x86: do not use $(ARCH) when not needed
[linux-2.6/kmemtrace.git] / crypto / blkcipher.c
blobf6c67f9d4e5c2f9085558991a6fc87893e269670
1 /*
2 * Block chaining cipher operations.
3 *
4 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
5 * multiple page boundaries by using temporary blocks. In user context,
6 * the kernel is given a chance to schedule us once per page.
8 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the Free
12 * Software Foundation; either version 2 of the License, or (at your option)
13 * any later version.
17 #include <linux/crypto.h>
18 #include <linux/errno.h>
19 #include <linux/hardirq.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/scatterlist.h>
23 #include <linux/seq_file.h>
24 #include <linux/slab.h>
25 #include <linux/string.h>
27 #include "internal.h"
28 #include "scatterwalk.h"
30 enum {
31 BLKCIPHER_WALK_PHYS = 1 << 0,
32 BLKCIPHER_WALK_SLOW = 1 << 1,
33 BLKCIPHER_WALK_COPY = 1 << 2,
34 BLKCIPHER_WALK_DIFF = 1 << 3,
37 static int blkcipher_walk_next(struct blkcipher_desc *desc,
38 struct blkcipher_walk *walk);
39 static int blkcipher_walk_first(struct blkcipher_desc *desc,
40 struct blkcipher_walk *walk);
42 static inline void blkcipher_map_src(struct blkcipher_walk *walk)
44 walk->src.virt.addr = scatterwalk_map(&walk->in, 0);
47 static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
49 walk->dst.virt.addr = scatterwalk_map(&walk->out, 1);
52 static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
54 scatterwalk_unmap(walk->src.virt.addr, 0);
57 static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
59 scatterwalk_unmap(walk->dst.virt.addr, 1);
62 /* Get a spot of the specified length that does not straddle a page.
63 * The caller needs to ensure that there is enough space for this operation.
65 static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
67 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
68 return max(start, end_page);
71 static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
72 struct blkcipher_walk *walk,
73 unsigned int bsize)
75 u8 *addr;
76 unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
78 addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
79 addr = blkcipher_get_spot(addr, bsize);
80 scatterwalk_copychunks(addr, &walk->out, bsize, 1);
81 return bsize;
84 static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
85 unsigned int n)
87 if (walk->flags & BLKCIPHER_WALK_COPY) {
88 blkcipher_map_dst(walk);
89 memcpy(walk->dst.virt.addr, walk->page, n);
90 blkcipher_unmap_dst(walk);
91 } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
92 blkcipher_unmap_src(walk);
93 if (walk->flags & BLKCIPHER_WALK_DIFF)
94 blkcipher_unmap_dst(walk);
97 scatterwalk_advance(&walk->in, n);
98 scatterwalk_advance(&walk->out, n);
100 return n;
103 int blkcipher_walk_done(struct blkcipher_desc *desc,
104 struct blkcipher_walk *walk, int err)
106 struct crypto_blkcipher *tfm = desc->tfm;
107 unsigned int nbytes = 0;
109 if (likely(err >= 0)) {
110 unsigned int n = walk->nbytes - err;
112 if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
113 n = blkcipher_done_fast(walk, n);
114 else if (WARN_ON(err)) {
115 err = -EINVAL;
116 goto err;
117 } else
118 n = blkcipher_done_slow(tfm, walk, n);
120 nbytes = walk->total - n;
121 err = 0;
124 scatterwalk_done(&walk->in, 0, nbytes);
125 scatterwalk_done(&walk->out, 1, nbytes);
127 walk->total = nbytes;
128 walk->nbytes = nbytes;
130 if (nbytes) {
131 crypto_yield(desc->flags);
132 return blkcipher_walk_next(desc, walk);
135 err:
136 if (walk->iv != desc->info)
137 memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
138 if (walk->buffer != walk->page)
139 kfree(walk->buffer);
140 if (walk->page)
141 free_page((unsigned long)walk->page);
143 return err;
145 EXPORT_SYMBOL_GPL(blkcipher_walk_done);
147 static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
148 struct blkcipher_walk *walk,
149 unsigned int bsize,
150 unsigned int alignmask)
152 unsigned int n;
153 unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
155 if (walk->buffer)
156 goto ok;
158 walk->buffer = walk->page;
159 if (walk->buffer)
160 goto ok;
162 n = aligned_bsize * 3 - (alignmask + 1) +
163 (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
164 walk->buffer = kmalloc(n, GFP_ATOMIC);
165 if (!walk->buffer)
166 return blkcipher_walk_done(desc, walk, -ENOMEM);
169 walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
170 alignmask + 1);
171 walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
172 walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
173 aligned_bsize, bsize);
175 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
177 walk->nbytes = bsize;
178 walk->flags |= BLKCIPHER_WALK_SLOW;
180 return 0;
183 static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
185 u8 *tmp = walk->page;
187 blkcipher_map_src(walk);
188 memcpy(tmp, walk->src.virt.addr, walk->nbytes);
189 blkcipher_unmap_src(walk);
191 walk->src.virt.addr = tmp;
192 walk->dst.virt.addr = tmp;
194 return 0;
197 static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
198 struct blkcipher_walk *walk)
200 unsigned long diff;
202 walk->src.phys.page = scatterwalk_page(&walk->in);
203 walk->src.phys.offset = offset_in_page(walk->in.offset);
204 walk->dst.phys.page = scatterwalk_page(&walk->out);
205 walk->dst.phys.offset = offset_in_page(walk->out.offset);
207 if (walk->flags & BLKCIPHER_WALK_PHYS)
208 return 0;
210 diff = walk->src.phys.offset - walk->dst.phys.offset;
211 diff |= walk->src.virt.page - walk->dst.virt.page;
213 blkcipher_map_src(walk);
214 walk->dst.virt.addr = walk->src.virt.addr;
216 if (diff) {
217 walk->flags |= BLKCIPHER_WALK_DIFF;
218 blkcipher_map_dst(walk);
221 return 0;
224 static int blkcipher_walk_next(struct blkcipher_desc *desc,
225 struct blkcipher_walk *walk)
227 struct crypto_blkcipher *tfm = desc->tfm;
228 unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
229 unsigned int bsize;
230 unsigned int n;
231 int err;
233 n = walk->total;
234 if (unlikely(n < crypto_blkcipher_blocksize(tfm))) {
235 desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
236 return blkcipher_walk_done(desc, walk, -EINVAL);
239 walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
240 BLKCIPHER_WALK_DIFF);
241 if (!scatterwalk_aligned(&walk->in, alignmask) ||
242 !scatterwalk_aligned(&walk->out, alignmask)) {
243 walk->flags |= BLKCIPHER_WALK_COPY;
244 if (!walk->page) {
245 walk->page = (void *)__get_free_page(GFP_ATOMIC);
246 if (!walk->page)
247 n = 0;
251 bsize = min(walk->blocksize, n);
252 n = scatterwalk_clamp(&walk->in, n);
253 n = scatterwalk_clamp(&walk->out, n);
255 if (unlikely(n < bsize)) {
256 err = blkcipher_next_slow(desc, walk, bsize, alignmask);
257 goto set_phys_lowmem;
260 walk->nbytes = n;
261 if (walk->flags & BLKCIPHER_WALK_COPY) {
262 err = blkcipher_next_copy(walk);
263 goto set_phys_lowmem;
266 return blkcipher_next_fast(desc, walk);
268 set_phys_lowmem:
269 if (walk->flags & BLKCIPHER_WALK_PHYS) {
270 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
271 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
272 walk->src.phys.offset &= PAGE_SIZE - 1;
273 walk->dst.phys.offset &= PAGE_SIZE - 1;
275 return err;
278 static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
279 struct crypto_blkcipher *tfm,
280 unsigned int alignmask)
282 unsigned bs = walk->blocksize;
283 unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
284 unsigned aligned_bs = ALIGN(bs, alignmask + 1);
285 unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
286 (alignmask + 1);
287 u8 *iv;
289 size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
290 walk->buffer = kmalloc(size, GFP_ATOMIC);
291 if (!walk->buffer)
292 return -ENOMEM;
294 iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
295 iv = blkcipher_get_spot(iv, bs) + aligned_bs;
296 iv = blkcipher_get_spot(iv, bs) + aligned_bs;
297 iv = blkcipher_get_spot(iv, ivsize);
299 walk->iv = memcpy(iv, walk->iv, ivsize);
300 return 0;
303 int blkcipher_walk_virt(struct blkcipher_desc *desc,
304 struct blkcipher_walk *walk)
306 walk->flags &= ~BLKCIPHER_WALK_PHYS;
307 walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
308 return blkcipher_walk_first(desc, walk);
310 EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
312 int blkcipher_walk_phys(struct blkcipher_desc *desc,
313 struct blkcipher_walk *walk)
315 walk->flags |= BLKCIPHER_WALK_PHYS;
316 walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
317 return blkcipher_walk_first(desc, walk);
319 EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
321 static int blkcipher_walk_first(struct blkcipher_desc *desc,
322 struct blkcipher_walk *walk)
324 struct crypto_blkcipher *tfm = desc->tfm;
325 unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
327 if (WARN_ON_ONCE(in_irq()))
328 return -EDEADLK;
330 walk->nbytes = walk->total;
331 if (unlikely(!walk->total))
332 return 0;
334 walk->buffer = NULL;
335 walk->iv = desc->info;
336 if (unlikely(((unsigned long)walk->iv & alignmask))) {
337 int err = blkcipher_copy_iv(walk, tfm, alignmask);
338 if (err)
339 return err;
342 scatterwalk_start(&walk->in, walk->in.sg);
343 scatterwalk_start(&walk->out, walk->out.sg);
344 walk->page = NULL;
346 return blkcipher_walk_next(desc, walk);
349 int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
350 struct blkcipher_walk *walk,
351 unsigned int blocksize)
353 walk->flags &= ~BLKCIPHER_WALK_PHYS;
354 walk->blocksize = blocksize;
355 return blkcipher_walk_first(desc, walk);
357 EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
359 static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
360 unsigned int keylen)
362 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
363 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
364 int ret;
365 u8 *buffer, *alignbuffer;
366 unsigned long absize;
368 absize = keylen + alignmask;
369 buffer = kmalloc(absize, GFP_ATOMIC);
370 if (!buffer)
371 return -ENOMEM;
373 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
374 memcpy(alignbuffer, key, keylen);
375 ret = cipher->setkey(tfm, alignbuffer, keylen);
376 memset(alignbuffer, 0, keylen);
377 kfree(buffer);
378 return ret;
381 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
383 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
384 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
386 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
387 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
388 return -EINVAL;
391 if ((unsigned long)key & alignmask)
392 return setkey_unaligned(tfm, key, keylen);
394 return cipher->setkey(tfm, key, keylen);
397 static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
398 unsigned int keylen)
400 return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
403 static int async_encrypt(struct ablkcipher_request *req)
405 struct crypto_tfm *tfm = req->base.tfm;
406 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
407 struct blkcipher_desc desc = {
408 .tfm = __crypto_blkcipher_cast(tfm),
409 .info = req->info,
410 .flags = req->base.flags,
414 return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
417 static int async_decrypt(struct ablkcipher_request *req)
419 struct crypto_tfm *tfm = req->base.tfm;
420 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
421 struct blkcipher_desc desc = {
422 .tfm = __crypto_blkcipher_cast(tfm),
423 .info = req->info,
424 .flags = req->base.flags,
427 return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
430 static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
431 u32 mask)
433 struct blkcipher_alg *cipher = &alg->cra_blkcipher;
434 unsigned int len = alg->cra_ctxsize;
436 type ^= CRYPTO_ALG_ASYNC;
437 mask &= CRYPTO_ALG_ASYNC;
438 if ((type & mask) && cipher->ivsize) {
439 len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
440 len += cipher->ivsize;
443 return len;
446 static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
448 struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
449 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
451 crt->setkey = async_setkey;
452 crt->encrypt = async_encrypt;
453 crt->decrypt = async_decrypt;
454 crt->ivsize = alg->ivsize;
456 return 0;
459 static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
461 struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
462 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
463 unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
464 unsigned long addr;
466 crt->setkey = setkey;
467 crt->encrypt = alg->encrypt;
468 crt->decrypt = alg->decrypt;
470 addr = (unsigned long)crypto_tfm_ctx(tfm);
471 addr = ALIGN(addr, align);
472 addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
473 crt->iv = (void *)addr;
475 return 0;
478 static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
480 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
482 if (alg->ivsize > PAGE_SIZE / 8)
483 return -EINVAL;
485 type ^= CRYPTO_ALG_ASYNC;
486 mask &= CRYPTO_ALG_ASYNC;
487 if (type & mask)
488 return crypto_init_blkcipher_ops_sync(tfm);
489 else
490 return crypto_init_blkcipher_ops_async(tfm);
493 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
494 __attribute__ ((unused));
495 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
497 seq_printf(m, "type : blkcipher\n");
498 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
499 seq_printf(m, "min keysize : %u\n", alg->cra_blkcipher.min_keysize);
500 seq_printf(m, "max keysize : %u\n", alg->cra_blkcipher.max_keysize);
501 seq_printf(m, "ivsize : %u\n", alg->cra_blkcipher.ivsize);
504 const struct crypto_type crypto_blkcipher_type = {
505 .ctxsize = crypto_blkcipher_ctxsize,
506 .init = crypto_init_blkcipher_ops,
507 #ifdef CONFIG_PROC_FS
508 .show = crypto_blkcipher_show,
509 #endif
511 EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
513 MODULE_LICENSE("GPL");
514 MODULE_DESCRIPTION("Generic block chaining cipher type");