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
ablkcipher_buffer_write(struct ablkcipher_buffer * p)35 static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
36 {
37 scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
38 }
39
__ablkcipher_walk_complete(struct ablkcipher_walk * walk)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
ablkcipher_queue_write(struct ablkcipher_walk * walk,struct ablkcipher_buffer * p)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 */
ablkcipher_get_spot(u8 * start,unsigned int len)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
ablkcipher_done_slow(struct ablkcipher_walk * walk,unsigned int n)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
ablkcipher_done_fast(struct ablkcipher_walk * walk,unsigned int n)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
ablkcipher_walk_done(struct ablkcipher_request * req,struct ablkcipher_walk * walk,int err)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
ablkcipher_next_slow(struct ablkcipher_request * req,struct ablkcipher_walk * walk,unsigned int bsize,unsigned int alignmask,void ** src_p,void ** dst_p)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
ablkcipher_copy_iv(struct ablkcipher_walk * walk,struct crypto_tfm * tfm,unsigned int alignmask)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
ablkcipher_next_fast(struct ablkcipher_request * req,struct ablkcipher_walk * walk)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
ablkcipher_walk_next(struct ablkcipher_request * req,struct ablkcipher_walk * walk)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
ablkcipher_walk_first(struct ablkcipher_request * req,struct ablkcipher_walk * walk)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
ablkcipher_walk_phys(struct ablkcipher_request * req,struct ablkcipher_walk * walk)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
setkey_unaligned(struct crypto_ablkcipher * tfm,const u8 * key,unsigned int keylen)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
setkey(struct crypto_ablkcipher * tfm,const u8 * key,unsigned int keylen)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
crypto_ablkcipher_ctxsize(struct crypto_alg * alg,u32 type,u32 mask)334 static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
335 u32 mask)
336 {
337 return alg->cra_ctxsize;
338 }
339
crypto_init_ablkcipher_ops(struct crypto_tfm * tfm,u32 type,u32 mask)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
crypto_ablkcipher_report(struct sk_buff * skb,struct crypto_alg * alg)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
crypto_ablkcipher_report(struct sk_buff * skb,struct crypto_alg * alg)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;
crypto_ablkcipher_show(struct seq_file * m,struct crypto_alg * alg)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);
408