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