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/crypto.h>
12#include <linux/kernel.h>
13#include <linux/slab.h>
14
15/**
16 * struct skcipher_request - Symmetric key cipher request
17 * @cryptlen: Number of bytes to encrypt or decrypt
18 * @iv: Initialisation Vector
19 * @src: Source SG list
20 * @dst: Destination SG list
21 * @base: Underlying async request request
22 * @__ctx: Start of private context data
23 */
24struct skcipher_request {
25 unsigned int cryptlen;
26
27 u8 *iv;
28
29 struct scatterlist *src;
30 struct scatterlist *dst;
31
32 struct crypto_async_request base;
33
34 void *__ctx[] CRYPTO_MINALIGN_ATTR;
35};
36
37struct crypto_skcipher {
38 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
39 unsigned int keylen);
40 int (*encrypt)(struct skcipher_request *req);
41 int (*decrypt)(struct skcipher_request *req);
42
43 unsigned int ivsize;
44 unsigned int reqsize;
45 unsigned int keysize;
46
47 struct crypto_tfm base;
48};
49
50struct crypto_sync_skcipher {
51 struct crypto_skcipher base;
52};
53
54/**
55 * struct skcipher_alg - symmetric key cipher definition
56 * @min_keysize: Minimum key size supported by the transformation. This is the
57 * smallest key length supported by this transformation algorithm.
58 * This must be set to one of the pre-defined values as this is
59 * not hardware specific. Possible values for this field can be
60 * found via git grep "_MIN_KEY_SIZE" include/crypto/
61 * @max_keysize: Maximum key size supported by the transformation. This is the
62 * largest key length supported by this transformation algorithm.
63 * This must be set to one of the pre-defined values as this is
64 * not hardware specific. Possible values for this field can be
65 * found via git grep "_MAX_KEY_SIZE" include/crypto/
66 * @setkey: Set key for the transformation. This function is used to either
67 * program a supplied key into the hardware or store the key in the
68 * transformation context for programming it later. Note that this
69 * function does modify the transformation context. This function can
70 * be called multiple times during the existence of the transformation
71 * object, so one must make sure the key is properly reprogrammed into
72 * the hardware. This function is also responsible for checking the key
73 * length for validity. In case a software fallback was put in place in
74 * the @cra_init call, this function might need to use the fallback if
75 * the algorithm doesn't support all of the key sizes.
76 * @encrypt: Encrypt a scatterlist of blocks. This function is used to encrypt
77 * the supplied scatterlist containing the blocks of data. The crypto
78 * API consumer is responsible for aligning the entries of the
79 * scatterlist properly and making sure the chunks are correctly
80 * sized. In case a software fallback was put in place in the
81 * @cra_init call, this function might need to use the fallback if
82 * the algorithm doesn't support all of the key sizes. In case the
83 * key was stored in transformation context, the key might need to be
84 * re-programmed into the hardware in this function. This function
85 * shall not modify the transformation context, as this function may
86 * be called in parallel with the same transformation object.
87 * @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt
88 * and the conditions are exactly the same.
89 * @init: Initialize the cryptographic transformation object. This function
90 * is used to initialize the cryptographic transformation object.
91 * This function is called only once at the instantiation time, right
92 * after the transformation context was allocated. In case the
93 * cryptographic hardware has some special requirements which need to
94 * be handled by software, this function shall check for the precise
95 * requirement of the transformation and put any software fallbacks
96 * in place.
97 * @exit: Deinitialize the cryptographic transformation object. This is a
98 * counterpart to @init, used to remove various changes set in
99 * @init.
100 * @ivsize: IV size applicable for transformation. The consumer must provide an
101 * IV of exactly that size to perform the encrypt or decrypt operation.
102 * @chunksize: Equal to the block size except for stream ciphers such as
103 * CTR where it is set to the underlying block size.
104 * @walksize: Equal to the chunk size except in cases where the algorithm is
105 * considerably more efficient if it can operate on multiple chunks
106 * in parallel. Should be a multiple of chunksize.
107 * @base: Definition of a generic crypto algorithm.
108 *
109 * All fields except @ivsize are mandatory and must be filled.
110 */
111struct skcipher_alg {
112 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
113 unsigned int keylen);
114 int (*encrypt)(struct skcipher_request *req);
115 int (*decrypt)(struct skcipher_request *req);
116 int (*init)(struct crypto_skcipher *tfm);
117 void (*exit)(struct crypto_skcipher *tfm);
118
119 unsigned int min_keysize;
120 unsigned int max_keysize;
121 unsigned int ivsize;
122 unsigned int chunksize;
123 unsigned int walksize;
124
125 struct crypto_alg base;
126};
127
128#define MAX_SYNC_SKCIPHER_REQSIZE 384
129/*
130 * This performs a type-check against the "tfm" argument to make sure
131 * all users have the correct skcipher tfm for doing on-stack requests.
132 */
133#define SYNC_SKCIPHER_REQUEST_ON_STACK(name, tfm) \
134 char __##name##_desc[sizeof(struct skcipher_request) + \
135 MAX_SYNC_SKCIPHER_REQSIZE + \
136 (!(sizeof((struct crypto_sync_skcipher *)1 == \
137 (typeof(tfm))1))) \
138 ] CRYPTO_MINALIGN_ATTR; \
139 struct skcipher_request *name = (void *)__##name##_desc
140
141/**
142 * DOC: Symmetric Key Cipher API
143 *
144 * Symmetric key cipher API is used with the ciphers of type
145 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
146 *
147 * Asynchronous cipher operations imply that the function invocation for a
148 * cipher request returns immediately before the completion of the operation.
149 * The cipher request is scheduled as a separate kernel thread and therefore
150 * load-balanced on the different CPUs via the process scheduler. To allow
151 * the kernel crypto API to inform the caller about the completion of a cipher
152 * request, the caller must provide a callback function. That function is
153 * invoked with the cipher handle when the request completes.
154 *
155 * To support the asynchronous operation, additional information than just the
156 * cipher handle must be supplied to the kernel crypto API. That additional
157 * information is given by filling in the skcipher_request data structure.
158 *
159 * For the symmetric key cipher API, the state is maintained with the tfm
160 * cipher handle. A single tfm can be used across multiple calls and in
161 * parallel. For asynchronous block cipher calls, context data supplied and
162 * only used by the caller can be referenced the request data structure in
163 * addition to the IV used for the cipher request. The maintenance of such
164 * state information would be important for a crypto driver implementer to
165 * have, because when calling the callback function upon completion of the
166 * cipher operation, that callback function may need some information about
167 * which operation just finished if it invoked multiple in parallel. This
168 * state information is unused by the kernel crypto API.
169 */
170
171static inline struct crypto_skcipher *__crypto_skcipher_cast(
172 struct crypto_tfm *tfm)
173{
174 return container_of(tfm, struct crypto_skcipher, base);
175}
176
177/**
178 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
179 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
180 * skcipher cipher
181 * @type: specifies the type of the cipher
182 * @mask: specifies the mask for the cipher
183 *
184 * Allocate a cipher handle for an skcipher. The returned struct
185 * crypto_skcipher is the cipher handle that is required for any subsequent
186 * API invocation for that skcipher.
187 *
188 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
189 * of an error, PTR_ERR() returns the error code.
190 */
191struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
192 u32 type, u32 mask);
193
194struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(const char *alg_name,
195 u32 type, u32 mask);
196
197static inline struct crypto_tfm *crypto_skcipher_tfm(
198 struct crypto_skcipher *tfm)
199{
200 return &tfm->base;
201}
202
203/**
204 * crypto_free_skcipher() - zeroize and free cipher handle
205 * @tfm: cipher handle to be freed
206 */
207static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
208{
209 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
210}
211
212static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm)
213{
214 crypto_free_skcipher(&tfm->base);
215}
216
217/**
218 * crypto_has_skcipher() - Search for the availability of an skcipher.
219 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
220 * skcipher
221 * @type: specifies the type of the cipher
222 * @mask: specifies the mask for the cipher
223 *
224 * Return: true when the skcipher is known to the kernel crypto API; false
225 * otherwise
226 */
227static inline int crypto_has_skcipher(const char *alg_name, u32 type,
228 u32 mask)
229{
230 return crypto_has_alg(alg_name, crypto_skcipher_type(type),
231 crypto_skcipher_mask(mask));
232}
233
234/**
235 * crypto_has_skcipher2() - Search for the availability of an skcipher.
236 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
237 * skcipher
238 * @type: specifies the type of the skcipher
239 * @mask: specifies the mask for the skcipher
240 *
241 * Return: true when the skcipher is known to the kernel crypto API; false
242 * otherwise
243 */
244int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask);
245
246static inline const char *crypto_skcipher_driver_name(
247 struct crypto_skcipher *tfm)
248{
249 return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
250}
251
252static inline struct skcipher_alg *crypto_skcipher_alg(
253 struct crypto_skcipher *tfm)
254{
255 return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
256 struct skcipher_alg, base);
257}
258
259static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg)
260{
261 if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
262 CRYPTO_ALG_TYPE_BLKCIPHER)
263 return alg->base.cra_blkcipher.ivsize;
264
265 if (alg->base.cra_ablkcipher.encrypt)
266 return alg->base.cra_ablkcipher.ivsize;
267
268 return alg->ivsize;
269}
270
271/**
272 * crypto_skcipher_ivsize() - obtain IV size
273 * @tfm: cipher handle
274 *
275 * The size of the IV for the skcipher referenced by the cipher handle is
276 * returned. This IV size may be zero if the cipher does not need an IV.
277 *
278 * Return: IV size in bytes
279 */
280static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
281{
282 return tfm->ivsize;
283}
284
285static inline unsigned int crypto_sync_skcipher_ivsize(
286 struct crypto_sync_skcipher *tfm)
287{
288 return crypto_skcipher_ivsize(&tfm->base);
289}
290
291/**
292 * crypto_skcipher_blocksize() - obtain block size of cipher
293 * @tfm: cipher handle
294 *
295 * The block size for the skcipher referenced with the cipher handle is
296 * returned. The caller may use that information to allocate appropriate
297 * memory for the data returned by the encryption or decryption operation
298 *
299 * Return: block size of cipher
300 */
301static inline unsigned int crypto_skcipher_blocksize(
302 struct crypto_skcipher *tfm)
303{
304 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
305}
306
307static inline unsigned int crypto_sync_skcipher_blocksize(
308 struct crypto_sync_skcipher *tfm)
309{
310 return crypto_skcipher_blocksize(&tfm->base);
311}
312
313static inline unsigned int crypto_skcipher_alignmask(
314 struct crypto_skcipher *tfm)
315{
316 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
317}
318
319static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
320{
321 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
322}
323
324static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
325 u32 flags)
326{
327 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
328}
329
330static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
331 u32 flags)
332{
333 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
334}
335
336static inline u32 crypto_sync_skcipher_get_flags(
337 struct crypto_sync_skcipher *tfm)
338{
339 return crypto_skcipher_get_flags(&tfm->base);
340}
341
342static inline void crypto_sync_skcipher_set_flags(
343 struct crypto_sync_skcipher *tfm, u32 flags)
344{
345 crypto_skcipher_set_flags(&tfm->base, flags);
346}
347
348static inline void crypto_sync_skcipher_clear_flags(
349 struct crypto_sync_skcipher *tfm, u32 flags)
350{
351 crypto_skcipher_clear_flags(&tfm->base, flags);
352}
353
354/**
355 * crypto_skcipher_setkey() - set key for cipher
356 * @tfm: cipher handle
357 * @key: buffer holding the key
358 * @keylen: length of the key in bytes
359 *
360 * The caller provided key is set for the skcipher referenced by the cipher
361 * handle.
362 *
363 * Note, the key length determines the cipher type. Many block ciphers implement
364 * different cipher modes depending on the key size, such as AES-128 vs AES-192
365 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
366 * is performed.
367 *
368 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
369 */
370static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
371 const u8 *key, unsigned int keylen)
372{
373 return tfm->setkey(tfm, key, keylen);
374}
375
376static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
377 const u8 *key, unsigned int keylen)
378{
379 return crypto_skcipher_setkey(&tfm->base, key, keylen);
380}
381
382static inline unsigned int crypto_skcipher_default_keysize(
383 struct crypto_skcipher *tfm)
384{
385 return tfm->keysize;
386}
387
388/**
389 * crypto_skcipher_reqtfm() - obtain cipher handle from request
390 * @req: skcipher_request out of which the cipher handle is to be obtained
391 *
392 * Return the crypto_skcipher handle when furnishing an skcipher_request
393 * data structure.
394 *
395 * Return: crypto_skcipher handle
396 */
397static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
398 struct skcipher_request *req)
399{
400 return __crypto_skcipher_cast(req->base.tfm);
401}
402
403static inline struct crypto_sync_skcipher *crypto_sync_skcipher_reqtfm(
404 struct skcipher_request *req)
405{
406 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
407
408 return container_of(tfm, struct crypto_sync_skcipher, base);
409}
410
411/**
412 * crypto_skcipher_encrypt() - encrypt plaintext
413 * @req: reference to the skcipher_request handle that holds all information
414 * needed to perform the cipher operation
415 *
416 * Encrypt plaintext data using the skcipher_request handle. That data
417 * structure and how it is filled with data is discussed with the
418 * skcipher_request_* functions.
419 *
420 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
421 */
422int crypto_skcipher_encrypt(struct skcipher_request *req);
423
424/**
425 * crypto_skcipher_decrypt() - decrypt ciphertext
426 * @req: reference to the skcipher_request handle that holds all information
427 * needed to perform the cipher operation
428 *
429 * Decrypt ciphertext data using the skcipher_request handle. That data
430 * structure and how it is filled with data is discussed with the
431 * skcipher_request_* functions.
432 *
433 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
434 */
435int crypto_skcipher_decrypt(struct skcipher_request *req);
436
437/**
438 * DOC: Symmetric Key Cipher Request Handle
439 *
440 * The skcipher_request data structure contains all pointers to data
441 * required for the symmetric key cipher operation. This includes the cipher
442 * handle (which can be used by multiple skcipher_request instances), pointer
443 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
444 * as a handle to the skcipher_request_* API calls in a similar way as
445 * skcipher handle to the crypto_skcipher_* API calls.
446 */
447
448/**
449 * crypto_skcipher_reqsize() - obtain size of the request data structure
450 * @tfm: cipher handle
451 *
452 * Return: number of bytes
453 */
454static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
455{
456 return tfm->reqsize;
457}
458
459/**
460 * skcipher_request_set_tfm() - update cipher handle reference in request
461 * @req: request handle to be modified
462 * @tfm: cipher handle that shall be added to the request handle
463 *
464 * Allow the caller to replace the existing skcipher handle in the request
465 * data structure with a different one.
466 */
467static inline void skcipher_request_set_tfm(struct skcipher_request *req,
468 struct crypto_skcipher *tfm)
469{
470 req->base.tfm = crypto_skcipher_tfm(tfm);
471}
472
473static inline void skcipher_request_set_sync_tfm(struct skcipher_request *req,
474 struct crypto_sync_skcipher *tfm)
475{
476 skcipher_request_set_tfm(req, &tfm->base);
477}
478
479static inline struct skcipher_request *skcipher_request_cast(
480 struct crypto_async_request *req)
481{
482 return container_of(req, struct skcipher_request, base);
483}
484
485/**
486 * skcipher_request_alloc() - allocate request data structure
487 * @tfm: cipher handle to be registered with the request
488 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
489 *
490 * Allocate the request data structure that must be used with the skcipher
491 * encrypt and decrypt API calls. During the allocation, the provided skcipher
492 * handle is registered in the request data structure.
493 *
494 * Return: allocated request handle in case of success, or NULL if out of memory
495 */
496static inline struct skcipher_request *skcipher_request_alloc(
497 struct crypto_skcipher *tfm, gfp_t gfp)
498{
499 struct skcipher_request *req;
500
501 req = kmalloc(sizeof(struct skcipher_request) +
502 crypto_skcipher_reqsize(tfm), gfp);
503
504 if (likely(req))
505 skcipher_request_set_tfm(req, tfm);
506
507 return req;
508}
509
510/**
511 * skcipher_request_free() - zeroize and free request data structure
512 * @req: request data structure cipher handle to be freed
513 */
514static inline void skcipher_request_free(struct skcipher_request *req)
515{
516 kzfree(req);
517}
518
519static inline void skcipher_request_zero(struct skcipher_request *req)
520{
521 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
522
523 memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
524}
525
526/**
527 * skcipher_request_set_callback() - set asynchronous callback function
528 * @req: request handle
529 * @flags: specify zero or an ORing of the flags
530 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
531 * increase the wait queue beyond the initial maximum size;
532 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
533 * @compl: callback function pointer to be registered with the request handle
534 * @data: The data pointer refers to memory that is not used by the kernel
535 * crypto API, but provided to the callback function for it to use. Here,
536 * the caller can provide a reference to memory the callback function can
537 * operate on. As the callback function is invoked asynchronously to the
538 * related functionality, it may need to access data structures of the
539 * related functionality which can be referenced using this pointer. The
540 * callback function can access the memory via the "data" field in the
541 * crypto_async_request data structure provided to the callback function.
542 *
543 * This function allows setting the callback function that is triggered once the
544 * cipher operation completes.
545 *
546 * The callback function is registered with the skcipher_request handle and
547 * must comply with the following template::
548 *
549 * void callback_function(struct crypto_async_request *req, int error)
550 */
551static inline void skcipher_request_set_callback(struct skcipher_request *req,
552 u32 flags,
553 crypto_completion_t compl,
554 void *data)
555{
556 req->base.complete = compl;
557 req->base.data = data;
558 req->base.flags = flags;
559}
560
561/**
562 * skcipher_request_set_crypt() - set data buffers
563 * @req: request handle
564 * @src: source scatter / gather list
565 * @dst: destination scatter / gather list
566 * @cryptlen: number of bytes to process from @src
567 * @iv: IV for the cipher operation which must comply with the IV size defined
568 * by crypto_skcipher_ivsize
569 *
570 * This function allows setting of the source data and destination data
571 * scatter / gather lists.
572 *
573 * For encryption, the source is treated as the plaintext and the
574 * destination is the ciphertext. For a decryption operation, the use is
575 * reversed - the source is the ciphertext and the destination is the plaintext.
576 */
577static inline void skcipher_request_set_crypt(
578 struct skcipher_request *req,
579 struct scatterlist *src, struct scatterlist *dst,
580 unsigned int cryptlen, void *iv)
581{
582 req->src = src;
583 req->dst = dst;
584 req->cryptlen = cryptlen;
585 req->iv = iv;
586}
587
588#endif /* _CRYPTO_SKCIPHER_H */
589
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