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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Symmetric key ciphers.
4 *
5 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8#ifndef _CRYPTO_SKCIPHER_H
9#define _CRYPTO_SKCIPHER_H
10
11#include <linux/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 crypto_istat_cipher - statistics for cipher algorithm
69 * @encrypt_cnt: number of encrypt requests
70 * @encrypt_tlen: total data size handled by encrypt requests
71 * @decrypt_cnt: number of decrypt requests
72 * @decrypt_tlen: total data size handled by decrypt requests
73 * @err_cnt: number of error for cipher requests
74 */
75struct crypto_istat_cipher {
76 atomic64_t encrypt_cnt;
77 atomic64_t encrypt_tlen;
78 atomic64_t decrypt_cnt;
79 atomic64_t decrypt_tlen;
80 atomic64_t err_cnt;
81};
82
83#ifdef CONFIG_CRYPTO_STATS
84#define SKCIPHER_ALG_COMMON_STAT struct crypto_istat_cipher stat;
85#else
86#define SKCIPHER_ALG_COMMON_STAT
87#endif
88
89/*
90 * struct skcipher_alg_common - common properties of skcipher_alg
91 * @min_keysize: Minimum key size supported by the transformation. This is the
92 * smallest key length supported by this transformation algorithm.
93 * This must be set to one of the pre-defined values as this is
94 * not hardware specific. Possible values for this field can be
95 * found via git grep "_MIN_KEY_SIZE" include/crypto/
96 * @max_keysize: Maximum key size supported by the transformation. This is the
97 * largest key length supported by this transformation algorithm.
98 * This must be set to one of the pre-defined values as this is
99 * not hardware specific. Possible values for this field can be
100 * found via git grep "_MAX_KEY_SIZE" include/crypto/
101 * @ivsize: IV size applicable for transformation. The consumer must provide an
102 * IV of exactly that size to perform the encrypt or decrypt operation.
103 * @chunksize: Equal to the block size except for stream ciphers such as
104 * CTR where it is set to the underlying block size.
105 * @statesize: Size of the internal state for the algorithm.
106 * @stat: Statistics for cipher algorithm
107 * @base: Definition of a generic crypto algorithm.
108 */
109#define SKCIPHER_ALG_COMMON { \
110 unsigned int min_keysize; \
111 unsigned int max_keysize; \
112 unsigned int ivsize; \
113 unsigned int chunksize; \
114 unsigned int statesize; \
115 \
116 SKCIPHER_ALG_COMMON_STAT \
117 \
118 struct crypto_alg base; \
119}
120struct skcipher_alg_common SKCIPHER_ALG_COMMON;
121
122/**
123 * struct skcipher_alg - symmetric key cipher definition
124 * @setkey: Set key for the transformation. This function is used to either
125 * program a supplied key into the hardware or store the key in the
126 * transformation context for programming it later. Note that this
127 * function does modify the transformation context. This function can
128 * be called multiple times during the existence of the transformation
129 * object, so one must make sure the key is properly reprogrammed into
130 * the hardware. This function is also responsible for checking the key
131 * length for validity. In case a software fallback was put in place in
132 * the @cra_init call, this function might need to use the fallback if
133 * the algorithm doesn't support all of the key sizes.
134 * @encrypt: Encrypt a scatterlist of blocks. This function is used to encrypt
135 * the supplied scatterlist containing the blocks of data. The crypto
136 * API consumer is responsible for aligning the entries of the
137 * scatterlist properly and making sure the chunks are correctly
138 * sized. In case a software fallback was put in place in the
139 * @cra_init call, this function might need to use the fallback if
140 * the algorithm doesn't support all of the key sizes. In case the
141 * key was stored in transformation context, the key might need to be
142 * re-programmed into the hardware in this function. This function
143 * shall not modify the transformation context, as this function may
144 * be called in parallel with the same transformation object.
145 * @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt
146 * and the conditions are exactly the same.
147 * @export: Export partial state of the transformation. This function dumps the
148 * entire state of the ongoing transformation into a provided block of
149 * data so it can be @import 'ed back later on. This is useful in case
150 * you want to save partial result of the transformation after
151 * processing certain amount of data and reload this partial result
152 * multiple times later on for multiple re-use. No data processing
153 * happens at this point.
154 * @import: Import partial state of the transformation. This function loads the
155 * entire state of the ongoing transformation from a provided block of
156 * data so the transformation can continue from this point onward. No
157 * data processing happens at this point.
158 * @init: Initialize the cryptographic transformation object. This function
159 * is used to initialize the cryptographic transformation object.
160 * This function is called only once at the instantiation time, right
161 * after the transformation context was allocated. In case the
162 * cryptographic hardware has some special requirements which need to
163 * be handled by software, this function shall check for the precise
164 * requirement of the transformation and put any software fallbacks
165 * in place.
166 * @exit: Deinitialize the cryptographic transformation object. This is a
167 * counterpart to @init, used to remove various changes set in
168 * @init.
169 * @walksize: Equal to the chunk size except in cases where the algorithm is
170 * considerably more efficient if it can operate on multiple chunks
171 * in parallel. Should be a multiple of chunksize.
172 * @co: see struct skcipher_alg_common
173 *
174 * All fields except @ivsize are mandatory and must be filled.
175 */
176struct skcipher_alg {
177 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
178 unsigned int keylen);
179 int (*encrypt)(struct skcipher_request *req);
180 int (*decrypt)(struct skcipher_request *req);
181 int (*export)(struct skcipher_request *req, void *out);
182 int (*import)(struct skcipher_request *req, const void *in);
183 int (*init)(struct crypto_skcipher *tfm);
184 void (*exit)(struct crypto_skcipher *tfm);
185
186 unsigned int walksize;
187
188 union {
189 struct SKCIPHER_ALG_COMMON;
190 struct skcipher_alg_common co;
191 };
192};
193
194/**
195 * struct lskcipher_alg - linear symmetric key cipher definition
196 * @setkey: Set key for the transformation. This function is used to either
197 * program a supplied key into the hardware or store the key in the
198 * transformation context for programming it later. Note that this
199 * function does modify the transformation context. This function can
200 * be called multiple times during the existence of the transformation
201 * object, so one must make sure the key is properly reprogrammed into
202 * the hardware. This function is also responsible for checking the key
203 * length for validity. In case a software fallback was put in place in
204 * the @cra_init call, this function might need to use the fallback if
205 * the algorithm doesn't support all of the key sizes.
206 * @encrypt: Encrypt a number of bytes. This function is used to encrypt
207 * the supplied data. This function shall not modify
208 * the transformation context, as this function may be called
209 * in parallel with the same transformation object. Data
210 * may be left over if length is not a multiple of blocks
211 * and there is more to come (final == false). The number of
212 * left-over bytes should be returned in case of success.
213 * The siv field shall be as long as ivsize + statesize with
214 * the IV placed at the front. The state will be used by the
215 * algorithm internally.
216 * @decrypt: Decrypt a number of bytes. This is a reverse counterpart to
217 * @encrypt and the conditions are exactly the same.
218 * @init: Initialize the cryptographic transformation object. This function
219 * is used to initialize the cryptographic transformation object.
220 * This function is called only once at the instantiation time, right
221 * after the transformation context was allocated.
222 * @exit: Deinitialize the cryptographic transformation object. This is a
223 * counterpart to @init, used to remove various changes set in
224 * @init.
225 * @co: see struct skcipher_alg_common
226 */
227struct lskcipher_alg {
228 int (*setkey)(struct crypto_lskcipher *tfm, const u8 *key,
229 unsigned int keylen);
230 int (*encrypt)(struct crypto_lskcipher *tfm, const u8 *src,
231 u8 *dst, unsigned len, u8 *siv, u32 flags);
232 int (*decrypt)(struct crypto_lskcipher *tfm, const u8 *src,
233 u8 *dst, unsigned len, u8 *siv, u32 flags);
234 int (*init)(struct crypto_lskcipher *tfm);
235 void (*exit)(struct crypto_lskcipher *tfm);
236
237 struct skcipher_alg_common co;
238};
239
240#define MAX_SYNC_SKCIPHER_REQSIZE 384
241/*
242 * This performs a type-check against the "tfm" argument to make sure
243 * all users have the correct skcipher tfm for doing on-stack requests.
244 */
245#define SYNC_SKCIPHER_REQUEST_ON_STACK(name, tfm) \
246 char __##name##_desc[sizeof(struct skcipher_request) + \
247 MAX_SYNC_SKCIPHER_REQSIZE + \
248 (!(sizeof((struct crypto_sync_skcipher *)1 == \
249 (typeof(tfm))1))) \
250 ] CRYPTO_MINALIGN_ATTR; \
251 struct skcipher_request *name = (void *)__##name##_desc
252
253/**
254 * DOC: Symmetric Key Cipher API
255 *
256 * Symmetric key cipher API is used with the ciphers of type
257 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
258 *
259 * Asynchronous cipher operations imply that the function invocation for a
260 * cipher request returns immediately before the completion of the operation.
261 * The cipher request is scheduled as a separate kernel thread and therefore
262 * load-balanced on the different CPUs via the process scheduler. To allow
263 * the kernel crypto API to inform the caller about the completion of a cipher
264 * request, the caller must provide a callback function. That function is
265 * invoked with the cipher handle when the request completes.
266 *
267 * To support the asynchronous operation, additional information than just the
268 * cipher handle must be supplied to the kernel crypto API. That additional
269 * information is given by filling in the skcipher_request data structure.
270 *
271 * For the symmetric key cipher API, the state is maintained with the tfm
272 * cipher handle. A single tfm can be used across multiple calls and in
273 * parallel. For asynchronous block cipher calls, context data supplied and
274 * only used by the caller can be referenced the request data structure in
275 * addition to the IV used for the cipher request. The maintenance of such
276 * state information would be important for a crypto driver implementer to
277 * have, because when calling the callback function upon completion of the
278 * cipher operation, that callback function may need some information about
279 * which operation just finished if it invoked multiple in parallel. This
280 * state information is unused by the kernel crypto API.
281 */
282
283static inline struct crypto_skcipher *__crypto_skcipher_cast(
284 struct crypto_tfm *tfm)
285{
286 return container_of(tfm, struct crypto_skcipher, base);
287}
288
289/**
290 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
291 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
292 * skcipher cipher
293 * @type: specifies the type of the cipher
294 * @mask: specifies the mask for the cipher
295 *
296 * Allocate a cipher handle for an skcipher. The returned struct
297 * crypto_skcipher is the cipher handle that is required for any subsequent
298 * API invocation for that skcipher.
299 *
300 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
301 * of an error, PTR_ERR() returns the error code.
302 */
303struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
304 u32 type, u32 mask);
305
306struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(const char *alg_name,
307 u32 type, u32 mask);
308
309
310/**
311 * crypto_alloc_lskcipher() - allocate linear symmetric key cipher handle
312 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
313 * lskcipher
314 * @type: specifies the type of the cipher
315 * @mask: specifies the mask for the cipher
316 *
317 * Allocate a cipher handle for an lskcipher. The returned struct
318 * crypto_lskcipher is the cipher handle that is required for any subsequent
319 * API invocation for that lskcipher.
320 *
321 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
322 * of an error, PTR_ERR() returns the error code.
323 */
324struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name,
325 u32 type, u32 mask);
326
327static inline struct crypto_tfm *crypto_skcipher_tfm(
328 struct crypto_skcipher *tfm)
329{
330 return &tfm->base;
331}
332
333static inline struct crypto_tfm *crypto_lskcipher_tfm(
334 struct crypto_lskcipher *tfm)
335{
336 return &tfm->base;
337}
338
339/**
340 * crypto_free_skcipher() - zeroize and free cipher handle
341 * @tfm: cipher handle to be freed
342 *
343 * If @tfm is a NULL or error pointer, this function does nothing.
344 */
345static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
346{
347 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
348}
349
350static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm)
351{
352 crypto_free_skcipher(&tfm->base);
353}
354
355/**
356 * crypto_free_lskcipher() - zeroize and free cipher handle
357 * @tfm: cipher handle to be freed
358 *
359 * If @tfm is a NULL or error pointer, this function does nothing.
360 */
361static inline void crypto_free_lskcipher(struct crypto_lskcipher *tfm)
362{
363 crypto_destroy_tfm(tfm, crypto_lskcipher_tfm(tfm));
364}
365
366/**
367 * crypto_has_skcipher() - Search for the availability of an skcipher.
368 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
369 * skcipher
370 * @type: specifies the type of the skcipher
371 * @mask: specifies the mask for the skcipher
372 *
373 * Return: true when the skcipher is known to the kernel crypto API; false
374 * otherwise
375 */
376int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask);
377
378static inline const char *crypto_skcipher_driver_name(
379 struct crypto_skcipher *tfm)
380{
381 return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
382}
383
384static inline const char *crypto_lskcipher_driver_name(
385 struct crypto_lskcipher *tfm)
386{
387 return crypto_tfm_alg_driver_name(crypto_lskcipher_tfm(tfm));
388}
389
390static inline struct skcipher_alg_common *crypto_skcipher_alg_common(
391 struct crypto_skcipher *tfm)
392{
393 return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
394 struct skcipher_alg_common, base);
395}
396
397static inline struct skcipher_alg *crypto_skcipher_alg(
398 struct crypto_skcipher *tfm)
399{
400 return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
401 struct skcipher_alg, base);
402}
403
404static inline struct lskcipher_alg *crypto_lskcipher_alg(
405 struct crypto_lskcipher *tfm)
406{
407 return container_of(crypto_lskcipher_tfm(tfm)->__crt_alg,
408 struct lskcipher_alg, co.base);
409}
410
411/**
412 * crypto_skcipher_ivsize() - obtain IV size
413 * @tfm: cipher handle
414 *
415 * The size of the IV for the skcipher referenced by the cipher handle is
416 * returned. This IV size may be zero if the cipher does not need an IV.
417 *
418 * Return: IV size in bytes
419 */
420static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
421{
422 return crypto_skcipher_alg_common(tfm)->ivsize;
423}
424
425static inline unsigned int crypto_sync_skcipher_ivsize(
426 struct crypto_sync_skcipher *tfm)
427{
428 return crypto_skcipher_ivsize(&tfm->base);
429}
430
431/**
432 * crypto_lskcipher_ivsize() - obtain IV size
433 * @tfm: cipher handle
434 *
435 * The size of the IV for the lskcipher referenced by the cipher handle is
436 * returned. This IV size may be zero if the cipher does not need an IV.
437 *
438 * Return: IV size in bytes
439 */
440static inline unsigned int crypto_lskcipher_ivsize(
441 struct crypto_lskcipher *tfm)
442{
443 return crypto_lskcipher_alg(tfm)->co.ivsize;
444}
445
446/**
447 * crypto_skcipher_blocksize() - obtain block size of cipher
448 * @tfm: cipher handle
449 *
450 * The block size for the skcipher referenced with the cipher handle is
451 * returned. The caller may use that information to allocate appropriate
452 * memory for the data returned by the encryption or decryption operation
453 *
454 * Return: block size of cipher
455 */
456static inline unsigned int crypto_skcipher_blocksize(
457 struct crypto_skcipher *tfm)
458{
459 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
460}
461
462/**
463 * crypto_lskcipher_blocksize() - obtain block size of cipher
464 * @tfm: cipher handle
465 *
466 * The block size for the lskcipher referenced with the cipher handle is
467 * returned. The caller may use that information to allocate appropriate
468 * memory for the data returned by the encryption or decryption operation
469 *
470 * Return: block size of cipher
471 */
472static inline unsigned int crypto_lskcipher_blocksize(
473 struct crypto_lskcipher *tfm)
474{
475 return crypto_tfm_alg_blocksize(crypto_lskcipher_tfm(tfm));
476}
477
478/**
479 * crypto_skcipher_chunksize() - obtain chunk size
480 * @tfm: cipher handle
481 *
482 * The block size is set to one for ciphers such as CTR. However,
483 * you still need to provide incremental updates in multiples of
484 * the underlying block size as the IV does not have sub-block
485 * granularity. This is known in this API as the chunk size.
486 *
487 * Return: chunk size in bytes
488 */
489static inline unsigned int crypto_skcipher_chunksize(
490 struct crypto_skcipher *tfm)
491{
492 return crypto_skcipher_alg_common(tfm)->chunksize;
493}
494
495/**
496 * crypto_lskcipher_chunksize() - obtain chunk size
497 * @tfm: cipher handle
498 *
499 * The block size is set to one for ciphers such as CTR. However,
500 * you still need to provide incremental updates in multiples of
501 * the underlying block size as the IV does not have sub-block
502 * granularity. This is known in this API as the chunk size.
503 *
504 * Return: chunk size in bytes
505 */
506static inline unsigned int crypto_lskcipher_chunksize(
507 struct crypto_lskcipher *tfm)
508{
509 return crypto_lskcipher_alg(tfm)->co.chunksize;
510}
511
512/**
513 * crypto_skcipher_statesize() - obtain state size
514 * @tfm: cipher handle
515 *
516 * Some algorithms cannot be chained with the IV alone. They carry
517 * internal state which must be replicated if data is to be processed
518 * incrementally. The size of that state can be obtained with this
519 * function.
520 *
521 * Return: state size in bytes
522 */
523static inline unsigned int crypto_skcipher_statesize(
524 struct crypto_skcipher *tfm)
525{
526 return crypto_skcipher_alg_common(tfm)->statesize;
527}
528
529/**
530 * crypto_lskcipher_statesize() - obtain state size
531 * @tfm: cipher handle
532 *
533 * Some algorithms cannot be chained with the IV alone. They carry
534 * internal state which must be replicated if data is to be processed
535 * incrementally. The size of that state can be obtained with this
536 * function.
537 *
538 * Return: state size in bytes
539 */
540static inline unsigned int crypto_lskcipher_statesize(
541 struct crypto_lskcipher *tfm)
542{
543 return crypto_lskcipher_alg(tfm)->co.statesize;
544}
545
546static inline unsigned int crypto_sync_skcipher_blocksize(
547 struct crypto_sync_skcipher *tfm)
548{
549 return crypto_skcipher_blocksize(&tfm->base);
550}
551
552static inline unsigned int crypto_skcipher_alignmask(
553 struct crypto_skcipher *tfm)
554{
555 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
556}
557
558static inline unsigned int crypto_lskcipher_alignmask(
559 struct crypto_lskcipher *tfm)
560{
561 return crypto_tfm_alg_alignmask(crypto_lskcipher_tfm(tfm));
562}
563
564static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
565{
566 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
567}
568
569static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
570 u32 flags)
571{
572 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
573}
574
575static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
576 u32 flags)
577{
578 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
579}
580
581static inline u32 crypto_sync_skcipher_get_flags(
582 struct crypto_sync_skcipher *tfm)
583{
584 return crypto_skcipher_get_flags(&tfm->base);
585}
586
587static inline void crypto_sync_skcipher_set_flags(
588 struct crypto_sync_skcipher *tfm, u32 flags)
589{
590 crypto_skcipher_set_flags(&tfm->base, flags);
591}
592
593static inline void crypto_sync_skcipher_clear_flags(
594 struct crypto_sync_skcipher *tfm, u32 flags)
595{
596 crypto_skcipher_clear_flags(&tfm->base, flags);
597}
598
599static inline u32 crypto_lskcipher_get_flags(struct crypto_lskcipher *tfm)
600{
601 return crypto_tfm_get_flags(crypto_lskcipher_tfm(tfm));
602}
603
604static inline void crypto_lskcipher_set_flags(struct crypto_lskcipher *tfm,
605 u32 flags)
606{
607 crypto_tfm_set_flags(crypto_lskcipher_tfm(tfm), flags);
608}
609
610static inline void crypto_lskcipher_clear_flags(struct crypto_lskcipher *tfm,
611 u32 flags)
612{
613 crypto_tfm_clear_flags(crypto_lskcipher_tfm(tfm), flags);
614}
615
616/**
617 * crypto_skcipher_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 skcipher 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 */
632int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
633 const u8 *key, unsigned int keylen);
634
635static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
636 const u8 *key, unsigned int keylen)
637{
638 return crypto_skcipher_setkey(&tfm->base, key, keylen);
639}
640
641/**
642 * crypto_lskcipher_setkey() - set key for cipher
643 * @tfm: cipher handle
644 * @key: buffer holding the key
645 * @keylen: length of the key in bytes
646 *
647 * The caller provided key is set for the lskcipher referenced by the cipher
648 * handle.
649 *
650 * Note, the key length determines the cipher type. Many block ciphers implement
651 * different cipher modes depending on the key size, such as AES-128 vs AES-192
652 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
653 * is performed.
654 *
655 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
656 */
657int crypto_lskcipher_setkey(struct crypto_lskcipher *tfm,
658 const u8 *key, unsigned int keylen);
659
660static inline unsigned int crypto_skcipher_min_keysize(
661 struct crypto_skcipher *tfm)
662{
663 return crypto_skcipher_alg_common(tfm)->min_keysize;
664}
665
666static inline unsigned int crypto_skcipher_max_keysize(
667 struct crypto_skcipher *tfm)
668{
669 return crypto_skcipher_alg_common(tfm)->max_keysize;
670}
671
672static inline unsigned int crypto_lskcipher_min_keysize(
673 struct crypto_lskcipher *tfm)
674{
675 return crypto_lskcipher_alg(tfm)->co.min_keysize;
676}
677
678static inline unsigned int crypto_lskcipher_max_keysize(
679 struct crypto_lskcipher *tfm)
680{
681 return crypto_lskcipher_alg(tfm)->co.max_keysize;
682}
683
684/**
685 * crypto_skcipher_reqtfm() - obtain cipher handle from request
686 * @req: skcipher_request out of which the cipher handle is to be obtained
687 *
688 * Return the crypto_skcipher handle when furnishing an skcipher_request
689 * data structure.
690 *
691 * Return: crypto_skcipher handle
692 */
693static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
694 struct skcipher_request *req)
695{
696 return __crypto_skcipher_cast(req->base.tfm);
697}
698
699static inline struct crypto_sync_skcipher *crypto_sync_skcipher_reqtfm(
700 struct skcipher_request *req)
701{
702 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
703
704 return container_of(tfm, struct crypto_sync_skcipher, base);
705}
706
707/**
708 * crypto_skcipher_encrypt() - encrypt plaintext
709 * @req: reference to the skcipher_request handle that holds all information
710 * needed to perform the cipher operation
711 *
712 * Encrypt plaintext data using the skcipher_request handle. That data
713 * structure and how it is filled with data is discussed with the
714 * skcipher_request_* functions.
715 *
716 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
717 */
718int crypto_skcipher_encrypt(struct skcipher_request *req);
719
720/**
721 * crypto_skcipher_decrypt() - decrypt ciphertext
722 * @req: reference to the skcipher_request handle that holds all information
723 * needed to perform the cipher operation
724 *
725 * Decrypt ciphertext data using the skcipher_request handle. That data
726 * structure and how it is filled with data is discussed with the
727 * skcipher_request_* functions.
728 *
729 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
730 */
731int crypto_skcipher_decrypt(struct skcipher_request *req);
732
733/**
734 * crypto_skcipher_export() - export partial state
735 * @req: reference to the skcipher_request handle that holds all information
736 * needed to perform the operation
737 * @out: output buffer of sufficient size that can hold the state
738 *
739 * Export partial state of the transformation. This function dumps the
740 * entire state of the ongoing transformation into a provided block of
741 * data so it can be @import 'ed back later on. This is useful in case
742 * you want to save partial result of the transformation after
743 * processing certain amount of data and reload this partial result
744 * multiple times later on for multiple re-use. No data processing
745 * happens at this point.
746 *
747 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
748 */
749int crypto_skcipher_export(struct skcipher_request *req, void *out);
750
751/**
752 * crypto_skcipher_import() - import partial state
753 * @req: reference to the skcipher_request handle that holds all information
754 * needed to perform the operation
755 * @in: buffer holding the state
756 *
757 * Import partial state of the transformation. This function loads the
758 * entire state of the ongoing transformation from a provided block of
759 * data so the transformation can continue from this point onward. No
760 * data processing happens at this point.
761 *
762 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
763 */
764int crypto_skcipher_import(struct skcipher_request *req, const void *in);
765
766/**
767 * crypto_lskcipher_encrypt() - encrypt plaintext
768 * @tfm: lskcipher handle
769 * @src: source buffer
770 * @dst: destination buffer
771 * @len: number of bytes to process
772 * @siv: IV + state for the cipher operation. The length of the IV must
773 * comply with the IV size defined by crypto_lskcipher_ivsize. The
774 * IV is then followed with a buffer with the length as specified by
775 * crypto_lskcipher_statesize.
776 * Encrypt plaintext data using the lskcipher handle.
777 *
778 * Return: >=0 if the cipher operation was successful, if positive
779 * then this many bytes have been left unprocessed;
780 * < 0 if an error occurred
781 */
782int crypto_lskcipher_encrypt(struct crypto_lskcipher *tfm, const u8 *src,
783 u8 *dst, unsigned len, u8 *siv);
784
785/**
786 * crypto_lskcipher_decrypt() - decrypt ciphertext
787 * @tfm: lskcipher handle
788 * @src: source buffer
789 * @dst: destination buffer
790 * @len: number of bytes to process
791 * @siv: IV + state for the cipher operation. The length of the IV must
792 * comply with the IV size defined by crypto_lskcipher_ivsize. The
793 * IV is then followed with a buffer with the length as specified by
794 * crypto_lskcipher_statesize.
795 *
796 * Decrypt ciphertext data using the lskcipher handle.
797 *
798 * Return: >=0 if the cipher operation was successful, if positive
799 * then this many bytes have been left unprocessed;
800 * < 0 if an error occurred
801 */
802int crypto_lskcipher_decrypt(struct crypto_lskcipher *tfm, const u8 *src,
803 u8 *dst, unsigned len, u8 *siv);
804
805/**
806 * DOC: Symmetric Key Cipher Request Handle
807 *
808 * The skcipher_request data structure contains all pointers to data
809 * required for the symmetric key cipher operation. This includes the cipher
810 * handle (which can be used by multiple skcipher_request instances), pointer
811 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
812 * as a handle to the skcipher_request_* API calls in a similar way as
813 * skcipher handle to the crypto_skcipher_* API calls.
814 */
815
816/**
817 * crypto_skcipher_reqsize() - obtain size of the request data structure
818 * @tfm: cipher handle
819 *
820 * Return: number of bytes
821 */
822static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
823{
824 return tfm->reqsize;
825}
826
827/**
828 * skcipher_request_set_tfm() - update cipher handle reference in request
829 * @req: request handle to be modified
830 * @tfm: cipher handle that shall be added to the request handle
831 *
832 * Allow the caller to replace the existing skcipher handle in the request
833 * data structure with a different one.
834 */
835static inline void skcipher_request_set_tfm(struct skcipher_request *req,
836 struct crypto_skcipher *tfm)
837{
838 req->base.tfm = crypto_skcipher_tfm(tfm);
839}
840
841static inline void skcipher_request_set_sync_tfm(struct skcipher_request *req,
842 struct crypto_sync_skcipher *tfm)
843{
844 skcipher_request_set_tfm(req, &tfm->base);
845}
846
847static inline struct skcipher_request *skcipher_request_cast(
848 struct crypto_async_request *req)
849{
850 return container_of(req, struct skcipher_request, base);
851}
852
853/**
854 * skcipher_request_alloc() - allocate request data structure
855 * @tfm: cipher handle to be registered with the request
856 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
857 *
858 * Allocate the request data structure that must be used with the skcipher
859 * encrypt and decrypt API calls. During the allocation, the provided skcipher
860 * handle is registered in the request data structure.
861 *
862 * Return: allocated request handle in case of success, or NULL if out of memory
863 */
864static inline struct skcipher_request *skcipher_request_alloc(
865 struct crypto_skcipher *tfm, gfp_t gfp)
866{
867 struct skcipher_request *req;
868
869 req = kmalloc(sizeof(struct skcipher_request) +
870 crypto_skcipher_reqsize(tfm), gfp);
871
872 if (likely(req))
873 skcipher_request_set_tfm(req, tfm);
874
875 return req;
876}
877
878/**
879 * skcipher_request_free() - zeroize and free request data structure
880 * @req: request data structure cipher handle to be freed
881 */
882static inline void skcipher_request_free(struct skcipher_request *req)
883{
884 kfree_sensitive(req);
885}
886
887static inline void skcipher_request_zero(struct skcipher_request *req)
888{
889 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
890
891 memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
892}
893
894/**
895 * skcipher_request_set_callback() - set asynchronous callback function
896 * @req: request handle
897 * @flags: specify zero or an ORing of the flags
898 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
899 * increase the wait queue beyond the initial maximum size;
900 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
901 * @compl: callback function pointer to be registered with the request handle
902 * @data: The data pointer refers to memory that is not used by the kernel
903 * crypto API, but provided to the callback function for it to use. Here,
904 * the caller can provide a reference to memory the callback function can
905 * operate on. As the callback function is invoked asynchronously to the
906 * related functionality, it may need to access data structures of the
907 * related functionality which can be referenced using this pointer. The
908 * callback function can access the memory via the "data" field in the
909 * crypto_async_request data structure provided to the callback function.
910 *
911 * This function allows setting the callback function that is triggered once the
912 * cipher operation completes.
913 *
914 * The callback function is registered with the skcipher_request handle and
915 * must comply with the following template::
916 *
917 * void callback_function(struct crypto_async_request *req, int error)
918 */
919static inline void skcipher_request_set_callback(struct skcipher_request *req,
920 u32 flags,
921 crypto_completion_t compl,
922 void *data)
923{
924 req->base.complete = compl;
925 req->base.data = data;
926 req->base.flags = flags;
927}
928
929/**
930 * skcipher_request_set_crypt() - set data buffers
931 * @req: request handle
932 * @src: source scatter / gather list
933 * @dst: destination scatter / gather list
934 * @cryptlen: number of bytes to process from @src
935 * @iv: IV for the cipher operation which must comply with the IV size defined
936 * by crypto_skcipher_ivsize
937 *
938 * This function allows setting of the source data and destination data
939 * scatter / gather lists.
940 *
941 * For encryption, the source is treated as the plaintext and the
942 * destination is the ciphertext. For a decryption operation, the use is
943 * reversed - the source is the ciphertext and the destination is the plaintext.
944 */
945static inline void skcipher_request_set_crypt(
946 struct skcipher_request *req,
947 struct scatterlist *src, struct scatterlist *dst,
948 unsigned int cryptlen, void *iv)
949{
950 req->src = src;
951 req->dst = dst;
952 req->cryptlen = cryptlen;
953 req->iv = iv;
954}
955
956#endif /* _CRYPTO_SKCIPHER_H */
957
1/*
2 * Symmetric key ciphers.
3 *
4 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#ifndef _CRYPTO_SKCIPHER_H
14#define _CRYPTO_SKCIPHER_H
15
16#include <linux/crypto.h>
17#include <linux/kernel.h>
18#include <linux/slab.h>
19
20/**
21 * struct skcipher_request - Symmetric key cipher request
22 * @cryptlen: Number of bytes to encrypt or decrypt
23 * @iv: Initialisation Vector
24 * @src: Source SG list
25 * @dst: Destination SG list
26 * @base: Underlying async request request
27 * @__ctx: Start of private context data
28 */
29struct skcipher_request {
30 unsigned int cryptlen;
31
32 u8 *iv;
33
34 struct scatterlist *src;
35 struct scatterlist *dst;
36
37 struct crypto_async_request base;
38
39 void *__ctx[] CRYPTO_MINALIGN_ATTR;
40};
41
42/**
43 * struct skcipher_givcrypt_request - Crypto request with IV generation
44 * @seq: Sequence number for IV generation
45 * @giv: Space for generated IV
46 * @creq: The crypto request itself
47 */
48struct skcipher_givcrypt_request {
49 u64 seq;
50 u8 *giv;
51
52 struct ablkcipher_request creq;
53};
54
55struct crypto_skcipher {
56 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
57 unsigned int keylen);
58 int (*encrypt)(struct skcipher_request *req);
59 int (*decrypt)(struct skcipher_request *req);
60
61 unsigned int ivsize;
62 unsigned int reqsize;
63 unsigned int keysize;
64
65 struct crypto_tfm base;
66};
67
68#define SKCIPHER_REQUEST_ON_STACK(name, tfm) \
69 char __##name##_desc[sizeof(struct skcipher_request) + \
70 crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
71 struct skcipher_request *name = (void *)__##name##_desc
72
73static inline struct crypto_ablkcipher *skcipher_givcrypt_reqtfm(
74 struct skcipher_givcrypt_request *req)
75{
76 return crypto_ablkcipher_reqtfm(&req->creq);
77}
78
79static inline int crypto_skcipher_givencrypt(
80 struct skcipher_givcrypt_request *req)
81{
82 struct ablkcipher_tfm *crt =
83 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
84 return crt->givencrypt(req);
85};
86
87static inline int crypto_skcipher_givdecrypt(
88 struct skcipher_givcrypt_request *req)
89{
90 struct ablkcipher_tfm *crt =
91 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
92 return crt->givdecrypt(req);
93};
94
95static inline void skcipher_givcrypt_set_tfm(
96 struct skcipher_givcrypt_request *req, struct crypto_ablkcipher *tfm)
97{
98 req->creq.base.tfm = crypto_ablkcipher_tfm(tfm);
99}
100
101static inline struct skcipher_givcrypt_request *skcipher_givcrypt_cast(
102 struct crypto_async_request *req)
103{
104 return container_of(ablkcipher_request_cast(req),
105 struct skcipher_givcrypt_request, creq);
106}
107
108static inline struct skcipher_givcrypt_request *skcipher_givcrypt_alloc(
109 struct crypto_ablkcipher *tfm, gfp_t gfp)
110{
111 struct skcipher_givcrypt_request *req;
112
113 req = kmalloc(sizeof(struct skcipher_givcrypt_request) +
114 crypto_ablkcipher_reqsize(tfm), gfp);
115
116 if (likely(req))
117 skcipher_givcrypt_set_tfm(req, tfm);
118
119 return req;
120}
121
122static inline void skcipher_givcrypt_free(struct skcipher_givcrypt_request *req)
123{
124 kfree(req);
125}
126
127static inline void skcipher_givcrypt_set_callback(
128 struct skcipher_givcrypt_request *req, u32 flags,
129 crypto_completion_t compl, void *data)
130{
131 ablkcipher_request_set_callback(&req->creq, flags, compl, data);
132}
133
134static inline void skcipher_givcrypt_set_crypt(
135 struct skcipher_givcrypt_request *req,
136 struct scatterlist *src, struct scatterlist *dst,
137 unsigned int nbytes, void *iv)
138{
139 ablkcipher_request_set_crypt(&req->creq, src, dst, nbytes, iv);
140}
141
142static inline void skcipher_givcrypt_set_giv(
143 struct skcipher_givcrypt_request *req, u8 *giv, u64 seq)
144{
145 req->giv = giv;
146 req->seq = seq;
147}
148
149/**
150 * DOC: Symmetric Key Cipher API
151 *
152 * Symmetric key cipher API is used with the ciphers of type
153 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
154 *
155 * Asynchronous cipher operations imply that the function invocation for a
156 * cipher request returns immediately before the completion of the operation.
157 * The cipher request is scheduled as a separate kernel thread and therefore
158 * load-balanced on the different CPUs via the process scheduler. To allow
159 * the kernel crypto API to inform the caller about the completion of a cipher
160 * request, the caller must provide a callback function. That function is
161 * invoked with the cipher handle when the request completes.
162 *
163 * To support the asynchronous operation, additional information than just the
164 * cipher handle must be supplied to the kernel crypto API. That additional
165 * information is given by filling in the skcipher_request data structure.
166 *
167 * For the symmetric key cipher API, the state is maintained with the tfm
168 * cipher handle. A single tfm can be used across multiple calls and in
169 * parallel. For asynchronous block cipher calls, context data supplied and
170 * only used by the caller can be referenced the request data structure in
171 * addition to the IV used for the cipher request. The maintenance of such
172 * state information would be important for a crypto driver implementer to
173 * have, because when calling the callback function upon completion of the
174 * cipher operation, that callback function may need some information about
175 * which operation just finished if it invoked multiple in parallel. This
176 * state information is unused by the kernel crypto API.
177 */
178
179static inline struct crypto_skcipher *__crypto_skcipher_cast(
180 struct crypto_tfm *tfm)
181{
182 return container_of(tfm, struct crypto_skcipher, base);
183}
184
185/**
186 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
187 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
188 * skcipher cipher
189 * @type: specifies the type of the cipher
190 * @mask: specifies the mask for the cipher
191 *
192 * Allocate a cipher handle for an skcipher. The returned struct
193 * crypto_skcipher is the cipher handle that is required for any subsequent
194 * API invocation for that skcipher.
195 *
196 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
197 * of an error, PTR_ERR() returns the error code.
198 */
199struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
200 u32 type, u32 mask);
201
202static inline struct crypto_tfm *crypto_skcipher_tfm(
203 struct crypto_skcipher *tfm)
204{
205 return &tfm->base;
206}
207
208/**
209 * crypto_free_skcipher() - zeroize and free cipher handle
210 * @tfm: cipher handle to be freed
211 */
212static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
213{
214 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
215}
216
217/**
218 * crypto_has_skcipher() - Search for the availability of an skcipher.
219 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
220 * skcipher
221 * @type: specifies the type of the cipher
222 * @mask: specifies the mask for the cipher
223 *
224 * Return: true when the skcipher is known to the kernel crypto API; false
225 * otherwise
226 */
227static inline int crypto_has_skcipher(const char *alg_name, u32 type,
228 u32 mask)
229{
230 return crypto_has_alg(alg_name, crypto_skcipher_type(type),
231 crypto_skcipher_mask(mask));
232}
233
234static inline const char *crypto_skcipher_driver_name(
235 struct crypto_skcipher *tfm)
236{
237 return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
238}
239
240/**
241 * crypto_skcipher_ivsize() - obtain IV size
242 * @tfm: cipher handle
243 *
244 * The size of the IV for the skcipher referenced by the cipher handle is
245 * returned. This IV size may be zero if the cipher does not need an IV.
246 *
247 * Return: IV size in bytes
248 */
249static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
250{
251 return tfm->ivsize;
252}
253
254/**
255 * crypto_skcipher_blocksize() - obtain block size of cipher
256 * @tfm: cipher handle
257 *
258 * The block size for the skcipher referenced with the cipher handle is
259 * returned. The caller may use that information to allocate appropriate
260 * memory for the data returned by the encryption or decryption operation
261 *
262 * Return: block size of cipher
263 */
264static inline unsigned int crypto_skcipher_blocksize(
265 struct crypto_skcipher *tfm)
266{
267 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
268}
269
270static inline unsigned int crypto_skcipher_alignmask(
271 struct crypto_skcipher *tfm)
272{
273 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
274}
275
276static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
277{
278 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
279}
280
281static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
282 u32 flags)
283{
284 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
285}
286
287static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
288 u32 flags)
289{
290 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
291}
292
293/**
294 * crypto_skcipher_setkey() - set key for cipher
295 * @tfm: cipher handle
296 * @key: buffer holding the key
297 * @keylen: length of the key in bytes
298 *
299 * The caller provided key is set for the skcipher referenced by the cipher
300 * handle.
301 *
302 * Note, the key length determines the cipher type. Many block ciphers implement
303 * different cipher modes depending on the key size, such as AES-128 vs AES-192
304 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
305 * is performed.
306 *
307 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
308 */
309static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
310 const u8 *key, unsigned int keylen)
311{
312 return tfm->setkey(tfm, key, keylen);
313}
314
315static inline bool crypto_skcipher_has_setkey(struct crypto_skcipher *tfm)
316{
317 return tfm->keysize;
318}
319
320static inline unsigned int crypto_skcipher_default_keysize(
321 struct crypto_skcipher *tfm)
322{
323 return tfm->keysize;
324}
325
326/**
327 * crypto_skcipher_reqtfm() - obtain cipher handle from request
328 * @req: skcipher_request out of which the cipher handle is to be obtained
329 *
330 * Return the crypto_skcipher handle when furnishing an skcipher_request
331 * data structure.
332 *
333 * Return: crypto_skcipher handle
334 */
335static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
336 struct skcipher_request *req)
337{
338 return __crypto_skcipher_cast(req->base.tfm);
339}
340
341/**
342 * crypto_skcipher_encrypt() - encrypt plaintext
343 * @req: reference to the skcipher_request handle that holds all information
344 * needed to perform the cipher operation
345 *
346 * Encrypt plaintext data using the skcipher_request handle. That data
347 * structure and how it is filled with data is discussed with the
348 * skcipher_request_* functions.
349 *
350 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
351 */
352static inline int crypto_skcipher_encrypt(struct skcipher_request *req)
353{
354 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
355
356 return tfm->encrypt(req);
357}
358
359/**
360 * crypto_skcipher_decrypt() - decrypt ciphertext
361 * @req: reference to the skcipher_request handle that holds all information
362 * needed to perform the cipher operation
363 *
364 * Decrypt ciphertext data using the skcipher_request handle. That data
365 * structure and how it is filled with data is discussed with the
366 * skcipher_request_* functions.
367 *
368 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
369 */
370static inline int crypto_skcipher_decrypt(struct skcipher_request *req)
371{
372 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
373
374 return tfm->decrypt(req);
375}
376
377/**
378 * DOC: Symmetric Key Cipher Request Handle
379 *
380 * The skcipher_request data structure contains all pointers to data
381 * required for the symmetric key cipher operation. This includes the cipher
382 * handle (which can be used by multiple skcipher_request instances), pointer
383 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
384 * as a handle to the skcipher_request_* API calls in a similar way as
385 * skcipher handle to the crypto_skcipher_* API calls.
386 */
387
388/**
389 * crypto_skcipher_reqsize() - obtain size of the request data structure
390 * @tfm: cipher handle
391 *
392 * Return: number of bytes
393 */
394static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
395{
396 return tfm->reqsize;
397}
398
399/**
400 * skcipher_request_set_tfm() - update cipher handle reference in request
401 * @req: request handle to be modified
402 * @tfm: cipher handle that shall be added to the request handle
403 *
404 * Allow the caller to replace the existing skcipher handle in the request
405 * data structure with a different one.
406 */
407static inline void skcipher_request_set_tfm(struct skcipher_request *req,
408 struct crypto_skcipher *tfm)
409{
410 req->base.tfm = crypto_skcipher_tfm(tfm);
411}
412
413static inline struct skcipher_request *skcipher_request_cast(
414 struct crypto_async_request *req)
415{
416 return container_of(req, struct skcipher_request, base);
417}
418
419/**
420 * skcipher_request_alloc() - allocate request data structure
421 * @tfm: cipher handle to be registered with the request
422 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
423 *
424 * Allocate the request data structure that must be used with the skcipher
425 * encrypt and decrypt API calls. During the allocation, the provided skcipher
426 * handle is registered in the request data structure.
427 *
428 * Return: allocated request handle in case of success; IS_ERR() is true in case
429 * of an error, PTR_ERR() returns the error code.
430 */
431static inline struct skcipher_request *skcipher_request_alloc(
432 struct crypto_skcipher *tfm, gfp_t gfp)
433{
434 struct skcipher_request *req;
435
436 req = kmalloc(sizeof(struct skcipher_request) +
437 crypto_skcipher_reqsize(tfm), gfp);
438
439 if (likely(req))
440 skcipher_request_set_tfm(req, tfm);
441
442 return req;
443}
444
445/**
446 * skcipher_request_free() - zeroize and free request data structure
447 * @req: request data structure cipher handle to be freed
448 */
449static inline void skcipher_request_free(struct skcipher_request *req)
450{
451 kzfree(req);
452}
453
454static inline void skcipher_request_zero(struct skcipher_request *req)
455{
456 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
457
458 memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
459}
460
461/**
462 * skcipher_request_set_callback() - set asynchronous callback function
463 * @req: request handle
464 * @flags: specify zero or an ORing of the flags
465 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
466 * increase the wait queue beyond the initial maximum size;
467 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
468 * @compl: callback function pointer to be registered with the request handle
469 * @data: The data pointer refers to memory that is not used by the kernel
470 * crypto API, but provided to the callback function for it to use. Here,
471 * the caller can provide a reference to memory the callback function can
472 * operate on. As the callback function is invoked asynchronously to the
473 * related functionality, it may need to access data structures of the
474 * related functionality which can be referenced using this pointer. The
475 * callback function can access the memory via the "data" field in the
476 * crypto_async_request data structure provided to the callback function.
477 *
478 * This function allows setting the callback function that is triggered once the
479 * cipher operation completes.
480 *
481 * The callback function is registered with the skcipher_request handle and
482 * must comply with the following template
483 *
484 * void callback_function(struct crypto_async_request *req, int error)
485 */
486static inline void skcipher_request_set_callback(struct skcipher_request *req,
487 u32 flags,
488 crypto_completion_t compl,
489 void *data)
490{
491 req->base.complete = compl;
492 req->base.data = data;
493 req->base.flags = flags;
494}
495
496/**
497 * skcipher_request_set_crypt() - set data buffers
498 * @req: request handle
499 * @src: source scatter / gather list
500 * @dst: destination scatter / gather list
501 * @cryptlen: number of bytes to process from @src
502 * @iv: IV for the cipher operation which must comply with the IV size defined
503 * by crypto_skcipher_ivsize
504 *
505 * This function allows setting of the source data and destination data
506 * scatter / gather lists.
507 *
508 * For encryption, the source is treated as the plaintext and the
509 * destination is the ciphertext. For a decryption operation, the use is
510 * reversed - the source is the ciphertext and the destination is the plaintext.
511 */
512static inline void skcipher_request_set_crypt(
513 struct skcipher_request *req,
514 struct scatterlist *src, struct scatterlist *dst,
515 unsigned int cryptlen, void *iv)
516{
517 req->src = src;
518 req->dst = dst;
519 req->cryptlen = cryptlen;
520 req->iv = iv;
521}
522
523#endif /* _CRYPTO_SKCIPHER_H */
524