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v3.1
 
  1/*
  2 * Symmetric key ciphers.
  3 * 
  4 * Copyright (c) 2007 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_givcrypt_request - Crypto request with IV generation
 22 *	@seq: Sequence number for IV generation
 23 *	@giv: Space for generated IV
 24 *	@creq: The crypto request itself
 25 */
 26struct skcipher_givcrypt_request {
 27	u64 seq;
 28	u8 *giv;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 29
 30	struct ablkcipher_request creq;
 31};
 32
 33static inline struct crypto_ablkcipher *skcipher_givcrypt_reqtfm(
 34	struct skcipher_givcrypt_request *req)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 35{
 36	return crypto_ablkcipher_reqtfm(&req->creq);
 37}
 38
 39static inline int crypto_skcipher_givencrypt(
 40	struct skcipher_givcrypt_request *req)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 41{
 42	struct ablkcipher_tfm *crt =
 43		crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
 44	return crt->givencrypt(req);
 45};
 46
 47static inline int crypto_skcipher_givdecrypt(
 48	struct skcipher_givcrypt_request *req)
 
 
 
 49{
 50	struct ablkcipher_tfm *crt =
 51		crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
 52	return crt->givdecrypt(req);
 53};
 54
 55static inline void skcipher_givcrypt_set_tfm(
 56	struct skcipher_givcrypt_request *req, struct crypto_ablkcipher *tfm)
 57{
 58	req->creq.base.tfm = crypto_ablkcipher_tfm(tfm);
 59}
 60
 61static inline struct skcipher_givcrypt_request *skcipher_givcrypt_cast(
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 62	struct crypto_async_request *req)
 63{
 64	return container_of(ablkcipher_request_cast(req),
 65			    struct skcipher_givcrypt_request, creq);
 66}
 67
 68static inline struct skcipher_givcrypt_request *skcipher_givcrypt_alloc(
 69	struct crypto_ablkcipher *tfm, gfp_t gfp)
 
 
 
 
 
 
 
 
 
 
 
 70{
 71	struct skcipher_givcrypt_request *req;
 72
 73	req = kmalloc(sizeof(struct skcipher_givcrypt_request) +
 74		      crypto_ablkcipher_reqsize(tfm), gfp);
 75
 76	if (likely(req))
 77		skcipher_givcrypt_set_tfm(req, tfm);
 78
 79	return req;
 80}
 81
 82static inline void skcipher_givcrypt_free(struct skcipher_givcrypt_request *req)
 
 
 
 
 83{
 84	kfree(req);
 85}
 86
 87static inline void skcipher_givcrypt_set_callback(
 88	struct skcipher_givcrypt_request *req, u32 flags,
 89	crypto_completion_t complete, void *data)
 90{
 91	ablkcipher_request_set_callback(&req->creq, flags, complete, data);
 
 
 92}
 93
 94static inline void skcipher_givcrypt_set_crypt(
 95	struct skcipher_givcrypt_request *req,
 96	struct scatterlist *src, struct scatterlist *dst,
 97	unsigned int nbytes, void *iv)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 98{
 99	ablkcipher_request_set_crypt(&req->creq, src, dst, nbytes, iv);
 
 
100}
101
102static inline void skcipher_givcrypt_set_giv(
103	struct skcipher_givcrypt_request *req, u8 *giv, u64 seq)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
104{
105	req->giv = giv;
106	req->seq = seq;
 
 
107}
108
109#endif	/* _CRYPTO_SKCIPHER_H */
110
v5.4
  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/crypto.h>
 12#include <linux/kernel.h>
 13#include <linux/slab.h>
 14
 15/**
 16 *	struct skcipher_request - Symmetric key cipher request
 17 *	@cryptlen: Number of bytes to encrypt or decrypt
 18 *	@iv: Initialisation Vector
 19 *	@src: Source SG list
 20 *	@dst: Destination SG list
 21 *	@base: Underlying async request request
 22 *	@__ctx: Start of private context data
 23 */
 24struct skcipher_request {
 25	unsigned int cryptlen;
 26
 27	u8 *iv;
 28
 29	struct scatterlist *src;
 30	struct scatterlist *dst;
 31
 32	struct crypto_async_request base;
 33
 34	void *__ctx[] CRYPTO_MINALIGN_ATTR;
 35};
 36
 37struct crypto_skcipher {
 38	int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
 39	              unsigned int keylen);
 40	int (*encrypt)(struct skcipher_request *req);
 41	int (*decrypt)(struct skcipher_request *req);
 42
 43	unsigned int ivsize;
 44	unsigned int reqsize;
 45	unsigned int keysize;
 46
 47	struct crypto_tfm base;
 48};
 49
 50struct crypto_sync_skcipher {
 51	struct crypto_skcipher base;
 52};
 53
 54/**
 55 * struct skcipher_alg - symmetric key cipher definition
 56 * @min_keysize: Minimum key size supported by the transformation. This is the
 57 *		 smallest key length supported by this transformation algorithm.
 58 *		 This must be set to one of the pre-defined values as this is
 59 *		 not hardware specific. Possible values for this field can be
 60 *		 found via git grep "_MIN_KEY_SIZE" include/crypto/
 61 * @max_keysize: Maximum key size supported by the transformation. This is the
 62 *		 largest key length supported by this transformation algorithm.
 63 *		 This must be set to one of the pre-defined values as this is
 64 *		 not hardware specific. Possible values for this field can be
 65 *		 found via git grep "_MAX_KEY_SIZE" include/crypto/
 66 * @setkey: Set key for the transformation. This function is used to either
 67 *	    program a supplied key into the hardware or store the key in the
 68 *	    transformation context for programming it later. Note that this
 69 *	    function does modify the transformation context. This function can
 70 *	    be called multiple times during the existence of the transformation
 71 *	    object, so one must make sure the key is properly reprogrammed into
 72 *	    the hardware. This function is also responsible for checking the key
 73 *	    length for validity. In case a software fallback was put in place in
 74 *	    the @cra_init call, this function might need to use the fallback if
 75 *	    the algorithm doesn't support all of the key sizes.
 76 * @encrypt: Encrypt a scatterlist of blocks. This function is used to encrypt
 77 *	     the supplied scatterlist containing the blocks of data. The crypto
 78 *	     API consumer is responsible for aligning the entries of the
 79 *	     scatterlist properly and making sure the chunks are correctly
 80 *	     sized. In case a software fallback was put in place in the
 81 *	     @cra_init call, this function might need to use the fallback if
 82 *	     the algorithm doesn't support all of the key sizes. In case the
 83 *	     key was stored in transformation context, the key might need to be
 84 *	     re-programmed into the hardware in this function. This function
 85 *	     shall not modify the transformation context, as this function may
 86 *	     be called in parallel with the same transformation object.
 87 * @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt
 88 *	     and the conditions are exactly the same.
 89 * @init: Initialize the cryptographic transformation object. This function
 90 *	  is used to initialize the cryptographic transformation object.
 91 *	  This function is called only once at the instantiation time, right
 92 *	  after the transformation context was allocated. In case the
 93 *	  cryptographic hardware has some special requirements which need to
 94 *	  be handled by software, this function shall check for the precise
 95 *	  requirement of the transformation and put any software fallbacks
 96 *	  in place.
 97 * @exit: Deinitialize the cryptographic transformation object. This is a
 98 *	  counterpart to @init, used to remove various changes set in
 99 *	  @init.
100 * @ivsize: IV size applicable for transformation. The consumer must provide an
101 *	    IV of exactly that size to perform the encrypt or decrypt operation.
102 * @chunksize: Equal to the block size except for stream ciphers such as
103 *	       CTR where it is set to the underlying block size.
104 * @walksize: Equal to the chunk size except in cases where the algorithm is
105 * 	      considerably more efficient if it can operate on multiple chunks
106 * 	      in parallel. Should be a multiple of chunksize.
107 * @base: Definition of a generic crypto algorithm.
108 *
109 * All fields except @ivsize are mandatory and must be filled.
110 */
111struct skcipher_alg {
112	int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
113	              unsigned int keylen);
114	int (*encrypt)(struct skcipher_request *req);
115	int (*decrypt)(struct skcipher_request *req);
116	int (*init)(struct crypto_skcipher *tfm);
117	void (*exit)(struct crypto_skcipher *tfm);
118
119	unsigned int min_keysize;
120	unsigned int max_keysize;
121	unsigned int ivsize;
122	unsigned int chunksize;
123	unsigned int walksize;
124
125	struct crypto_alg base;
126};
127
128#define MAX_SYNC_SKCIPHER_REQSIZE      384
129/*
130 * This performs a type-check against the "tfm" argument to make sure
131 * all users have the correct skcipher tfm for doing on-stack requests.
132 */
133#define SYNC_SKCIPHER_REQUEST_ON_STACK(name, tfm) \
134	char __##name##_desc[sizeof(struct skcipher_request) + \
135			     MAX_SYNC_SKCIPHER_REQSIZE + \
136			     (!(sizeof((struct crypto_sync_skcipher *)1 == \
137				       (typeof(tfm))1))) \
138			    ] CRYPTO_MINALIGN_ATTR; \
139	struct skcipher_request *name = (void *)__##name##_desc
140
141/**
142 * DOC: Symmetric Key Cipher API
143 *
144 * Symmetric key cipher API is used with the ciphers of type
145 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
146 *
147 * Asynchronous cipher operations imply that the function invocation for a
148 * cipher request returns immediately before the completion of the operation.
149 * The cipher request is scheduled as a separate kernel thread and therefore
150 * load-balanced on the different CPUs via the process scheduler. To allow
151 * the kernel crypto API to inform the caller about the completion of a cipher
152 * request, the caller must provide a callback function. That function is
153 * invoked with the cipher handle when the request completes.
154 *
155 * To support the asynchronous operation, additional information than just the
156 * cipher handle must be supplied to the kernel crypto API. That additional
157 * information is given by filling in the skcipher_request data structure.
158 *
159 * For the symmetric key cipher API, the state is maintained with the tfm
160 * cipher handle. A single tfm can be used across multiple calls and in
161 * parallel. For asynchronous block cipher calls, context data supplied and
162 * only used by the caller can be referenced the request data structure in
163 * addition to the IV used for the cipher request. The maintenance of such
164 * state information would be important for a crypto driver implementer to
165 * have, because when calling the callback function upon completion of the
166 * cipher operation, that callback function may need some information about
167 * which operation just finished if it invoked multiple in parallel. This
168 * state information is unused by the kernel crypto API.
169 */
170
171static inline struct crypto_skcipher *__crypto_skcipher_cast(
172	struct crypto_tfm *tfm)
173{
174	return container_of(tfm, struct crypto_skcipher, base);
175}
176
177/**
178 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
179 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
180 *	      skcipher cipher
181 * @type: specifies the type of the cipher
182 * @mask: specifies the mask for the cipher
183 *
184 * Allocate a cipher handle for an skcipher. The returned struct
185 * crypto_skcipher is the cipher handle that is required for any subsequent
186 * API invocation for that skcipher.
187 *
188 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
189 *	   of an error, PTR_ERR() returns the error code.
190 */
191struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
192					      u32 type, u32 mask);
193
194struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(const char *alg_name,
195					      u32 type, u32 mask);
196
197static inline struct crypto_tfm *crypto_skcipher_tfm(
198	struct crypto_skcipher *tfm)
199{
200	return &tfm->base;
201}
 
 
202
203/**
204 * crypto_free_skcipher() - zeroize and free cipher handle
205 * @tfm: cipher handle to be freed
206 */
207static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
208{
209	crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
210}
 
 
211
212static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm)
 
213{
214	crypto_free_skcipher(&tfm->base);
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
234/**
235 * crypto_has_skcipher2() - Search for the availability of an skcipher.
236 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
237 *	      skcipher
238 * @type: specifies the type of the skcipher
239 * @mask: specifies the mask for the skcipher
240 *
241 * Return: true when the skcipher is known to the kernel crypto API; false
242 *	   otherwise
243 */
244int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask);
245
246static inline const char *crypto_skcipher_driver_name(
247	struct crypto_skcipher *tfm)
248{
249	return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
250}
251
252static inline struct skcipher_alg *crypto_skcipher_alg(
253	struct crypto_skcipher *tfm)
254{
255	return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
256			    struct skcipher_alg, base);
257}
258
259static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg)
260{
261	if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
262	    CRYPTO_ALG_TYPE_BLKCIPHER)
263		return alg->base.cra_blkcipher.ivsize;
264
265	if (alg->base.cra_ablkcipher.encrypt)
266		return alg->base.cra_ablkcipher.ivsize;
267
268	return alg->ivsize;
269}
270
271/**
272 * crypto_skcipher_ivsize() - obtain IV size
273 * @tfm: cipher handle
274 *
275 * The size of the IV for the skcipher referenced by the cipher handle is
276 * returned. This IV size may be zero if the cipher does not need an IV.
277 *
278 * Return: IV size in bytes
279 */
280static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
281{
282	return tfm->ivsize;
283}
284
285static inline unsigned int crypto_sync_skcipher_ivsize(
286	struct crypto_sync_skcipher *tfm)
287{
288	return crypto_skcipher_ivsize(&tfm->base);
289}
290
291/**
292 * crypto_skcipher_blocksize() - obtain block size of cipher
293 * @tfm: cipher handle
294 *
295 * The block size for the skcipher referenced with the cipher handle is
296 * returned. The caller may use that information to allocate appropriate
297 * memory for the data returned by the encryption or decryption operation
298 *
299 * Return: block size of cipher
300 */
301static inline unsigned int crypto_skcipher_blocksize(
302	struct crypto_skcipher *tfm)
303{
304	return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
305}
306
307static inline unsigned int crypto_sync_skcipher_blocksize(
308	struct crypto_sync_skcipher *tfm)
309{
310	return crypto_skcipher_blocksize(&tfm->base);
311}
312
313static inline unsigned int crypto_skcipher_alignmask(
314	struct crypto_skcipher *tfm)
315{
316	return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
317}
318
319static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
320{
321	return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
322}
323
324static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
325					       u32 flags)
326{
327	crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
328}
329
330static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
331						 u32 flags)
332{
333	crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
334}
335
336static inline u32 crypto_sync_skcipher_get_flags(
337	struct crypto_sync_skcipher *tfm)
338{
339	return crypto_skcipher_get_flags(&tfm->base);
340}
341
342static inline void crypto_sync_skcipher_set_flags(
343	struct crypto_sync_skcipher *tfm, u32 flags)
344{
345	crypto_skcipher_set_flags(&tfm->base, flags);
346}
347
348static inline void crypto_sync_skcipher_clear_flags(
349	struct crypto_sync_skcipher *tfm, u32 flags)
350{
351	crypto_skcipher_clear_flags(&tfm->base, flags);
352}
353
354/**
355 * crypto_skcipher_setkey() - set key for cipher
356 * @tfm: cipher handle
357 * @key: buffer holding the key
358 * @keylen: length of the key in bytes
359 *
360 * The caller provided key is set for the skcipher referenced by the cipher
361 * handle.
362 *
363 * Note, the key length determines the cipher type. Many block ciphers implement
364 * different cipher modes depending on the key size, such as AES-128 vs AES-192
365 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
366 * is performed.
367 *
368 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
369 */
370static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
371					 const u8 *key, unsigned int keylen)
372{
373	return tfm->setkey(tfm, key, keylen);
374}
375
376static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
377					 const u8 *key, unsigned int keylen)
378{
379	return crypto_skcipher_setkey(&tfm->base, key, keylen);
380}
381
382static inline unsigned int crypto_skcipher_default_keysize(
383	struct crypto_skcipher *tfm)
384{
385	return tfm->keysize;
386}
387
388/**
389 * crypto_skcipher_reqtfm() - obtain cipher handle from request
390 * @req: skcipher_request out of which the cipher handle is to be obtained
391 *
392 * Return the crypto_skcipher handle when furnishing an skcipher_request
393 * data structure.
394 *
395 * Return: crypto_skcipher handle
396 */
397static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
398	struct skcipher_request *req)
399{
400	return __crypto_skcipher_cast(req->base.tfm);
401}
402
403static inline struct crypto_sync_skcipher *crypto_sync_skcipher_reqtfm(
404	struct skcipher_request *req)
405{
406	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
407
408	return container_of(tfm, struct crypto_sync_skcipher, base);
409}
410
411/**
412 * crypto_skcipher_encrypt() - encrypt plaintext
413 * @req: reference to the skcipher_request handle that holds all information
414 *	 needed to perform the cipher operation
415 *
416 * Encrypt plaintext data using the skcipher_request handle. That data
417 * structure and how it is filled with data is discussed with the
418 * skcipher_request_* functions.
419 *
420 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
421 */
422int crypto_skcipher_encrypt(struct skcipher_request *req);
423
424/**
425 * crypto_skcipher_decrypt() - decrypt ciphertext
426 * @req: reference to the skcipher_request handle that holds all information
427 *	 needed to perform the cipher operation
428 *
429 * Decrypt ciphertext data using the skcipher_request handle. That data
430 * structure and how it is filled with data is discussed with the
431 * skcipher_request_* functions.
432 *
433 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
434 */
435int crypto_skcipher_decrypt(struct skcipher_request *req);
436
437/**
438 * DOC: Symmetric Key Cipher Request Handle
439 *
440 * The skcipher_request data structure contains all pointers to data
441 * required for the symmetric key cipher operation. This includes the cipher
442 * handle (which can be used by multiple skcipher_request instances), pointer
443 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
444 * as a handle to the skcipher_request_* API calls in a similar way as
445 * skcipher handle to the crypto_skcipher_* API calls.
446 */
447
448/**
449 * crypto_skcipher_reqsize() - obtain size of the request data structure
450 * @tfm: cipher handle
451 *
452 * Return: number of bytes
453 */
454static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
455{
456	return tfm->reqsize;
457}
458
459/**
460 * skcipher_request_set_tfm() - update cipher handle reference in request
461 * @req: request handle to be modified
462 * @tfm: cipher handle that shall be added to the request handle
463 *
464 * Allow the caller to replace the existing skcipher handle in the request
465 * data structure with a different one.
466 */
467static inline void skcipher_request_set_tfm(struct skcipher_request *req,
468					    struct crypto_skcipher *tfm)
469{
470	req->base.tfm = crypto_skcipher_tfm(tfm);
471}
472
473static inline void skcipher_request_set_sync_tfm(struct skcipher_request *req,
474					    struct crypto_sync_skcipher *tfm)
475{
476	skcipher_request_set_tfm(req, &tfm->base);
477}
478
479static inline struct skcipher_request *skcipher_request_cast(
480	struct crypto_async_request *req)
481{
482	return container_of(req, struct skcipher_request, base);
 
483}
484
485/**
486 * skcipher_request_alloc() - allocate request data structure
487 * @tfm: cipher handle to be registered with the request
488 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
489 *
490 * Allocate the request data structure that must be used with the skcipher
491 * encrypt and decrypt API calls. During the allocation, the provided skcipher
492 * handle is registered in the request data structure.
493 *
494 * Return: allocated request handle in case of success, or NULL if out of memory
495 */
496static inline struct skcipher_request *skcipher_request_alloc(
497	struct crypto_skcipher *tfm, gfp_t gfp)
498{
499	struct skcipher_request *req;
500
501	req = kmalloc(sizeof(struct skcipher_request) +
502		      crypto_skcipher_reqsize(tfm), gfp);
503
504	if (likely(req))
505		skcipher_request_set_tfm(req, tfm);
506
507	return req;
508}
509
510/**
511 * skcipher_request_free() - zeroize and free request data structure
512 * @req: request data structure cipher handle to be freed
513 */
514static inline void skcipher_request_free(struct skcipher_request *req)
515{
516	kzfree(req);
517}
518
519static inline void skcipher_request_zero(struct skcipher_request *req)
 
 
520{
521	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
522
523	memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
524}
525
526/**
527 * skcipher_request_set_callback() - set asynchronous callback function
528 * @req: request handle
529 * @flags: specify zero or an ORing of the flags
530 *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
531 *	   increase the wait queue beyond the initial maximum size;
532 *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
533 * @compl: callback function pointer to be registered with the request handle
534 * @data: The data pointer refers to memory that is not used by the kernel
535 *	  crypto API, but provided to the callback function for it to use. Here,
536 *	  the caller can provide a reference to memory the callback function can
537 *	  operate on. As the callback function is invoked asynchronously to the
538 *	  related functionality, it may need to access data structures of the
539 *	  related functionality which can be referenced using this pointer. The
540 *	  callback function can access the memory via the "data" field in the
541 *	  crypto_async_request data structure provided to the callback function.
542 *
543 * This function allows setting the callback function that is triggered once the
544 * cipher operation completes.
545 *
546 * The callback function is registered with the skcipher_request handle and
547 * must comply with the following template::
548 *
549 *	void callback_function(struct crypto_async_request *req, int error)
550 */
551static inline void skcipher_request_set_callback(struct skcipher_request *req,
552						 u32 flags,
553						 crypto_completion_t compl,
554						 void *data)
555{
556	req->base.complete = compl;
557	req->base.data = data;
558	req->base.flags = flags;
559}
560
561/**
562 * skcipher_request_set_crypt() - set data buffers
563 * @req: request handle
564 * @src: source scatter / gather list
565 * @dst: destination scatter / gather list
566 * @cryptlen: number of bytes to process from @src
567 * @iv: IV for the cipher operation which must comply with the IV size defined
568 *      by crypto_skcipher_ivsize
569 *
570 * This function allows setting of the source data and destination data
571 * scatter / gather lists.
572 *
573 * For encryption, the source is treated as the plaintext and the
574 * destination is the ciphertext. For a decryption operation, the use is
575 * reversed - the source is the ciphertext and the destination is the plaintext.
576 */
577static inline void skcipher_request_set_crypt(
578	struct skcipher_request *req,
579	struct scatterlist *src, struct scatterlist *dst,
580	unsigned int cryptlen, void *iv)
581{
582	req->src = src;
583	req->dst = dst;
584	req->cryptlen = cryptlen;
585	req->iv = iv;
586}
587
588#endif	/* _CRYPTO_SKCIPHER_H */
589