treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
[muen/linux.git] / crypto / ablkcipher.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Asynchronous block chaining cipher operations.
4  *
5  * This is the asynchronous version of blkcipher.c indicating completion
6  * via a callback.
7  *
8  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
9  */
10
11 #include <crypto/internal/skcipher.h>
12 #include <linux/err.h>
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/seq_file.h>
16 #include <linux/cryptouser.h>
17 #include <linux/compiler.h>
18 #include <net/netlink.h>
19
20 #include <crypto/scatterwalk.h>
21
22 #include "internal.h"
23
24 struct ablkcipher_buffer {
25         struct list_head        entry;
26         struct scatter_walk     dst;
27         unsigned int            len;
28         void                    *data;
29 };
30
31 enum {
32         ABLKCIPHER_WALK_SLOW = 1 << 0,
33 };
34
35 static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
36 {
37         scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
38 }
39
40 void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
41 {
42         struct ablkcipher_buffer *p, *tmp;
43
44         list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
45                 ablkcipher_buffer_write(p);
46                 list_del(&p->entry);
47                 kfree(p);
48         }
49 }
50 EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
51
52 static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
53                                           struct ablkcipher_buffer *p)
54 {
55         p->dst = walk->out;
56         list_add_tail(&p->entry, &walk->buffers);
57 }
58
59 /* Get a spot of the specified length that does not straddle a page.
60  * The caller needs to ensure that there is enough space for this operation.
61  */
62 static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
63 {
64         u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
65
66         return max(start, end_page);
67 }
68
69 static inline void ablkcipher_done_slow(struct ablkcipher_walk *walk,
70                                         unsigned int n)
71 {
72         for (;;) {
73                 unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
74
75                 if (len_this_page > n)
76                         len_this_page = n;
77                 scatterwalk_advance(&walk->out, n);
78                 if (n == len_this_page)
79                         break;
80                 n -= len_this_page;
81                 scatterwalk_start(&walk->out, sg_next(walk->out.sg));
82         }
83 }
84
85 static inline void ablkcipher_done_fast(struct ablkcipher_walk *walk,
86                                         unsigned int n)
87 {
88         scatterwalk_advance(&walk->in, n);
89         scatterwalk_advance(&walk->out, n);
90 }
91
92 static int ablkcipher_walk_next(struct ablkcipher_request *req,
93                                 struct ablkcipher_walk *walk);
94
95 int ablkcipher_walk_done(struct ablkcipher_request *req,
96                          struct ablkcipher_walk *walk, int err)
97 {
98         struct crypto_tfm *tfm = req->base.tfm;
99         unsigned int n; /* bytes processed */
100         bool more;
101
102         if (unlikely(err < 0))
103                 goto finish;
104
105         n = walk->nbytes - err;
106         walk->total -= n;
107         more = (walk->total != 0);
108
109         if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW))) {
110                 ablkcipher_done_fast(walk, n);
111         } else {
112                 if (WARN_ON(err)) {
113                         /* unexpected case; didn't process all bytes */
114                         err = -EINVAL;
115                         goto finish;
116                 }
117                 ablkcipher_done_slow(walk, n);
118         }
119
120         scatterwalk_done(&walk->in, 0, more);
121         scatterwalk_done(&walk->out, 1, more);
122
123         if (more) {
124                 crypto_yield(req->base.flags);
125                 return ablkcipher_walk_next(req, walk);
126         }
127         err = 0;
128 finish:
129         walk->nbytes = 0;
130         if (walk->iv != req->info)
131                 memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
132         kfree(walk->iv_buffer);
133         return err;
134 }
135 EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
136
137 static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
138                                        struct ablkcipher_walk *walk,
139                                        unsigned int bsize,
140                                        unsigned int alignmask,
141                                        void **src_p, void **dst_p)
142 {
143         unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
144         struct ablkcipher_buffer *p;
145         void *src, *dst, *base;
146         unsigned int n;
147
148         n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
149         n += (aligned_bsize * 3 - (alignmask + 1) +
150               (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
151
152         p = kmalloc(n, GFP_ATOMIC);
153         if (!p)
154                 return ablkcipher_walk_done(req, walk, -ENOMEM);
155
156         base = p + 1;
157
158         dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
159         src = dst = ablkcipher_get_spot(dst, bsize);
160
161         p->len = bsize;
162         p->data = dst;
163
164         scatterwalk_copychunks(src, &walk->in, bsize, 0);
165
166         ablkcipher_queue_write(walk, p);
167
168         walk->nbytes = bsize;
169         walk->flags |= ABLKCIPHER_WALK_SLOW;
170
171         *src_p = src;
172         *dst_p = dst;
173
174         return 0;
175 }
176
177 static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
178                                      struct crypto_tfm *tfm,
179                                      unsigned int alignmask)
180 {
181         unsigned bs = walk->blocksize;
182         unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
183         unsigned aligned_bs = ALIGN(bs, alignmask + 1);
184         unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
185                             (alignmask + 1);
186         u8 *iv;
187
188         size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
189         walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
190         if (!walk->iv_buffer)
191                 return -ENOMEM;
192
193         iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
194         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
195         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
196         iv = ablkcipher_get_spot(iv, ivsize);
197
198         walk->iv = memcpy(iv, walk->iv, ivsize);
199         return 0;
200 }
201
202 static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
203                                        struct ablkcipher_walk *walk)
204 {
205         walk->src.page = scatterwalk_page(&walk->in);
206         walk->src.offset = offset_in_page(walk->in.offset);
207         walk->dst.page = scatterwalk_page(&walk->out);
208         walk->dst.offset = offset_in_page(walk->out.offset);
209
210         return 0;
211 }
212
213 static int ablkcipher_walk_next(struct ablkcipher_request *req,
214                                 struct ablkcipher_walk *walk)
215 {
216         struct crypto_tfm *tfm = req->base.tfm;
217         unsigned int alignmask, bsize, n;
218         void *src, *dst;
219         int err;
220
221         alignmask = crypto_tfm_alg_alignmask(tfm);
222         n = walk->total;
223         if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
224                 req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
225                 return ablkcipher_walk_done(req, walk, -EINVAL);
226         }
227
228         walk->flags &= ~ABLKCIPHER_WALK_SLOW;
229         src = dst = NULL;
230
231         bsize = min(walk->blocksize, n);
232         n = scatterwalk_clamp(&walk->in, n);
233         n = scatterwalk_clamp(&walk->out, n);
234
235         if (n < bsize ||
236             !scatterwalk_aligned(&walk->in, alignmask) ||
237             !scatterwalk_aligned(&walk->out, alignmask)) {
238                 err = ablkcipher_next_slow(req, walk, bsize, alignmask,
239                                            &src, &dst);
240                 goto set_phys_lowmem;
241         }
242
243         walk->nbytes = n;
244
245         return ablkcipher_next_fast(req, walk);
246
247 set_phys_lowmem:
248         if (err >= 0) {
249                 walk->src.page = virt_to_page(src);
250                 walk->dst.page = virt_to_page(dst);
251                 walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
252                 walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
253         }
254
255         return err;
256 }
257
258 static int ablkcipher_walk_first(struct ablkcipher_request *req,
259                                  struct ablkcipher_walk *walk)
260 {
261         struct crypto_tfm *tfm = req->base.tfm;
262         unsigned int alignmask;
263
264         alignmask = crypto_tfm_alg_alignmask(tfm);
265         if (WARN_ON_ONCE(in_irq()))
266                 return -EDEADLK;
267
268         walk->iv = req->info;
269         walk->nbytes = walk->total;
270         if (unlikely(!walk->total))
271                 return 0;
272
273         walk->iv_buffer = NULL;
274         if (unlikely(((unsigned long)walk->iv & alignmask))) {
275                 int err = ablkcipher_copy_iv(walk, tfm, alignmask);
276
277                 if (err)
278                         return err;
279         }
280
281         scatterwalk_start(&walk->in, walk->in.sg);
282         scatterwalk_start(&walk->out, walk->out.sg);
283
284         return ablkcipher_walk_next(req, walk);
285 }
286
287 int ablkcipher_walk_phys(struct ablkcipher_request *req,
288                          struct ablkcipher_walk *walk)
289 {
290         walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
291         return ablkcipher_walk_first(req, walk);
292 }
293 EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
294
295 static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
296                             unsigned int keylen)
297 {
298         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
299         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
300         int ret;
301         u8 *buffer, *alignbuffer;
302         unsigned long absize;
303
304         absize = keylen + alignmask;
305         buffer = kmalloc(absize, GFP_ATOMIC);
306         if (!buffer)
307                 return -ENOMEM;
308
309         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
310         memcpy(alignbuffer, key, keylen);
311         ret = cipher->setkey(tfm, alignbuffer, keylen);
312         memset(alignbuffer, 0, keylen);
313         kfree(buffer);
314         return ret;
315 }
316
317 static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
318                   unsigned int keylen)
319 {
320         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
321         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
322
323         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
324                 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
325                 return -EINVAL;
326         }
327
328         if ((unsigned long)key & alignmask)
329                 return setkey_unaligned(tfm, key, keylen);
330
331         return cipher->setkey(tfm, key, keylen);
332 }
333
334 static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
335                                               u32 mask)
336 {
337         return alg->cra_ctxsize;
338 }
339
340 static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
341                                       u32 mask)
342 {
343         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
344         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
345
346         if (alg->ivsize > PAGE_SIZE / 8)
347                 return -EINVAL;
348
349         crt->setkey = setkey;
350         crt->encrypt = alg->encrypt;
351         crt->decrypt = alg->decrypt;
352         crt->base = __crypto_ablkcipher_cast(tfm);
353         crt->ivsize = alg->ivsize;
354
355         return 0;
356 }
357
358 #ifdef CONFIG_NET
359 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
360 {
361         struct crypto_report_blkcipher rblkcipher;
362
363         memset(&rblkcipher, 0, sizeof(rblkcipher));
364
365         strscpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
366         strscpy(rblkcipher.geniv, "<default>", sizeof(rblkcipher.geniv));
367
368         rblkcipher.blocksize = alg->cra_blocksize;
369         rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
370         rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
371         rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
372
373         return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
374                        sizeof(rblkcipher), &rblkcipher);
375 }
376 #else
377 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
378 {
379         return -ENOSYS;
380 }
381 #endif
382
383 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
384         __maybe_unused;
385 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
386 {
387         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
388
389         seq_printf(m, "type         : ablkcipher\n");
390         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
391                                              "yes" : "no");
392         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
393         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
394         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
395         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
396         seq_printf(m, "geniv        : <default>\n");
397 }
398
399 const struct crypto_type crypto_ablkcipher_type = {
400         .ctxsize = crypto_ablkcipher_ctxsize,
401         .init = crypto_init_ablkcipher_ops,
402 #ifdef CONFIG_PROC_FS
403         .show = crypto_ablkcipher_show,
404 #endif
405         .report = crypto_ablkcipher_report,
406 };
407 EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);