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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Symmetric key ciphers.
4 *
5 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8#ifndef _CRYPTO_SKCIPHER_H
9#define _CRYPTO_SKCIPHER_H
10
11#include <linux/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 */
200static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
201{
202 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
203}
204
205static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm)
206{
207 crypto_free_skcipher(&tfm->base);
208}
209
210/**
211 * crypto_has_skcipher() - Search for the availability of an skcipher.
212 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
213 * skcipher
214 * @type: specifies the type of the skcipher
215 * @mask: specifies the mask for the skcipher
216 *
217 * Return: true when the skcipher is known to the kernel crypto API; false
218 * otherwise
219 */
220int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask);
221
222static inline const char *crypto_skcipher_driver_name(
223 struct crypto_skcipher *tfm)
224{
225 return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
226}
227
228static inline struct skcipher_alg *crypto_skcipher_alg(
229 struct crypto_skcipher *tfm)
230{
231 return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
232 struct skcipher_alg, base);
233}
234
235static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg)
236{
237 return alg->ivsize;
238}
239
240/**
241 * crypto_skcipher_ivsize() - obtain IV size
242 * @tfm: cipher handle
243 *
244 * The size of the IV for the skcipher referenced by the cipher handle is
245 * returned. This IV size may be zero if the cipher does not need an IV.
246 *
247 * Return: IV size in bytes
248 */
249static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
250{
251 return crypto_skcipher_alg(tfm)->ivsize;
252}
253
254static inline unsigned int crypto_sync_skcipher_ivsize(
255 struct crypto_sync_skcipher *tfm)
256{
257 return crypto_skcipher_ivsize(&tfm->base);
258}
259
260/**
261 * crypto_skcipher_blocksize() - obtain block size of cipher
262 * @tfm: cipher handle
263 *
264 * The block size for the skcipher referenced with the cipher handle is
265 * returned. The caller may use that information to allocate appropriate
266 * memory for the data returned by the encryption or decryption operation
267 *
268 * Return: block size of cipher
269 */
270static inline unsigned int crypto_skcipher_blocksize(
271 struct crypto_skcipher *tfm)
272{
273 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
274}
275
276static inline unsigned int crypto_skcipher_alg_chunksize(
277 struct skcipher_alg *alg)
278{
279 return alg->chunksize;
280}
281
282/**
283 * crypto_skcipher_chunksize() - obtain chunk size
284 * @tfm: cipher handle
285 *
286 * The block size is set to one for ciphers such as CTR. However,
287 * you still need to provide incremental updates in multiples of
288 * the underlying block size as the IV does not have sub-block
289 * granularity. This is known in this API as the chunk size.
290 *
291 * Return: chunk size in bytes
292 */
293static inline unsigned int crypto_skcipher_chunksize(
294 struct crypto_skcipher *tfm)
295{
296 return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm));
297}
298
299static inline unsigned int crypto_sync_skcipher_blocksize(
300 struct crypto_sync_skcipher *tfm)
301{
302 return crypto_skcipher_blocksize(&tfm->base);
303}
304
305static inline unsigned int crypto_skcipher_alignmask(
306 struct crypto_skcipher *tfm)
307{
308 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
309}
310
311static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
312{
313 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
314}
315
316static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
317 u32 flags)
318{
319 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
320}
321
322static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
323 u32 flags)
324{
325 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
326}
327
328static inline u32 crypto_sync_skcipher_get_flags(
329 struct crypto_sync_skcipher *tfm)
330{
331 return crypto_skcipher_get_flags(&tfm->base);
332}
333
334static inline void crypto_sync_skcipher_set_flags(
335 struct crypto_sync_skcipher *tfm, u32 flags)
336{
337 crypto_skcipher_set_flags(&tfm->base, flags);
338}
339
340static inline void crypto_sync_skcipher_clear_flags(
341 struct crypto_sync_skcipher *tfm, u32 flags)
342{
343 crypto_skcipher_clear_flags(&tfm->base, flags);
344}
345
346/**
347 * crypto_skcipher_setkey() - set key for cipher
348 * @tfm: cipher handle
349 * @key: buffer holding the key
350 * @keylen: length of the key in bytes
351 *
352 * The caller provided key is set for the skcipher referenced by the cipher
353 * handle.
354 *
355 * Note, the key length determines the cipher type. Many block ciphers implement
356 * different cipher modes depending on the key size, such as AES-128 vs AES-192
357 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
358 * is performed.
359 *
360 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
361 */
362int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
363 const u8 *key, unsigned int keylen);
364
365static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
366 const u8 *key, unsigned int keylen)
367{
368 return crypto_skcipher_setkey(&tfm->base, key, keylen);
369}
370
371static inline unsigned int crypto_skcipher_min_keysize(
372 struct crypto_skcipher *tfm)
373{
374 return crypto_skcipher_alg(tfm)->min_keysize;
375}
376
377static inline unsigned int crypto_skcipher_max_keysize(
378 struct crypto_skcipher *tfm)
379{
380 return crypto_skcipher_alg(tfm)->max_keysize;
381}
382
383/**
384 * crypto_skcipher_reqtfm() - obtain cipher handle from request
385 * @req: skcipher_request out of which the cipher handle is to be obtained
386 *
387 * Return the crypto_skcipher handle when furnishing an skcipher_request
388 * data structure.
389 *
390 * Return: crypto_skcipher handle
391 */
392static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
393 struct skcipher_request *req)
394{
395 return __crypto_skcipher_cast(req->base.tfm);
396}
397
398static inline struct crypto_sync_skcipher *crypto_sync_skcipher_reqtfm(
399 struct skcipher_request *req)
400{
401 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
402
403 return container_of(tfm, struct crypto_sync_skcipher, base);
404}
405
406/**
407 * crypto_skcipher_encrypt() - encrypt plaintext
408 * @req: reference to the skcipher_request handle that holds all information
409 * needed to perform the cipher operation
410 *
411 * Encrypt plaintext data using the skcipher_request handle. That data
412 * structure and how it is filled with data is discussed with the
413 * skcipher_request_* functions.
414 *
415 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
416 */
417int crypto_skcipher_encrypt(struct skcipher_request *req);
418
419/**
420 * crypto_skcipher_decrypt() - decrypt ciphertext
421 * @req: reference to the skcipher_request handle that holds all information
422 * needed to perform the cipher operation
423 *
424 * Decrypt ciphertext data using the skcipher_request handle. That data
425 * structure and how it is filled with data is discussed with the
426 * skcipher_request_* functions.
427 *
428 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
429 */
430int crypto_skcipher_decrypt(struct skcipher_request *req);
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 void skcipher_request_set_sync_tfm(struct skcipher_request *req,
469 struct crypto_sync_skcipher *tfm)
470{
471 skcipher_request_set_tfm(req, &tfm->base);
472}
473
474static inline struct skcipher_request *skcipher_request_cast(
475 struct crypto_async_request *req)
476{
477 return container_of(req, struct skcipher_request, base);
478}
479
480/**
481 * skcipher_request_alloc() - allocate request data structure
482 * @tfm: cipher handle to be registered with the request
483 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
484 *
485 * Allocate the request data structure that must be used with the skcipher
486 * encrypt and decrypt API calls. During the allocation, the provided skcipher
487 * handle is registered in the request data structure.
488 *
489 * Return: allocated request handle in case of success, or NULL if out of memory
490 */
491static inline struct skcipher_request *skcipher_request_alloc(
492 struct crypto_skcipher *tfm, gfp_t gfp)
493{
494 struct skcipher_request *req;
495
496 req = kmalloc(sizeof(struct skcipher_request) +
497 crypto_skcipher_reqsize(tfm), gfp);
498
499 if (likely(req))
500 skcipher_request_set_tfm(req, tfm);
501
502 return req;
503}
504
505/**
506 * skcipher_request_free() - zeroize and free request data structure
507 * @req: request data structure cipher handle to be freed
508 */
509static inline void skcipher_request_free(struct skcipher_request *req)
510{
511 kfree_sensitive(req);
512}
513
514static inline void skcipher_request_zero(struct skcipher_request *req)
515{
516 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
517
518 memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
519}
520
521/**
522 * skcipher_request_set_callback() - set asynchronous callback function
523 * @req: request handle
524 * @flags: specify zero or an ORing of the flags
525 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
526 * increase the wait queue beyond the initial maximum size;
527 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
528 * @compl: callback function pointer to be registered with the request handle
529 * @data: The data pointer refers to memory that is not used by the kernel
530 * crypto API, but provided to the callback function for it to use. Here,
531 * the caller can provide a reference to memory the callback function can
532 * operate on. As the callback function is invoked asynchronously to the
533 * related functionality, it may need to access data structures of the
534 * related functionality which can be referenced using this pointer. The
535 * callback function can access the memory via the "data" field in the
536 * crypto_async_request data structure provided to the callback function.
537 *
538 * This function allows setting the callback function that is triggered once the
539 * cipher operation completes.
540 *
541 * The callback function is registered with the skcipher_request handle and
542 * must comply with the following template::
543 *
544 * void callback_function(struct crypto_async_request *req, int error)
545 */
546static inline void skcipher_request_set_callback(struct skcipher_request *req,
547 u32 flags,
548 crypto_completion_t compl,
549 void *data)
550{
551 req->base.complete = compl;
552 req->base.data = data;
553 req->base.flags = flags;
554}
555
556/**
557 * skcipher_request_set_crypt() - set data buffers
558 * @req: request handle
559 * @src: source scatter / gather list
560 * @dst: destination scatter / gather list
561 * @cryptlen: number of bytes to process from @src
562 * @iv: IV for the cipher operation which must comply with the IV size defined
563 * by crypto_skcipher_ivsize
564 *
565 * This function allows setting of the source data and destination data
566 * scatter / gather lists.
567 *
568 * For encryption, the source is treated as the plaintext and the
569 * destination is the ciphertext. For a decryption operation, the use is
570 * reversed - the source is the ciphertext and the destination is the plaintext.
571 */
572static inline void skcipher_request_set_crypt(
573 struct skcipher_request *req,
574 struct scatterlist *src, struct scatterlist *dst,
575 unsigned int cryptlen, void *iv)
576{
577 req->src = src;
578 req->dst = dst;
579 req->cryptlen = cryptlen;
580 req->iv = iv;
581}
582
583#endif /* _CRYPTO_SKCIPHER_H */
584
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 * @walksize: Equal to the chunk size except in cases where the algorithm is
119 * considerably more efficient if it can operate on multiple chunks
120 * in parallel. Should be a multiple of chunksize.
121 * @base: Definition of a generic crypto algorithm.
122 *
123 * All fields except @ivsize are mandatory and must be filled.
124 */
125struct skcipher_alg {
126 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
127 unsigned int keylen);
128 int (*encrypt)(struct skcipher_request *req);
129 int (*decrypt)(struct skcipher_request *req);
130 int (*init)(struct crypto_skcipher *tfm);
131 void (*exit)(struct crypto_skcipher *tfm);
132
133 unsigned int min_keysize;
134 unsigned int max_keysize;
135 unsigned int ivsize;
136 unsigned int chunksize;
137 unsigned int walksize;
138
139 struct crypto_alg base;
140};
141
142#define SKCIPHER_REQUEST_ON_STACK(name, tfm) \
143 char __##name##_desc[sizeof(struct skcipher_request) + \
144 crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
145 struct skcipher_request *name = (void *)__##name##_desc
146
147/**
148 * DOC: Symmetric Key Cipher API
149 *
150 * Symmetric key cipher API is used with the ciphers of type
151 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
152 *
153 * Asynchronous cipher operations imply that the function invocation for a
154 * cipher request returns immediately before the completion of the operation.
155 * The cipher request is scheduled as a separate kernel thread and therefore
156 * load-balanced on the different CPUs via the process scheduler. To allow
157 * the kernel crypto API to inform the caller about the completion of a cipher
158 * request, the caller must provide a callback function. That function is
159 * invoked with the cipher handle when the request completes.
160 *
161 * To support the asynchronous operation, additional information than just the
162 * cipher handle must be supplied to the kernel crypto API. That additional
163 * information is given by filling in the skcipher_request data structure.
164 *
165 * For the symmetric key cipher API, the state is maintained with the tfm
166 * cipher handle. A single tfm can be used across multiple calls and in
167 * parallel. For asynchronous block cipher calls, context data supplied and
168 * only used by the caller can be referenced the request data structure in
169 * addition to the IV used for the cipher request. The maintenance of such
170 * state information would be important for a crypto driver implementer to
171 * have, because when calling the callback function upon completion of the
172 * cipher operation, that callback function may need some information about
173 * which operation just finished if it invoked multiple in parallel. This
174 * state information is unused by the kernel crypto API.
175 */
176
177static inline struct crypto_skcipher *__crypto_skcipher_cast(
178 struct crypto_tfm *tfm)
179{
180 return container_of(tfm, struct crypto_skcipher, base);
181}
182
183/**
184 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
185 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
186 * skcipher cipher
187 * @type: specifies the type of the cipher
188 * @mask: specifies the mask for the cipher
189 *
190 * Allocate a cipher handle for an skcipher. The returned struct
191 * crypto_skcipher is the cipher handle that is required for any subsequent
192 * API invocation for that skcipher.
193 *
194 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
195 * of an error, PTR_ERR() returns the error code.
196 */
197struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
198 u32 type, u32 mask);
199
200static inline struct crypto_tfm *crypto_skcipher_tfm(
201 struct crypto_skcipher *tfm)
202{
203 return &tfm->base;
204}
205
206/**
207 * crypto_free_skcipher() - zeroize and free cipher handle
208 * @tfm: cipher handle to be freed
209 */
210static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
211{
212 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
213}
214
215/**
216 * crypto_has_skcipher() - Search for the availability of an skcipher.
217 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
218 * skcipher
219 * @type: specifies the type of the cipher
220 * @mask: specifies the mask for the cipher
221 *
222 * Return: true when the skcipher is known to the kernel crypto API; false
223 * otherwise
224 */
225static inline int crypto_has_skcipher(const char *alg_name, u32 type,
226 u32 mask)
227{
228 return crypto_has_alg(alg_name, crypto_skcipher_type(type),
229 crypto_skcipher_mask(mask));
230}
231
232/**
233 * crypto_has_skcipher2() - Search for the availability of an skcipher.
234 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
235 * skcipher
236 * @type: specifies the type of the skcipher
237 * @mask: specifies the mask for the skcipher
238 *
239 * Return: true when the skcipher is known to the kernel crypto API; false
240 * otherwise
241 */
242int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask);
243
244static inline const char *crypto_skcipher_driver_name(
245 struct crypto_skcipher *tfm)
246{
247 return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
248}
249
250static inline struct skcipher_alg *crypto_skcipher_alg(
251 struct crypto_skcipher *tfm)
252{
253 return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
254 struct skcipher_alg, base);
255}
256
257static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg)
258{
259 if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
260 CRYPTO_ALG_TYPE_BLKCIPHER)
261 return alg->base.cra_blkcipher.ivsize;
262
263 if (alg->base.cra_ablkcipher.encrypt)
264 return alg->base.cra_ablkcipher.ivsize;
265
266 return alg->ivsize;
267}
268
269/**
270 * crypto_skcipher_ivsize() - obtain IV size
271 * @tfm: cipher handle
272 *
273 * The size of the IV for the skcipher referenced by the cipher handle is
274 * returned. This IV size may be zero if the cipher does not need an IV.
275 *
276 * Return: IV size in bytes
277 */
278static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
279{
280 return tfm->ivsize;
281}
282
283static inline unsigned int crypto_skcipher_alg_chunksize(
284 struct skcipher_alg *alg)
285{
286 if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
287 CRYPTO_ALG_TYPE_BLKCIPHER)
288 return alg->base.cra_blocksize;
289
290 if (alg->base.cra_ablkcipher.encrypt)
291 return alg->base.cra_blocksize;
292
293 return alg->chunksize;
294}
295
296static inline unsigned int crypto_skcipher_alg_walksize(
297 struct skcipher_alg *alg)
298{
299 if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
300 CRYPTO_ALG_TYPE_BLKCIPHER)
301 return alg->base.cra_blocksize;
302
303 if (alg->base.cra_ablkcipher.encrypt)
304 return alg->base.cra_blocksize;
305
306 return alg->walksize;
307}
308
309/**
310 * crypto_skcipher_chunksize() - obtain chunk size
311 * @tfm: cipher handle
312 *
313 * The block size is set to one for ciphers such as CTR. However,
314 * you still need to provide incremental updates in multiples of
315 * the underlying block size as the IV does not have sub-block
316 * granularity. This is known in this API as the chunk size.
317 *
318 * Return: chunk size in bytes
319 */
320static inline unsigned int crypto_skcipher_chunksize(
321 struct crypto_skcipher *tfm)
322{
323 return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm));
324}
325
326/**
327 * crypto_skcipher_walksize() - obtain walk size
328 * @tfm: cipher handle
329 *
330 * In some cases, algorithms can only perform optimally when operating on
331 * multiple blocks in parallel. This is reflected by the walksize, which
332 * must be a multiple of the chunksize (or equal if the concern does not
333 * apply)
334 *
335 * Return: walk size in bytes
336 */
337static inline unsigned int crypto_skcipher_walksize(
338 struct crypto_skcipher *tfm)
339{
340 return crypto_skcipher_alg_walksize(crypto_skcipher_alg(tfm));
341}
342
343/**
344 * crypto_skcipher_blocksize() - obtain block size of cipher
345 * @tfm: cipher handle
346 *
347 * The block size for the skcipher referenced with the cipher handle is
348 * returned. The caller may use that information to allocate appropriate
349 * memory for the data returned by the encryption or decryption operation
350 *
351 * Return: block size of cipher
352 */
353static inline unsigned int crypto_skcipher_blocksize(
354 struct crypto_skcipher *tfm)
355{
356 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
357}
358
359static inline unsigned int crypto_skcipher_alignmask(
360 struct crypto_skcipher *tfm)
361{
362 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
363}
364
365static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
366{
367 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
368}
369
370static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
371 u32 flags)
372{
373 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
374}
375
376static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
377 u32 flags)
378{
379 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
380}
381
382/**
383 * crypto_skcipher_setkey() - set key for cipher
384 * @tfm: cipher handle
385 * @key: buffer holding the key
386 * @keylen: length of the key in bytes
387 *
388 * The caller provided key is set for the skcipher referenced by the cipher
389 * handle.
390 *
391 * Note, the key length determines the cipher type. Many block ciphers implement
392 * different cipher modes depending on the key size, such as AES-128 vs AES-192
393 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
394 * is performed.
395 *
396 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
397 */
398static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
399 const u8 *key, unsigned int keylen)
400{
401 return tfm->setkey(tfm, key, keylen);
402}
403
404static inline unsigned int crypto_skcipher_default_keysize(
405 struct crypto_skcipher *tfm)
406{
407 return tfm->keysize;
408}
409
410/**
411 * crypto_skcipher_reqtfm() - obtain cipher handle from request
412 * @req: skcipher_request out of which the cipher handle is to be obtained
413 *
414 * Return the crypto_skcipher handle when furnishing an skcipher_request
415 * data structure.
416 *
417 * Return: crypto_skcipher handle
418 */
419static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
420 struct skcipher_request *req)
421{
422 return __crypto_skcipher_cast(req->base.tfm);
423}
424
425/**
426 * crypto_skcipher_encrypt() - encrypt plaintext
427 * @req: reference to the skcipher_request handle that holds all information
428 * needed to perform the cipher operation
429 *
430 * Encrypt plaintext 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 */
436static inline int crypto_skcipher_encrypt(struct skcipher_request *req)
437{
438 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
439
440 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
441 return -ENOKEY;
442
443 return tfm->encrypt(req);
444}
445
446/**
447 * crypto_skcipher_decrypt() - decrypt ciphertext
448 * @req: reference to the skcipher_request handle that holds all information
449 * needed to perform the cipher operation
450 *
451 * Decrypt ciphertext data using the skcipher_request handle. That data
452 * structure and how it is filled with data is discussed with the
453 * skcipher_request_* functions.
454 *
455 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
456 */
457static inline int crypto_skcipher_decrypt(struct skcipher_request *req)
458{
459 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
460
461 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
462 return -ENOKEY;
463
464 return tfm->decrypt(req);
465}
466
467/**
468 * DOC: Symmetric Key Cipher Request Handle
469 *
470 * The skcipher_request data structure contains all pointers to data
471 * required for the symmetric key cipher operation. This includes the cipher
472 * handle (which can be used by multiple skcipher_request instances), pointer
473 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
474 * as a handle to the skcipher_request_* API calls in a similar way as
475 * skcipher handle to the crypto_skcipher_* API calls.
476 */
477
478/**
479 * crypto_skcipher_reqsize() - obtain size of the request data structure
480 * @tfm: cipher handle
481 *
482 * Return: number of bytes
483 */
484static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
485{
486 return tfm->reqsize;
487}
488
489/**
490 * skcipher_request_set_tfm() - update cipher handle reference in request
491 * @req: request handle to be modified
492 * @tfm: cipher handle that shall be added to the request handle
493 *
494 * Allow the caller to replace the existing skcipher handle in the request
495 * data structure with a different one.
496 */
497static inline void skcipher_request_set_tfm(struct skcipher_request *req,
498 struct crypto_skcipher *tfm)
499{
500 req->base.tfm = crypto_skcipher_tfm(tfm);
501}
502
503static inline struct skcipher_request *skcipher_request_cast(
504 struct crypto_async_request *req)
505{
506 return container_of(req, struct skcipher_request, base);
507}
508
509/**
510 * skcipher_request_alloc() - allocate request data structure
511 * @tfm: cipher handle to be registered with the request
512 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
513 *
514 * Allocate the request data structure that must be used with the skcipher
515 * encrypt and decrypt API calls. During the allocation, the provided skcipher
516 * handle is registered in the request data structure.
517 *
518 * Return: allocated request handle in case of success, or NULL if out of memory
519 */
520static inline struct skcipher_request *skcipher_request_alloc(
521 struct crypto_skcipher *tfm, gfp_t gfp)
522{
523 struct skcipher_request *req;
524
525 req = kmalloc(sizeof(struct skcipher_request) +
526 crypto_skcipher_reqsize(tfm), gfp);
527
528 if (likely(req))
529 skcipher_request_set_tfm(req, tfm);
530
531 return req;
532}
533
534/**
535 * skcipher_request_free() - zeroize and free request data structure
536 * @req: request data structure cipher handle to be freed
537 */
538static inline void skcipher_request_free(struct skcipher_request *req)
539{
540 kzfree(req);
541}
542
543static inline void skcipher_request_zero(struct skcipher_request *req)
544{
545 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
546
547 memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
548}
549
550/**
551 * skcipher_request_set_callback() - set asynchronous callback function
552 * @req: request handle
553 * @flags: specify zero or an ORing of the flags
554 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
555 * increase the wait queue beyond the initial maximum size;
556 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
557 * @compl: callback function pointer to be registered with the request handle
558 * @data: The data pointer refers to memory that is not used by the kernel
559 * crypto API, but provided to the callback function for it to use. Here,
560 * the caller can provide a reference to memory the callback function can
561 * operate on. As the callback function is invoked asynchronously to the
562 * related functionality, it may need to access data structures of the
563 * related functionality which can be referenced using this pointer. The
564 * callback function can access the memory via the "data" field in the
565 * crypto_async_request data structure provided to the callback function.
566 *
567 * This function allows setting the callback function that is triggered once the
568 * cipher operation completes.
569 *
570 * The callback function is registered with the skcipher_request handle and
571 * must comply with the following template::
572 *
573 * void callback_function(struct crypto_async_request *req, int error)
574 */
575static inline void skcipher_request_set_callback(struct skcipher_request *req,
576 u32 flags,
577 crypto_completion_t compl,
578 void *data)
579{
580 req->base.complete = compl;
581 req->base.data = data;
582 req->base.flags = flags;
583}
584
585/**
586 * skcipher_request_set_crypt() - set data buffers
587 * @req: request handle
588 * @src: source scatter / gather list
589 * @dst: destination scatter / gather list
590 * @cryptlen: number of bytes to process from @src
591 * @iv: IV for the cipher operation which must comply with the IV size defined
592 * by crypto_skcipher_ivsize
593 *
594 * This function allows setting of the source data and destination data
595 * scatter / gather lists.
596 *
597 * For encryption, the source is treated as the plaintext and the
598 * destination is the ciphertext. For a decryption operation, the use is
599 * reversed - the source is the ciphertext and the destination is the plaintext.
600 */
601static inline void skcipher_request_set_crypt(
602 struct skcipher_request *req,
603 struct scatterlist *src, struct scatterlist *dst,
604 unsigned int cryptlen, void *iv)
605{
606 req->src = src;
607 req->dst = dst;
608 req->cryptlen = cryptlen;
609 req->iv = iv;
610}
611
612#endif /* _CRYPTO_SKCIPHER_H */
613