT
141
142 scatterwalk_done(&walk_in, 0, nbytes);
143 scatterwalk_done(&walk_out, 1, nbytes);
144
145 if (!nbytes)
95477377 146 break;
1da177e4
LT
147
148 crypto_yield(tfm);
149 }
95477377
HX
150
151 if (buffer)
152 free_page(buffer);
153
154 return 0;
1da177e4
LT
155}
156
c774e93e
HX
157static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,
158 u8 *dst, const u8 *src,
159 unsigned int nbytes)
1da177e4 160{
c774e93e
HX
161 struct crypto_tfm *tfm = desc->tfm;
162 void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
163 int bsize = crypto_tfm_alg_blocksize(tfm);
164
165 void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
166 u8 *iv = desc->info;
167 unsigned int done = 0;
168
169 do {
170 xor(iv, src);
171 fn(crypto_tfm_ctx(tfm), dst, iv);
172 memcpy(iv, dst, bsize);
1da177e4 173
c774e93e
HX
174 src += bsize;
175 dst += bsize;
176 } while ((done += bsize) < nbytes);
177
178 return done;
1da177e4
LT
179}
180
c774e93e
HX
181static unsigned int cbc_process_decrypt(const struct cipher_desc *desc,
182 u8 *dst, const u8 *src,
183 unsigned int nbytes)
1da177e4 184{
c774e93e
HX
185 struct crypto_tfm *tfm = desc->tfm;
186 void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
187 int bsize = crypto_tfm_alg_blocksize(tfm);
188
189 u8 stack[src == dst ? bsize : 0];
190 u8 *buf = stack;
191 u8 **dst_p = src == dst ? &buf : &dst;
192
193 void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
194 u8 *iv = desc->info;
195 unsigned int done = 0;
196
197 do {
198 u8 *tmp_dst = *dst_p;
1da177e4 199
c774e93e
HX
200 fn(crypto_tfm_ctx(tfm), tmp_dst, src);
201 xor(tmp_dst, iv);
202 memcpy(iv, src, bsize);
203 if (tmp_dst != dst)
204 memcpy(dst, tmp_dst, bsize);
205
206 src += bsize;
207 dst += bsize;
208 } while ((done += bsize) < nbytes);
209
210 return done;
1da177e4
LT
211}
212
c774e93e
HX
213static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst,
214 const u8 *src, unsigned int nbytes)
1da177e4 215{
c774e93e
HX
216 struct crypto_tfm *tfm = desc->tfm;
217 int bsize = crypto_tfm_alg_blocksize(tfm);
218 void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
219 unsigned int done = 0;
220
221 do {
222 fn(crypto_tfm_ctx(tfm), dst, src);
223
224 src += bsize;
225 dst += bsize;
226 } while ((done += bsize) < nbytes);
227
228 return done;
1da177e4
LT
229}
230
231static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
232{
233 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
234
235 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
236 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
237 return -EINVAL;
238 } else
239 return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen,
240 &tfm->crt_flags);
241}
242
243static int ecb_encrypt(struct crypto_tfm *tfm,
244 struct scatterlist *dst,
245 struct scatterlist *src, unsigned int nbytes)
246{
c774e93e 247 struct cipher_desc desc;
40725181 248 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e
HX
249
250 desc.tfm = tfm;
40725181
HX
251 desc.crfn = cipher->cia_encrypt;
252 desc.prfn = cipher->cia_encrypt_ecb ?: ecb_process;
c774e93e
HX
253
254 return crypt(&desc, dst, src, nbytes);
1da177e4
LT
255}
256
257static int ecb_decrypt(struct crypto_tfm *tfm,
258 struct scatterlist *dst,
259 struct scatterlist *src,
260 unsigned int nbytes)
261{
c774e93e 262 struct cipher_desc desc;
40725181 263 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e
HX
264
265 desc.tfm = tfm;
40725181
HX
266 desc.crfn = cipher->cia_decrypt;
267 desc.prfn = cipher->cia_decrypt_ecb ?: ecb_process;
c774e93e
HX
268
269 return crypt(&desc, dst, src, nbytes);
1da177e4
LT
270}
271
272static int cbc_encrypt(struct crypto_tfm *tfm,
273 struct scatterlist *dst,
274 struct scatterlist *src,
275 unsigned int nbytes)
276{
c774e93e 277 struct cipher_desc desc;
40725181 278 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e
HX
279
280 desc.tfm = tfm;
40725181
HX
281 desc.crfn = cipher->cia_encrypt;
282 desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
c774e93e
HX
283 desc.info = tfm->crt_cipher.cit_iv;
284
285 return crypt(&desc, dst, src, nbytes);
1da177e4
LT
286}
287
288static int cbc_encrypt_iv(struct crypto_tfm *tfm,
289 struct scatterlist *dst,
290 struct scatterlist *src,
291 unsigned int nbytes, u8 *iv)
292{
c774e93e 293 struct cipher_desc desc;
40725181 294 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e
HX
295
296 desc.tfm = tfm;
40725181
HX
297 desc.crfn = cipher->cia_encrypt;
298 desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
c774e93e
HX
299 desc.info = iv;
300
301 return crypt(&desc, dst, src, nbytes);
1da177e4
LT
302}
303
304static int cbc_decrypt(struct crypto_tfm *tfm,
305 struct scatterlist *dst,
306 struct scatterlist *src,
307 unsigned int nbytes)
308{
c774e93e 309 struct cipher_desc desc;
40725181 310 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e
HX
311
312 desc.tfm = tfm;
40725181
HX
313 desc.crfn = cipher->cia_decrypt;
314 desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
c774e93e
HX
315 desc.info = tfm->crt_cipher.cit_iv;
316
317 return crypt(&desc, dst, src, nbytes);
1da177e4
LT
318}
319
320static int cbc_decrypt_iv(struct crypto_tfm *tfm,
321 struct scatterlist *dst,
322 struct scatterlist *src,
323 unsigned int nbytes, u8 *iv)
324{
c774e93e 325 struct cipher_desc desc;
40725181 326 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e
HX
327
328 desc.tfm = tfm;
40725181
HX
329 desc.crfn = cipher->cia_decrypt;
330 desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
c774e93e
HX
331 desc.info = iv;
332
333 return crypt(&desc, dst, src, nbytes);
1da177e4
LT
334}
335
336static int nocrypt(struct crypto_tfm *tfm,
337 struct scatterlist *dst,
338 struct scatterlist *src,
339 unsigned int nbytes)
340{
341 return -ENOSYS;
342}
343
344static int nocrypt_iv(struct crypto_tfm *tfm,
345 struct scatterlist *dst,
346 struct scatterlist *src,
347 unsigned int nbytes, u8 *iv)
348{
349 return -ENOSYS;
350}
351
352int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
353{
354 u32 mode = flags & CRYPTO_TFM_MODE_MASK;
355
356 tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
357 if (flags & CRYPTO_TFM_REQ_WEAK_KEY)
358 tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY;
359
360 return 0;
361}
362
363int crypto_init_cipher_ops(struct crypto_tfm *tfm)
364{
365 int ret = 0;
366 struct cipher_tfm *ops = &tfm->crt_cipher;
367
368 ops->cit_setkey = setkey;
369
370 switch (tfm->crt_cipher.cit_mode) {
371 case CRYPTO_TFM_MODE_ECB:
372 ops->cit_encrypt = ecb_encrypt;
373 ops->cit_decrypt = ecb_decrypt;
374 break;
375
376 case CRYPTO_TFM_MODE_CBC:
377 ops->cit_encrypt = cbc_encrypt;
378 ops->cit_decrypt = cbc_decrypt;
379 ops->cit_encrypt_iv = cbc_encrypt_iv;
380 ops->cit_decrypt_iv = cbc_decrypt_iv;
381 break;
382
383 case CRYPTO_TFM_MODE_CFB:
384 ops->cit_encrypt = nocrypt;
385 ops->cit_decrypt = nocrypt;
386 ops->cit_encrypt_iv = nocrypt_iv;
387 ops->cit_decrypt_iv = nocrypt_iv;
388 break;
389
390 case CRYPTO_TFM_MODE_CTR:
391 ops->cit_encrypt = nocrypt;
392 ops->cit_decrypt = nocrypt;
393 ops->cit_encrypt_iv = nocrypt_iv;
394 ops->cit_decrypt_iv = nocrypt_iv;
395 break;
396
397 default:
398 BUG();
399 }
400
401 if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
fbdae9f3
HX
402 unsigned int align;
403 unsigned long addr;
1da177e4
LT
404
405 switch (crypto_tfm_alg_blocksize(tfm)) {
406 case 8:
407 ops->cit_xor_block = xor_64;
408 break;
409
410 case 16:
411 ops->cit_xor_block = xor_128;
412 break;
413
414 default:
415 printk(KERN_WARNING "%s: block size %u not supported\n",
416 crypto_tfm_alg_name(tfm),
417 crypto_tfm_alg_blocksize(tfm));
418 ret = -EINVAL;
419 goto out;
420 }
421
422 ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
fbdae9f3
HX
423 align = crypto_tfm_alg_alignmask(tfm) + 1;
424 addr = (unsigned long)crypto_tfm_ctx(tfm);
425 addr = ALIGN(addr, align);
426 addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
427 ops->cit_iv = (void *)addr;
1da177e4
LT
428 }
429
430out:
431 return ret;
432}
433
434void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
435{
1da177e4 436}