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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Symmetric key ciphers.
4 *
5 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8#ifndef _CRYPTO_SKCIPHER_H
9#define _CRYPTO_SKCIPHER_H
10
11#include <linux/container_of.h>
12#include <linux/crypto.h>
13#include <linux/slab.h>
14#include <linux/string.h>
15#include <linux/types.h>
16
17struct scatterlist;
18
19/**
20 * struct skcipher_request - Symmetric key cipher request
21 * @cryptlen: Number of bytes to encrypt or decrypt
22 * @iv: Initialisation Vector
23 * @src: Source SG list
24 * @dst: Destination SG list
25 * @base: Underlying async request
26 * @__ctx: Start of private context data
27 */
28struct skcipher_request {
29 unsigned int cryptlen;
30
31 u8 *iv;
32
33 struct scatterlist *src;
34 struct scatterlist *dst;
35
36 struct crypto_async_request base;
37
38 void *__ctx[] CRYPTO_MINALIGN_ATTR;
39};
40
41struct crypto_skcipher {
42 unsigned int reqsize;
43
44 struct crypto_tfm base;
45};
46
47struct crypto_sync_skcipher {
48 struct crypto_skcipher base;
49};
50
51/**
52 * struct skcipher_alg - symmetric key cipher definition
53 * @min_keysize: Minimum key size supported by the transformation. This is the
54 * smallest key length supported by this transformation algorithm.
55 * This must be set to one of the pre-defined values as this is
56 * not hardware specific. Possible values for this field can be
57 * found via git grep "_MIN_KEY_SIZE" include/crypto/
58 * @max_keysize: Maximum key size supported by the transformation. This is the
59 * largest key length supported by this transformation algorithm.
60 * This must be set to one of the pre-defined values as this is
61 * not hardware specific. Possible values for this field can be
62 * found via git grep "_MAX_KEY_SIZE" include/crypto/
63 * @setkey: Set key for the transformation. This function is used to either
64 * program a supplied key into the hardware or store the key in the
65 * transformation context for programming it later. Note that this
66 * function does modify the transformation context. This function can
67 * be called multiple times during the existence of the transformation
68 * object, so one must make sure the key is properly reprogrammed into
69 * the hardware. This function is also responsible for checking the key
70 * length for validity. In case a software fallback was put in place in
71 * the @cra_init call, this function might need to use the fallback if
72 * the algorithm doesn't support all of the key sizes.
73 * @encrypt: Encrypt a scatterlist of blocks. This function is used to encrypt
74 * the supplied scatterlist containing the blocks of data. The crypto
75 * API consumer is responsible for aligning the entries of the
76 * scatterlist properly and making sure the chunks are correctly
77 * sized. In case a software fallback was put in place in the
78 * @cra_init call, this function might need to use the fallback if
79 * the algorithm doesn't support all of the key sizes. In case the
80 * key was stored in transformation context, the key might need to be
81 * re-programmed into the hardware in this function. This function
82 * shall not modify the transformation context, as this function may
83 * be called in parallel with the same transformation object.
84 * @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt
85 * and the conditions are exactly the same.
86 * @init: Initialize the cryptographic transformation object. This function
87 * is used to initialize the cryptographic transformation object.
88 * This function is called only once at the instantiation time, right
89 * after the transformation context was allocated. In case the
90 * cryptographic hardware has some special requirements which need to
91 * be handled by software, this function shall check for the precise
92 * requirement of the transformation and put any software fallbacks
93 * in place.
94 * @exit: Deinitialize the cryptographic transformation object. This is a
95 * counterpart to @init, used to remove various changes set in
96 * @init.
97 * @ivsize: IV size applicable for transformation. The consumer must provide an
98 * IV of exactly that size to perform the encrypt or decrypt operation.
99 * @chunksize: Equal to the block size except for stream ciphers such as
100 * CTR where it is set to the underlying block size.
101 * @walksize: Equal to the chunk size except in cases where the algorithm is
102 * considerably more efficient if it can operate on multiple chunks
103 * in parallel. Should be a multiple of chunksize.
104 * @base: Definition of a generic crypto algorithm.
105 *
106 * All fields except @ivsize are mandatory and must be filled.
107 */
108struct skcipher_alg {
109 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
110 unsigned int keylen);
111 int (*encrypt)(struct skcipher_request *req);
112 int (*decrypt)(struct skcipher_request *req);
113 int (*init)(struct crypto_skcipher *tfm);
114 void (*exit)(struct crypto_skcipher *tfm);
115
116 unsigned int min_keysize;
117 unsigned int max_keysize;
118 unsigned int ivsize;
119 unsigned int chunksize;
120 unsigned int walksize;
121
122 struct crypto_alg base;
123};
124
125#define MAX_SYNC_SKCIPHER_REQSIZE 384
126/*
127 * This performs a type-check against the "tfm" argument to make sure
128 * all users have the correct skcipher tfm for doing on-stack requests.
129 */
130#define SYNC_SKCIPHER_REQUEST_ON_STACK(name, tfm) \
131 char __##name##_desc[sizeof(struct skcipher_request) + \
132 MAX_SYNC_SKCIPHER_REQSIZE + \
133 (!(sizeof((struct crypto_sync_skcipher *)1 == \
134 (typeof(tfm))1))) \
135 ] CRYPTO_MINALIGN_ATTR; \
136 struct skcipher_request *name = (void *)__##name##_desc
137
138/**
139 * DOC: Symmetric Key Cipher API
140 *
141 * Symmetric key cipher API is used with the ciphers of type
142 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
143 *
144 * Asynchronous cipher operations imply that the function invocation for a
145 * cipher request returns immediately before the completion of the operation.
146 * The cipher request is scheduled as a separate kernel thread and therefore
147 * load-balanced on the different CPUs via the process scheduler. To allow
148 * the kernel crypto API to inform the caller about the completion of a cipher
149 * request, the caller must provide a callback function. That function is
150 * invoked with the cipher handle when the request completes.
151 *
152 * To support the asynchronous operation, additional information than just the
153 * cipher handle must be supplied to the kernel crypto API. That additional
154 * information is given by filling in the skcipher_request data structure.
155 *
156 * For the symmetric key cipher API, the state is maintained with the tfm
157 * cipher handle. A single tfm can be used across multiple calls and in
158 * parallel. For asynchronous block cipher calls, context data supplied and
159 * only used by the caller can be referenced the request data structure in
160 * addition to the IV used for the cipher request. The maintenance of such
161 * state information would be important for a crypto driver implementer to
162 * have, because when calling the callback function upon completion of the
163 * cipher operation, that callback function may need some information about
164 * which operation just finished if it invoked multiple in parallel. This
165 * state information is unused by the kernel crypto API.
166 */
167
168static inline struct crypto_skcipher *__crypto_skcipher_cast(
169 struct crypto_tfm *tfm)
170{
171 return container_of(tfm, struct crypto_skcipher, base);
172}
173
174/**
175 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
176 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
177 * skcipher cipher
178 * @type: specifies the type of the cipher
179 * @mask: specifies the mask for the cipher
180 *
181 * Allocate a cipher handle for an skcipher. The returned struct
182 * crypto_skcipher is the cipher handle that is required for any subsequent
183 * API invocation for that skcipher.
184 *
185 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
186 * of an error, PTR_ERR() returns the error code.
187 */
188struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
189 u32 type, u32 mask);
190
191struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(const char *alg_name,
192 u32 type, u32 mask);
193
194static inline struct crypto_tfm *crypto_skcipher_tfm(
195 struct crypto_skcipher *tfm)
196{
197 return &tfm->base;
198}
199
200/**
201 * crypto_free_skcipher() - zeroize and free cipher handle
202 * @tfm: cipher handle to be freed
203 *
204 * If @tfm is a NULL or error pointer, this function does nothing.
205 */
206static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
207{
208 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
209}
210
211static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm)
212{
213 crypto_free_skcipher(&tfm->base);
214}
215
216/**
217 * crypto_has_skcipher() - Search for the availability of an skcipher.
218 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
219 * skcipher
220 * @type: specifies the type of the skcipher
221 * @mask: specifies the mask for the skcipher
222 *
223 * Return: true when the skcipher is known to the kernel crypto API; false
224 * otherwise
225 */
226int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask);
227
228static inline const char *crypto_skcipher_driver_name(
229 struct crypto_skcipher *tfm)
230{
231 return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
232}
233
234static inline struct skcipher_alg *crypto_skcipher_alg(
235 struct crypto_skcipher *tfm)
236{
237 return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
238 struct skcipher_alg, base);
239}
240
241static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg)
242{
243 return alg->ivsize;
244}
245
246/**
247 * crypto_skcipher_ivsize() - obtain IV size
248 * @tfm: cipher handle
249 *
250 * The size of the IV for the skcipher referenced by the cipher handle is
251 * returned. This IV size may be zero if the cipher does not need an IV.
252 *
253 * Return: IV size in bytes
254 */
255static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
256{
257 return crypto_skcipher_alg(tfm)->ivsize;
258}
259
260static inline unsigned int crypto_sync_skcipher_ivsize(
261 struct crypto_sync_skcipher *tfm)
262{
263 return crypto_skcipher_ivsize(&tfm->base);
264}
265
266/**
267 * crypto_skcipher_blocksize() - obtain block size of cipher
268 * @tfm: cipher handle
269 *
270 * The block size for the skcipher referenced with the cipher handle is
271 * returned. The caller may use that information to allocate appropriate
272 * memory for the data returned by the encryption or decryption operation
273 *
274 * Return: block size of cipher
275 */
276static inline unsigned int crypto_skcipher_blocksize(
277 struct crypto_skcipher *tfm)
278{
279 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
280}
281
282static inline unsigned int crypto_skcipher_alg_chunksize(
283 struct skcipher_alg *alg)
284{
285 return alg->chunksize;
286}
287
288/**
289 * crypto_skcipher_chunksize() - obtain chunk size
290 * @tfm: cipher handle
291 *
292 * The block size is set to one for ciphers such as CTR. However,
293 * you still need to provide incremental updates in multiples of
294 * the underlying block size as the IV does not have sub-block
295 * granularity. This is known in this API as the chunk size.
296 *
297 * Return: chunk size in bytes
298 */
299static inline unsigned int crypto_skcipher_chunksize(
300 struct crypto_skcipher *tfm)
301{
302 return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm));
303}
304
305static inline unsigned int crypto_sync_skcipher_blocksize(
306 struct crypto_sync_skcipher *tfm)
307{
308 return crypto_skcipher_blocksize(&tfm->base);
309}
310
311static inline unsigned int crypto_skcipher_alignmask(
312 struct crypto_skcipher *tfm)
313{
314 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
315}
316
317static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
318{
319 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
320}
321
322static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
323 u32 flags)
324{
325 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
326}
327
328static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
329 u32 flags)
330{
331 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
332}
333
334static inline u32 crypto_sync_skcipher_get_flags(
335 struct crypto_sync_skcipher *tfm)
336{
337 return crypto_skcipher_get_flags(&tfm->base);
338}
339
340static inline void crypto_sync_skcipher_set_flags(
341 struct crypto_sync_skcipher *tfm, u32 flags)
342{
343 crypto_skcipher_set_flags(&tfm->base, flags);
344}
345
346static inline void crypto_sync_skcipher_clear_flags(
347 struct crypto_sync_skcipher *tfm, u32 flags)
348{
349 crypto_skcipher_clear_flags(&tfm->base, flags);
350}
351
352/**
353 * crypto_skcipher_setkey() - set key for cipher
354 * @tfm: cipher handle
355 * @key: buffer holding the key
356 * @keylen: length of the key in bytes
357 *
358 * The caller provided key is set for the skcipher referenced by the cipher
359 * handle.
360 *
361 * Note, the key length determines the cipher type. Many block ciphers implement
362 * different cipher modes depending on the key size, such as AES-128 vs AES-192
363 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
364 * is performed.
365 *
366 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
367 */
368int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
369 const u8 *key, unsigned int keylen);
370
371static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
372 const u8 *key, unsigned int keylen)
373{
374 return crypto_skcipher_setkey(&tfm->base, key, keylen);
375}
376
377static inline unsigned int crypto_skcipher_min_keysize(
378 struct crypto_skcipher *tfm)
379{
380 return crypto_skcipher_alg(tfm)->min_keysize;
381}
382
383static inline unsigned int crypto_skcipher_max_keysize(
384 struct crypto_skcipher *tfm)
385{
386 return crypto_skcipher_alg(tfm)->max_keysize;
387}
388
389/**
390 * crypto_skcipher_reqtfm() - obtain cipher handle from request
391 * @req: skcipher_request out of which the cipher handle is to be obtained
392 *
393 * Return the crypto_skcipher handle when furnishing an skcipher_request
394 * data structure.
395 *
396 * Return: crypto_skcipher handle
397 */
398static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
399 struct skcipher_request *req)
400{
401 return __crypto_skcipher_cast(req->base.tfm);
402}
403
404static inline struct crypto_sync_skcipher *crypto_sync_skcipher_reqtfm(
405 struct skcipher_request *req)
406{
407 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
408
409 return container_of(tfm, struct crypto_sync_skcipher, base);
410}
411
412/**
413 * crypto_skcipher_encrypt() - encrypt plaintext
414 * @req: reference to the skcipher_request handle that holds all information
415 * needed to perform the cipher operation
416 *
417 * Encrypt plaintext data using the skcipher_request handle. That data
418 * structure and how it is filled with data is discussed with the
419 * skcipher_request_* functions.
420 *
421 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
422 */
423int crypto_skcipher_encrypt(struct skcipher_request *req);
424
425/**
426 * crypto_skcipher_decrypt() - decrypt ciphertext
427 * @req: reference to the skcipher_request handle that holds all information
428 * needed to perform the cipher operation
429 *
430 * Decrypt ciphertext data using the skcipher_request handle. That data
431 * structure and how it is filled with data is discussed with the
432 * skcipher_request_* functions.
433 *
434 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
435 */
436int crypto_skcipher_decrypt(struct skcipher_request *req);
437
438/**
439 * DOC: Symmetric Key Cipher Request Handle
440 *
441 * The skcipher_request data structure contains all pointers to data
442 * required for the symmetric key cipher operation. This includes the cipher
443 * handle (which can be used by multiple skcipher_request instances), pointer
444 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
445 * as a handle to the skcipher_request_* API calls in a similar way as
446 * skcipher handle to the crypto_skcipher_* API calls.
447 */
448
449/**
450 * crypto_skcipher_reqsize() - obtain size of the request data structure
451 * @tfm: cipher handle
452 *
453 * Return: number of bytes
454 */
455static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
456{
457 return tfm->reqsize;
458}
459
460/**
461 * skcipher_request_set_tfm() - update cipher handle reference in request
462 * @req: request handle to be modified
463 * @tfm: cipher handle that shall be added to the request handle
464 *
465 * Allow the caller to replace the existing skcipher handle in the request
466 * data structure with a different one.
467 */
468static inline void skcipher_request_set_tfm(struct skcipher_request *req,
469 struct crypto_skcipher *tfm)
470{
471 req->base.tfm = crypto_skcipher_tfm(tfm);
472}
473
474static inline void skcipher_request_set_sync_tfm(struct skcipher_request *req,
475 struct crypto_sync_skcipher *tfm)
476{
477 skcipher_request_set_tfm(req, &tfm->base);
478}
479
480static inline struct skcipher_request *skcipher_request_cast(
481 struct crypto_async_request *req)
482{
483 return container_of(req, struct skcipher_request, base);
484}
485
486/**
487 * skcipher_request_alloc() - allocate request data structure
488 * @tfm: cipher handle to be registered with the request
489 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
490 *
491 * Allocate the request data structure that must be used with the skcipher
492 * encrypt and decrypt API calls. During the allocation, the provided skcipher
493 * handle is registered in the request data structure.
494 *
495 * Return: allocated request handle in case of success, or NULL if out of memory
496 */
497static inline struct skcipher_request *skcipher_request_alloc(
498 struct crypto_skcipher *tfm, gfp_t gfp)
499{
500 struct skcipher_request *req;
501
502 req = kmalloc(sizeof(struct skcipher_request) +
503 crypto_skcipher_reqsize(tfm), gfp);
504
505 if (likely(req))
506 skcipher_request_set_tfm(req, tfm);
507
508 return req;
509}
510
511/**
512 * skcipher_request_free() - zeroize and free request data structure
513 * @req: request data structure cipher handle to be freed
514 */
515static inline void skcipher_request_free(struct skcipher_request *req)
516{
517 kfree_sensitive(req);
518}
519
520static inline void skcipher_request_zero(struct skcipher_request *req)
521{
522 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
523
524 memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
525}
526
527/**
528 * skcipher_request_set_callback() - set asynchronous callback function
529 * @req: request handle
530 * @flags: specify zero or an ORing of the flags
531 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
532 * increase the wait queue beyond the initial maximum size;
533 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
534 * @compl: callback function pointer to be registered with the request handle
535 * @data: The data pointer refers to memory that is not used by the kernel
536 * crypto API, but provided to the callback function for it to use. Here,
537 * the caller can provide a reference to memory the callback function can
538 * operate on. As the callback function is invoked asynchronously to the
539 * related functionality, it may need to access data structures of the
540 * related functionality which can be referenced using this pointer. The
541 * callback function can access the memory via the "data" field in the
542 * crypto_async_request data structure provided to the callback function.
543 *
544 * This function allows setting the callback function that is triggered once the
545 * cipher operation completes.
546 *
547 * The callback function is registered with the skcipher_request handle and
548 * must comply with the following template::
549 *
550 * void callback_function(struct crypto_async_request *req, int error)
551 */
552static inline void skcipher_request_set_callback(struct skcipher_request *req,
553 u32 flags,
554 crypto_completion_t compl,
555 void *data)
556{
557 req->base.complete = compl;
558 req->base.data = data;
559 req->base.flags = flags;
560}
561
562/**
563 * skcipher_request_set_crypt() - set data buffers
564 * @req: request handle
565 * @src: source scatter / gather list
566 * @dst: destination scatter / gather list
567 * @cryptlen: number of bytes to process from @src
568 * @iv: IV for the cipher operation which must comply with the IV size defined
569 * by crypto_skcipher_ivsize
570 *
571 * This function allows setting of the source data and destination data
572 * scatter / gather lists.
573 *
574 * For encryption, the source is treated as the plaintext and the
575 * destination is the ciphertext. For a decryption operation, the use is
576 * reversed - the source is the ciphertext and the destination is the plaintext.
577 */
578static inline void skcipher_request_set_crypt(
579 struct skcipher_request *req,
580 struct scatterlist *src, struct scatterlist *dst,
581 unsigned int cryptlen, void *iv)
582{
583 req->src = src;
584 req->dst = dst;
585 req->cryptlen = cryptlen;
586 req->iv = iv;
587}
588
589#endif /* _CRYPTO_SKCIPHER_H */
590
1/*
2 * Symmetric key ciphers.
3 *
4 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#ifndef _CRYPTO_SKCIPHER_H
14#define _CRYPTO_SKCIPHER_H
15
16#include <linux/crypto.h>
17#include <linux/kernel.h>
18#include <linux/slab.h>
19
20/**
21 * struct skcipher_request - Symmetric key cipher request
22 * @cryptlen: Number of bytes to encrypt or decrypt
23 * @iv: Initialisation Vector
24 * @src: Source SG list
25 * @dst: Destination SG list
26 * @base: Underlying async request request
27 * @__ctx: Start of private context data
28 */
29struct skcipher_request {
30 unsigned int cryptlen;
31
32 u8 *iv;
33
34 struct scatterlist *src;
35 struct scatterlist *dst;
36
37 struct crypto_async_request base;
38
39 void *__ctx[] CRYPTO_MINALIGN_ATTR;
40};
41
42/**
43 * struct skcipher_givcrypt_request - Crypto request with IV generation
44 * @seq: Sequence number for IV generation
45 * @giv: Space for generated IV
46 * @creq: The crypto request itself
47 */
48struct skcipher_givcrypt_request {
49 u64 seq;
50 u8 *giv;
51
52 struct ablkcipher_request creq;
53};
54
55struct crypto_skcipher {
56 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
57 unsigned int keylen);
58 int (*encrypt)(struct skcipher_request *req);
59 int (*decrypt)(struct skcipher_request *req);
60
61 unsigned int ivsize;
62 unsigned int reqsize;
63 unsigned int keysize;
64
65 struct crypto_tfm base;
66};
67
68#define SKCIPHER_REQUEST_ON_STACK(name, tfm) \
69 char __##name##_desc[sizeof(struct skcipher_request) + \
70 crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
71 struct skcipher_request *name = (void *)__##name##_desc
72
73static inline struct crypto_ablkcipher *skcipher_givcrypt_reqtfm(
74 struct skcipher_givcrypt_request *req)
75{
76 return crypto_ablkcipher_reqtfm(&req->creq);
77}
78
79static inline int crypto_skcipher_givencrypt(
80 struct skcipher_givcrypt_request *req)
81{
82 struct ablkcipher_tfm *crt =
83 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
84 return crt->givencrypt(req);
85};
86
87static inline int crypto_skcipher_givdecrypt(
88 struct skcipher_givcrypt_request *req)
89{
90 struct ablkcipher_tfm *crt =
91 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
92 return crt->givdecrypt(req);
93};
94
95static inline void skcipher_givcrypt_set_tfm(
96 struct skcipher_givcrypt_request *req, struct crypto_ablkcipher *tfm)
97{
98 req->creq.base.tfm = crypto_ablkcipher_tfm(tfm);
99}
100
101static inline struct skcipher_givcrypt_request *skcipher_givcrypt_cast(
102 struct crypto_async_request *req)
103{
104 return container_of(ablkcipher_request_cast(req),
105 struct skcipher_givcrypt_request, creq);
106}
107
108static inline struct skcipher_givcrypt_request *skcipher_givcrypt_alloc(
109 struct crypto_ablkcipher *tfm, gfp_t gfp)
110{
111 struct skcipher_givcrypt_request *req;
112
113 req = kmalloc(sizeof(struct skcipher_givcrypt_request) +
114 crypto_ablkcipher_reqsize(tfm), gfp);
115
116 if (likely(req))
117 skcipher_givcrypt_set_tfm(req, tfm);
118
119 return req;
120}
121
122static inline void skcipher_givcrypt_free(struct skcipher_givcrypt_request *req)
123{
124 kfree(req);
125}
126
127static inline void skcipher_givcrypt_set_callback(
128 struct skcipher_givcrypt_request *req, u32 flags,
129 crypto_completion_t compl, void *data)
130{
131 ablkcipher_request_set_callback(&req->creq, flags, compl, data);
132}
133
134static inline void skcipher_givcrypt_set_crypt(
135 struct skcipher_givcrypt_request *req,
136 struct scatterlist *src, struct scatterlist *dst,
137 unsigned int nbytes, void *iv)
138{
139 ablkcipher_request_set_crypt(&req->creq, src, dst, nbytes, iv);
140}
141
142static inline void skcipher_givcrypt_set_giv(
143 struct skcipher_givcrypt_request *req, u8 *giv, u64 seq)
144{
145 req->giv = giv;
146 req->seq = seq;
147}
148
149/**
150 * DOC: Symmetric Key Cipher API
151 *
152 * Symmetric key cipher API is used with the ciphers of type
153 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
154 *
155 * Asynchronous cipher operations imply that the function invocation for a
156 * cipher request returns immediately before the completion of the operation.
157 * The cipher request is scheduled as a separate kernel thread and therefore
158 * load-balanced on the different CPUs via the process scheduler. To allow
159 * the kernel crypto API to inform the caller about the completion of a cipher
160 * request, the caller must provide a callback function. That function is
161 * invoked with the cipher handle when the request completes.
162 *
163 * To support the asynchronous operation, additional information than just the
164 * cipher handle must be supplied to the kernel crypto API. That additional
165 * information is given by filling in the skcipher_request data structure.
166 *
167 * For the symmetric key cipher API, the state is maintained with the tfm
168 * cipher handle. A single tfm can be used across multiple calls and in
169 * parallel. For asynchronous block cipher calls, context data supplied and
170 * only used by the caller can be referenced the request data structure in
171 * addition to the IV used for the cipher request. The maintenance of such
172 * state information would be important for a crypto driver implementer to
173 * have, because when calling the callback function upon completion of the
174 * cipher operation, that callback function may need some information about
175 * which operation just finished if it invoked multiple in parallel. This
176 * state information is unused by the kernel crypto API.
177 */
178
179static inline struct crypto_skcipher *__crypto_skcipher_cast(
180 struct crypto_tfm *tfm)
181{
182 return container_of(tfm, struct crypto_skcipher, base);
183}
184
185/**
186 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
187 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
188 * skcipher cipher
189 * @type: specifies the type of the cipher
190 * @mask: specifies the mask for the cipher
191 *
192 * Allocate a cipher handle for an skcipher. The returned struct
193 * crypto_skcipher is the cipher handle that is required for any subsequent
194 * API invocation for that skcipher.
195 *
196 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
197 * of an error, PTR_ERR() returns the error code.
198 */
199struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
200 u32 type, u32 mask);
201
202static inline struct crypto_tfm *crypto_skcipher_tfm(
203 struct crypto_skcipher *tfm)
204{
205 return &tfm->base;
206}
207
208/**
209 * crypto_free_skcipher() - zeroize and free cipher handle
210 * @tfm: cipher handle to be freed
211 */
212static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
213{
214 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
215}
216
217/**
218 * crypto_has_skcipher() - Search for the availability of an skcipher.
219 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
220 * skcipher
221 * @type: specifies the type of the cipher
222 * @mask: specifies the mask for the cipher
223 *
224 * Return: true when the skcipher is known to the kernel crypto API; false
225 * otherwise
226 */
227static inline int crypto_has_skcipher(const char *alg_name, u32 type,
228 u32 mask)
229{
230 return crypto_has_alg(alg_name, crypto_skcipher_type(type),
231 crypto_skcipher_mask(mask));
232}
233
234static inline const char *crypto_skcipher_driver_name(
235 struct crypto_skcipher *tfm)
236{
237 return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
238}
239
240/**
241 * crypto_skcipher_ivsize() - obtain IV size
242 * @tfm: cipher handle
243 *
244 * The size of the IV for the skcipher referenced by the cipher handle is
245 * returned. This IV size may be zero if the cipher does not need an IV.
246 *
247 * Return: IV size in bytes
248 */
249static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
250{
251 return tfm->ivsize;
252}
253
254/**
255 * crypto_skcipher_blocksize() - obtain block size of cipher
256 * @tfm: cipher handle
257 *
258 * The block size for the skcipher referenced with the cipher handle is
259 * returned. The caller may use that information to allocate appropriate
260 * memory for the data returned by the encryption or decryption operation
261 *
262 * Return: block size of cipher
263 */
264static inline unsigned int crypto_skcipher_blocksize(
265 struct crypto_skcipher *tfm)
266{
267 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
268}
269
270static inline unsigned int crypto_skcipher_alignmask(
271 struct crypto_skcipher *tfm)
272{
273 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
274}
275
276static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
277{
278 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
279}
280
281static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
282 u32 flags)
283{
284 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
285}
286
287static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
288 u32 flags)
289{
290 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
291}
292
293/**
294 * crypto_skcipher_setkey() - set key for cipher
295 * @tfm: cipher handle
296 * @key: buffer holding the key
297 * @keylen: length of the key in bytes
298 *
299 * The caller provided key is set for the skcipher referenced by the cipher
300 * handle.
301 *
302 * Note, the key length determines the cipher type. Many block ciphers implement
303 * different cipher modes depending on the key size, such as AES-128 vs AES-192
304 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
305 * is performed.
306 *
307 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
308 */
309static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
310 const u8 *key, unsigned int keylen)
311{
312 return tfm->setkey(tfm, key, keylen);
313}
314
315static inline bool crypto_skcipher_has_setkey(struct crypto_skcipher *tfm)
316{
317 return tfm->keysize;
318}
319
320static inline unsigned int crypto_skcipher_default_keysize(
321 struct crypto_skcipher *tfm)
322{
323 return tfm->keysize;
324}
325
326/**
327 * crypto_skcipher_reqtfm() - obtain cipher handle from request
328 * @req: skcipher_request out of which the cipher handle is to be obtained
329 *
330 * Return the crypto_skcipher handle when furnishing an skcipher_request
331 * data structure.
332 *
333 * Return: crypto_skcipher handle
334 */
335static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
336 struct skcipher_request *req)
337{
338 return __crypto_skcipher_cast(req->base.tfm);
339}
340
341/**
342 * crypto_skcipher_encrypt() - encrypt plaintext
343 * @req: reference to the skcipher_request handle that holds all information
344 * needed to perform the cipher operation
345 *
346 * Encrypt plaintext data using the skcipher_request handle. That data
347 * structure and how it is filled with data is discussed with the
348 * skcipher_request_* functions.
349 *
350 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
351 */
352static inline int crypto_skcipher_encrypt(struct skcipher_request *req)
353{
354 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
355
356 return tfm->encrypt(req);
357}
358
359/**
360 * crypto_skcipher_decrypt() - decrypt ciphertext
361 * @req: reference to the skcipher_request handle that holds all information
362 * needed to perform the cipher operation
363 *
364 * Decrypt ciphertext data using the skcipher_request handle. That data
365 * structure and how it is filled with data is discussed with the
366 * skcipher_request_* functions.
367 *
368 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
369 */
370static inline int crypto_skcipher_decrypt(struct skcipher_request *req)
371{
372 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
373
374 return tfm->decrypt(req);
375}
376
377/**
378 * DOC: Symmetric Key Cipher Request Handle
379 *
380 * The skcipher_request data structure contains all pointers to data
381 * required for the symmetric key cipher operation. This includes the cipher
382 * handle (which can be used by multiple skcipher_request instances), pointer
383 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
384 * as a handle to the skcipher_request_* API calls in a similar way as
385 * skcipher handle to the crypto_skcipher_* API calls.
386 */
387
388/**
389 * crypto_skcipher_reqsize() - obtain size of the request data structure
390 * @tfm: cipher handle
391 *
392 * Return: number of bytes
393 */
394static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
395{
396 return tfm->reqsize;
397}
398
399/**
400 * skcipher_request_set_tfm() - update cipher handle reference in request
401 * @req: request handle to be modified
402 * @tfm: cipher handle that shall be added to the request handle
403 *
404 * Allow the caller to replace the existing skcipher handle in the request
405 * data structure with a different one.
406 */
407static inline void skcipher_request_set_tfm(struct skcipher_request *req,
408 struct crypto_skcipher *tfm)
409{
410 req->base.tfm = crypto_skcipher_tfm(tfm);
411}
412
413static inline struct skcipher_request *skcipher_request_cast(
414 struct crypto_async_request *req)
415{
416 return container_of(req, struct skcipher_request, base);
417}
418
419/**
420 * skcipher_request_alloc() - allocate request data structure
421 * @tfm: cipher handle to be registered with the request
422 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
423 *
424 * Allocate the request data structure that must be used with the skcipher
425 * encrypt and decrypt API calls. During the allocation, the provided skcipher
426 * handle is registered in the request data structure.
427 *
428 * Return: allocated request handle in case of success; IS_ERR() is true in case
429 * of an error, PTR_ERR() returns the error code.
430 */
431static inline struct skcipher_request *skcipher_request_alloc(
432 struct crypto_skcipher *tfm, gfp_t gfp)
433{
434 struct skcipher_request *req;
435
436 req = kmalloc(sizeof(struct skcipher_request) +
437 crypto_skcipher_reqsize(tfm), gfp);
438
439 if (likely(req))
440 skcipher_request_set_tfm(req, tfm);
441
442 return req;
443}
444
445/**
446 * skcipher_request_free() - zeroize and free request data structure
447 * @req: request data structure cipher handle to be freed
448 */
449static inline void skcipher_request_free(struct skcipher_request *req)
450{
451 kzfree(req);
452}
453
454static inline void skcipher_request_zero(struct skcipher_request *req)
455{
456 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
457
458 memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
459}
460
461/**
462 * skcipher_request_set_callback() - set asynchronous callback function
463 * @req: request handle
464 * @flags: specify zero or an ORing of the flags
465 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
466 * increase the wait queue beyond the initial maximum size;
467 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
468 * @compl: callback function pointer to be registered with the request handle
469 * @data: The data pointer refers to memory that is not used by the kernel
470 * crypto API, but provided to the callback function for it to use. Here,
471 * the caller can provide a reference to memory the callback function can
472 * operate on. As the callback function is invoked asynchronously to the
473 * related functionality, it may need to access data structures of the
474 * related functionality which can be referenced using this pointer. The
475 * callback function can access the memory via the "data" field in the
476 * crypto_async_request data structure provided to the callback function.
477 *
478 * This function allows setting the callback function that is triggered once the
479 * cipher operation completes.
480 *
481 * The callback function is registered with the skcipher_request handle and
482 * must comply with the following template
483 *
484 * void callback_function(struct crypto_async_request *req, int error)
485 */
486static inline void skcipher_request_set_callback(struct skcipher_request *req,
487 u32 flags,
488 crypto_completion_t compl,
489 void *data)
490{
491 req->base.complete = compl;
492 req->base.data = data;
493 req->base.flags = flags;
494}
495
496/**
497 * skcipher_request_set_crypt() - set data buffers
498 * @req: request handle
499 * @src: source scatter / gather list
500 * @dst: destination scatter / gather list
501 * @cryptlen: number of bytes to process from @src
502 * @iv: IV for the cipher operation which must comply with the IV size defined
503 * by crypto_skcipher_ivsize
504 *
505 * This function allows setting of the source data and destination data
506 * scatter / gather lists.
507 *
508 * For encryption, the source is treated as the plaintext and the
509 * destination is the ciphertext. For a decryption operation, the use is
510 * reversed - the source is the ciphertext and the destination is the plaintext.
511 */
512static inline void skcipher_request_set_crypt(
513 struct skcipher_request *req,
514 struct scatterlist *src, struct scatterlist *dst,
515 unsigned int cryptlen, void *iv)
516{
517 req->src = src;
518 req->dst = dst;
519 req->cryptlen = cryptlen;
520 req->iv = iv;
521}
522
523#endif /* _CRYPTO_SKCIPHER_H */
524