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

 
  1/*
  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