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