xref: /linux/include/crypto/hash.h (revision c24a65b6a27c78d8540409800886b6622ea86ebf)
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 /* Set this bit for virtual address instead of SG list. */
16 #define CRYPTO_AHASH_REQ_VIRT	0x00000001
17 
18 struct crypto_ahash;
19 
20 /**
21  * DOC: Message Digest Algorithm Definitions
22  *
23  * These data structures define modular message digest algorithm
24  * implementations, managed via crypto_register_ahash(),
25  * crypto_register_shash(), crypto_unregister_ahash() and
26  * crypto_unregister_shash().
27  */
28 
29 /*
30  * struct hash_alg_common - define properties of message digest
31  * @digestsize: Size of the result of the transformation. A buffer of this size
32  *	        must be available to the @final and @finup calls, so they can
33  *	        store the resulting hash into it. For various predefined sizes,
34  *	        search include/crypto/ using
35  *	        git grep _DIGEST_SIZE include/crypto.
36  * @statesize: Size of the block for partial state of the transformation. A
37  *	       buffer of this size must be passed to the @export function as it
38  *	       will save the partial state of the transformation into it. On the
39  *	       other side, the @import function will load the state from a
40  *	       buffer of this size as well.
41  * @base: Start of data structure of cipher algorithm. The common data
42  *	  structure of crypto_alg contains information common to all ciphers.
43  *	  The hash_alg_common data structure now adds the hash-specific
44  *	  information.
45  */
46 #define HASH_ALG_COMMON {		\
47 	unsigned int digestsize;	\
48 	unsigned int statesize;		\
49 					\
50 	struct crypto_alg base;		\
51 }
52 struct hash_alg_common HASH_ALG_COMMON;
53 
54 struct ahash_request {
55 	struct crypto_async_request base;
56 
57 	unsigned int nbytes;
58 	union {
59 		struct scatterlist *src;
60 		const u8 *svirt;
61 	};
62 	u8 *result;
63 
64 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
65 };
66 
67 /**
68  * struct ahash_alg - asynchronous message digest definition
69  * @init: **[mandatory]** Initialize the transformation context. Intended only to initialize the
70  *	  state of the HASH transformation at the beginning. This shall fill in
71  *	  the internal structures used during the entire duration of the whole
72  *	  transformation. No data processing happens at this point. Driver code
73  *	  implementation must not use req->result.
74  * @update: **[mandatory]** Push a chunk of data into the driver for transformation. This
75  *	   function actually pushes blocks of data from upper layers into the
76  *	   driver, which then passes those to the hardware as seen fit. This
77  *	   function must not finalize the HASH transformation by calculating the
78  *	   final message digest as this only adds more data into the
79  *	   transformation. This function shall not modify the transformation
80  *	   context, as this function may be called in parallel with the same
81  *	   transformation object. Data processing can happen synchronously
82  *	   [SHASH] or asynchronously [AHASH] at this point. Driver must not use
83  *	   req->result.
84  * @final: **[mandatory]** Retrieve result from the driver. This function finalizes the
85  *	   transformation and retrieves the resulting hash from the driver and
86  *	   pushes it back to upper layers. No data processing happens at this
87  *	   point unless hardware requires it to finish the transformation
88  *	   (then the data buffered by the device driver is processed).
89  * @finup: **[optional]** Combination of @update and @final. This function is effectively a
90  *	   combination of @update and @final calls issued in sequence. As some
91  *	   hardware cannot do @update and @final separately, this callback was
92  *	   added to allow such hardware to be used at least by IPsec. Data
93  *	   processing can happen synchronously [SHASH] or asynchronously [AHASH]
94  *	   at this point.
95  * @digest: Combination of @init and @update and @final. This function
96  *	    effectively behaves as the entire chain of operations, @init,
97  *	    @update and @final issued in sequence. Just like @finup, this was
98  *	    added for hardware which cannot do even the @finup, but can only do
99  *	    the whole transformation in one run. Data processing can happen
100  *	    synchronously [SHASH] or asynchronously [AHASH] at this point.
101  * @setkey: Set optional key used by the hashing algorithm. Intended to push
102  *	    optional key used by the hashing algorithm from upper layers into
103  *	    the driver. This function can store the key in the transformation
104  *	    context or can outright program it into the hardware. In the former
105  *	    case, one must be careful to program the key into the hardware at
106  *	    appropriate time and one must be careful that .setkey() can be
107  *	    called multiple times during the existence of the transformation
108  *	    object. Not  all hashing algorithms do implement this function as it
109  *	    is only needed for keyed message digests. SHAx/MDx/CRCx do NOT
110  *	    implement this function. HMAC(MDx)/HMAC(SHAx)/CMAC(AES) do implement
111  *	    this function. This function must be called before any other of the
112  *	    @init, @update, @final, @finup, @digest is called. No data
113  *	    processing happens at this point.
114  * @export: Export partial state of the transformation. This function dumps the
115  *	    entire state of the ongoing transformation into a provided block of
116  *	    data so it can be @import 'ed back later on. This is useful in case
117  *	    you want to save partial result of the transformation after
118  *	    processing certain amount of data and reload this partial result
119  *	    multiple times later on for multiple re-use. No data processing
120  *	    happens at this point. Driver must not use req->result.
121  * @import: Import partial state of the transformation. This function loads the
122  *	    entire state of the ongoing transformation from a provided block of
123  *	    data so the transformation can continue from this point onward. No
124  *	    data processing happens at this point. Driver must not use
125  *	    req->result.
126  * @init_tfm: Initialize the cryptographic transformation object.
127  *	      This function is called only once at the instantiation
128  *	      time, right after the transformation context was
129  *	      allocated. In case the cryptographic hardware has
130  *	      some special requirements which need to be handled
131  *	      by software, this function shall check for the precise
132  *	      requirement of the transformation and put any software
133  *	      fallbacks in place.
134  * @exit_tfm: Deinitialize the cryptographic transformation object.
135  *	      This is a counterpart to @init_tfm, used to remove
136  *	      various changes set in @init_tfm.
137  * @clone_tfm: Copy transform into new object, may allocate memory.
138  * @reqsize: Size of the request context.
139  * @halg: see struct hash_alg_common
140  */
141 struct ahash_alg {
142 	int (*init)(struct ahash_request *req);
143 	int (*update)(struct ahash_request *req);
144 	int (*final)(struct ahash_request *req);
145 	int (*finup)(struct ahash_request *req);
146 	int (*digest)(struct ahash_request *req);
147 	int (*export)(struct ahash_request *req, void *out);
148 	int (*import)(struct ahash_request *req, const void *in);
149 	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
150 		      unsigned int keylen);
151 	int (*init_tfm)(struct crypto_ahash *tfm);
152 	void (*exit_tfm)(struct crypto_ahash *tfm);
153 	int (*clone_tfm)(struct crypto_ahash *dst, struct crypto_ahash *src);
154 
155 	unsigned int reqsize;
156 
157 	struct hash_alg_common halg;
158 };
159 
160 struct shash_desc {
161 	struct crypto_shash *tfm;
162 	void *__ctx[] __aligned(ARCH_SLAB_MINALIGN);
163 };
164 
165 #define HASH_MAX_DIGESTSIZE	 64
166 
167 /*
168  * Worst case is hmac(sha3-224-generic).  Its context is a nested 'shash_desc'
169  * containing a 'struct sha3_state'.
170  */
171 #define HASH_MAX_DESCSIZE	(sizeof(struct shash_desc) + 360)
172 
173 #define SHASH_DESC_ON_STACK(shash, ctx)					     \
174 	char __##shash##_desc[sizeof(struct shash_desc) + HASH_MAX_DESCSIZE] \
175 		__aligned(__alignof__(struct shash_desc));		     \
176 	struct shash_desc *shash = (struct shash_desc *)__##shash##_desc
177 
178 /**
179  * struct shash_alg - synchronous message digest definition
180  * @init: see struct ahash_alg
181  * @update: see struct ahash_alg
182  * @final: see struct ahash_alg
183  * @finup: see struct ahash_alg
184  * @digest: see struct ahash_alg
185  * @export: see struct ahash_alg
186  * @import: see struct ahash_alg
187  * @setkey: see struct ahash_alg
188  * @init_tfm: Initialize the cryptographic transformation object.
189  *	      This function is called only once at the instantiation
190  *	      time, right after the transformation context was
191  *	      allocated. In case the cryptographic hardware has
192  *	      some special requirements which need to be handled
193  *	      by software, this function shall check for the precise
194  *	      requirement of the transformation and put any software
195  *	      fallbacks in place.
196  * @exit_tfm: Deinitialize the cryptographic transformation object.
197  *	      This is a counterpart to @init_tfm, used to remove
198  *	      various changes set in @init_tfm.
199  * @clone_tfm: Copy transform into new object, may allocate memory.
200  * @descsize: Size of the operational state for the message digest. This state
201  * 	      size is the memory size that needs to be allocated for
202  *	      shash_desc.__ctx
203  * @halg: see struct hash_alg_common
204  * @HASH_ALG_COMMON: see struct hash_alg_common
205  */
206 struct shash_alg {
207 	int (*init)(struct shash_desc *desc);
208 	int (*update)(struct shash_desc *desc, const u8 *data,
209 		      unsigned int len);
210 	int (*final)(struct shash_desc *desc, u8 *out);
211 	int (*finup)(struct shash_desc *desc, const u8 *data,
212 		     unsigned int len, u8 *out);
213 	int (*digest)(struct shash_desc *desc, const u8 *data,
214 		      unsigned int len, u8 *out);
215 	int (*export)(struct shash_desc *desc, void *out);
216 	int (*import)(struct shash_desc *desc, const void *in);
217 	int (*setkey)(struct crypto_shash *tfm, const u8 *key,
218 		      unsigned int keylen);
219 	int (*init_tfm)(struct crypto_shash *tfm);
220 	void (*exit_tfm)(struct crypto_shash *tfm);
221 	int (*clone_tfm)(struct crypto_shash *dst, struct crypto_shash *src);
222 
223 	unsigned int descsize;
224 
225 	union {
226 		struct HASH_ALG_COMMON;
227 		struct hash_alg_common halg;
228 	};
229 };
230 #undef HASH_ALG_COMMON
231 
232 struct crypto_ahash {
233 	bool using_shash; /* Underlying algorithm is shash, not ahash */
234 	unsigned int statesize;
235 	unsigned int reqsize;
236 	struct crypto_tfm base;
237 };
238 
239 struct crypto_shash {
240 	unsigned int descsize;
241 	struct crypto_tfm base;
242 };
243 
244 /**
245  * DOC: Asynchronous Message Digest API
246  *
247  * The asynchronous message digest API is used with the ciphers of type
248  * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
249  *
250  * The asynchronous cipher operation discussion provided for the
251  * CRYPTO_ALG_TYPE_SKCIPHER API applies here as well.
252  */
253 
254 static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
255 {
256 	return container_of(tfm, struct crypto_ahash, base);
257 }
258 
259 /**
260  * crypto_alloc_ahash() - allocate ahash cipher handle
261  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
262  *	      ahash cipher
263  * @type: specifies the type of the cipher
264  * @mask: specifies the mask for the cipher
265  *
266  * Allocate a cipher handle for an ahash. The returned struct
267  * crypto_ahash is the cipher handle that is required for any subsequent
268  * API invocation for that ahash.
269  *
270  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
271  *	   of an error, PTR_ERR() returns the error code.
272  */
273 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
274 					u32 mask);
275 
276 struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *tfm);
277 
278 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
279 {
280 	return &tfm->base;
281 }
282 
283 /**
284  * crypto_free_ahash() - zeroize and free the ahash handle
285  * @tfm: cipher handle to be freed
286  *
287  * If @tfm is a NULL or error pointer, this function does nothing.
288  */
289 static inline void crypto_free_ahash(struct crypto_ahash *tfm)
290 {
291 	crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm));
292 }
293 
294 /**
295  * crypto_has_ahash() - Search for the availability of an ahash.
296  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
297  *	      ahash
298  * @type: specifies the type of the ahash
299  * @mask: specifies the mask for the ahash
300  *
301  * Return: true when the ahash is known to the kernel crypto API; false
302  *	   otherwise
303  */
304 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
305 
306 static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
307 {
308 	return crypto_tfm_alg_name(crypto_ahash_tfm(tfm));
309 }
310 
311 static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
312 {
313 	return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm));
314 }
315 
316 /**
317  * crypto_ahash_blocksize() - obtain block size for cipher
318  * @tfm: cipher handle
319  *
320  * The block size for the message digest cipher referenced with the cipher
321  * handle is returned.
322  *
323  * Return: block size of cipher
324  */
325 static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
326 {
327 	return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
328 }
329 
330 static inline struct hash_alg_common *__crypto_hash_alg_common(
331 	struct crypto_alg *alg)
332 {
333 	return container_of(alg, struct hash_alg_common, base);
334 }
335 
336 static inline struct hash_alg_common *crypto_hash_alg_common(
337 	struct crypto_ahash *tfm)
338 {
339 	return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg);
340 }
341 
342 /**
343  * crypto_ahash_digestsize() - obtain message digest size
344  * @tfm: cipher handle
345  *
346  * The size for the message digest created by the message digest cipher
347  * referenced with the cipher handle is returned.
348  *
349  *
350  * Return: message digest size of cipher
351  */
352 static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
353 {
354 	return crypto_hash_alg_common(tfm)->digestsize;
355 }
356 
357 /**
358  * crypto_ahash_statesize() - obtain size of the ahash state
359  * @tfm: cipher handle
360  *
361  * Return the size of the ahash state. With the crypto_ahash_export()
362  * function, the caller can export the state into a buffer whose size is
363  * defined with this function.
364  *
365  * Return: size of the ahash state
366  */
367 static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
368 {
369 	return tfm->statesize;
370 }
371 
372 static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
373 {
374 	return crypto_tfm_get_flags(crypto_ahash_tfm(tfm));
375 }
376 
377 static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
378 {
379 	crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags);
380 }
381 
382 static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
383 {
384 	crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags);
385 }
386 
387 /**
388  * crypto_ahash_reqtfm() - obtain cipher handle from request
389  * @req: asynchronous request handle that contains the reference to the ahash
390  *	 cipher handle
391  *
392  * Return the ahash cipher handle that is registered with the asynchronous
393  * request handle ahash_request.
394  *
395  * Return: ahash cipher handle
396  */
397 static inline struct crypto_ahash *crypto_ahash_reqtfm(
398 	struct ahash_request *req)
399 {
400 	return __crypto_ahash_cast(req->base.tfm);
401 }
402 
403 /**
404  * crypto_ahash_reqsize() - obtain size of the request data structure
405  * @tfm: cipher handle
406  *
407  * Return: size of the request data
408  */
409 static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
410 {
411 	return tfm->reqsize;
412 }
413 
414 static inline void *ahash_request_ctx(struct ahash_request *req)
415 {
416 	return req->__ctx;
417 }
418 
419 /**
420  * crypto_ahash_setkey - set key for cipher handle
421  * @tfm: cipher handle
422  * @key: buffer holding the key
423  * @keylen: length of the key in bytes
424  *
425  * The caller provided key is set for the ahash cipher. The cipher
426  * handle must point to a keyed hash in order for this function to succeed.
427  *
428  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
429  */
430 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
431 			unsigned int keylen);
432 
433 /**
434  * crypto_ahash_finup() - update and finalize message digest
435  * @req: reference to the ahash_request handle that holds all information
436  *	 needed to perform the cipher operation
437  *
438  * This function is a "short-hand" for the function calls of
439  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
440  * meaning as discussed for those separate functions.
441  *
442  * Return: see crypto_ahash_final()
443  */
444 int crypto_ahash_finup(struct ahash_request *req);
445 
446 /**
447  * crypto_ahash_final() - calculate message digest
448  * @req: reference to the ahash_request handle that holds all information
449  *	 needed to perform the cipher operation
450  *
451  * Finalize the message digest operation and create the message digest
452  * based on all data added to the cipher handle. The message digest is placed
453  * into the output buffer registered with the ahash_request handle.
454  *
455  * Return:
456  * 0		if the message digest was successfully calculated;
457  * -EINPROGRESS	if data is fed into hardware (DMA) or queued for later;
458  * -EBUSY	if queue is full and request should be resubmitted later;
459  * other < 0	if an error occurred
460  */
461 int crypto_ahash_final(struct ahash_request *req);
462 
463 /**
464  * crypto_ahash_digest() - calculate message digest for a buffer
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 crypto_ahash_init,
469  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
470  * meaning as discussed for those separate three functions.
471  *
472  * Return: see crypto_ahash_final()
473  */
474 int crypto_ahash_digest(struct ahash_request *req);
475 
476 /**
477  * crypto_ahash_export() - extract current message digest state
478  * @req: reference to the ahash_request handle whose state is exported
479  * @out: output buffer of sufficient size that can hold the hash state
480  *
481  * This function exports the hash state of the ahash_request handle into the
482  * caller-allocated output buffer out which must have sufficient size (e.g. by
483  * calling crypto_ahash_statesize()).
484  *
485  * Return: 0 if the export was successful; < 0 if an error occurred
486  */
487 int crypto_ahash_export(struct ahash_request *req, void *out);
488 
489 /**
490  * crypto_ahash_import() - import message digest state
491  * @req: reference to ahash_request handle the state is imported into
492  * @in: buffer holding the state
493  *
494  * This function imports the hash state into the ahash_request handle from the
495  * input buffer. That buffer should have been generated with the
496  * crypto_ahash_export function.
497  *
498  * Return: 0 if the import was successful; < 0 if an error occurred
499  */
500 int crypto_ahash_import(struct ahash_request *req, const void *in);
501 
502 /**
503  * crypto_ahash_init() - (re)initialize message digest handle
504  * @req: ahash_request handle that already is initialized with all necessary
505  *	 data using the ahash_request_* API functions
506  *
507  * The call (re-)initializes the message digest referenced by the ahash_request
508  * handle. Any potentially existing state created by previous operations is
509  * discarded.
510  *
511  * Return: see crypto_ahash_final()
512  */
513 int crypto_ahash_init(struct ahash_request *req);
514 
515 /**
516  * crypto_ahash_update() - add data to message digest for processing
517  * @req: ahash_request handle that was previously initialized with the
518  *	 crypto_ahash_init call.
519  *
520  * Updates the message digest state of the &ahash_request handle. The input data
521  * is pointed to by the scatter/gather list registered in the &ahash_request
522  * handle
523  *
524  * Return: see crypto_ahash_final()
525  */
526 int crypto_ahash_update(struct ahash_request *req);
527 
528 /**
529  * DOC: Asynchronous Hash Request Handle
530  *
531  * The &ahash_request data structure contains all pointers to data
532  * required for the asynchronous cipher operation. This includes the cipher
533  * handle (which can be used by multiple &ahash_request instances), pointer
534  * to plaintext and the message digest output buffer, asynchronous callback
535  * function, etc. It acts as a handle to the ahash_request_* API calls in a
536  * similar way as ahash handle to the crypto_ahash_* API calls.
537  */
538 
539 /**
540  * ahash_request_set_tfm() - update cipher handle reference in request
541  * @req: request handle to be modified
542  * @tfm: cipher handle that shall be added to the request handle
543  *
544  * Allow the caller to replace the existing ahash handle in the request
545  * data structure with a different one.
546  */
547 static inline void ahash_request_set_tfm(struct ahash_request *req,
548 					 struct crypto_ahash *tfm)
549 {
550 	req->base.tfm = crypto_ahash_tfm(tfm);
551 }
552 
553 /**
554  * ahash_request_alloc() - allocate request data structure
555  * @tfm: cipher handle to be registered with the request
556  * @gfp: memory allocation flag that is handed to kmalloc by the API call.
557  *
558  * Allocate the request data structure that must be used with the ahash
559  * message digest API calls. During
560  * the allocation, the provided ahash handle
561  * is registered in the request data structure.
562  *
563  * Return: allocated request handle in case of success, or NULL if out of memory
564  */
565 static inline struct ahash_request *ahash_request_alloc_noprof(
566 	struct crypto_ahash *tfm, gfp_t gfp)
567 {
568 	struct ahash_request *req;
569 
570 	req = kmalloc_noprof(sizeof(struct ahash_request) +
571 			     crypto_ahash_reqsize(tfm), gfp);
572 
573 	if (likely(req))
574 		ahash_request_set_tfm(req, tfm);
575 
576 	return req;
577 }
578 #define ahash_request_alloc(...)	alloc_hooks(ahash_request_alloc_noprof(__VA_ARGS__))
579 
580 /**
581  * ahash_request_free() - zeroize and free the request data structure
582  * @req: request data structure cipher handle to be freed
583  */
584 void ahash_request_free(struct ahash_request *req);
585 
586 static inline struct ahash_request *ahash_request_cast(
587 	struct crypto_async_request *req)
588 {
589 	return container_of(req, struct ahash_request, base);
590 }
591 
592 /**
593  * ahash_request_set_callback() - set asynchronous callback function
594  * @req: request handle
595  * @flags: specify zero or an ORing of the flags
596  *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
597  *	   increase the wait queue beyond the initial maximum size;
598  *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
599  * @compl: callback function pointer to be registered with the request handle
600  * @data: The data pointer refers to memory that is not used by the kernel
601  *	  crypto API, but provided to the callback function for it to use. Here,
602  *	  the caller can provide a reference to memory the callback function can
603  *	  operate on. As the callback function is invoked asynchronously to the
604  *	  related functionality, it may need to access data structures of the
605  *	  related functionality which can be referenced using this pointer. The
606  *	  callback function can access the memory via the "data" field in the
607  *	  &crypto_async_request data structure provided to the callback function.
608  *
609  * This function allows setting the callback function that is triggered once
610  * the cipher operation completes.
611  *
612  * The callback function is registered with the &ahash_request handle and
613  * must comply with the following template::
614  *
615  *	void callback_function(struct crypto_async_request *req, int error)
616  */
617 static inline void ahash_request_set_callback(struct ahash_request *req,
618 					      u32 flags,
619 					      crypto_completion_t compl,
620 					      void *data)
621 {
622 	u32 keep = CRYPTO_AHASH_REQ_VIRT;
623 
624 	req->base.complete = compl;
625 	req->base.data = data;
626 	flags &= ~keep;
627 	req->base.flags &= keep;
628 	req->base.flags |= flags;
629 	crypto_reqchain_init(&req->base);
630 }
631 
632 /**
633  * ahash_request_set_crypt() - set data buffers
634  * @req: ahash_request handle to be updated
635  * @src: source scatter/gather list
636  * @result: buffer that is filled with the message digest -- the caller must
637  *	    ensure that the buffer has sufficient space by, for example, calling
638  *	    crypto_ahash_digestsize()
639  * @nbytes: number of bytes to process from the source scatter/gather list
640  *
641  * By using this call, the caller references the source scatter/gather list.
642  * The source scatter/gather list points to the data the message digest is to
643  * be calculated for.
644  */
645 static inline void ahash_request_set_crypt(struct ahash_request *req,
646 					   struct scatterlist *src, u8 *result,
647 					   unsigned int nbytes)
648 {
649 	req->src = src;
650 	req->nbytes = nbytes;
651 	req->result = result;
652 	req->base.flags &= ~CRYPTO_AHASH_REQ_VIRT;
653 }
654 
655 /**
656  * ahash_request_set_virt() - set virtual address data buffers
657  * @req: ahash_request handle to be updated
658  * @src: source virtual address
659  * @result: buffer that is filled with the message digest -- the caller must
660  *	    ensure that the buffer has sufficient space by, for example, calling
661  *	    crypto_ahash_digestsize()
662  * @nbytes: number of bytes to process from the source virtual address
663  *
664  * By using this call, the caller references the source virtual address.
665  * The source virtual address points to the data the message digest is to
666  * be calculated for.
667  */
668 static inline void ahash_request_set_virt(struct ahash_request *req,
669 					  const u8 *src, u8 *result,
670 					  unsigned int nbytes)
671 {
672 	req->svirt = src;
673 	req->nbytes = nbytes;
674 	req->result = result;
675 	req->base.flags |= CRYPTO_AHASH_REQ_VIRT;
676 }
677 
678 static inline void ahash_request_chain(struct ahash_request *req,
679 				       struct ahash_request *head)
680 {
681 	crypto_request_chain(&req->base, &head->base);
682 }
683 
684 /**
685  * DOC: Synchronous Message Digest API
686  *
687  * The synchronous message digest API is used with the ciphers of type
688  * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
689  *
690  * The message digest API is able to maintain state information for the
691  * caller.
692  *
693  * The synchronous message digest API can store user-related context in its
694  * shash_desc request data structure.
695  */
696 
697 /**
698  * crypto_alloc_shash() - allocate message digest handle
699  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
700  *	      message digest cipher
701  * @type: specifies the type of the cipher
702  * @mask: specifies the mask for the cipher
703  *
704  * Allocate a cipher handle for a message digest. The returned &struct
705  * crypto_shash is the cipher handle that is required for any subsequent
706  * API invocation for that message digest.
707  *
708  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
709  *	   of an error, PTR_ERR() returns the error code.
710  */
711 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
712 					u32 mask);
713 
714 struct crypto_shash *crypto_clone_shash(struct crypto_shash *tfm);
715 
716 int crypto_has_shash(const char *alg_name, u32 type, u32 mask);
717 
718 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
719 {
720 	return &tfm->base;
721 }
722 
723 /**
724  * crypto_free_shash() - zeroize and free the message digest handle
725  * @tfm: cipher handle to be freed
726  *
727  * If @tfm is a NULL or error pointer, this function does nothing.
728  */
729 static inline void crypto_free_shash(struct crypto_shash *tfm)
730 {
731 	crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
732 }
733 
734 static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
735 {
736 	return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
737 }
738 
739 static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
740 {
741 	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
742 }
743 
744 /**
745  * crypto_shash_blocksize() - obtain block size for cipher
746  * @tfm: cipher handle
747  *
748  * The block size for the message digest cipher referenced with the cipher
749  * handle is returned.
750  *
751  * Return: block size of cipher
752  */
753 static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
754 {
755 	return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm));
756 }
757 
758 static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
759 {
760 	return container_of(alg, struct shash_alg, base);
761 }
762 
763 static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
764 {
765 	return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg);
766 }
767 
768 /**
769  * crypto_shash_digestsize() - obtain message digest size
770  * @tfm: cipher handle
771  *
772  * The size for the message digest created by the message digest cipher
773  * referenced with the cipher handle is returned.
774  *
775  * Return: digest size of cipher
776  */
777 static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
778 {
779 	return crypto_shash_alg(tfm)->digestsize;
780 }
781 
782 static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
783 {
784 	return crypto_shash_alg(tfm)->statesize;
785 }
786 
787 static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
788 {
789 	return crypto_tfm_get_flags(crypto_shash_tfm(tfm));
790 }
791 
792 static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
793 {
794 	crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags);
795 }
796 
797 static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
798 {
799 	crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags);
800 }
801 
802 /**
803  * crypto_shash_descsize() - obtain the operational state size
804  * @tfm: cipher handle
805  *
806  * The size of the operational state the cipher needs during operation is
807  * returned for the hash referenced with the cipher handle. This size is
808  * required to calculate the memory requirements to allow the caller allocating
809  * sufficient memory for operational state.
810  *
811  * The operational state is defined with struct shash_desc where the size of
812  * that data structure is to be calculated as
813  * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
814  *
815  * Return: size of the operational state
816  */
817 static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
818 {
819 	return tfm->descsize;
820 }
821 
822 static inline void *shash_desc_ctx(struct shash_desc *desc)
823 {
824 	return desc->__ctx;
825 }
826 
827 /**
828  * crypto_shash_setkey() - set key for message digest
829  * @tfm: cipher handle
830  * @key: buffer holding the key
831  * @keylen: length of the key in bytes
832  *
833  * The caller provided key is set for the keyed message digest cipher. The
834  * cipher handle must point to a keyed message digest cipher in order for this
835  * function to succeed.
836  *
837  * Context: Any context.
838  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
839  */
840 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
841 			unsigned int keylen);
842 
843 /**
844  * crypto_shash_digest() - calculate message digest for buffer
845  * @desc: see crypto_shash_final()
846  * @data: see crypto_shash_update()
847  * @len: see crypto_shash_update()
848  * @out: see crypto_shash_final()
849  *
850  * This function is a "short-hand" for the function calls of crypto_shash_init,
851  * crypto_shash_update and crypto_shash_final. The parameters have the same
852  * meaning as discussed for those separate three functions.
853  *
854  * Context: Any context.
855  * Return: 0 if the message digest creation was successful; < 0 if an error
856  *	   occurred
857  */
858 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
859 			unsigned int len, u8 *out);
860 
861 /**
862  * crypto_shash_tfm_digest() - calculate message digest for buffer
863  * @tfm: hash transformation object
864  * @data: see crypto_shash_update()
865  * @len: see crypto_shash_update()
866  * @out: see crypto_shash_final()
867  *
868  * This is a simplified version of crypto_shash_digest() for users who don't
869  * want to allocate their own hash descriptor (shash_desc).  Instead,
870  * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
871  * directly, and it allocates a hash descriptor on the stack internally.
872  * Note that this stack allocation may be fairly large.
873  *
874  * Context: Any context.
875  * Return: 0 on success; < 0 if an error occurred.
876  */
877 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
878 			    unsigned int len, u8 *out);
879 
880 /**
881  * crypto_shash_export() - extract operational state for message digest
882  * @desc: reference to the operational state handle whose state is exported
883  * @out: output buffer of sufficient size that can hold the hash state
884  *
885  * This function exports the hash state of the operational state handle into the
886  * caller-allocated output buffer out which must have sufficient size (e.g. by
887  * calling crypto_shash_descsize).
888  *
889  * Context: Any context.
890  * Return: 0 if the export creation was successful; < 0 if an error occurred
891  */
892 int crypto_shash_export(struct shash_desc *desc, void *out);
893 
894 /**
895  * crypto_shash_import() - import operational state
896  * @desc: reference to the operational state handle the state imported into
897  * @in: buffer holding the state
898  *
899  * This function imports the hash state into the operational state handle from
900  * the input buffer. That buffer should have been generated with the
901  * crypto_ahash_export function.
902  *
903  * Context: Any context.
904  * Return: 0 if the import was successful; < 0 if an error occurred
905  */
906 int crypto_shash_import(struct shash_desc *desc, const void *in);
907 
908 /**
909  * crypto_shash_init() - (re)initialize message digest
910  * @desc: operational state handle that is already filled
911  *
912  * The call (re-)initializes the message digest referenced by the
913  * operational state handle. Any potentially existing state created by
914  * previous operations is discarded.
915  *
916  * Context: Any context.
917  * Return: 0 if the message digest initialization was successful; < 0 if an
918  *	   error occurred
919  */
920 static inline int crypto_shash_init(struct shash_desc *desc)
921 {
922 	struct crypto_shash *tfm = desc->tfm;
923 
924 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
925 		return -ENOKEY;
926 
927 	return crypto_shash_alg(tfm)->init(desc);
928 }
929 
930 /**
931  * crypto_shash_update() - add data to message digest for processing
932  * @desc: operational state handle that is already initialized
933  * @data: input data to be added to the message digest
934  * @len: length of the input data
935  *
936  * Updates the message digest state of the operational state handle.
937  *
938  * Context: Any context.
939  * Return: 0 if the message digest update was successful; < 0 if an error
940  *	   occurred
941  */
942 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
943 			unsigned int len);
944 
945 /**
946  * crypto_shash_final() - calculate message digest
947  * @desc: operational state handle that is already filled with data
948  * @out: output buffer filled with the message digest
949  *
950  * Finalize the message digest operation and create the message digest
951  * based on all data added to the cipher handle. The message digest is placed
952  * into the output buffer. The caller must ensure that the output buffer is
953  * large enough by using crypto_shash_digestsize.
954  *
955  * Context: Any context.
956  * Return: 0 if the message digest creation was successful; < 0 if an error
957  *	   occurred
958  */
959 int crypto_shash_final(struct shash_desc *desc, u8 *out);
960 
961 /**
962  * crypto_shash_finup() - calculate message digest of buffer
963  * @desc: see crypto_shash_final()
964  * @data: see crypto_shash_update()
965  * @len: see crypto_shash_update()
966  * @out: see crypto_shash_final()
967  *
968  * This function is a "short-hand" for the function calls of
969  * crypto_shash_update and crypto_shash_final. The parameters have the same
970  * meaning as discussed for those separate functions.
971  *
972  * Context: Any context.
973  * Return: 0 if the message digest creation was successful; < 0 if an error
974  *	   occurred
975  */
976 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
977 		       unsigned int len, u8 *out);
978 
979 static inline void shash_desc_zero(struct shash_desc *desc)
980 {
981 	memzero_explicit(desc,
982 			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
983 }
984 
985 static inline int ahash_request_err(struct ahash_request *req)
986 {
987 	return req->base.err;
988 }
989 
990 static inline bool ahash_is_async(struct crypto_ahash *tfm)
991 {
992 	return crypto_tfm_is_async(&tfm->base);
993 }
994 
995 #endif	/* _CRYPTO_HASH_H */
996