xref: /openbmc/linux/include/crypto/hash.h (revision c616fb0c)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Hash: Hash algorithms under the crypto API
4  *
5  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
6  */
7 
8 #ifndef _CRYPTO_HASH_H
9 #define _CRYPTO_HASH_H
10 
11 #include <linux/atomic.h>
12 #include <linux/crypto.h>
13 #include <linux/string.h>
14 
15 struct crypto_ahash;
16 
17 /**
18  * DOC: Message Digest Algorithm Definitions
19  *
20  * These data structures define modular message digest algorithm
21  * implementations, managed via crypto_register_ahash(),
22  * crypto_register_shash(), crypto_unregister_ahash() and
23  * crypto_unregister_shash().
24  */
25 
26 /*
27  * struct crypto_istat_hash - statistics for has algorithm
28  * @hash_cnt:		number of hash requests
29  * @hash_tlen:		total data size hashed
30  * @err_cnt:		number of error for hash requests
31  */
32 struct crypto_istat_hash {
33 	atomic64_t hash_cnt;
34 	atomic64_t hash_tlen;
35 	atomic64_t err_cnt;
36 };
37 
38 #ifdef CONFIG_CRYPTO_STATS
39 #define HASH_ALG_COMMON_STAT struct crypto_istat_hash stat;
40 #else
41 #define HASH_ALG_COMMON_STAT
42 #endif
43 
44 /*
45  * struct hash_alg_common - define properties of message digest
46  * @stat: Statistics for hash algorithm.
47  * @digestsize: Size of the result of the transformation. A buffer of this size
48  *	        must be available to the @final and @finup calls, so they can
49  *	        store the resulting hash into it. For various predefined sizes,
50  *	        search include/crypto/ using
51  *	        git grep _DIGEST_SIZE include/crypto.
52  * @statesize: Size of the block for partial state of the transformation. A
53  *	       buffer of this size must be passed to the @export function as it
54  *	       will save the partial state of the transformation into it. On the
55  *	       other side, the @import function will load the state from a
56  *	       buffer of this size as well.
57  * @base: Start of data structure of cipher algorithm. The common data
58  *	  structure of crypto_alg contains information common to all ciphers.
59  *	  The hash_alg_common data structure now adds the hash-specific
60  *	  information.
61  */
62 #define HASH_ALG_COMMON {		\
63 	HASH_ALG_COMMON_STAT		\
64 					\
65 	unsigned int digestsize;	\
66 	unsigned int statesize;		\
67 					\
68 	struct crypto_alg base;		\
69 }
70 struct hash_alg_common HASH_ALG_COMMON;
71 
72 struct ahash_request {
73 	struct crypto_async_request base;
74 
75 	unsigned int nbytes;
76 	struct scatterlist *src;
77 	u8 *result;
78 
79 	/* This field may only be used by the ahash API code. */
80 	void *priv;
81 
82 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
83 };
84 
85 /**
86  * struct ahash_alg - asynchronous message digest definition
87  * @init: **[mandatory]** Initialize the transformation context. Intended only to initialize the
88  *	  state of the HASH transformation at the beginning. This shall fill in
89  *	  the internal structures used during the entire duration of the whole
90  *	  transformation. No data processing happens at this point. Driver code
91  *	  implementation must not use req->result.
92  * @update: **[mandatory]** Push a chunk of data into the driver for transformation. This
93  *	   function actually pushes blocks of data from upper layers into the
94  *	   driver, which then passes those to the hardware as seen fit. This
95  *	   function must not finalize the HASH transformation by calculating the
96  *	   final message digest as this only adds more data into the
97  *	   transformation. This function shall not modify the transformation
98  *	   context, as this function may be called in parallel with the same
99  *	   transformation object. Data processing can happen synchronously
100  *	   [SHASH] or asynchronously [AHASH] at this point. Driver must not use
101  *	   req->result.
102  * @final: **[mandatory]** Retrieve result from the driver. This function finalizes the
103  *	   transformation and retrieves the resulting hash from the driver and
104  *	   pushes it back to upper layers. No data processing happens at this
105  *	   point unless hardware requires it to finish the transformation
106  *	   (then the data buffered by the device driver is processed).
107  * @finup: **[optional]** Combination of @update and @final. This function is effectively a
108  *	   combination of @update and @final calls issued in sequence. As some
109  *	   hardware cannot do @update and @final separately, this callback was
110  *	   added to allow such hardware to be used at least by IPsec. Data
111  *	   processing can happen synchronously [SHASH] or asynchronously [AHASH]
112  *	   at this point.
113  * @digest: Combination of @init and @update and @final. This function
114  *	    effectively behaves as the entire chain of operations, @init,
115  *	    @update and @final issued in sequence. Just like @finup, this was
116  *	    added for hardware which cannot do even the @finup, but can only do
117  *	    the whole transformation in one run. Data processing can happen
118  *	    synchronously [SHASH] or asynchronously [AHASH] at this point.
119  * @setkey: Set optional key used by the hashing algorithm. Intended to push
120  *	    optional key used by the hashing algorithm from upper layers into
121  *	    the driver. This function can store the key in the transformation
122  *	    context or can outright program it into the hardware. In the former
123  *	    case, one must be careful to program the key into the hardware at
124  *	    appropriate time and one must be careful that .setkey() can be
125  *	    called multiple times during the existence of the transformation
126  *	    object. Not  all hashing algorithms do implement this function as it
127  *	    is only needed for keyed message digests. SHAx/MDx/CRCx do NOT
128  *	    implement this function. HMAC(MDx)/HMAC(SHAx)/CMAC(AES) do implement
129  *	    this function. This function must be called before any other of the
130  *	    @init, @update, @final, @finup, @digest is called. No data
131  *	    processing happens at this point.
132  * @export: Export partial state of the transformation. This function dumps the
133  *	    entire state of the ongoing transformation into a provided block of
134  *	    data so it can be @import 'ed back later on. This is useful in case
135  *	    you want to save partial result of the transformation after
136  *	    processing certain amount of data and reload this partial result
137  *	    multiple times later on for multiple re-use. No data processing
138  *	    happens at this point. Driver must not use req->result.
139  * @import: Import partial state of the transformation. This function loads the
140  *	    entire state of the ongoing transformation from a provided block of
141  *	    data so the transformation can continue from this point onward. No
142  *	    data processing happens at this point. Driver must not use
143  *	    req->result.
144  * @init_tfm: Initialize the cryptographic transformation object.
145  *	      This function is called only once at the instantiation
146  *	      time, right after the transformation context was
147  *	      allocated. In case the cryptographic hardware has
148  *	      some special requirements which need to be handled
149  *	      by software, this function shall check for the precise
150  *	      requirement of the transformation and put any software
151  *	      fallbacks in place.
152  * @exit_tfm: Deinitialize the cryptographic transformation object.
153  *	      This is a counterpart to @init_tfm, used to remove
154  *	      various changes set in @init_tfm.
155  * @halg: see struct hash_alg_common
156  */
157 struct ahash_alg {
158 	int (*init)(struct ahash_request *req);
159 	int (*update)(struct ahash_request *req);
160 	int (*final)(struct ahash_request *req);
161 	int (*finup)(struct ahash_request *req);
162 	int (*digest)(struct ahash_request *req);
163 	int (*export)(struct ahash_request *req, void *out);
164 	int (*import)(struct ahash_request *req, const void *in);
165 	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
166 		      unsigned int keylen);
167 	int (*init_tfm)(struct crypto_ahash *tfm);
168 	void (*exit_tfm)(struct crypto_ahash *tfm);
169 
170 	struct hash_alg_common halg;
171 };
172 
173 struct shash_desc {
174 	struct crypto_shash *tfm;
175 	void *__ctx[] __aligned(ARCH_SLAB_MINALIGN);
176 };
177 
178 #define HASH_MAX_DIGESTSIZE	 64
179 
180 /*
181  * Worst case is hmac(sha3-224-generic).  Its context is a nested 'shash_desc'
182  * containing a 'struct sha3_state'.
183  */
184 #define HASH_MAX_DESCSIZE	(sizeof(struct shash_desc) + 360)
185 
186 #define HASH_MAX_STATESIZE	512
187 
188 #define SHASH_DESC_ON_STACK(shash, ctx)					     \
189 	char __##shash##_desc[sizeof(struct shash_desc) + HASH_MAX_DESCSIZE] \
190 		__aligned(__alignof__(struct shash_desc));		     \
191 	struct shash_desc *shash = (struct shash_desc *)__##shash##_desc
192 
193 /**
194  * struct shash_alg - synchronous message digest definition
195  * @init: see struct ahash_alg
196  * @update: see struct ahash_alg
197  * @final: see struct ahash_alg
198  * @finup: see struct ahash_alg
199  * @digest: see struct ahash_alg
200  * @export: see struct ahash_alg
201  * @import: see struct ahash_alg
202  * @setkey: see struct ahash_alg
203  * @init_tfm: Initialize the cryptographic transformation object.
204  *	      This function is called only once at the instantiation
205  *	      time, right after the transformation context was
206  *	      allocated. In case the cryptographic hardware has
207  *	      some special requirements which need to be handled
208  *	      by software, this function shall check for the precise
209  *	      requirement of the transformation and put any software
210  *	      fallbacks in place.
211  * @exit_tfm: Deinitialize the cryptographic transformation object.
212  *	      This is a counterpart to @init_tfm, used to remove
213  *	      various changes set in @init_tfm.
214  * @digestsize: see struct ahash_alg
215  * @statesize: see struct ahash_alg
216  * @descsize: Size of the operational state for the message digest. This state
217  * 	      size is the memory size that needs to be allocated for
218  *	      shash_desc.__ctx
219  * @stat: Statistics for hash algorithm.
220  * @base: internally used
221  * @halg: see struct hash_alg_common
222  * @HASH_ALG_COMMON: see struct hash_alg_common
223  */
224 struct shash_alg {
225 	int (*init)(struct shash_desc *desc);
226 	int (*update)(struct shash_desc *desc, const u8 *data,
227 		      unsigned int len);
228 	int (*final)(struct shash_desc *desc, u8 *out);
229 	int (*finup)(struct shash_desc *desc, const u8 *data,
230 		     unsigned int len, u8 *out);
231 	int (*digest)(struct shash_desc *desc, const u8 *data,
232 		      unsigned int len, u8 *out);
233 	int (*export)(struct shash_desc *desc, void *out);
234 	int (*import)(struct shash_desc *desc, const void *in);
235 	int (*setkey)(struct crypto_shash *tfm, const u8 *key,
236 		      unsigned int keylen);
237 	int (*init_tfm)(struct crypto_shash *tfm);
238 	void (*exit_tfm)(struct crypto_shash *tfm);
239 
240 	unsigned int descsize;
241 
242 	union {
243 		struct HASH_ALG_COMMON;
244 		struct hash_alg_common halg;
245 	};
246 };
247 #undef HASH_ALG_COMMON
248 #undef HASH_ALG_COMMON_STAT
249 
250 struct crypto_ahash {
251 	int (*init)(struct ahash_request *req);
252 	int (*update)(struct ahash_request *req);
253 	int (*final)(struct ahash_request *req);
254 	int (*finup)(struct ahash_request *req);
255 	int (*digest)(struct ahash_request *req);
256 	int (*export)(struct ahash_request *req, void *out);
257 	int (*import)(struct ahash_request *req, const void *in);
258 	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
259 		      unsigned int keylen);
260 
261 	unsigned int reqsize;
262 	struct crypto_tfm base;
263 };
264 
265 struct crypto_shash {
266 	unsigned int descsize;
267 	struct crypto_tfm base;
268 };
269 
270 /**
271  * DOC: Asynchronous Message Digest API
272  *
273  * The asynchronous message digest API is used with the ciphers of type
274  * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
275  *
276  * The asynchronous cipher operation discussion provided for the
277  * CRYPTO_ALG_TYPE_SKCIPHER API applies here as well.
278  */
279 
280 static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
281 {
282 	return container_of(tfm, struct crypto_ahash, base);
283 }
284 
285 /**
286  * crypto_alloc_ahash() - allocate ahash cipher handle
287  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
288  *	      ahash cipher
289  * @type: specifies the type of the cipher
290  * @mask: specifies the mask for the cipher
291  *
292  * Allocate a cipher handle for an ahash. The returned struct
293  * crypto_ahash is the cipher handle that is required for any subsequent
294  * API invocation for that ahash.
295  *
296  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
297  *	   of an error, PTR_ERR() returns the error code.
298  */
299 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
300 					u32 mask);
301 
302 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
303 {
304 	return &tfm->base;
305 }
306 
307 /**
308  * crypto_free_ahash() - zeroize and free the ahash handle
309  * @tfm: cipher handle to be freed
310  *
311  * If @tfm is a NULL or error pointer, this function does nothing.
312  */
313 static inline void crypto_free_ahash(struct crypto_ahash *tfm)
314 {
315 	crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm));
316 }
317 
318 /**
319  * crypto_has_ahash() - Search for the availability of an ahash.
320  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
321  *	      ahash
322  * @type: specifies the type of the ahash
323  * @mask: specifies the mask for the ahash
324  *
325  * Return: true when the ahash is known to the kernel crypto API; false
326  *	   otherwise
327  */
328 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
329 
330 static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
331 {
332 	return crypto_tfm_alg_name(crypto_ahash_tfm(tfm));
333 }
334 
335 static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
336 {
337 	return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm));
338 }
339 
340 static inline unsigned int crypto_ahash_alignmask(
341 	struct crypto_ahash *tfm)
342 {
343 	return crypto_tfm_alg_alignmask(crypto_ahash_tfm(tfm));
344 }
345 
346 /**
347  * crypto_ahash_blocksize() - obtain block size for cipher
348  * @tfm: cipher handle
349  *
350  * The block size for the message digest cipher referenced with the cipher
351  * handle is returned.
352  *
353  * Return: block size of cipher
354  */
355 static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
356 {
357 	return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
358 }
359 
360 static inline struct hash_alg_common *__crypto_hash_alg_common(
361 	struct crypto_alg *alg)
362 {
363 	return container_of(alg, struct hash_alg_common, base);
364 }
365 
366 static inline struct hash_alg_common *crypto_hash_alg_common(
367 	struct crypto_ahash *tfm)
368 {
369 	return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg);
370 }
371 
372 /**
373  * crypto_ahash_digestsize() - obtain message digest size
374  * @tfm: cipher handle
375  *
376  * The size for the message digest created by the message digest cipher
377  * referenced with the cipher handle is returned.
378  *
379  *
380  * Return: message digest size of cipher
381  */
382 static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
383 {
384 	return crypto_hash_alg_common(tfm)->digestsize;
385 }
386 
387 /**
388  * crypto_ahash_statesize() - obtain size of the ahash state
389  * @tfm: cipher handle
390  *
391  * Return the size of the ahash state. With the crypto_ahash_export()
392  * function, the caller can export the state into a buffer whose size is
393  * defined with this function.
394  *
395  * Return: size of the ahash state
396  */
397 static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
398 {
399 	return crypto_hash_alg_common(tfm)->statesize;
400 }
401 
402 static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
403 {
404 	return crypto_tfm_get_flags(crypto_ahash_tfm(tfm));
405 }
406 
407 static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
408 {
409 	crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags);
410 }
411 
412 static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
413 {
414 	crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags);
415 }
416 
417 /**
418  * crypto_ahash_reqtfm() - obtain cipher handle from request
419  * @req: asynchronous request handle that contains the reference to the ahash
420  *	 cipher handle
421  *
422  * Return the ahash cipher handle that is registered with the asynchronous
423  * request handle ahash_request.
424  *
425  * Return: ahash cipher handle
426  */
427 static inline struct crypto_ahash *crypto_ahash_reqtfm(
428 	struct ahash_request *req)
429 {
430 	return __crypto_ahash_cast(req->base.tfm);
431 }
432 
433 /**
434  * crypto_ahash_reqsize() - obtain size of the request data structure
435  * @tfm: cipher handle
436  *
437  * Return: size of the request data
438  */
439 static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
440 {
441 	return tfm->reqsize;
442 }
443 
444 static inline void *ahash_request_ctx(struct ahash_request *req)
445 {
446 	return req->__ctx;
447 }
448 
449 /**
450  * crypto_ahash_setkey - set key for cipher handle
451  * @tfm: cipher handle
452  * @key: buffer holding the key
453  * @keylen: length of the key in bytes
454  *
455  * The caller provided key is set for the ahash cipher. The cipher
456  * handle must point to a keyed hash in order for this function to succeed.
457  *
458  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
459  */
460 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
461 			unsigned int keylen);
462 
463 /**
464  * crypto_ahash_finup() - update and finalize message digest
465  * @req: reference to the ahash_request handle that holds all information
466  *	 needed to perform the cipher operation
467  *
468  * This function is a "short-hand" for the function calls of
469  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
470  * meaning as discussed for those separate functions.
471  *
472  * Return: see crypto_ahash_final()
473  */
474 int crypto_ahash_finup(struct ahash_request *req);
475 
476 /**
477  * crypto_ahash_final() - calculate message digest
478  * @req: reference to the ahash_request handle that holds all information
479  *	 needed to perform the cipher operation
480  *
481  * Finalize the message digest operation and create the message digest
482  * based on all data added to the cipher handle. The message digest is placed
483  * into the output buffer registered with the ahash_request handle.
484  *
485  * Return:
486  * 0		if the message digest was successfully calculated;
487  * -EINPROGRESS	if data is fed into hardware (DMA) or queued for later;
488  * -EBUSY	if queue is full and request should be resubmitted later;
489  * other < 0	if an error occurred
490  */
491 int crypto_ahash_final(struct ahash_request *req);
492 
493 /**
494  * crypto_ahash_digest() - calculate message digest for a buffer
495  * @req: reference to the ahash_request handle that holds all information
496  *	 needed to perform the cipher operation
497  *
498  * This function is a "short-hand" for the function calls of crypto_ahash_init,
499  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
500  * meaning as discussed for those separate three functions.
501  *
502  * Return: see crypto_ahash_final()
503  */
504 int crypto_ahash_digest(struct ahash_request *req);
505 
506 /**
507  * crypto_ahash_export() - extract current message digest state
508  * @req: reference to the ahash_request handle whose state is exported
509  * @out: output buffer of sufficient size that can hold the hash state
510  *
511  * This function exports the hash state of the ahash_request handle into the
512  * caller-allocated output buffer out which must have sufficient size (e.g. by
513  * calling crypto_ahash_statesize()).
514  *
515  * Return: 0 if the export was successful; < 0 if an error occurred
516  */
517 static inline int crypto_ahash_export(struct ahash_request *req, void *out)
518 {
519 	return crypto_ahash_reqtfm(req)->export(req, out);
520 }
521 
522 /**
523  * crypto_ahash_import() - import message digest state
524  * @req: reference to ahash_request handle the state is imported into
525  * @in: buffer holding the state
526  *
527  * This function imports the hash state into the ahash_request handle from the
528  * input buffer. That buffer should have been generated with the
529  * crypto_ahash_export function.
530  *
531  * Return: 0 if the import was successful; < 0 if an error occurred
532  */
533 static inline int crypto_ahash_import(struct ahash_request *req, const void *in)
534 {
535 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
536 
537 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
538 		return -ENOKEY;
539 
540 	return tfm->import(req, in);
541 }
542 
543 /**
544  * crypto_ahash_init() - (re)initialize message digest handle
545  * @req: ahash_request handle that already is initialized with all necessary
546  *	 data using the ahash_request_* API functions
547  *
548  * The call (re-)initializes the message digest referenced by the ahash_request
549  * handle. Any potentially existing state created by previous operations is
550  * discarded.
551  *
552  * Return: see crypto_ahash_final()
553  */
554 static inline int crypto_ahash_init(struct ahash_request *req)
555 {
556 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
557 
558 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
559 		return -ENOKEY;
560 
561 	return tfm->init(req);
562 }
563 
564 static inline struct crypto_istat_hash *hash_get_stat(
565 	struct hash_alg_common *alg)
566 {
567 #ifdef CONFIG_CRYPTO_STATS
568 	return &alg->stat;
569 #else
570 	return NULL;
571 #endif
572 }
573 
574 static inline int crypto_hash_errstat(struct hash_alg_common *alg, int err)
575 {
576 	if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
577 		return err;
578 
579 	if (err && err != -EINPROGRESS && err != -EBUSY)
580 		atomic64_inc(&hash_get_stat(alg)->err_cnt);
581 
582 	return err;
583 }
584 
585 /**
586  * crypto_ahash_update() - add data to message digest for processing
587  * @req: ahash_request handle that was previously initialized with the
588  *	 crypto_ahash_init call.
589  *
590  * Updates the message digest state of the &ahash_request handle. The input data
591  * is pointed to by the scatter/gather list registered in the &ahash_request
592  * handle
593  *
594  * Return: see crypto_ahash_final()
595  */
596 static inline int crypto_ahash_update(struct ahash_request *req)
597 {
598 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
599 	struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
600 
601 	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
602 		atomic64_add(req->nbytes, &hash_get_stat(alg)->hash_tlen);
603 
604 	return crypto_hash_errstat(alg, tfm->update(req));
605 }
606 
607 /**
608  * DOC: Asynchronous Hash Request Handle
609  *
610  * The &ahash_request data structure contains all pointers to data
611  * required for the asynchronous cipher operation. This includes the cipher
612  * handle (which can be used by multiple &ahash_request instances), pointer
613  * to plaintext and the message digest output buffer, asynchronous callback
614  * function, etc. It acts as a handle to the ahash_request_* API calls in a
615  * similar way as ahash handle to the crypto_ahash_* API calls.
616  */
617 
618 /**
619  * ahash_request_set_tfm() - update cipher handle reference in request
620  * @req: request handle to be modified
621  * @tfm: cipher handle that shall be added to the request handle
622  *
623  * Allow the caller to replace the existing ahash handle in the request
624  * data structure with a different one.
625  */
626 static inline void ahash_request_set_tfm(struct ahash_request *req,
627 					 struct crypto_ahash *tfm)
628 {
629 	req->base.tfm = crypto_ahash_tfm(tfm);
630 }
631 
632 /**
633  * ahash_request_alloc() - allocate request data structure
634  * @tfm: cipher handle to be registered with the request
635  * @gfp: memory allocation flag that is handed to kmalloc by the API call.
636  *
637  * Allocate the request data structure that must be used with the ahash
638  * message digest API calls. During
639  * the allocation, the provided ahash handle
640  * is registered in the request data structure.
641  *
642  * Return: allocated request handle in case of success, or NULL if out of memory
643  */
644 static inline struct ahash_request *ahash_request_alloc(
645 	struct crypto_ahash *tfm, gfp_t gfp)
646 {
647 	struct ahash_request *req;
648 
649 	req = kmalloc(sizeof(struct ahash_request) +
650 		      crypto_ahash_reqsize(tfm), gfp);
651 
652 	if (likely(req))
653 		ahash_request_set_tfm(req, tfm);
654 
655 	return req;
656 }
657 
658 /**
659  * ahash_request_free() - zeroize and free the request data structure
660  * @req: request data structure cipher handle to be freed
661  */
662 static inline void ahash_request_free(struct ahash_request *req)
663 {
664 	kfree_sensitive(req);
665 }
666 
667 static inline void ahash_request_zero(struct ahash_request *req)
668 {
669 	memzero_explicit(req, sizeof(*req) +
670 			      crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));
671 }
672 
673 static inline struct ahash_request *ahash_request_cast(
674 	struct crypto_async_request *req)
675 {
676 	return container_of(req, struct ahash_request, base);
677 }
678 
679 /**
680  * ahash_request_set_callback() - set asynchronous callback function
681  * @req: request handle
682  * @flags: specify zero or an ORing of the flags
683  *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
684  *	   increase the wait queue beyond the initial maximum size;
685  *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
686  * @compl: callback function pointer to be registered with the request handle
687  * @data: The data pointer refers to memory that is not used by the kernel
688  *	  crypto API, but provided to the callback function for it to use. Here,
689  *	  the caller can provide a reference to memory the callback function can
690  *	  operate on. As the callback function is invoked asynchronously to the
691  *	  related functionality, it may need to access data structures of the
692  *	  related functionality which can be referenced using this pointer. The
693  *	  callback function can access the memory via the "data" field in the
694  *	  &crypto_async_request data structure provided to the callback function.
695  *
696  * This function allows setting the callback function that is triggered once
697  * the cipher operation completes.
698  *
699  * The callback function is registered with the &ahash_request handle and
700  * must comply with the following template::
701  *
702  *	void callback_function(struct crypto_async_request *req, int error)
703  */
704 static inline void ahash_request_set_callback(struct ahash_request *req,
705 					      u32 flags,
706 					      crypto_completion_t compl,
707 					      void *data)
708 {
709 	req->base.complete = compl;
710 	req->base.data = data;
711 	req->base.flags = flags;
712 }
713 
714 /**
715  * ahash_request_set_crypt() - set data buffers
716  * @req: ahash_request handle to be updated
717  * @src: source scatter/gather list
718  * @result: buffer that is filled with the message digest -- the caller must
719  *	    ensure that the buffer has sufficient space by, for example, calling
720  *	    crypto_ahash_digestsize()
721  * @nbytes: number of bytes to process from the source scatter/gather list
722  *
723  * By using this call, the caller references the source scatter/gather list.
724  * The source scatter/gather list points to the data the message digest is to
725  * be calculated for.
726  */
727 static inline void ahash_request_set_crypt(struct ahash_request *req,
728 					   struct scatterlist *src, u8 *result,
729 					   unsigned int nbytes)
730 {
731 	req->src = src;
732 	req->nbytes = nbytes;
733 	req->result = result;
734 }
735 
736 /**
737  * DOC: Synchronous Message Digest API
738  *
739  * The synchronous message digest API is used with the ciphers of type
740  * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
741  *
742  * The message digest API is able to maintain state information for the
743  * caller.
744  *
745  * The synchronous message digest API can store user-related context in its
746  * shash_desc request data structure.
747  */
748 
749 /**
750  * crypto_alloc_shash() - allocate message digest handle
751  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
752  *	      message digest cipher
753  * @type: specifies the type of the cipher
754  * @mask: specifies the mask for the cipher
755  *
756  * Allocate a cipher handle for a message digest. The returned &struct
757  * crypto_shash is the cipher handle that is required for any subsequent
758  * API invocation for that message digest.
759  *
760  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
761  *	   of an error, PTR_ERR() returns the error code.
762  */
763 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
764 					u32 mask);
765 
766 int crypto_has_shash(const char *alg_name, u32 type, u32 mask);
767 
768 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
769 {
770 	return &tfm->base;
771 }
772 
773 /**
774  * crypto_free_shash() - zeroize and free the message digest handle
775  * @tfm: cipher handle to be freed
776  *
777  * If @tfm is a NULL or error pointer, this function does nothing.
778  */
779 static inline void crypto_free_shash(struct crypto_shash *tfm)
780 {
781 	crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
782 }
783 
784 static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
785 {
786 	return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
787 }
788 
789 static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
790 {
791 	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
792 }
793 
794 static inline unsigned int crypto_shash_alignmask(
795 	struct crypto_shash *tfm)
796 {
797 	return crypto_tfm_alg_alignmask(crypto_shash_tfm(tfm));
798 }
799 
800 /**
801  * crypto_shash_blocksize() - obtain block size for cipher
802  * @tfm: cipher handle
803  *
804  * The block size for the message digest cipher referenced with the cipher
805  * handle is returned.
806  *
807  * Return: block size of cipher
808  */
809 static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
810 {
811 	return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm));
812 }
813 
814 static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
815 {
816 	return container_of(alg, struct shash_alg, base);
817 }
818 
819 static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
820 {
821 	return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg);
822 }
823 
824 /**
825  * crypto_shash_digestsize() - obtain message digest size
826  * @tfm: cipher handle
827  *
828  * The size for the message digest created by the message digest cipher
829  * referenced with the cipher handle is returned.
830  *
831  * Return: digest size of cipher
832  */
833 static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
834 {
835 	return crypto_shash_alg(tfm)->digestsize;
836 }
837 
838 static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
839 {
840 	return crypto_shash_alg(tfm)->statesize;
841 }
842 
843 static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
844 {
845 	return crypto_tfm_get_flags(crypto_shash_tfm(tfm));
846 }
847 
848 static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
849 {
850 	crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags);
851 }
852 
853 static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
854 {
855 	crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags);
856 }
857 
858 /**
859  * crypto_shash_descsize() - obtain the operational state size
860  * @tfm: cipher handle
861  *
862  * The size of the operational state the cipher needs during operation is
863  * returned for the hash referenced with the cipher handle. This size is
864  * required to calculate the memory requirements to allow the caller allocating
865  * sufficient memory for operational state.
866  *
867  * The operational state is defined with struct shash_desc where the size of
868  * that data structure is to be calculated as
869  * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
870  *
871  * Return: size of the operational state
872  */
873 static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
874 {
875 	return tfm->descsize;
876 }
877 
878 static inline void *shash_desc_ctx(struct shash_desc *desc)
879 {
880 	return desc->__ctx;
881 }
882 
883 /**
884  * crypto_shash_setkey() - set key for message digest
885  * @tfm: cipher handle
886  * @key: buffer holding the key
887  * @keylen: length of the key in bytes
888  *
889  * The caller provided key is set for the keyed message digest cipher. The
890  * cipher handle must point to a keyed message digest cipher in order for this
891  * function to succeed.
892  *
893  * Context: Any context.
894  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
895  */
896 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
897 			unsigned int keylen);
898 
899 /**
900  * crypto_shash_digest() - calculate message digest for buffer
901  * @desc: see crypto_shash_final()
902  * @data: see crypto_shash_update()
903  * @len: see crypto_shash_update()
904  * @out: see crypto_shash_final()
905  *
906  * This function is a "short-hand" for the function calls of crypto_shash_init,
907  * crypto_shash_update and crypto_shash_final. The parameters have the same
908  * meaning as discussed for those separate three functions.
909  *
910  * Context: Any context.
911  * Return: 0 if the message digest creation was successful; < 0 if an error
912  *	   occurred
913  */
914 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
915 			unsigned int len, u8 *out);
916 
917 /**
918  * crypto_shash_tfm_digest() - calculate message digest for buffer
919  * @tfm: hash transformation object
920  * @data: see crypto_shash_update()
921  * @len: see crypto_shash_update()
922  * @out: see crypto_shash_final()
923  *
924  * This is a simplified version of crypto_shash_digest() for users who don't
925  * want to allocate their own hash descriptor (shash_desc).  Instead,
926  * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
927  * directly, and it allocates a hash descriptor on the stack internally.
928  * Note that this stack allocation may be fairly large.
929  *
930  * Context: Any context.
931  * Return: 0 on success; < 0 if an error occurred.
932  */
933 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
934 			    unsigned int len, u8 *out);
935 
936 /**
937  * crypto_shash_export() - extract operational state for message digest
938  * @desc: reference to the operational state handle whose state is exported
939  * @out: output buffer of sufficient size that can hold the hash state
940  *
941  * This function exports the hash state of the operational state handle into the
942  * caller-allocated output buffer out which must have sufficient size (e.g. by
943  * calling crypto_shash_descsize).
944  *
945  * Context: Any context.
946  * Return: 0 if the export creation was successful; < 0 if an error occurred
947  */
948 static inline int crypto_shash_export(struct shash_desc *desc, void *out)
949 {
950 	return crypto_shash_alg(desc->tfm)->export(desc, out);
951 }
952 
953 /**
954  * crypto_shash_import() - import operational state
955  * @desc: reference to the operational state handle the state imported into
956  * @in: buffer holding the state
957  *
958  * This function imports the hash state into the operational state handle from
959  * the input buffer. That buffer should have been generated with the
960  * crypto_ahash_export function.
961  *
962  * Context: Any context.
963  * Return: 0 if the import was successful; < 0 if an error occurred
964  */
965 static inline int crypto_shash_import(struct shash_desc *desc, const void *in)
966 {
967 	struct crypto_shash *tfm = desc->tfm;
968 
969 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
970 		return -ENOKEY;
971 
972 	return crypto_shash_alg(tfm)->import(desc, in);
973 }
974 
975 /**
976  * crypto_shash_init() - (re)initialize message digest
977  * @desc: operational state handle that is already filled
978  *
979  * The call (re-)initializes the message digest referenced by the
980  * operational state handle. Any potentially existing state created by
981  * previous operations is discarded.
982  *
983  * Context: Any context.
984  * Return: 0 if the message digest initialization was successful; < 0 if an
985  *	   error occurred
986  */
987 static inline int crypto_shash_init(struct shash_desc *desc)
988 {
989 	struct crypto_shash *tfm = desc->tfm;
990 
991 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
992 		return -ENOKEY;
993 
994 	return crypto_shash_alg(tfm)->init(desc);
995 }
996 
997 /**
998  * crypto_shash_update() - add data to message digest for processing
999  * @desc: operational state handle that is already initialized
1000  * @data: input data to be added to the message digest
1001  * @len: length of the input data
1002  *
1003  * Updates the message digest state of the operational state handle.
1004  *
1005  * Context: Any context.
1006  * Return: 0 if the message digest update was successful; < 0 if an error
1007  *	   occurred
1008  */
1009 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
1010 			unsigned int len);
1011 
1012 /**
1013  * crypto_shash_final() - calculate message digest
1014  * @desc: operational state handle that is already filled with data
1015  * @out: output buffer filled with the message digest
1016  *
1017  * Finalize the message digest operation and create the message digest
1018  * based on all data added to the cipher handle. The message digest is placed
1019  * into the output buffer. The caller must ensure that the output buffer is
1020  * large enough by using crypto_shash_digestsize.
1021  *
1022  * Context: Any context.
1023  * Return: 0 if the message digest creation was successful; < 0 if an error
1024  *	   occurred
1025  */
1026 int crypto_shash_final(struct shash_desc *desc, u8 *out);
1027 
1028 /**
1029  * crypto_shash_finup() - calculate message digest of buffer
1030  * @desc: see crypto_shash_final()
1031  * @data: see crypto_shash_update()
1032  * @len: see crypto_shash_update()
1033  * @out: see crypto_shash_final()
1034  *
1035  * This function is a "short-hand" for the function calls of
1036  * crypto_shash_update and crypto_shash_final. The parameters have the same
1037  * meaning as discussed for those separate functions.
1038  *
1039  * Context: Any context.
1040  * Return: 0 if the message digest creation was successful; < 0 if an error
1041  *	   occurred
1042  */
1043 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
1044 		       unsigned int len, u8 *out);
1045 
1046 static inline void shash_desc_zero(struct shash_desc *desc)
1047 {
1048 	memzero_explicit(desc,
1049 			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
1050 }
1051 
1052 #endif	/* _CRYPTO_HASH_H */
1053