Commit | Line | Data |
---|---|---|
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 |
26 | static 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 | ||
32 | static 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 | |
40 | static unsigned int crypt_slow(const struct cipher_desc *desc, | |
41 | struct scatter_walk *in, | |
42 | struct scatter_walk *out, unsigned int bsize) | |
1da177e4 | 43 | { |
9d853c37 | 44 | unsigned long 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 |
61 | static 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 | 93 | static 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 | ||
915e8561 HX |
157 | static int crypt_iv_unaligned(struct cipher_desc *desc, |
158 | struct scatterlist *dst, | |
159 | struct scatterlist *src, | |
160 | unsigned int nbytes) | |
161 | { | |
162 | struct crypto_tfm *tfm = desc->tfm; | |
9d853c37 | 163 | unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); |
915e8561 HX |
164 | u8 *iv = desc->info; |
165 | ||
166 | if (unlikely(((unsigned long)iv & alignmask))) { | |
167 | unsigned int ivsize = tfm->crt_cipher.cit_ivsize; | |
168 | u8 buffer[ivsize + alignmask]; | |
169 | u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); | |
170 | int err; | |
171 | ||
172 | desc->info = memcpy(tmp, iv, ivsize); | |
173 | err = crypt(desc, dst, src, nbytes); | |
174 | memcpy(iv, tmp, ivsize); | |
175 | ||
176 | return err; | |
177 | } | |
178 | ||
179 | return crypt(desc, dst, src, nbytes); | |
180 | } | |
181 | ||
c774e93e HX |
182 | static unsigned int cbc_process_encrypt(const struct cipher_desc *desc, |
183 | u8 *dst, const u8 *src, | |
184 | unsigned int nbytes) | |
1da177e4 | 185 | { |
c774e93e HX |
186 | struct crypto_tfm *tfm = desc->tfm; |
187 | void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block; | |
188 | int bsize = crypto_tfm_alg_blocksize(tfm); | |
189 | ||
190 | void (*fn)(void *, u8 *, const u8 *) = desc->crfn; | |
191 | u8 *iv = desc->info; | |
192 | unsigned int done = 0; | |
193 | ||
fe2d5295 HX |
194 | nbytes -= bsize; |
195 | ||
c774e93e HX |
196 | do { |
197 | xor(iv, src); | |
198 | fn(crypto_tfm_ctx(tfm), dst, iv); | |
199 | memcpy(iv, dst, bsize); | |
1da177e4 | 200 | |
c774e93e HX |
201 | src += bsize; |
202 | dst += bsize; | |
fe2d5295 | 203 | } while ((done += bsize) <= nbytes); |
c774e93e HX |
204 | |
205 | return done; | |
1da177e4 LT |
206 | } |
207 | ||
c774e93e HX |
208 | static unsigned int cbc_process_decrypt(const struct cipher_desc *desc, |
209 | u8 *dst, const u8 *src, | |
210 | unsigned int nbytes) | |
1da177e4 | 211 | { |
c774e93e HX |
212 | struct crypto_tfm *tfm = desc->tfm; |
213 | void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block; | |
214 | int bsize = crypto_tfm_alg_blocksize(tfm); | |
827c3911 | 215 | unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm); |
c774e93e | 216 | |
827c3911 HX |
217 | u8 stack[src == dst ? bsize + alignmask : 0]; |
218 | u8 *buf = (u8 *)ALIGN((unsigned long)stack, alignmask + 1); | |
c774e93e HX |
219 | u8 **dst_p = src == dst ? &buf : &dst; |
220 | ||
221 | void (*fn)(void *, u8 *, const u8 *) = desc->crfn; | |
222 | u8 *iv = desc->info; | |
223 | unsigned int done = 0; | |
224 | ||
fe2d5295 HX |
225 | nbytes -= bsize; |
226 | ||
c774e93e HX |
227 | do { |
228 | u8 *tmp_dst = *dst_p; | |
1da177e4 | 229 | |
c774e93e HX |
230 | fn(crypto_tfm_ctx(tfm), tmp_dst, src); |
231 | xor(tmp_dst, iv); | |
232 | memcpy(iv, src, bsize); | |
233 | if (tmp_dst != dst) | |
234 | memcpy(dst, tmp_dst, bsize); | |
235 | ||
236 | src += bsize; | |
237 | dst += bsize; | |
fe2d5295 | 238 | } while ((done += bsize) <= nbytes); |
c774e93e HX |
239 | |
240 | return done; | |
1da177e4 LT |
241 | } |
242 | ||
c774e93e HX |
243 | static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst, |
244 | const u8 *src, unsigned int nbytes) | |
1da177e4 | 245 | { |
c774e93e HX |
246 | struct crypto_tfm *tfm = desc->tfm; |
247 | int bsize = crypto_tfm_alg_blocksize(tfm); | |
248 | void (*fn)(void *, u8 *, const u8 *) = desc->crfn; | |
249 | unsigned int done = 0; | |
250 | ||
fe2d5295 HX |
251 | nbytes -= bsize; |
252 | ||
c774e93e HX |
253 | do { |
254 | fn(crypto_tfm_ctx(tfm), dst, src); | |
255 | ||
256 | src += bsize; | |
257 | dst += bsize; | |
fe2d5295 | 258 | } while ((done += bsize) <= nbytes); |
c774e93e HX |
259 | |
260 | return done; | |
1da177e4 LT |
261 | } |
262 | ||
263 | static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) | |
264 | { | |
265 | struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; | |
266 | ||
267 | if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) { | |
268 | tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; | |
269 | return -EINVAL; | |
270 | } else | |
271 | return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen, | |
272 | &tfm->crt_flags); | |
273 | } | |
274 | ||
275 | static int ecb_encrypt(struct crypto_tfm *tfm, | |
276 | struct scatterlist *dst, | |
277 | struct scatterlist *src, unsigned int nbytes) | |
278 | { | |
c774e93e | 279 | struct cipher_desc desc; |
40725181 | 280 | struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; |
c774e93e HX |
281 | |
282 | desc.tfm = tfm; | |
40725181 HX |
283 | desc.crfn = cipher->cia_encrypt; |
284 | desc.prfn = cipher->cia_encrypt_ecb ?: ecb_process; | |
c774e93e HX |
285 | |
286 | return crypt(&desc, dst, src, nbytes); | |
1da177e4 LT |
287 | } |
288 | ||
289 | static int ecb_decrypt(struct crypto_tfm *tfm, | |
290 | struct scatterlist *dst, | |
291 | struct scatterlist *src, | |
292 | unsigned int nbytes) | |
293 | { | |
c774e93e | 294 | struct cipher_desc desc; |
40725181 | 295 | struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; |
c774e93e HX |
296 | |
297 | desc.tfm = tfm; | |
40725181 HX |
298 | desc.crfn = cipher->cia_decrypt; |
299 | desc.prfn = cipher->cia_decrypt_ecb ?: ecb_process; | |
c774e93e HX |
300 | |
301 | return crypt(&desc, dst, src, nbytes); | |
1da177e4 LT |
302 | } |
303 | ||
304 | static int cbc_encrypt(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_encrypt; |
314 | desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt; | |
c774e93e HX |
315 | desc.info = tfm->crt_cipher.cit_iv; |
316 | ||
317 | return crypt(&desc, dst, src, nbytes); | |
1da177e4 LT |
318 | } |
319 | ||
320 | static int cbc_encrypt_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_encrypt; |
330 | desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt; | |
c774e93e HX |
331 | desc.info = iv; |
332 | ||
915e8561 | 333 | return crypt_iv_unaligned(&desc, dst, src, nbytes); |
1da177e4 LT |
334 | } |
335 | ||
336 | static int cbc_decrypt(struct crypto_tfm *tfm, | |
337 | struct scatterlist *dst, | |
338 | struct scatterlist *src, | |
339 | unsigned int nbytes) | |
340 | { | |
c774e93e | 341 | struct cipher_desc desc; |
40725181 | 342 | struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; |
c774e93e HX |
343 | |
344 | desc.tfm = tfm; | |
40725181 HX |
345 | desc.crfn = cipher->cia_decrypt; |
346 | desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt; | |
c774e93e HX |
347 | desc.info = tfm->crt_cipher.cit_iv; |
348 | ||
349 | return crypt(&desc, dst, src, nbytes); | |
1da177e4 LT |
350 | } |
351 | ||
352 | static int cbc_decrypt_iv(struct crypto_tfm *tfm, | |
353 | struct scatterlist *dst, | |
354 | struct scatterlist *src, | |
355 | unsigned int nbytes, u8 *iv) | |
356 | { | |
c774e93e | 357 | struct cipher_desc desc; |
40725181 | 358 | struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; |
c774e93e HX |
359 | |
360 | desc.tfm = tfm; | |
40725181 HX |
361 | desc.crfn = cipher->cia_decrypt; |
362 | desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt; | |
c774e93e HX |
363 | desc.info = iv; |
364 | ||
915e8561 | 365 | return crypt_iv_unaligned(&desc, dst, src, nbytes); |
1da177e4 LT |
366 | } |
367 | ||
368 | static int nocrypt(struct crypto_tfm *tfm, | |
369 | struct scatterlist *dst, | |
370 | struct scatterlist *src, | |
371 | unsigned int nbytes) | |
372 | { | |
373 | return -ENOSYS; | |
374 | } | |
375 | ||
376 | static int nocrypt_iv(struct crypto_tfm *tfm, | |
377 | struct scatterlist *dst, | |
378 | struct scatterlist *src, | |
379 | unsigned int nbytes, u8 *iv) | |
380 | { | |
381 | return -ENOSYS; | |
382 | } | |
383 | ||
384 | int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags) | |
385 | { | |
386 | u32 mode = flags & CRYPTO_TFM_MODE_MASK; | |
1da177e4 | 387 | tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB; |
1da177e4 LT |
388 | return 0; |
389 | } | |
390 | ||
391 | int crypto_init_cipher_ops(struct crypto_tfm *tfm) | |
392 | { | |
393 | int ret = 0; | |
394 | struct cipher_tfm *ops = &tfm->crt_cipher; | |
395 | ||
396 | ops->cit_setkey = setkey; | |
397 | ||
398 | switch (tfm->crt_cipher.cit_mode) { | |
399 | case CRYPTO_TFM_MODE_ECB: | |
400 | ops->cit_encrypt = ecb_encrypt; | |
401 | ops->cit_decrypt = ecb_decrypt; | |
402 | break; | |
403 | ||
404 | case CRYPTO_TFM_MODE_CBC: | |
405 | ops->cit_encrypt = cbc_encrypt; | |
406 | ops->cit_decrypt = cbc_decrypt; | |
407 | ops->cit_encrypt_iv = cbc_encrypt_iv; | |
408 | ops->cit_decrypt_iv = cbc_decrypt_iv; | |
409 | break; | |
410 | ||
411 | case CRYPTO_TFM_MODE_CFB: | |
412 | ops->cit_encrypt = nocrypt; | |
413 | ops->cit_decrypt = nocrypt; | |
414 | ops->cit_encrypt_iv = nocrypt_iv; | |
415 | ops->cit_decrypt_iv = nocrypt_iv; | |
416 | break; | |
417 | ||
418 | case CRYPTO_TFM_MODE_CTR: | |
419 | ops->cit_encrypt = nocrypt; | |
420 | ops->cit_decrypt = nocrypt; | |
421 | ops->cit_encrypt_iv = nocrypt_iv; | |
422 | ops->cit_decrypt_iv = nocrypt_iv; | |
423 | break; | |
424 | ||
425 | default: | |
426 | BUG(); | |
427 | } | |
428 | ||
429 | if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) { | |
9d853c37 | 430 | unsigned long align; |
fbdae9f3 | 431 | unsigned long addr; |
1da177e4 LT |
432 | |
433 | switch (crypto_tfm_alg_blocksize(tfm)) { | |
434 | case 8: | |
435 | ops->cit_xor_block = xor_64; | |
436 | break; | |
437 | ||
438 | case 16: | |
439 | ops->cit_xor_block = xor_128; | |
440 | break; | |
441 | ||
442 | default: | |
443 | printk(KERN_WARNING "%s: block size %u not supported\n", | |
444 | crypto_tfm_alg_name(tfm), | |
445 | crypto_tfm_alg_blocksize(tfm)); | |
446 | ret = -EINVAL; | |
447 | goto out; | |
448 | } | |
449 | ||
450 | ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm); | |
fbdae9f3 HX |
451 | align = crypto_tfm_alg_alignmask(tfm) + 1; |
452 | addr = (unsigned long)crypto_tfm_ctx(tfm); | |
453 | addr = ALIGN(addr, align); | |
454 | addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align); | |
455 | ops->cit_iv = (void *)addr; | |
1da177e4 LT |
456 | } |
457 | ||
458 | out: | |
459 | return ret; | |
460 | } | |
461 | ||
462 | void crypto_exit_cipher_ops(struct crypto_tfm *tfm) | |
463 | { | |
1da177e4 | 464 | } |