xref: /linux/include/crypto/skcipher.h (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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/atomic.h>
12 #include <linux/container_of.h>
13 #include <linux/crypto.h>
14 #include <linux/slab.h>
15 #include <linux/string.h>
16 #include <linux/types.h>
17 
18 /* Set this bit if the lskcipher operation is a continuation. */
19 #define CRYPTO_LSKCIPHER_FLAG_CONT	0x00000001
20 /* Set this bit if the lskcipher operation is final. */
21 #define CRYPTO_LSKCIPHER_FLAG_FINAL	0x00000002
22 /* The bit CRYPTO_TFM_REQ_MAY_SLEEP can also be set if needed. */
23 
24 /* Set this bit if the skcipher operation is a continuation. */
25 #define CRYPTO_SKCIPHER_REQ_CONT	0x00000001
26 /* Set this bit if the skcipher operation is not final. */
27 #define CRYPTO_SKCIPHER_REQ_NOTFINAL	0x00000002
28 
29 struct scatterlist;
30 
31 /**
32  *	struct skcipher_request - Symmetric key cipher request
33  *	@cryptlen: Number of bytes to encrypt or decrypt
34  *	@iv: Initialisation Vector
35  *	@src: Source SG list
36  *	@dst: Destination SG list
37  *	@base: Underlying async request
38  *	@__ctx: Start of private context data
39  */
40 struct skcipher_request {
41 	unsigned int cryptlen;
42 
43 	u8 *iv;
44 
45 	struct scatterlist *src;
46 	struct scatterlist *dst;
47 
48 	struct crypto_async_request base;
49 
50 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
51 };
52 
53 struct crypto_skcipher {
54 	unsigned int reqsize;
55 
56 	struct crypto_tfm base;
57 };
58 
59 struct crypto_sync_skcipher {
60 	struct crypto_skcipher base;
61 };
62 
63 struct crypto_lskcipher {
64 	struct crypto_tfm base;
65 };
66 
67 /*
68  * struct skcipher_alg_common - common properties of skcipher_alg
69  * @min_keysize: Minimum key size supported by the transformation. This is the
70  *		 smallest key length supported by this transformation algorithm.
71  *		 This must be set to one of the pre-defined values as this is
72  *		 not hardware specific. Possible values for this field can be
73  *		 found via git grep "_MIN_KEY_SIZE" include/crypto/
74  * @max_keysize: Maximum key size supported by the transformation. This is the
75  *		 largest key length supported by this transformation algorithm.
76  *		 This must be set to one of the pre-defined values as this is
77  *		 not hardware specific. Possible values for this field can be
78  *		 found via git grep "_MAX_KEY_SIZE" include/crypto/
79  * @ivsize: IV size applicable for transformation. The consumer must provide an
80  *	    IV of exactly that size to perform the encrypt or decrypt operation.
81  * @chunksize: Equal to the block size except for stream ciphers such as
82  *	       CTR where it is set to the underlying block size.
83  * @statesize: Size of the internal state for the algorithm.
84  * @base: Definition of a generic crypto algorithm.
85  */
86 #define SKCIPHER_ALG_COMMON {		\
87 	unsigned int min_keysize;	\
88 	unsigned int max_keysize;	\
89 	unsigned int ivsize;		\
90 	unsigned int chunksize;		\
91 	unsigned int statesize;		\
92 					\
93 	struct crypto_alg base;		\
94 }
95 struct skcipher_alg_common SKCIPHER_ALG_COMMON;
96 
97 /**
98  * struct skcipher_alg - symmetric key cipher definition
99  * @setkey: Set key for the transformation. This function is used to either
100  *	    program a supplied key into the hardware or store the key in the
101  *	    transformation context for programming it later. Note that this
102  *	    function does modify the transformation context. This function can
103  *	    be called multiple times during the existence of the transformation
104  *	    object, so one must make sure the key is properly reprogrammed into
105  *	    the hardware. This function is also responsible for checking the key
106  *	    length for validity. In case a software fallback was put in place in
107  *	    the @cra_init call, this function might need to use the fallback if
108  *	    the algorithm doesn't support all of the key sizes.
109  * @encrypt: Encrypt a scatterlist of blocks. This function is used to encrypt
110  *	     the supplied scatterlist containing the blocks of data. The crypto
111  *	     API consumer is responsible for aligning the entries of the
112  *	     scatterlist properly and making sure the chunks are correctly
113  *	     sized. In case a software fallback was put in place in the
114  *	     @cra_init call, this function might need to use the fallback if
115  *	     the algorithm doesn't support all of the key sizes. In case the
116  *	     key was stored in transformation context, the key might need to be
117  *	     re-programmed into the hardware in this function. This function
118  *	     shall not modify the transformation context, as this function may
119  *	     be called in parallel with the same transformation object.
120  * @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt
121  *	     and the conditions are exactly the same.
122  * @export: Export partial state of the transformation. This function dumps the
123  *	    entire state of the ongoing transformation into a provided block of
124  *	    data so it can be @import 'ed back later on. This is useful in case
125  *	    you want to save partial result of the transformation after
126  *	    processing certain amount of data and reload this partial result
127  *	    multiple times later on for multiple re-use. No data processing
128  *	    happens at this point.
129  * @import: Import partial state of the transformation. This function loads the
130  *	    entire state of the ongoing transformation from a provided block of
131  *	    data so the transformation can continue from this point onward. No
132  *	    data processing happens at this point.
133  * @init: Initialize the cryptographic transformation object. This function
134  *	  is used to initialize the cryptographic transformation object.
135  *	  This function is called only once at the instantiation time, right
136  *	  after the transformation context was allocated. In case the
137  *	  cryptographic hardware has some special requirements which need to
138  *	  be handled by software, this function shall check for the precise
139  *	  requirement of the transformation and put any software fallbacks
140  *	  in place.
141  * @exit: Deinitialize the cryptographic transformation object. This is a
142  *	  counterpart to @init, used to remove various changes set in
143  *	  @init.
144  * @walksize: Equal to the chunk size except in cases where the algorithm is
145  * 	      considerably more efficient if it can operate on multiple chunks
146  * 	      in parallel. Should be a multiple of chunksize.
147  * @co: see struct skcipher_alg_common
148  *
149  * All fields except @ivsize are mandatory and must be filled.
150  */
151 struct skcipher_alg {
152 	int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
153 	              unsigned int keylen);
154 	int (*encrypt)(struct skcipher_request *req);
155 	int (*decrypt)(struct skcipher_request *req);
156 	int (*export)(struct skcipher_request *req, void *out);
157 	int (*import)(struct skcipher_request *req, const void *in);
158 	int (*init)(struct crypto_skcipher *tfm);
159 	void (*exit)(struct crypto_skcipher *tfm);
160 
161 	unsigned int walksize;
162 
163 	union {
164 		struct SKCIPHER_ALG_COMMON;
165 		struct skcipher_alg_common co;
166 	};
167 };
168 
169 /**
170  * struct lskcipher_alg - linear symmetric key cipher definition
171  * @setkey: Set key for the transformation. This function is used to either
172  *	    program a supplied key into the hardware or store the key in the
173  *	    transformation context for programming it later. Note that this
174  *	    function does modify the transformation context. This function can
175  *	    be called multiple times during the existence of the transformation
176  *	    object, so one must make sure the key is properly reprogrammed into
177  *	    the hardware. This function is also responsible for checking the key
178  *	    length for validity. In case a software fallback was put in place in
179  *	    the @cra_init call, this function might need to use the fallback if
180  *	    the algorithm doesn't support all of the key sizes.
181  * @encrypt: Encrypt a number of bytes. This function is used to encrypt
182  *	     the supplied data.  This function shall not modify
183  *	     the transformation context, as this function may be called
184  *	     in parallel with the same transformation object.  Data
185  *	     may be left over if length is not a multiple of blocks
186  *	     and there is more to come (final == false).  The number of
187  *	     left-over bytes should be returned in case of success.
188  *	     The siv field shall be as long as ivsize + statesize with
189  *	     the IV placed at the front.  The state will be used by the
190  *	     algorithm internally.
191  * @decrypt: Decrypt a number of bytes. This is a reverse counterpart to
192  *	     @encrypt and the conditions are exactly the same.
193  * @init: Initialize the cryptographic transformation object. This function
194  *	  is used to initialize the cryptographic transformation object.
195  *	  This function is called only once at the instantiation time, right
196  *	  after the transformation context was allocated.
197  * @exit: Deinitialize the cryptographic transformation object. This is a
198  *	  counterpart to @init, used to remove various changes set in
199  *	  @init.
200  * @co: see struct skcipher_alg_common
201  */
202 struct lskcipher_alg {
203 	int (*setkey)(struct crypto_lskcipher *tfm, const u8 *key,
204 	              unsigned int keylen);
205 	int (*encrypt)(struct crypto_lskcipher *tfm, const u8 *src,
206 		       u8 *dst, unsigned len, u8 *siv, u32 flags);
207 	int (*decrypt)(struct crypto_lskcipher *tfm, const u8 *src,
208 		       u8 *dst, unsigned len, u8 *siv, u32 flags);
209 	int (*init)(struct crypto_lskcipher *tfm);
210 	void (*exit)(struct crypto_lskcipher *tfm);
211 
212 	struct skcipher_alg_common co;
213 };
214 
215 #define MAX_SYNC_SKCIPHER_REQSIZE      384
216 /*
217  * This performs a type-check against the "tfm" argument to make sure
218  * all users have the correct skcipher tfm for doing on-stack requests.
219  */
220 #define SYNC_SKCIPHER_REQUEST_ON_STACK(name, tfm) \
221 	char __##name##_desc[sizeof(struct skcipher_request) + \
222 			     MAX_SYNC_SKCIPHER_REQSIZE + \
223 			     (!(sizeof((struct crypto_sync_skcipher *)1 == \
224 				       (typeof(tfm))1))) \
225 			    ] CRYPTO_MINALIGN_ATTR; \
226 	struct skcipher_request *name = (void *)__##name##_desc
227 
228 /**
229  * DOC: Symmetric Key Cipher API
230  *
231  * Symmetric key cipher API is used with the ciphers of type
232  * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
233  *
234  * Asynchronous cipher operations imply that the function invocation for a
235  * cipher request returns immediately before the completion of the operation.
236  * The cipher request is scheduled as a separate kernel thread and therefore
237  * load-balanced on the different CPUs via the process scheduler. To allow
238  * the kernel crypto API to inform the caller about the completion of a cipher
239  * request, the caller must provide a callback function. That function is
240  * invoked with the cipher handle when the request completes.
241  *
242  * To support the asynchronous operation, additional information than just the
243  * cipher handle must be supplied to the kernel crypto API. That additional
244  * information is given by filling in the skcipher_request data structure.
245  *
246  * For the symmetric key cipher API, the state is maintained with the tfm
247  * cipher handle. A single tfm can be used across multiple calls and in
248  * parallel. For asynchronous block cipher calls, context data supplied and
249  * only used by the caller can be referenced the request data structure in
250  * addition to the IV used for the cipher request. The maintenance of such
251  * state information would be important for a crypto driver implementer to
252  * have, because when calling the callback function upon completion of the
253  * cipher operation, that callback function may need some information about
254  * which operation just finished if it invoked multiple in parallel. This
255  * state information is unused by the kernel crypto API.
256  */
257 
258 static inline struct crypto_skcipher *__crypto_skcipher_cast(
259 	struct crypto_tfm *tfm)
260 {
261 	return container_of(tfm, struct crypto_skcipher, base);
262 }
263 
264 /**
265  * crypto_alloc_skcipher() - allocate symmetric key cipher handle
266  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
267  *	      skcipher cipher
268  * @type: specifies the type of the cipher
269  * @mask: specifies the mask for the cipher
270  *
271  * Allocate a cipher handle for an skcipher. The returned struct
272  * crypto_skcipher is the cipher handle that is required for any subsequent
273  * API invocation for that skcipher.
274  *
275  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
276  *	   of an error, PTR_ERR() returns the error code.
277  */
278 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
279 					      u32 type, u32 mask);
280 
281 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(const char *alg_name,
282 					      u32 type, u32 mask);
283 
284 
285 /**
286  * crypto_alloc_lskcipher() - allocate linear symmetric key cipher handle
287  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
288  *	      lskcipher
289  * @type: specifies the type of the cipher
290  * @mask: specifies the mask for the cipher
291  *
292  * Allocate a cipher handle for an lskcipher. The returned struct
293  * crypto_lskcipher is the cipher handle that is required for any subsequent
294  * API invocation for that lskcipher.
295  *
296  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
297  *	   of an error, PTR_ERR() returns the error code.
298  */
299 struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name,
300 						u32 type, u32 mask);
301 
302 static inline struct crypto_tfm *crypto_skcipher_tfm(
303 	struct crypto_skcipher *tfm)
304 {
305 	return &tfm->base;
306 }
307 
308 static inline struct crypto_tfm *crypto_lskcipher_tfm(
309 	struct crypto_lskcipher *tfm)
310 {
311 	return &tfm->base;
312 }
313 
314 /**
315  * crypto_free_skcipher() - zeroize and free cipher handle
316  * @tfm: cipher handle to be freed
317  *
318  * If @tfm is a NULL or error pointer, this function does nothing.
319  */
320 static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
321 {
322 	crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
323 }
324 
325 static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm)
326 {
327 	crypto_free_skcipher(&tfm->base);
328 }
329 
330 /**
331  * crypto_free_lskcipher() - zeroize and free cipher handle
332  * @tfm: cipher handle to be freed
333  *
334  * If @tfm is a NULL or error pointer, this function does nothing.
335  */
336 static inline void crypto_free_lskcipher(struct crypto_lskcipher *tfm)
337 {
338 	crypto_destroy_tfm(tfm, crypto_lskcipher_tfm(tfm));
339 }
340 
341 /**
342  * crypto_has_skcipher() - Search for the availability of an skcipher.
343  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
344  *	      skcipher
345  * @type: specifies the type of the skcipher
346  * @mask: specifies the mask for the skcipher
347  *
348  * Return: true when the skcipher is known to the kernel crypto API; false
349  *	   otherwise
350  */
351 int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask);
352 
353 static inline const char *crypto_skcipher_driver_name(
354 	struct crypto_skcipher *tfm)
355 {
356 	return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
357 }
358 
359 static inline const char *crypto_lskcipher_driver_name(
360 	struct crypto_lskcipher *tfm)
361 {
362 	return crypto_tfm_alg_driver_name(crypto_lskcipher_tfm(tfm));
363 }
364 
365 static inline struct skcipher_alg_common *crypto_skcipher_alg_common(
366 	struct crypto_skcipher *tfm)
367 {
368 	return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
369 			    struct skcipher_alg_common, base);
370 }
371 
372 static inline struct skcipher_alg *crypto_skcipher_alg(
373 	struct crypto_skcipher *tfm)
374 {
375 	return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
376 			    struct skcipher_alg, base);
377 }
378 
379 static inline struct lskcipher_alg *crypto_lskcipher_alg(
380 	struct crypto_lskcipher *tfm)
381 {
382 	return container_of(crypto_lskcipher_tfm(tfm)->__crt_alg,
383 			    struct lskcipher_alg, co.base);
384 }
385 
386 /**
387  * crypto_skcipher_ivsize() - obtain IV size
388  * @tfm: cipher handle
389  *
390  * The size of the IV for the skcipher referenced by the cipher handle is
391  * returned. This IV size may be zero if the cipher does not need an IV.
392  *
393  * Return: IV size in bytes
394  */
395 static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
396 {
397 	return crypto_skcipher_alg_common(tfm)->ivsize;
398 }
399 
400 static inline unsigned int crypto_sync_skcipher_ivsize(
401 	struct crypto_sync_skcipher *tfm)
402 {
403 	return crypto_skcipher_ivsize(&tfm->base);
404 }
405 
406 /**
407  * crypto_lskcipher_ivsize() - obtain IV size
408  * @tfm: cipher handle
409  *
410  * The size of the IV for the lskcipher referenced by the cipher handle is
411  * returned. This IV size may be zero if the cipher does not need an IV.
412  *
413  * Return: IV size in bytes
414  */
415 static inline unsigned int crypto_lskcipher_ivsize(
416 	struct crypto_lskcipher *tfm)
417 {
418 	return crypto_lskcipher_alg(tfm)->co.ivsize;
419 }
420 
421 /**
422  * crypto_skcipher_blocksize() - obtain block size of cipher
423  * @tfm: cipher handle
424  *
425  * The block size for the skcipher referenced with the cipher handle is
426  * returned. The caller may use that information to allocate appropriate
427  * memory for the data returned by the encryption or decryption operation
428  *
429  * Return: block size of cipher
430  */
431 static inline unsigned int crypto_skcipher_blocksize(
432 	struct crypto_skcipher *tfm)
433 {
434 	return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
435 }
436 
437 /**
438  * crypto_lskcipher_blocksize() - obtain block size of cipher
439  * @tfm: cipher handle
440  *
441  * The block size for the lskcipher referenced with the cipher handle is
442  * returned. The caller may use that information to allocate appropriate
443  * memory for the data returned by the encryption or decryption operation
444  *
445  * Return: block size of cipher
446  */
447 static inline unsigned int crypto_lskcipher_blocksize(
448 	struct crypto_lskcipher *tfm)
449 {
450 	return crypto_tfm_alg_blocksize(crypto_lskcipher_tfm(tfm));
451 }
452 
453 /**
454  * crypto_skcipher_chunksize() - obtain chunk size
455  * @tfm: cipher handle
456  *
457  * The block size is set to one for ciphers such as CTR.  However,
458  * you still need to provide incremental updates in multiples of
459  * the underlying block size as the IV does not have sub-block
460  * granularity.  This is known in this API as the chunk size.
461  *
462  * Return: chunk size in bytes
463  */
464 static inline unsigned int crypto_skcipher_chunksize(
465 	struct crypto_skcipher *tfm)
466 {
467 	return crypto_skcipher_alg_common(tfm)->chunksize;
468 }
469 
470 /**
471  * crypto_lskcipher_chunksize() - obtain chunk size
472  * @tfm: cipher handle
473  *
474  * The block size is set to one for ciphers such as CTR.  However,
475  * you still need to provide incremental updates in multiples of
476  * the underlying block size as the IV does not have sub-block
477  * granularity.  This is known in this API as the chunk size.
478  *
479  * Return: chunk size in bytes
480  */
481 static inline unsigned int crypto_lskcipher_chunksize(
482 	struct crypto_lskcipher *tfm)
483 {
484 	return crypto_lskcipher_alg(tfm)->co.chunksize;
485 }
486 
487 /**
488  * crypto_skcipher_statesize() - obtain state size
489  * @tfm: cipher handle
490  *
491  * Some algorithms cannot be chained with the IV alone.  They carry
492  * internal state which must be replicated if data is to be processed
493  * incrementally.  The size of that state can be obtained with this
494  * function.
495  *
496  * Return: state size in bytes
497  */
498 static inline unsigned int crypto_skcipher_statesize(
499 	struct crypto_skcipher *tfm)
500 {
501 	return crypto_skcipher_alg_common(tfm)->statesize;
502 }
503 
504 /**
505  * crypto_lskcipher_statesize() - obtain state size
506  * @tfm: cipher handle
507  *
508  * Some algorithms cannot be chained with the IV alone.  They carry
509  * internal state which must be replicated if data is to be processed
510  * incrementally.  The size of that state can be obtained with this
511  * function.
512  *
513  * Return: state size in bytes
514  */
515 static inline unsigned int crypto_lskcipher_statesize(
516 	struct crypto_lskcipher *tfm)
517 {
518 	return crypto_lskcipher_alg(tfm)->co.statesize;
519 }
520 
521 static inline unsigned int crypto_sync_skcipher_blocksize(
522 	struct crypto_sync_skcipher *tfm)
523 {
524 	return crypto_skcipher_blocksize(&tfm->base);
525 }
526 
527 static inline unsigned int crypto_skcipher_alignmask(
528 	struct crypto_skcipher *tfm)
529 {
530 	return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
531 }
532 
533 static inline unsigned int crypto_lskcipher_alignmask(
534 	struct crypto_lskcipher *tfm)
535 {
536 	return crypto_tfm_alg_alignmask(crypto_lskcipher_tfm(tfm));
537 }
538 
539 static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
540 {
541 	return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
542 }
543 
544 static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
545 					       u32 flags)
546 {
547 	crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
548 }
549 
550 static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
551 						 u32 flags)
552 {
553 	crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
554 }
555 
556 static inline u32 crypto_sync_skcipher_get_flags(
557 	struct crypto_sync_skcipher *tfm)
558 {
559 	return crypto_skcipher_get_flags(&tfm->base);
560 }
561 
562 static inline void crypto_sync_skcipher_set_flags(
563 	struct crypto_sync_skcipher *tfm, u32 flags)
564 {
565 	crypto_skcipher_set_flags(&tfm->base, flags);
566 }
567 
568 static inline void crypto_sync_skcipher_clear_flags(
569 	struct crypto_sync_skcipher *tfm, u32 flags)
570 {
571 	crypto_skcipher_clear_flags(&tfm->base, flags);
572 }
573 
574 static inline u32 crypto_lskcipher_get_flags(struct crypto_lskcipher *tfm)
575 {
576 	return crypto_tfm_get_flags(crypto_lskcipher_tfm(tfm));
577 }
578 
579 static inline void crypto_lskcipher_set_flags(struct crypto_lskcipher *tfm,
580 					       u32 flags)
581 {
582 	crypto_tfm_set_flags(crypto_lskcipher_tfm(tfm), flags);
583 }
584 
585 static inline void crypto_lskcipher_clear_flags(struct crypto_lskcipher *tfm,
586 						 u32 flags)
587 {
588 	crypto_tfm_clear_flags(crypto_lskcipher_tfm(tfm), flags);
589 }
590 
591 /**
592  * crypto_skcipher_setkey() - set key for cipher
593  * @tfm: cipher handle
594  * @key: buffer holding the key
595  * @keylen: length of the key in bytes
596  *
597  * The caller provided key is set for the skcipher referenced by the cipher
598  * handle.
599  *
600  * Note, the key length determines the cipher type. Many block ciphers implement
601  * different cipher modes depending on the key size, such as AES-128 vs AES-192
602  * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
603  * is performed.
604  *
605  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
606  */
607 int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
608 			   const u8 *key, unsigned int keylen);
609 
610 static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
611 					 const u8 *key, unsigned int keylen)
612 {
613 	return crypto_skcipher_setkey(&tfm->base, key, keylen);
614 }
615 
616 /**
617  * crypto_lskcipher_setkey() - set key for cipher
618  * @tfm: cipher handle
619  * @key: buffer holding the key
620  * @keylen: length of the key in bytes
621  *
622  * The caller provided key is set for the lskcipher referenced by the cipher
623  * handle.
624  *
625  * Note, the key length determines the cipher type. Many block ciphers implement
626  * different cipher modes depending on the key size, such as AES-128 vs AES-192
627  * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
628  * is performed.
629  *
630  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
631  */
632 int crypto_lskcipher_setkey(struct crypto_lskcipher *tfm,
633 			    const u8 *key, unsigned int keylen);
634 
635 static inline unsigned int crypto_skcipher_min_keysize(
636 	struct crypto_skcipher *tfm)
637 {
638 	return crypto_skcipher_alg_common(tfm)->min_keysize;
639 }
640 
641 static inline unsigned int crypto_skcipher_max_keysize(
642 	struct crypto_skcipher *tfm)
643 {
644 	return crypto_skcipher_alg_common(tfm)->max_keysize;
645 }
646 
647 static inline unsigned int crypto_lskcipher_min_keysize(
648 	struct crypto_lskcipher *tfm)
649 {
650 	return crypto_lskcipher_alg(tfm)->co.min_keysize;
651 }
652 
653 static inline unsigned int crypto_lskcipher_max_keysize(
654 	struct crypto_lskcipher *tfm)
655 {
656 	return crypto_lskcipher_alg(tfm)->co.max_keysize;
657 }
658 
659 /**
660  * crypto_skcipher_reqtfm() - obtain cipher handle from request
661  * @req: skcipher_request out of which the cipher handle is to be obtained
662  *
663  * Return the crypto_skcipher handle when furnishing an skcipher_request
664  * data structure.
665  *
666  * Return: crypto_skcipher handle
667  */
668 static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
669 	struct skcipher_request *req)
670 {
671 	return __crypto_skcipher_cast(req->base.tfm);
672 }
673 
674 static inline struct crypto_sync_skcipher *crypto_sync_skcipher_reqtfm(
675 	struct skcipher_request *req)
676 {
677 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
678 
679 	return container_of(tfm, struct crypto_sync_skcipher, base);
680 }
681 
682 /**
683  * crypto_skcipher_encrypt() - encrypt plaintext
684  * @req: reference to the skcipher_request handle that holds all information
685  *	 needed to perform the cipher operation
686  *
687  * Encrypt plaintext data using the skcipher_request handle. That data
688  * structure and how it is filled with data is discussed with the
689  * skcipher_request_* functions.
690  *
691  * Return: 0 if the cipher operation was successful; < 0 if an error occurred
692  */
693 int crypto_skcipher_encrypt(struct skcipher_request *req);
694 
695 /**
696  * crypto_skcipher_decrypt() - decrypt ciphertext
697  * @req: reference to the skcipher_request handle that holds all information
698  *	 needed to perform the cipher operation
699  *
700  * Decrypt ciphertext data using the skcipher_request handle. That data
701  * structure and how it is filled with data is discussed with the
702  * skcipher_request_* functions.
703  *
704  * Return: 0 if the cipher operation was successful; < 0 if an error occurred
705  */
706 int crypto_skcipher_decrypt(struct skcipher_request *req);
707 
708 /**
709  * crypto_skcipher_export() - export partial state
710  * @req: reference to the skcipher_request handle that holds all information
711  *	 needed to perform the operation
712  * @out: output buffer of sufficient size that can hold the state
713  *
714  * Export partial state of the transformation. This function dumps the
715  * entire state of the ongoing transformation into a provided block of
716  * data so it can be @import 'ed back later on. This is useful in case
717  * you want to save partial result of the transformation after
718  * processing certain amount of data and reload this partial result
719  * multiple times later on for multiple re-use. No data processing
720  * happens at this point.
721  *
722  * Return: 0 if the cipher operation was successful; < 0 if an error occurred
723  */
724 int crypto_skcipher_export(struct skcipher_request *req, void *out);
725 
726 /**
727  * crypto_skcipher_import() - import partial state
728  * @req: reference to the skcipher_request handle that holds all information
729  *	 needed to perform the operation
730  * @in: buffer holding the state
731  *
732  * Import partial state of the transformation. This function loads the
733  * entire state of the ongoing transformation from a provided block of
734  * data so the transformation can continue from this point onward. No
735  * data processing happens at this point.
736  *
737  * Return: 0 if the cipher operation was successful; < 0 if an error occurred
738  */
739 int crypto_skcipher_import(struct skcipher_request *req, const void *in);
740 
741 /**
742  * crypto_lskcipher_encrypt() - encrypt plaintext
743  * @tfm: lskcipher handle
744  * @src: source buffer
745  * @dst: destination buffer
746  * @len: number of bytes to process
747  * @siv: IV + state for the cipher operation.  The length of the IV must
748  *	 comply with the IV size defined by crypto_lskcipher_ivsize.  The
749  *	 IV is then followed with a buffer with the length as specified by
750  *	 crypto_lskcipher_statesize.
751  * Encrypt plaintext data using the lskcipher handle.
752  *
753  * Return: >=0 if the cipher operation was successful, if positive
754  *	   then this many bytes have been left unprocessed;
755  *	   < 0 if an error occurred
756  */
757 int crypto_lskcipher_encrypt(struct crypto_lskcipher *tfm, const u8 *src,
758 			     u8 *dst, unsigned len, u8 *siv);
759 
760 /**
761  * crypto_lskcipher_decrypt() - decrypt ciphertext
762  * @tfm: lskcipher handle
763  * @src: source buffer
764  * @dst: destination buffer
765  * @len: number of bytes to process
766  * @siv: IV + state for the cipher operation.  The length of the IV must
767  *	 comply with the IV size defined by crypto_lskcipher_ivsize.  The
768  *	 IV is then followed with a buffer with the length as specified by
769  *	 crypto_lskcipher_statesize.
770  *
771  * Decrypt ciphertext data using the lskcipher handle.
772  *
773  * Return: >=0 if the cipher operation was successful, if positive
774  *	   then this many bytes have been left unprocessed;
775  *	   < 0 if an error occurred
776  */
777 int crypto_lskcipher_decrypt(struct crypto_lskcipher *tfm, const u8 *src,
778 			     u8 *dst, unsigned len, u8 *siv);
779 
780 /**
781  * DOC: Symmetric Key Cipher Request Handle
782  *
783  * The skcipher_request data structure contains all pointers to data
784  * required for the symmetric key cipher operation. This includes the cipher
785  * handle (which can be used by multiple skcipher_request instances), pointer
786  * to plaintext and ciphertext, asynchronous callback function, etc. It acts
787  * as a handle to the skcipher_request_* API calls in a similar way as
788  * skcipher handle to the crypto_skcipher_* API calls.
789  */
790 
791 /**
792  * crypto_skcipher_reqsize() - obtain size of the request data structure
793  * @tfm: cipher handle
794  *
795  * Return: number of bytes
796  */
797 static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
798 {
799 	return tfm->reqsize;
800 }
801 
802 /**
803  * skcipher_request_set_tfm() - update cipher handle reference in request
804  * @req: request handle to be modified
805  * @tfm: cipher handle that shall be added to the request handle
806  *
807  * Allow the caller to replace the existing skcipher handle in the request
808  * data structure with a different one.
809  */
810 static inline void skcipher_request_set_tfm(struct skcipher_request *req,
811 					    struct crypto_skcipher *tfm)
812 {
813 	req->base.tfm = crypto_skcipher_tfm(tfm);
814 }
815 
816 static inline void skcipher_request_set_sync_tfm(struct skcipher_request *req,
817 					    struct crypto_sync_skcipher *tfm)
818 {
819 	skcipher_request_set_tfm(req, &tfm->base);
820 }
821 
822 static inline struct skcipher_request *skcipher_request_cast(
823 	struct crypto_async_request *req)
824 {
825 	return container_of(req, struct skcipher_request, base);
826 }
827 
828 /**
829  * skcipher_request_alloc() - allocate request data structure
830  * @tfm: cipher handle to be registered with the request
831  * @gfp: memory allocation flag that is handed to kmalloc by the API call.
832  *
833  * Allocate the request data structure that must be used with the skcipher
834  * encrypt and decrypt API calls. During the allocation, the provided skcipher
835  * handle is registered in the request data structure.
836  *
837  * Return: allocated request handle in case of success, or NULL if out of memory
838  */
839 static inline struct skcipher_request *skcipher_request_alloc_noprof(
840 	struct crypto_skcipher *tfm, gfp_t gfp)
841 {
842 	struct skcipher_request *req;
843 
844 	req = kmalloc_noprof(sizeof(struct skcipher_request) +
845 			     crypto_skcipher_reqsize(tfm), gfp);
846 
847 	if (likely(req))
848 		skcipher_request_set_tfm(req, tfm);
849 
850 	return req;
851 }
852 #define skcipher_request_alloc(...)	alloc_hooks(skcipher_request_alloc_noprof(__VA_ARGS__))
853 
854 /**
855  * skcipher_request_free() - zeroize and free request data structure
856  * @req: request data structure cipher handle to be freed
857  */
858 static inline void skcipher_request_free(struct skcipher_request *req)
859 {
860 	kfree_sensitive(req);
861 }
862 
863 static inline void skcipher_request_zero(struct skcipher_request *req)
864 {
865 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
866 
867 	memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
868 }
869 
870 /**
871  * skcipher_request_set_callback() - set asynchronous callback function
872  * @req: request handle
873  * @flags: specify zero or an ORing of the flags
874  *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
875  *	   increase the wait queue beyond the initial maximum size;
876  *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
877  * @compl: callback function pointer to be registered with the request handle
878  * @data: The data pointer refers to memory that is not used by the kernel
879  *	  crypto API, but provided to the callback function for it to use. Here,
880  *	  the caller can provide a reference to memory the callback function can
881  *	  operate on. As the callback function is invoked asynchronously to the
882  *	  related functionality, it may need to access data structures of the
883  *	  related functionality which can be referenced using this pointer. The
884  *	  callback function can access the memory via the "data" field in the
885  *	  crypto_async_request data structure provided to the callback function.
886  *
887  * This function allows setting the callback function that is triggered once the
888  * cipher operation completes.
889  *
890  * The callback function is registered with the skcipher_request handle and
891  * must comply with the following template::
892  *
893  *	void callback_function(struct crypto_async_request *req, int error)
894  */
895 static inline void skcipher_request_set_callback(struct skcipher_request *req,
896 						 u32 flags,
897 						 crypto_completion_t compl,
898 						 void *data)
899 {
900 	req->base.complete = compl;
901 	req->base.data = data;
902 	req->base.flags = flags;
903 }
904 
905 /**
906  * skcipher_request_set_crypt() - set data buffers
907  * @req: request handle
908  * @src: source scatter / gather list
909  * @dst: destination scatter / gather list
910  * @cryptlen: number of bytes to process from @src
911  * @iv: IV for the cipher operation which must comply with the IV size defined
912  *      by crypto_skcipher_ivsize
913  *
914  * This function allows setting of the source data and destination data
915  * scatter / gather lists.
916  *
917  * For encryption, the source is treated as the plaintext and the
918  * destination is the ciphertext. For a decryption operation, the use is
919  * reversed - the source is the ciphertext and the destination is the plaintext.
920  */
921 static inline void skcipher_request_set_crypt(
922 	struct skcipher_request *req,
923 	struct scatterlist *src, struct scatterlist *dst,
924 	unsigned int cryptlen, void *iv)
925 {
926 	req->src = src;
927 	req->dst = dst;
928 	req->cryptlen = cryptlen;
929 	req->iv = iv;
930 }
931 
932 #endif	/* _CRYPTO_SKCIPHER_H */
933 
934