skcipher.h

  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
 29struct 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 */
 40struct 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
 53struct crypto_skcipher {
 54	unsigned int reqsize;
 55
 56	struct crypto_tfm base;
 57};
 58
 59struct crypto_sync_skcipher {
 60	struct crypto_skcipher base;
 61};
 62
 63struct 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}
 95struct 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 */
151struct 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 */
202struct 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			    ] CRYPTO_MINALIGN_ATTR; \
224	struct skcipher_request *name = \
225		(((struct skcipher_request *)__##name##_desc)->base.tfm = \
226			crypto_sync_skcipher_tfm((_tfm)), \
227		 (void *)__##name##_desc)
228
229/**
230 * DOC: Symmetric Key Cipher API
231 *
232 * Symmetric key cipher API is used with the ciphers of type
233 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
234 *
235 * Asynchronous cipher operations imply that the function invocation for a
236 * cipher request returns immediately before the completion of the operation.
237 * The cipher request is scheduled as a separate kernel thread and therefore
238 * load-balanced on the different CPUs via the process scheduler. To allow
239 * the kernel crypto API to inform the caller about the completion of a cipher
240 * request, the caller must provide a callback function. That function is
241 * invoked with the cipher handle when the request completes.
242 *
243 * To support the asynchronous operation, additional information than just the
244 * cipher handle must be supplied to the kernel crypto API. That additional
245 * information is given by filling in the skcipher_request data structure.
246 *
247 * For the symmetric key cipher API, the state is maintained with the tfm
248 * cipher handle. A single tfm can be used across multiple calls and in
249 * parallel. For asynchronous block cipher calls, context data supplied and
250 * only used by the caller can be referenced the request data structure in
251 * addition to the IV used for the cipher request. The maintenance of such
252 * state information would be important for a crypto driver implementer to
253 * have, because when calling the callback function upon completion of the
254 * cipher operation, that callback function may need some information about
255 * which operation just finished if it invoked multiple in parallel. This
256 * state information is unused by the kernel crypto API.
257 */
258
259static inline struct crypto_skcipher *__crypto_skcipher_cast(
260	struct crypto_tfm *tfm)
261{
262	return container_of(tfm, struct crypto_skcipher, base);
263}
264
265/**
266 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
267 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
268 *	      skcipher cipher
269 * @type: specifies the type of the cipher
270 * @mask: specifies the mask for the cipher
271 *
272 * Allocate a cipher handle for an skcipher. The returned struct
273 * crypto_skcipher is the cipher handle that is required for any subsequent
274 * API invocation for that skcipher.
275 *
276 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
277 *	   of an error, PTR_ERR() returns the error code.
278 */
279struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
280					      u32 type, u32 mask);
281
282struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(const char *alg_name,
283					      u32 type, u32 mask);
284
285
286/**
287 * crypto_alloc_lskcipher() - allocate linear symmetric key cipher handle
288 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
289 *	      lskcipher
290 * @type: specifies the type of the cipher
291 * @mask: specifies the mask for the cipher
292 *
293 * Allocate a cipher handle for an lskcipher. The returned struct
294 * crypto_lskcipher is the cipher handle that is required for any subsequent
295 * API invocation for that lskcipher.
296 *
297 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
298 *	   of an error, PTR_ERR() returns the error code.
299 */
300struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name,
301						u32 type, u32 mask);
302
303static inline struct crypto_tfm *crypto_skcipher_tfm(
304	struct crypto_skcipher *tfm)
305{
306	return &tfm->base;
307}
308
309static inline struct crypto_tfm *crypto_lskcipher_tfm(
310	struct crypto_lskcipher *tfm)
311{
312	return &tfm->base;
313}
314
315static inline struct crypto_tfm *crypto_sync_skcipher_tfm(
316	struct crypto_sync_skcipher *tfm)
317{
318	return crypto_skcipher_tfm(&tfm->base);
319}
320
321/**
322 * crypto_free_skcipher() - zeroize and free cipher handle
323 * @tfm: cipher handle to be freed
324 *
325 * If @tfm is a NULL or error pointer, this function does nothing.
326 */
327static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
328{
329	crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
330}
331
332static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm)
333{
334	crypto_free_skcipher(&tfm->base);
335}
336
337/**
338 * crypto_free_lskcipher() - zeroize and free cipher handle
339 * @tfm: cipher handle to be freed
340 *
341 * If @tfm is a NULL or error pointer, this function does nothing.
342 */
343static inline void crypto_free_lskcipher(struct crypto_lskcipher *tfm)
344{
345	crypto_destroy_tfm(tfm, crypto_lskcipher_tfm(tfm));
346}
347
348/**
349 * crypto_has_skcipher() - Search for the availability of an skcipher.
350 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
351 *	      skcipher
352 * @type: specifies the type of the skcipher
353 * @mask: specifies the mask for the skcipher
354 *
355 * Return: true when the skcipher is known to the kernel crypto API; false
356 *	   otherwise
357 */
358int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask);
359
360static inline const char *crypto_skcipher_driver_name(
361	struct crypto_skcipher *tfm)
362{
363	return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
364}
365
366static inline const char *crypto_lskcipher_driver_name(
367	struct crypto_lskcipher *tfm)
368{
369	return crypto_tfm_alg_driver_name(crypto_lskcipher_tfm(tfm));
370}
371
372static inline struct skcipher_alg_common *crypto_skcipher_alg_common(
373	struct crypto_skcipher *tfm)
374{
375	return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
376			    struct skcipher_alg_common, base);
377}
378
379static inline struct skcipher_alg *crypto_skcipher_alg(
380	struct crypto_skcipher *tfm)
381{
382	return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
383			    struct skcipher_alg, base);
384}
385
386static inline struct lskcipher_alg *crypto_lskcipher_alg(
387	struct crypto_lskcipher *tfm)
388{
389	return container_of(crypto_lskcipher_tfm(tfm)->__crt_alg,
390			    struct lskcipher_alg, co.base);
391}
392
393/**
394 * crypto_skcipher_ivsize() - obtain IV size
395 * @tfm: cipher handle
396 *
397 * The size of the IV for the skcipher referenced by the cipher handle is
398 * returned. This IV size may be zero if the cipher does not need an IV.
399 *
400 * Return: IV size in bytes
401 */
402static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
403{
404	return crypto_skcipher_alg_common(tfm)->ivsize;
405}
406
407static inline unsigned int crypto_sync_skcipher_ivsize(
408	struct crypto_sync_skcipher *tfm)
409{
410	return crypto_skcipher_ivsize(&tfm->base);
411}
412
413/**
414 * crypto_lskcipher_ivsize() - obtain IV size
415 * @tfm: cipher handle
416 *
417 * The size of the IV for the lskcipher referenced by the cipher handle is
418 * returned. This IV size may be zero if the cipher does not need an IV.
419 *
420 * Return: IV size in bytes
421 */
422static inline unsigned int crypto_lskcipher_ivsize(
423	struct crypto_lskcipher *tfm)
424{
425	return crypto_lskcipher_alg(tfm)->co.ivsize;
426}
427
428/**
429 * crypto_skcipher_blocksize() - obtain block size of cipher
430 * @tfm: cipher handle
431 *
432 * The block size for the skcipher referenced with the cipher handle is
433 * returned. The caller may use that information to allocate appropriate
434 * memory for the data returned by the encryption or decryption operation
435 *
436 * Return: block size of cipher
437 */
438static inline unsigned int crypto_skcipher_blocksize(
439	struct crypto_skcipher *tfm)
440{
441	return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
442}
443
444/**
445 * crypto_lskcipher_blocksize() - obtain block size of cipher
446 * @tfm: cipher handle
447 *
448 * The block size for the lskcipher referenced with the cipher handle is
449 * returned. The caller may use that information to allocate appropriate
450 * memory for the data returned by the encryption or decryption operation
451 *
452 * Return: block size of cipher
453 */
454static inline unsigned int crypto_lskcipher_blocksize(
455	struct crypto_lskcipher *tfm)
456{
457	return crypto_tfm_alg_blocksize(crypto_lskcipher_tfm(tfm));
458}
459
460/**
461 * crypto_skcipher_chunksize() - obtain chunk size
462 * @tfm: cipher handle
463 *
464 * The block size is set to one for ciphers such as CTR.  However,
465 * you still need to provide incremental updates in multiples of
466 * the underlying block size as the IV does not have sub-block
467 * granularity.  This is known in this API as the chunk size.
468 *
469 * Return: chunk size in bytes
470 */
471static inline unsigned int crypto_skcipher_chunksize(
472	struct crypto_skcipher *tfm)
473{
474	return crypto_skcipher_alg_common(tfm)->chunksize;
475}
476
477/**
478 * crypto_lskcipher_chunksize() - obtain chunk size
479 * @tfm: cipher handle
480 *
481 * The block size is set to one for ciphers such as CTR.  However,
482 * you still need to provide incremental updates in multiples of
483 * the underlying block size as the IV does not have sub-block
484 * granularity.  This is known in this API as the chunk size.
485 *
486 * Return: chunk size in bytes
487 */
488static inline unsigned int crypto_lskcipher_chunksize(
489	struct crypto_lskcipher *tfm)
490{
491	return crypto_lskcipher_alg(tfm)->co.chunksize;
492}
493
494/**
495 * crypto_skcipher_statesize() - obtain state size
496 * @tfm: cipher handle
497 *
498 * Some algorithms cannot be chained with the IV alone.  They carry
499 * internal state which must be replicated if data is to be processed
500 * incrementally.  The size of that state can be obtained with this
501 * function.
502 *
503 * Return: state size in bytes
504 */
505static inline unsigned int crypto_skcipher_statesize(
506	struct crypto_skcipher *tfm)
507{
508	return crypto_skcipher_alg_common(tfm)->statesize;
509}
510
511/**
512 * crypto_lskcipher_statesize() - obtain state size
513 * @tfm: cipher handle
514 *
515 * Some algorithms cannot be chained with the IV alone.  They carry
516 * internal state which must be replicated if data is to be processed
517 * incrementally.  The size of that state can be obtained with this
518 * function.
519 *
520 * Return: state size in bytes
521 */
522static inline unsigned int crypto_lskcipher_statesize(
523	struct crypto_lskcipher *tfm)
524{
525	return crypto_lskcipher_alg(tfm)->co.statesize;
526}
527
528static inline unsigned int crypto_sync_skcipher_blocksize(
529	struct crypto_sync_skcipher *tfm)
530{
531	return crypto_skcipher_blocksize(&tfm->base);
532}
533
534static inline unsigned int crypto_skcipher_alignmask(
535	struct crypto_skcipher *tfm)
536{
537	return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
538}
539
540static inline unsigned int crypto_lskcipher_alignmask(
541	struct crypto_lskcipher *tfm)
542{
543	return crypto_tfm_alg_alignmask(crypto_lskcipher_tfm(tfm));
544}
545
546static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
547{
548	return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
549}
550
551static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
552					       u32 flags)
553{
554	crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
555}
556
557static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
558						 u32 flags)
559{
560	crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
561}
562
563static inline u32 crypto_sync_skcipher_get_flags(
564	struct crypto_sync_skcipher *tfm)
565{
566	return crypto_skcipher_get_flags(&tfm->base);
567}
568
569static inline void crypto_sync_skcipher_set_flags(
570	struct crypto_sync_skcipher *tfm, u32 flags)
571{
572	crypto_skcipher_set_flags(&tfm->base, flags);
573}
574
575static inline void crypto_sync_skcipher_clear_flags(
576	struct crypto_sync_skcipher *tfm, u32 flags)
577{
578	crypto_skcipher_clear_flags(&tfm->base, flags);
579}
580
581static inline u32 crypto_lskcipher_get_flags(struct crypto_lskcipher *tfm)
582{
583	return crypto_tfm_get_flags(crypto_lskcipher_tfm(tfm));
584}
585
586static inline void crypto_lskcipher_set_flags(struct crypto_lskcipher *tfm,
587					       u32 flags)
588{
589	crypto_tfm_set_flags(crypto_lskcipher_tfm(tfm), flags);
590}
591
592static inline void crypto_lskcipher_clear_flags(struct crypto_lskcipher *tfm,
593						 u32 flags)
594{
595	crypto_tfm_clear_flags(crypto_lskcipher_tfm(tfm), flags);
596}
597
598/**
599 * crypto_skcipher_setkey() - set key for cipher
600 * @tfm: cipher handle
601 * @key: buffer holding the key
602 * @keylen: length of the key in bytes
603 *
604 * The caller provided key is set for the skcipher referenced by the cipher
605 * handle.
606 *
607 * Note, the key length determines the cipher type. Many block ciphers implement
608 * different cipher modes depending on the key size, such as AES-128 vs AES-192
609 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
610 * is performed.
611 *
612 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
613 */
614int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
615			   const u8 *key, unsigned int keylen);
616
617static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
618					 const u8 *key, unsigned int keylen)
619{
620	return crypto_skcipher_setkey(&tfm->base, key, keylen);
621}
622
623/**
624 * crypto_lskcipher_setkey() - set key for cipher
625 * @tfm: cipher handle
626 * @key: buffer holding the key
627 * @keylen: length of the key in bytes
628 *
629 * The caller provided key is set for the lskcipher referenced by the cipher
630 * handle.
631 *
632 * Note, the key length determines the cipher type. Many block ciphers implement
633 * different cipher modes depending on the key size, such as AES-128 vs AES-192
634 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
635 * is performed.
636 *
637 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
638 */
639int crypto_lskcipher_setkey(struct crypto_lskcipher *tfm,
640			    const u8 *key, unsigned int keylen);
641
642static inline unsigned int crypto_skcipher_min_keysize(
643	struct crypto_skcipher *tfm)
644{
645	return crypto_skcipher_alg_common(tfm)->min_keysize;
646}
647
648static inline unsigned int crypto_skcipher_max_keysize(
649	struct crypto_skcipher *tfm)
650{
651	return crypto_skcipher_alg_common(tfm)->max_keysize;
652}
653
654static inline unsigned int crypto_lskcipher_min_keysize(
655	struct crypto_lskcipher *tfm)
656{
657	return crypto_lskcipher_alg(tfm)->co.min_keysize;
658}
659
660static inline unsigned int crypto_lskcipher_max_keysize(
661	struct crypto_lskcipher *tfm)
662{
663	return crypto_lskcipher_alg(tfm)->co.max_keysize;
664}
665
666/**
667 * crypto_skcipher_reqtfm() - obtain cipher handle from request
668 * @req: skcipher_request out of which the cipher handle is to be obtained
669 *
670 * Return the crypto_skcipher handle when furnishing an skcipher_request
671 * data structure.
672 *
673 * Return: crypto_skcipher handle
674 */
675static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
676	struct skcipher_request *req)
677{
678	return __crypto_skcipher_cast(req->base.tfm);
679}
680
681static inline struct crypto_sync_skcipher *crypto_sync_skcipher_reqtfm(
682	struct skcipher_request *req)
683{
684	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
685
686	return container_of(tfm, struct crypto_sync_skcipher, base);
687}
688
689/**
690 * crypto_skcipher_encrypt() - encrypt plaintext
691 * @req: reference to the skcipher_request handle that holds all information
692 *	 needed to perform the cipher operation
693 *
694 * Encrypt plaintext data using the skcipher_request handle. That data
695 * structure and how it is filled with data is discussed with the
696 * skcipher_request_* functions.
697 *
698 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
699 */
700int crypto_skcipher_encrypt(struct skcipher_request *req);
701
702/**
703 * crypto_skcipher_decrypt() - decrypt ciphertext
704 * @req: reference to the skcipher_request handle that holds all information
705 *	 needed to perform the cipher operation
706 *
707 * Decrypt ciphertext data using the skcipher_request handle. That data
708 * structure and how it is filled with data is discussed with the
709 * skcipher_request_* functions.
710 *
711 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
712 */
713int crypto_skcipher_decrypt(struct skcipher_request *req);
714
715/**
716 * crypto_skcipher_export() - export partial state
717 * @req: reference to the skcipher_request handle that holds all information
718 *	 needed to perform the operation
719 * @out: output buffer of sufficient size that can hold the state
720 *
721 * Export partial state of the transformation. This function dumps the
722 * entire state of the ongoing transformation into a provided block of
723 * data so it can be @import 'ed back later on. This is useful in case
724 * you want to save partial result of the transformation after
725 * processing certain amount of data and reload this partial result
726 * multiple times later on for multiple re-use. No data processing
727 * happens at this point.
728 *
729 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
730 */
731int crypto_skcipher_export(struct skcipher_request *req, void *out);
732
733/**
734 * crypto_skcipher_import() - import partial state
735 * @req: reference to the skcipher_request handle that holds all information
736 *	 needed to perform the operation
737 * @in: buffer holding the state
738 *
739 * Import partial state of the transformation. This function loads the
740 * entire state of the ongoing transformation from a provided block of
741 * data so the transformation can continue from this point onward. No
742 * data processing happens at this point.
743 *
744 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
745 */
746int crypto_skcipher_import(struct skcipher_request *req, const void *in);
747
748/**
749 * crypto_lskcipher_encrypt() - encrypt plaintext
750 * @tfm: lskcipher handle
751 * @src: source buffer
752 * @dst: destination buffer
753 * @len: number of bytes to process
754 * @siv: IV + state for the cipher operation.  The length of the IV must
755 *	 comply with the IV size defined by crypto_lskcipher_ivsize.  The
756 *	 IV is then followed with a buffer with the length as specified by
757 *	 crypto_lskcipher_statesize.
758 * Encrypt plaintext data using the lskcipher handle.
759 *
760 * Return: >=0 if the cipher operation was successful, if positive
761 *	   then this many bytes have been left unprocessed;
762 *	   < 0 if an error occurred
763 */
764int crypto_lskcipher_encrypt(struct crypto_lskcipher *tfm, const u8 *src,
765			     u8 *dst, unsigned len, u8 *siv);
766
767/**
768 * crypto_lskcipher_decrypt() - decrypt ciphertext
769 * @tfm: lskcipher handle
770 * @src: source buffer
771 * @dst: destination buffer
772 * @len: number of bytes to process
773 * @siv: IV + state for the cipher operation.  The length of the IV must
774 *	 comply with the IV size defined by crypto_lskcipher_ivsize.  The
775 *	 IV is then followed with a buffer with the length as specified by
776 *	 crypto_lskcipher_statesize.
777 *
778 * Decrypt ciphertext data using the lskcipher handle.
779 *
780 * Return: >=0 if the cipher operation was successful, if positive
781 *	   then this many bytes have been left unprocessed;
782 *	   < 0 if an error occurred
783 */
784int crypto_lskcipher_decrypt(struct crypto_lskcipher *tfm, const u8 *src,
785			     u8 *dst, unsigned len, u8 *siv);
786
787/**
788 * DOC: Symmetric Key Cipher Request Handle
789 *
790 * The skcipher_request data structure contains all pointers to data
791 * required for the symmetric key cipher operation. This includes the cipher
792 * handle (which can be used by multiple skcipher_request instances), pointer
793 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
794 * as a handle to the skcipher_request_* API calls in a similar way as
795 * skcipher handle to the crypto_skcipher_* API calls.
796 */
797
798/**
799 * crypto_skcipher_reqsize() - obtain size of the request data structure
800 * @tfm: cipher handle
801 *
802 * Return: number of bytes
803 */
804static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
805{
806	return tfm->reqsize;
807}
808
809/**
810 * skcipher_request_set_tfm() - update cipher handle reference in request
811 * @req: request handle to be modified
812 * @tfm: cipher handle that shall be added to the request handle
813 *
814 * Allow the caller to replace the existing skcipher handle in the request
815 * data structure with a different one.
816 */
817static inline void skcipher_request_set_tfm(struct skcipher_request *req,
818					    struct crypto_skcipher *tfm)
819{
820	req->base.tfm = crypto_skcipher_tfm(tfm);
821}
822
823static inline void skcipher_request_set_sync_tfm(struct skcipher_request *req,
824					    struct crypto_sync_skcipher *tfm)
825{
826	skcipher_request_set_tfm(req, &tfm->base);
827}
828
829static inline struct skcipher_request *skcipher_request_cast(
830	struct crypto_async_request *req)
831{
832	return container_of(req, struct skcipher_request, base);
833}
834
835/**
836 * skcipher_request_alloc() - allocate request data structure
837 * @tfm: cipher handle to be registered with the request
838 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
839 *
840 * Allocate the request data structure that must be used with the skcipher
841 * encrypt and decrypt API calls. During the allocation, the provided skcipher
842 * handle is registered in the request data structure.
843 *
844 * Return: allocated request handle in case of success, or NULL if out of memory
845 */
846static inline struct skcipher_request *skcipher_request_alloc_noprof(
847	struct crypto_skcipher *tfm, gfp_t gfp)
848{
849	struct skcipher_request *req;
850
851	req = kmalloc_noprof(sizeof(struct skcipher_request) +
852			     crypto_skcipher_reqsize(tfm), gfp);
853
854	if (likely(req))
855		skcipher_request_set_tfm(req, tfm);
856
857	return req;
858}
859#define skcipher_request_alloc(...)	alloc_hooks(skcipher_request_alloc_noprof(__VA_ARGS__))
860
861/**
862 * skcipher_request_free() - zeroize and free request data structure
863 * @req: request data structure cipher handle to be freed
864 */
865static inline void skcipher_request_free(struct skcipher_request *req)
866{
867	kfree_sensitive(req);
868}
869
870static inline void skcipher_request_zero(struct skcipher_request *req)
871{
872	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
873
874	memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
875}
876
877/**
878 * skcipher_request_set_callback() - set asynchronous callback function
879 * @req: request handle
880 * @flags: specify zero or an ORing of the flags
881 *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
882 *	   increase the wait queue beyond the initial maximum size;
883 *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
884 * @compl: callback function pointer to be registered with the request handle
885 * @data: The data pointer refers to memory that is not used by the kernel
886 *	  crypto API, but provided to the callback function for it to use. Here,
887 *	  the caller can provide a reference to memory the callback function can
888 *	  operate on. As the callback function is invoked asynchronously to the
889 *	  related functionality, it may need to access data structures of the
890 *	  related functionality which can be referenced using this pointer. The
891 *	  callback function can access the memory via the "data" field in the
892 *	  crypto_async_request data structure provided to the callback function.
893 *
894 * This function allows setting the callback function that is triggered once the
895 * cipher operation completes.
896 *
897 * The callback function is registered with the skcipher_request handle and
898 * must comply with the following template::
899 *
900 *	void callback_function(struct crypto_async_request *req, int error)
901 */
902static inline void skcipher_request_set_callback(struct skcipher_request *req,
903						 u32 flags,
904						 crypto_completion_t compl,
905						 void *data)
906{
907	req->base.complete = compl;
908	req->base.data = data;
909	req->base.flags = flags;
910}
911
912/**
913 * skcipher_request_set_crypt() - set data buffers
914 * @req: request handle
915 * @src: source scatter / gather list
916 * @dst: destination scatter / gather list
917 * @cryptlen: number of bytes to process from @src
918 * @iv: IV for the cipher operation which must comply with the IV size defined
919 *      by crypto_skcipher_ivsize
920 *
921 * This function allows setting of the source data and destination data
922 * scatter / gather lists.
923 *
924 * For encryption, the source is treated as the plaintext and the
925 * destination is the ciphertext. For a decryption operation, the use is
926 * reversed - the source is the ciphertext and the destination is the plaintext.
927 */
928static inline void skcipher_request_set_crypt(
929	struct skcipher_request *req,
930	struct scatterlist *src, struct scatterlist *dst,
931	unsigned int cryptlen, void *iv)
932{
933	req->src = src;
934	req->dst = dst;
935	req->cryptlen = cryptlen;
936	req->iv = iv;
937}
938
939#endif	/* _CRYPTO_SKCIPHER_H */
940