xref: /linux/include/crypto/hash.h (revision 881f1bb5e25c8982ed963b2d319fc0fc732e55db)
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  * @clone_tfm: Copy transform into new object, may allocate memory.
156  * @halg: see struct hash_alg_common
157  */
158 struct ahash_alg {
159 	int (*init)(struct ahash_request *req);
160 	int (*update)(struct ahash_request *req);
161 	int (*final)(struct ahash_request *req);
162 	int (*finup)(struct ahash_request *req);
163 	int (*digest)(struct ahash_request *req);
164 	int (*export)(struct ahash_request *req, void *out);
165 	int (*import)(struct ahash_request *req, const void *in);
166 	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
167 		      unsigned int keylen);
168 	int (*init_tfm)(struct crypto_ahash *tfm);
169 	void (*exit_tfm)(struct crypto_ahash *tfm);
170 	int (*clone_tfm)(struct crypto_ahash *dst, struct crypto_ahash *src);
171 
172 	struct hash_alg_common halg;
173 };
174 
175 struct shash_desc {
176 	struct crypto_shash *tfm;
177 	void *__ctx[] __aligned(ARCH_SLAB_MINALIGN);
178 };
179 
180 #define HASH_MAX_DIGESTSIZE	 64
181 
182 /*
183  * Worst case is hmac(sha3-224-generic).  Its context is a nested 'shash_desc'
184  * containing a 'struct sha3_state'.
185  */
186 #define HASH_MAX_DESCSIZE	(sizeof(struct shash_desc) + 360)
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  * @clone_tfm: Copy transform into new object, may allocate memory.
215  * @descsize: Size of the operational state for the message digest. This state
216  * 	      size is the memory size that needs to be allocated for
217  *	      shash_desc.__ctx
218  * @halg: see struct hash_alg_common
219  * @HASH_ALG_COMMON: see struct hash_alg_common
220  */
221 struct shash_alg {
222 	int (*init)(struct shash_desc *desc);
223 	int (*update)(struct shash_desc *desc, const u8 *data,
224 		      unsigned int len);
225 	int (*final)(struct shash_desc *desc, u8 *out);
226 	int (*finup)(struct shash_desc *desc, const u8 *data,
227 		     unsigned int len, u8 *out);
228 	int (*digest)(struct shash_desc *desc, const u8 *data,
229 		      unsigned int len, u8 *out);
230 	int (*export)(struct shash_desc *desc, void *out);
231 	int (*import)(struct shash_desc *desc, const void *in);
232 	int (*setkey)(struct crypto_shash *tfm, const u8 *key,
233 		      unsigned int keylen);
234 	int (*init_tfm)(struct crypto_shash *tfm);
235 	void (*exit_tfm)(struct crypto_shash *tfm);
236 	int (*clone_tfm)(struct crypto_shash *dst, struct crypto_shash *src);
237 
238 	unsigned int descsize;
239 
240 	union {
241 		struct HASH_ALG_COMMON;
242 		struct hash_alg_common halg;
243 	};
244 };
245 #undef HASH_ALG_COMMON
246 #undef HASH_ALG_COMMON_STAT
247 
248 struct crypto_ahash {
249 	bool using_shash; /* Underlying algorithm is shash, not ahash */
250 	unsigned int statesize;
251 	unsigned int reqsize;
252 	struct crypto_tfm base;
253 };
254 
255 struct crypto_shash {
256 	unsigned int descsize;
257 	struct crypto_tfm base;
258 };
259 
260 /**
261  * DOC: Asynchronous Message Digest API
262  *
263  * The asynchronous message digest API is used with the ciphers of type
264  * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
265  *
266  * The asynchronous cipher operation discussion provided for the
267  * CRYPTO_ALG_TYPE_SKCIPHER API applies here as well.
268  */
269 
270 static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
271 {
272 	return container_of(tfm, struct crypto_ahash, base);
273 }
274 
275 /**
276  * crypto_alloc_ahash() - allocate ahash cipher handle
277  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
278  *	      ahash cipher
279  * @type: specifies the type of the cipher
280  * @mask: specifies the mask for the cipher
281  *
282  * Allocate a cipher handle for an ahash. The returned struct
283  * crypto_ahash is the cipher handle that is required for any subsequent
284  * API invocation for that ahash.
285  *
286  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
287  *	   of an error, PTR_ERR() returns the error code.
288  */
289 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
290 					u32 mask);
291 
292 struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *tfm);
293 
294 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
295 {
296 	return &tfm->base;
297 }
298 
299 /**
300  * crypto_free_ahash() - zeroize and free the ahash handle
301  * @tfm: cipher handle to be freed
302  *
303  * If @tfm is a NULL or error pointer, this function does nothing.
304  */
305 static inline void crypto_free_ahash(struct crypto_ahash *tfm)
306 {
307 	crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm));
308 }
309 
310 /**
311  * crypto_has_ahash() - Search for the availability of an ahash.
312  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
313  *	      ahash
314  * @type: specifies the type of the ahash
315  * @mask: specifies the mask for the ahash
316  *
317  * Return: true when the ahash is known to the kernel crypto API; false
318  *	   otherwise
319  */
320 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
321 
322 static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
323 {
324 	return crypto_tfm_alg_name(crypto_ahash_tfm(tfm));
325 }
326 
327 static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
328 {
329 	return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm));
330 }
331 
332 /**
333  * crypto_ahash_blocksize() - obtain block size for cipher
334  * @tfm: cipher handle
335  *
336  * The block size for the message digest cipher referenced with the cipher
337  * handle is returned.
338  *
339  * Return: block size of cipher
340  */
341 static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
342 {
343 	return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
344 }
345 
346 static inline struct hash_alg_common *__crypto_hash_alg_common(
347 	struct crypto_alg *alg)
348 {
349 	return container_of(alg, struct hash_alg_common, base);
350 }
351 
352 static inline struct hash_alg_common *crypto_hash_alg_common(
353 	struct crypto_ahash *tfm)
354 {
355 	return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg);
356 }
357 
358 /**
359  * crypto_ahash_digestsize() - obtain message digest size
360  * @tfm: cipher handle
361  *
362  * The size for the message digest created by the message digest cipher
363  * referenced with the cipher handle is returned.
364  *
365  *
366  * Return: message digest size of cipher
367  */
368 static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
369 {
370 	return crypto_hash_alg_common(tfm)->digestsize;
371 }
372 
373 /**
374  * crypto_ahash_statesize() - obtain size of the ahash state
375  * @tfm: cipher handle
376  *
377  * Return the size of the ahash state. With the crypto_ahash_export()
378  * function, the caller can export the state into a buffer whose size is
379  * defined with this function.
380  *
381  * Return: size of the ahash state
382  */
383 static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
384 {
385 	return tfm->statesize;
386 }
387 
388 static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
389 {
390 	return crypto_tfm_get_flags(crypto_ahash_tfm(tfm));
391 }
392 
393 static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
394 {
395 	crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags);
396 }
397 
398 static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
399 {
400 	crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags);
401 }
402 
403 /**
404  * crypto_ahash_reqtfm() - obtain cipher handle from request
405  * @req: asynchronous request handle that contains the reference to the ahash
406  *	 cipher handle
407  *
408  * Return the ahash cipher handle that is registered with the asynchronous
409  * request handle ahash_request.
410  *
411  * Return: ahash cipher handle
412  */
413 static inline struct crypto_ahash *crypto_ahash_reqtfm(
414 	struct ahash_request *req)
415 {
416 	return __crypto_ahash_cast(req->base.tfm);
417 }
418 
419 /**
420  * crypto_ahash_reqsize() - obtain size of the request data structure
421  * @tfm: cipher handle
422  *
423  * Return: size of the request data
424  */
425 static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
426 {
427 	return tfm->reqsize;
428 }
429 
430 static inline void *ahash_request_ctx(struct ahash_request *req)
431 {
432 	return req->__ctx;
433 }
434 
435 /**
436  * crypto_ahash_setkey - set key for cipher handle
437  * @tfm: cipher handle
438  * @key: buffer holding the key
439  * @keylen: length of the key in bytes
440  *
441  * The caller provided key is set for the ahash cipher. The cipher
442  * handle must point to a keyed hash in order for this function to succeed.
443  *
444  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
445  */
446 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
447 			unsigned int keylen);
448 
449 /**
450  * crypto_ahash_finup() - update and finalize message digest
451  * @req: reference to the ahash_request handle that holds all information
452  *	 needed to perform the cipher operation
453  *
454  * This function is a "short-hand" for the function calls of
455  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
456  * meaning as discussed for those separate functions.
457  *
458  * Return: see crypto_ahash_final()
459  */
460 int crypto_ahash_finup(struct ahash_request *req);
461 
462 /**
463  * crypto_ahash_final() - calculate message digest
464  * @req: reference to the ahash_request handle that holds all information
465  *	 needed to perform the cipher operation
466  *
467  * Finalize the message digest operation and create the message digest
468  * based on all data added to the cipher handle. The message digest is placed
469  * into the output buffer registered with the ahash_request handle.
470  *
471  * Return:
472  * 0		if the message digest was successfully calculated;
473  * -EINPROGRESS	if data is fed into hardware (DMA) or queued for later;
474  * -EBUSY	if queue is full and request should be resubmitted later;
475  * other < 0	if an error occurred
476  */
477 int crypto_ahash_final(struct ahash_request *req);
478 
479 /**
480  * crypto_ahash_digest() - calculate message digest for a buffer
481  * @req: reference to the ahash_request handle that holds all information
482  *	 needed to perform the cipher operation
483  *
484  * This function is a "short-hand" for the function calls of crypto_ahash_init,
485  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
486  * meaning as discussed for those separate three functions.
487  *
488  * Return: see crypto_ahash_final()
489  */
490 int crypto_ahash_digest(struct ahash_request *req);
491 
492 /**
493  * crypto_ahash_export() - extract current message digest state
494  * @req: reference to the ahash_request handle whose state is exported
495  * @out: output buffer of sufficient size that can hold the hash state
496  *
497  * This function exports the hash state of the ahash_request handle into the
498  * caller-allocated output buffer out which must have sufficient size (e.g. by
499  * calling crypto_ahash_statesize()).
500  *
501  * Return: 0 if the export was successful; < 0 if an error occurred
502  */
503 int crypto_ahash_export(struct ahash_request *req, void *out);
504 
505 /**
506  * crypto_ahash_import() - import message digest state
507  * @req: reference to ahash_request handle the state is imported into
508  * @in: buffer holding the state
509  *
510  * This function imports the hash state into the ahash_request handle from the
511  * input buffer. That buffer should have been generated with the
512  * crypto_ahash_export function.
513  *
514  * Return: 0 if the import was successful; < 0 if an error occurred
515  */
516 int crypto_ahash_import(struct ahash_request *req, const void *in);
517 
518 /**
519  * crypto_ahash_init() - (re)initialize message digest handle
520  * @req: ahash_request handle that already is initialized with all necessary
521  *	 data using the ahash_request_* API functions
522  *
523  * The call (re-)initializes the message digest referenced by the ahash_request
524  * handle. Any potentially existing state created by previous operations is
525  * discarded.
526  *
527  * Return: see crypto_ahash_final()
528  */
529 int crypto_ahash_init(struct ahash_request *req);
530 
531 /**
532  * crypto_ahash_update() - add data to message digest for processing
533  * @req: ahash_request handle that was previously initialized with the
534  *	 crypto_ahash_init call.
535  *
536  * Updates the message digest state of the &ahash_request handle. The input data
537  * is pointed to by the scatter/gather list registered in the &ahash_request
538  * handle
539  *
540  * Return: see crypto_ahash_final()
541  */
542 int crypto_ahash_update(struct ahash_request *req);
543 
544 /**
545  * DOC: Asynchronous Hash Request Handle
546  *
547  * The &ahash_request data structure contains all pointers to data
548  * required for the asynchronous cipher operation. This includes the cipher
549  * handle (which can be used by multiple &ahash_request instances), pointer
550  * to plaintext and the message digest output buffer, asynchronous callback
551  * function, etc. It acts as a handle to the ahash_request_* API calls in a
552  * similar way as ahash handle to the crypto_ahash_* API calls.
553  */
554 
555 /**
556  * ahash_request_set_tfm() - update cipher handle reference in request
557  * @req: request handle to be modified
558  * @tfm: cipher handle that shall be added to the request handle
559  *
560  * Allow the caller to replace the existing ahash handle in the request
561  * data structure with a different one.
562  */
563 static inline void ahash_request_set_tfm(struct ahash_request *req,
564 					 struct crypto_ahash *tfm)
565 {
566 	req->base.tfm = crypto_ahash_tfm(tfm);
567 }
568 
569 /**
570  * ahash_request_alloc() - allocate request data structure
571  * @tfm: cipher handle to be registered with the request
572  * @gfp: memory allocation flag that is handed to kmalloc by the API call.
573  *
574  * Allocate the request data structure that must be used with the ahash
575  * message digest API calls. During
576  * the allocation, the provided ahash handle
577  * is registered in the request data structure.
578  *
579  * Return: allocated request handle in case of success, or NULL if out of memory
580  */
581 static inline struct ahash_request *ahash_request_alloc_noprof(
582 	struct crypto_ahash *tfm, gfp_t gfp)
583 {
584 	struct ahash_request *req;
585 
586 	req = kmalloc_noprof(sizeof(struct ahash_request) +
587 			     crypto_ahash_reqsize(tfm), gfp);
588 
589 	if (likely(req))
590 		ahash_request_set_tfm(req, tfm);
591 
592 	return req;
593 }
594 #define ahash_request_alloc(...)	alloc_hooks(ahash_request_alloc_noprof(__VA_ARGS__))
595 
596 /**
597  * ahash_request_free() - zeroize and free the request data structure
598  * @req: request data structure cipher handle to be freed
599  */
600 static inline void ahash_request_free(struct ahash_request *req)
601 {
602 	kfree_sensitive(req);
603 }
604 
605 static inline void ahash_request_zero(struct ahash_request *req)
606 {
607 	memzero_explicit(req, sizeof(*req) +
608 			      crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));
609 }
610 
611 static inline struct ahash_request *ahash_request_cast(
612 	struct crypto_async_request *req)
613 {
614 	return container_of(req, struct ahash_request, base);
615 }
616 
617 /**
618  * ahash_request_set_callback() - set asynchronous callback function
619  * @req: request handle
620  * @flags: specify zero or an ORing of the flags
621  *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
622  *	   increase the wait queue beyond the initial maximum size;
623  *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
624  * @compl: callback function pointer to be registered with the request handle
625  * @data: The data pointer refers to memory that is not used by the kernel
626  *	  crypto API, but provided to the callback function for it to use. Here,
627  *	  the caller can provide a reference to memory the callback function can
628  *	  operate on. As the callback function is invoked asynchronously to the
629  *	  related functionality, it may need to access data structures of the
630  *	  related functionality which can be referenced using this pointer. The
631  *	  callback function can access the memory via the "data" field in the
632  *	  &crypto_async_request data structure provided to the callback function.
633  *
634  * This function allows setting the callback function that is triggered once
635  * the cipher operation completes.
636  *
637  * The callback function is registered with the &ahash_request handle and
638  * must comply with the following template::
639  *
640  *	void callback_function(struct crypto_async_request *req, int error)
641  */
642 static inline void ahash_request_set_callback(struct ahash_request *req,
643 					      u32 flags,
644 					      crypto_completion_t compl,
645 					      void *data)
646 {
647 	req->base.complete = compl;
648 	req->base.data = data;
649 	req->base.flags = flags;
650 }
651 
652 /**
653  * ahash_request_set_crypt() - set data buffers
654  * @req: ahash_request handle to be updated
655  * @src: source scatter/gather list
656  * @result: buffer that is filled with the message digest -- the caller must
657  *	    ensure that the buffer has sufficient space by, for example, calling
658  *	    crypto_ahash_digestsize()
659  * @nbytes: number of bytes to process from the source scatter/gather list
660  *
661  * By using this call, the caller references the source scatter/gather list.
662  * The source scatter/gather list points to the data the message digest is to
663  * be calculated for.
664  */
665 static inline void ahash_request_set_crypt(struct ahash_request *req,
666 					   struct scatterlist *src, u8 *result,
667 					   unsigned int nbytes)
668 {
669 	req->src = src;
670 	req->nbytes = nbytes;
671 	req->result = result;
672 }
673 
674 /**
675  * DOC: Synchronous Message Digest API
676  *
677  * The synchronous message digest API is used with the ciphers of type
678  * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
679  *
680  * The message digest API is able to maintain state information for the
681  * caller.
682  *
683  * The synchronous message digest API can store user-related context in its
684  * shash_desc request data structure.
685  */
686 
687 /**
688  * crypto_alloc_shash() - allocate message digest handle
689  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
690  *	      message digest cipher
691  * @type: specifies the type of the cipher
692  * @mask: specifies the mask for the cipher
693  *
694  * Allocate a cipher handle for a message digest. The returned &struct
695  * crypto_shash is the cipher handle that is required for any subsequent
696  * API invocation for that message digest.
697  *
698  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
699  *	   of an error, PTR_ERR() returns the error code.
700  */
701 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
702 					u32 mask);
703 
704 struct crypto_shash *crypto_clone_shash(struct crypto_shash *tfm);
705 
706 int crypto_has_shash(const char *alg_name, u32 type, u32 mask);
707 
708 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
709 {
710 	return &tfm->base;
711 }
712 
713 /**
714  * crypto_free_shash() - zeroize and free the message digest handle
715  * @tfm: cipher handle to be freed
716  *
717  * If @tfm is a NULL or error pointer, this function does nothing.
718  */
719 static inline void crypto_free_shash(struct crypto_shash *tfm)
720 {
721 	crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
722 }
723 
724 static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
725 {
726 	return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
727 }
728 
729 static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
730 {
731 	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
732 }
733 
734 /**
735  * crypto_shash_blocksize() - obtain block size for cipher
736  * @tfm: cipher handle
737  *
738  * The block size for the message digest cipher referenced with the cipher
739  * handle is returned.
740  *
741  * Return: block size of cipher
742  */
743 static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
744 {
745 	return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm));
746 }
747 
748 static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
749 {
750 	return container_of(alg, struct shash_alg, base);
751 }
752 
753 static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
754 {
755 	return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg);
756 }
757 
758 /**
759  * crypto_shash_digestsize() - obtain message digest size
760  * @tfm: cipher handle
761  *
762  * The size for the message digest created by the message digest cipher
763  * referenced with the cipher handle is returned.
764  *
765  * Return: digest size of cipher
766  */
767 static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
768 {
769 	return crypto_shash_alg(tfm)->digestsize;
770 }
771 
772 static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
773 {
774 	return crypto_shash_alg(tfm)->statesize;
775 }
776 
777 static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
778 {
779 	return crypto_tfm_get_flags(crypto_shash_tfm(tfm));
780 }
781 
782 static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
783 {
784 	crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags);
785 }
786 
787 static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
788 {
789 	crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags);
790 }
791 
792 /**
793  * crypto_shash_descsize() - obtain the operational state size
794  * @tfm: cipher handle
795  *
796  * The size of the operational state the cipher needs during operation is
797  * returned for the hash referenced with the cipher handle. This size is
798  * required to calculate the memory requirements to allow the caller allocating
799  * sufficient memory for operational state.
800  *
801  * The operational state is defined with struct shash_desc where the size of
802  * that data structure is to be calculated as
803  * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
804  *
805  * Return: size of the operational state
806  */
807 static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
808 {
809 	return tfm->descsize;
810 }
811 
812 static inline void *shash_desc_ctx(struct shash_desc *desc)
813 {
814 	return desc->__ctx;
815 }
816 
817 /**
818  * crypto_shash_setkey() - set key for message digest
819  * @tfm: cipher handle
820  * @key: buffer holding the key
821  * @keylen: length of the key in bytes
822  *
823  * The caller provided key is set for the keyed message digest cipher. The
824  * cipher handle must point to a keyed message digest cipher in order for this
825  * function to succeed.
826  *
827  * Context: Any context.
828  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
829  */
830 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
831 			unsigned int keylen);
832 
833 /**
834  * crypto_shash_digest() - calculate message digest for buffer
835  * @desc: see crypto_shash_final()
836  * @data: see crypto_shash_update()
837  * @len: see crypto_shash_update()
838  * @out: see crypto_shash_final()
839  *
840  * This function is a "short-hand" for the function calls of crypto_shash_init,
841  * crypto_shash_update and crypto_shash_final. The parameters have the same
842  * meaning as discussed for those separate three functions.
843  *
844  * Context: Any context.
845  * Return: 0 if the message digest creation was successful; < 0 if an error
846  *	   occurred
847  */
848 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
849 			unsigned int len, u8 *out);
850 
851 /**
852  * crypto_shash_tfm_digest() - calculate message digest for buffer
853  * @tfm: hash transformation object
854  * @data: see crypto_shash_update()
855  * @len: see crypto_shash_update()
856  * @out: see crypto_shash_final()
857  *
858  * This is a simplified version of crypto_shash_digest() for users who don't
859  * want to allocate their own hash descriptor (shash_desc).  Instead,
860  * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
861  * directly, and it allocates a hash descriptor on the stack internally.
862  * Note that this stack allocation may be fairly large.
863  *
864  * Context: Any context.
865  * Return: 0 on success; < 0 if an error occurred.
866  */
867 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
868 			    unsigned int len, u8 *out);
869 
870 /**
871  * crypto_shash_export() - extract operational state for message digest
872  * @desc: reference to the operational state handle whose state is exported
873  * @out: output buffer of sufficient size that can hold the hash state
874  *
875  * This function exports the hash state of the operational state handle into the
876  * caller-allocated output buffer out which must have sufficient size (e.g. by
877  * calling crypto_shash_descsize).
878  *
879  * Context: Any context.
880  * Return: 0 if the export creation was successful; < 0 if an error occurred
881  */
882 int crypto_shash_export(struct shash_desc *desc, void *out);
883 
884 /**
885  * crypto_shash_import() - import operational state
886  * @desc: reference to the operational state handle the state imported into
887  * @in: buffer holding the state
888  *
889  * This function imports the hash state into the operational state handle from
890  * the input buffer. That buffer should have been generated with the
891  * crypto_ahash_export function.
892  *
893  * Context: Any context.
894  * Return: 0 if the import was successful; < 0 if an error occurred
895  */
896 int crypto_shash_import(struct shash_desc *desc, const void *in);
897 
898 /**
899  * crypto_shash_init() - (re)initialize message digest
900  * @desc: operational state handle that is already filled
901  *
902  * The call (re-)initializes the message digest referenced by the
903  * operational state handle. Any potentially existing state created by
904  * previous operations is discarded.
905  *
906  * Context: Any context.
907  * Return: 0 if the message digest initialization was successful; < 0 if an
908  *	   error occurred
909  */
910 static inline int crypto_shash_init(struct shash_desc *desc)
911 {
912 	struct crypto_shash *tfm = desc->tfm;
913 
914 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
915 		return -ENOKEY;
916 
917 	return crypto_shash_alg(tfm)->init(desc);
918 }
919 
920 /**
921  * crypto_shash_update() - add data to message digest for processing
922  * @desc: operational state handle that is already initialized
923  * @data: input data to be added to the message digest
924  * @len: length of the input data
925  *
926  * Updates the message digest state of the operational state handle.
927  *
928  * Context: Any context.
929  * Return: 0 if the message digest update was successful; < 0 if an error
930  *	   occurred
931  */
932 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
933 			unsigned int len);
934 
935 /**
936  * crypto_shash_final() - calculate message digest
937  * @desc: operational state handle that is already filled with data
938  * @out: output buffer filled with the message digest
939  *
940  * Finalize the message digest operation and create the message digest
941  * based on all data added to the cipher handle. The message digest is placed
942  * into the output buffer. The caller must ensure that the output buffer is
943  * large enough by using crypto_shash_digestsize.
944  *
945  * Context: Any context.
946  * Return: 0 if the message digest creation was successful; < 0 if an error
947  *	   occurred
948  */
949 int crypto_shash_final(struct shash_desc *desc, u8 *out);
950 
951 /**
952  * crypto_shash_finup() - calculate message digest of buffer
953  * @desc: see crypto_shash_final()
954  * @data: see crypto_shash_update()
955  * @len: see crypto_shash_update()
956  * @out: see crypto_shash_final()
957  *
958  * This function is a "short-hand" for the function calls of
959  * crypto_shash_update and crypto_shash_final. The parameters have the same
960  * meaning as discussed for those separate functions.
961  *
962  * Context: Any context.
963  * Return: 0 if the message digest creation was successful; < 0 if an error
964  *	   occurred
965  */
966 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
967 		       unsigned int len, u8 *out);
968 
969 static inline void shash_desc_zero(struct shash_desc *desc)
970 {
971 	memzero_explicit(desc,
972 			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
973 }
974 
975 #endif	/* _CRYPTO_HASH_H */
976