drm/fb-helper: generic: Call drm_client_add() after setup is done
[linux-2.6-microblaze.git] / crypto / ablkcipher.c
1 /*
2  * Asynchronous block chaining cipher operations.
3  *
4  * This is the asynchronous version of blkcipher.c indicating completion
5  * via a callback.
6  *
7  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
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
16 #include <crypto/internal/skcipher.h>
17 #include <linux/err.h>
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
20 #include <linux/seq_file.h>
21 #include <linux/cryptouser.h>
22 #include <linux/compiler.h>
23 #include <net/netlink.h>
24
25 #include <crypto/scatterwalk.h>
26
27 #include "internal.h"
28
29 struct ablkcipher_buffer {
30         struct list_head        entry;
31         struct scatter_walk     dst;
32         unsigned int            len;
33         void                    *data;
34 };
35
36 enum {
37         ABLKCIPHER_WALK_SLOW = 1 << 0,
38 };
39
40 static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
41 {
42         scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
43 }
44
45 void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
46 {
47         struct ablkcipher_buffer *p, *tmp;
48
49         list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
50                 ablkcipher_buffer_write(p);
51                 list_del(&p->entry);
52                 kfree(p);
53         }
54 }
55 EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
56
57 static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
58                                           struct ablkcipher_buffer *p)
59 {
60         p->dst = walk->out;
61         list_add_tail(&p->entry, &walk->buffers);
62 }
63
64 /* Get a spot of the specified length that does not straddle a page.
65  * The caller needs to ensure that there is enough space for this operation.
66  */
67 static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
68 {
69         u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
70
71         return max(start, end_page);
72 }
73
74 static inline void ablkcipher_done_slow(struct ablkcipher_walk *walk,
75                                         unsigned int n)
76 {
77         for (;;) {
78                 unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
79
80                 if (len_this_page > n)
81                         len_this_page = n;
82                 scatterwalk_advance(&walk->out, n);
83                 if (n == len_this_page)
84                         break;
85                 n -= len_this_page;
86                 scatterwalk_start(&walk->out, sg_next(walk->out.sg));
87         }
88 }
89
90 static inline void ablkcipher_done_fast(struct ablkcipher_walk *walk,
91                                         unsigned int n)
92 {
93         scatterwalk_advance(&walk->in, n);
94         scatterwalk_advance(&walk->out, n);
95 }
96
97 static int ablkcipher_walk_next(struct ablkcipher_request *req,
98                                 struct ablkcipher_walk *walk);
99
100 int ablkcipher_walk_done(struct ablkcipher_request *req,
101                          struct ablkcipher_walk *walk, int err)
102 {
103         struct crypto_tfm *tfm = req->base.tfm;
104         unsigned int n; /* bytes processed */
105         bool more;
106
107         if (unlikely(err < 0))
108                 goto finish;
109
110         n = walk->nbytes - err;
111         walk->total -= n;
112         more = (walk->total != 0);
113
114         if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW))) {
115                 ablkcipher_done_fast(walk, n);
116         } else {
117                 if (WARN_ON(err)) {
118                         /* unexpected case; didn't process all bytes */
119                         err = -EINVAL;
120                         goto finish;
121                 }
122                 ablkcipher_done_slow(walk, n);
123         }
124
125         scatterwalk_done(&walk->in, 0, more);
126         scatterwalk_done(&walk->out, 1, more);
127
128         if (more) {
129                 crypto_yield(req->base.flags);
130                 return ablkcipher_walk_next(req, walk);
131         }
132         err = 0;
133 finish:
134         walk->nbytes = 0;
135         if (walk->iv != req->info)
136                 memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
137         kfree(walk->iv_buffer);
138         return err;
139 }
140 EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
141
142 static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
143                                        struct ablkcipher_walk *walk,
144                                        unsigned int bsize,
145                                        unsigned int alignmask,
146                                        void **src_p, void **dst_p)
147 {
148         unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
149         struct ablkcipher_buffer *p;
150         void *src, *dst, *base;
151         unsigned int n;
152
153         n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
154         n += (aligned_bsize * 3 - (alignmask + 1) +
155               (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
156
157         p = kmalloc(n, GFP_ATOMIC);
158         if (!p)
159                 return ablkcipher_walk_done(req, walk, -ENOMEM);
160
161         base = p + 1;
162
163         dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
164         src = dst = ablkcipher_get_spot(dst, bsize);
165
166         p->len = bsize;
167         p->data = dst;
168
169         scatterwalk_copychunks(src, &walk->in, bsize, 0);
170
171         ablkcipher_queue_write(walk, p);
172
173         walk->nbytes = bsize;
174         walk->flags |= ABLKCIPHER_WALK_SLOW;
175
176         *src_p = src;
177         *dst_p = dst;
178
179         return 0;
180 }
181
182 static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
183                                      struct crypto_tfm *tfm,
184                                      unsigned int alignmask)
185 {
186         unsigned bs = walk->blocksize;
187         unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
188         unsigned aligned_bs = ALIGN(bs, alignmask + 1);
189         unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
190                             (alignmask + 1);
191         u8 *iv;
192
193         size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
194         walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
195         if (!walk->iv_buffer)
196                 return -ENOMEM;
197
198         iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
199         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
200         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
201         iv = ablkcipher_get_spot(iv, ivsize);
202
203         walk->iv = memcpy(iv, walk->iv, ivsize);
204         return 0;
205 }
206
207 static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
208                                        struct ablkcipher_walk *walk)
209 {
210         walk->src.page = scatterwalk_page(&walk->in);
211         walk->src.offset = offset_in_page(walk->in.offset);
212         walk->dst.page = scatterwalk_page(&walk->out);
213         walk->dst.offset = offset_in_page(walk->out.offset);
214
215         return 0;
216 }
217
218 static int ablkcipher_walk_next(struct ablkcipher_request *req,
219                                 struct ablkcipher_walk *walk)
220 {
221         struct crypto_tfm *tfm = req->base.tfm;
222         unsigned int alignmask, bsize, n;
223         void *src, *dst;
224         int err;
225
226         alignmask = crypto_tfm_alg_alignmask(tfm);
227         n = walk->total;
228         if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
229                 req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
230                 return ablkcipher_walk_done(req, walk, -EINVAL);
231         }
232
233         walk->flags &= ~ABLKCIPHER_WALK_SLOW;
234         src = dst = NULL;
235
236         bsize = min(walk->blocksize, n);
237         n = scatterwalk_clamp(&walk->in, n);
238         n = scatterwalk_clamp(&walk->out, n);
239
240         if (n < bsize ||
241             !scatterwalk_aligned(&walk->in, alignmask) ||
242             !scatterwalk_aligned(&walk->out, alignmask)) {
243                 err = ablkcipher_next_slow(req, walk, bsize, alignmask,
244                                            &src, &dst);
245                 goto set_phys_lowmem;
246         }
247
248         walk->nbytes = n;
249
250         return ablkcipher_next_fast(req, walk);
251
252 set_phys_lowmem:
253         if (err >= 0) {
254                 walk->src.page = virt_to_page(src);
255                 walk->dst.page = virt_to_page(dst);
256                 walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
257                 walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
258         }
259
260         return err;
261 }
262
263 static int ablkcipher_walk_first(struct ablkcipher_request *req,
264                                  struct ablkcipher_walk *walk)
265 {
266         struct crypto_tfm *tfm = req->base.tfm;
267         unsigned int alignmask;
268
269         alignmask = crypto_tfm_alg_alignmask(tfm);
270         if (WARN_ON_ONCE(in_irq()))
271                 return -EDEADLK;
272
273         walk->iv = req->info;
274         walk->nbytes = walk->total;
275         if (unlikely(!walk->total))
276                 return 0;
277
278         walk->iv_buffer = NULL;
279         if (unlikely(((unsigned long)walk->iv & alignmask))) {
280                 int err = ablkcipher_copy_iv(walk, tfm, alignmask);
281
282                 if (err)
283                         return err;
284         }
285
286         scatterwalk_start(&walk->in, walk->in.sg);
287         scatterwalk_start(&walk->out, walk->out.sg);
288
289         return ablkcipher_walk_next(req, walk);
290 }
291
292 int ablkcipher_walk_phys(struct ablkcipher_request *req,
293                          struct ablkcipher_walk *walk)
294 {
295         walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
296         return ablkcipher_walk_first(req, walk);
297 }
298 EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
299
300 static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
301                             unsigned int keylen)
302 {
303         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
304         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
305         int ret;
306         u8 *buffer, *alignbuffer;
307         unsigned long absize;
308
309         absize = keylen + alignmask;
310         buffer = kmalloc(absize, GFP_ATOMIC);
311         if (!buffer)
312                 return -ENOMEM;
313
314         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
315         memcpy(alignbuffer, key, keylen);
316         ret = cipher->setkey(tfm, alignbuffer, keylen);
317         memset(alignbuffer, 0, keylen);
318         kfree(buffer);
319         return ret;
320 }
321
322 static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
323                   unsigned int keylen)
324 {
325         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
326         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
327
328         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
329                 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
330                 return -EINVAL;
331         }
332
333         if ((unsigned long)key & alignmask)
334                 return setkey_unaligned(tfm, key, keylen);
335
336         return cipher->setkey(tfm, key, keylen);
337 }
338
339 static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
340                                               u32 mask)
341 {
342         return alg->cra_ctxsize;
343 }
344
345 static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
346                                       u32 mask)
347 {
348         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
349         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
350
351         if (alg->ivsize > PAGE_SIZE / 8)
352                 return -EINVAL;
353
354         crt->setkey = setkey;
355         crt->encrypt = alg->encrypt;
356         crt->decrypt = alg->decrypt;
357         crt->base = __crypto_ablkcipher_cast(tfm);
358         crt->ivsize = alg->ivsize;
359
360         return 0;
361 }
362
363 #ifdef CONFIG_NET
364 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
365 {
366         struct crypto_report_blkcipher rblkcipher;
367
368         memset(&rblkcipher, 0, sizeof(rblkcipher));
369
370         strscpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
371         strscpy(rblkcipher.geniv, "<default>", sizeof(rblkcipher.geniv));
372
373         rblkcipher.blocksize = alg->cra_blocksize;
374         rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
375         rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
376         rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
377
378         return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
379                        sizeof(rblkcipher), &rblkcipher);
380 }
381 #else
382 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
383 {
384         return -ENOSYS;
385 }
386 #endif
387
388 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
389         __maybe_unused;
390 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
391 {
392         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
393
394         seq_printf(m, "type         : ablkcipher\n");
395         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
396                                              "yes" : "no");
397         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
398         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
399         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
400         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
401         seq_printf(m, "geniv        : <default>\n");
402 }
403
404 const struct crypto_type crypto_ablkcipher_type = {
405         .ctxsize = crypto_ablkcipher_ctxsize,
406         .init = crypto_init_ablkcipher_ops,
407 #ifdef CONFIG_PROC_FS
408         .show = crypto_ablkcipher_show,
409 #endif
410         .report = crypto_ablkcipher_report,
411 };
412 EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);