xref: /linux/include/crypto/hash.h (revision f788bb2fb915a79eae0a160580766ba52984d61f)
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/crypto.h>
12 #include <linux/string.h>
13 
14 struct crypto_ahash;
15 
16 /**
17  * DOC: Message Digest Algorithm Definitions
18  *
19  * These data structures define modular message digest algorithm
20  * implementations, managed via crypto_register_ahash(),
21  * crypto_register_shash(), crypto_unregister_ahash() and
22  * crypto_unregister_shash().
23  */
24 
25 /**
26  * struct hash_alg_common - define properties of message digest
27  * @digestsize: Size of the result of the transformation. A buffer of this size
28  *	        must be available to the @final and @finup calls, so they can
29  *	        store the resulting hash into it. For various predefined sizes,
30  *	        search include/crypto/ using
31  *	        git grep _DIGEST_SIZE include/crypto.
32  * @statesize: Size of the block for partial state of the transformation. A
33  *	       buffer of this size must be passed to the @export function as it
34  *	       will save the partial state of the transformation into it. On the
35  *	       other side, the @import function will load the state from a
36  *	       buffer of this size as well.
37  * @base: Start of data structure of cipher algorithm. The common data
38  *	  structure of crypto_alg contains information common to all ciphers.
39  *	  The hash_alg_common data structure now adds the hash-specific
40  *	  information.
41  */
42 struct hash_alg_common {
43 	unsigned int digestsize;
44 	unsigned int statesize;
45 
46 	struct crypto_alg base;
47 };
48 
49 struct ahash_request {
50 	struct crypto_async_request base;
51 
52 	unsigned int nbytes;
53 	struct scatterlist *src;
54 	u8 *result;
55 
56 	/* This field may only be used by the ahash API code. */
57 	void *priv;
58 
59 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
60 };
61 
62 #define AHASH_REQUEST_ON_STACK(name, ahash) \
63 	char __##name##_desc[sizeof(struct ahash_request) + \
64 		crypto_ahash_reqsize(ahash)] CRYPTO_MINALIGN_ATTR; \
65 	struct ahash_request *name = (void *)__##name##_desc
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  * @halg: see struct hash_alg_common
127  */
128 struct ahash_alg {
129 	int (*init)(struct ahash_request *req);
130 	int (*update)(struct ahash_request *req);
131 	int (*final)(struct ahash_request *req);
132 	int (*finup)(struct ahash_request *req);
133 	int (*digest)(struct ahash_request *req);
134 	int (*export)(struct ahash_request *req, void *out);
135 	int (*import)(struct ahash_request *req, const void *in);
136 	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
137 		      unsigned int keylen);
138 
139 	struct hash_alg_common halg;
140 };
141 
142 struct shash_desc {
143 	struct crypto_shash *tfm;
144 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
145 };
146 
147 #define HASH_MAX_DIGESTSIZE	 64
148 
149 /*
150  * Worst case is hmac(sha3-224-generic).  Its context is a nested 'shash_desc'
151  * containing a 'struct sha3_state'.
152  */
153 #define HASH_MAX_DESCSIZE	(sizeof(struct shash_desc) + 360)
154 
155 #define HASH_MAX_STATESIZE	512
156 
157 #define SHASH_DESC_ON_STACK(shash, ctx)				  \
158 	char __##shash##_desc[sizeof(struct shash_desc) +	  \
159 		HASH_MAX_DESCSIZE] CRYPTO_MINALIGN_ATTR; \
160 	struct shash_desc *shash = (struct shash_desc *)__##shash##_desc
161 
162 /**
163  * struct shash_alg - synchronous message digest definition
164  * @init: see struct ahash_alg
165  * @update: see struct ahash_alg
166  * @final: see struct ahash_alg
167  * @finup: see struct ahash_alg
168  * @digest: see struct ahash_alg
169  * @export: see struct ahash_alg
170  * @import: see struct ahash_alg
171  * @setkey: see struct ahash_alg
172  * @init_tfm: Initialize the cryptographic transformation object.
173  *	      This function is called only once at the instantiation
174  *	      time, right after the transformation context was
175  *	      allocated. In case the cryptographic hardware has
176  *	      some special requirements which need to be handled
177  *	      by software, this function shall check for the precise
178  *	      requirement of the transformation and put any software
179  *	      fallbacks in place.
180  * @exit_tfm: Deinitialize the cryptographic transformation object.
181  *	      This is a counterpart to @init_tfm, used to remove
182  *	      various changes set in @init_tfm.
183  * @digestsize: see struct ahash_alg
184  * @statesize: see struct ahash_alg
185  * @descsize: Size of the operational state for the message digest. This state
186  * 	      size is the memory size that needs to be allocated for
187  *	      shash_desc.__ctx
188  * @base: internally used
189  */
190 struct shash_alg {
191 	int (*init)(struct shash_desc *desc);
192 	int (*update)(struct shash_desc *desc, const u8 *data,
193 		      unsigned int len);
194 	int (*final)(struct shash_desc *desc, u8 *out);
195 	int (*finup)(struct shash_desc *desc, const u8 *data,
196 		     unsigned int len, u8 *out);
197 	int (*digest)(struct shash_desc *desc, const u8 *data,
198 		      unsigned int len, u8 *out);
199 	int (*export)(struct shash_desc *desc, void *out);
200 	int (*import)(struct shash_desc *desc, const void *in);
201 	int (*setkey)(struct crypto_shash *tfm, const u8 *key,
202 		      unsigned int keylen);
203 	int (*init_tfm)(struct crypto_shash *tfm);
204 	void (*exit_tfm)(struct crypto_shash *tfm);
205 
206 	unsigned int descsize;
207 
208 	/* These fields must match hash_alg_common. */
209 	unsigned int digestsize
210 		__attribute__ ((aligned(__alignof__(struct hash_alg_common))));
211 	unsigned int statesize;
212 
213 	struct crypto_alg base;
214 };
215 
216 struct crypto_ahash {
217 	int (*init)(struct ahash_request *req);
218 	int (*update)(struct ahash_request *req);
219 	int (*final)(struct ahash_request *req);
220 	int (*finup)(struct ahash_request *req);
221 	int (*digest)(struct ahash_request *req);
222 	int (*export)(struct ahash_request *req, void *out);
223 	int (*import)(struct ahash_request *req, const void *in);
224 	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
225 		      unsigned int keylen);
226 
227 	unsigned int reqsize;
228 	struct crypto_tfm base;
229 };
230 
231 struct crypto_shash {
232 	unsigned int descsize;
233 	struct crypto_tfm base;
234 };
235 
236 /**
237  * DOC: Asynchronous Message Digest API
238  *
239  * The asynchronous message digest API is used with the ciphers of type
240  * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
241  *
242  * The asynchronous cipher operation discussion provided for the
243  * CRYPTO_ALG_TYPE_SKCIPHER API applies here as well.
244  */
245 
246 static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
247 {
248 	return container_of(tfm, struct crypto_ahash, base);
249 }
250 
251 /**
252  * crypto_alloc_ahash() - allocate ahash cipher handle
253  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
254  *	      ahash cipher
255  * @type: specifies the type of the cipher
256  * @mask: specifies the mask for the cipher
257  *
258  * Allocate a cipher handle for an ahash. The returned struct
259  * crypto_ahash is the cipher handle that is required for any subsequent
260  * API invocation for that ahash.
261  *
262  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
263  *	   of an error, PTR_ERR() returns the error code.
264  */
265 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
266 					u32 mask);
267 
268 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
269 {
270 	return &tfm->base;
271 }
272 
273 /**
274  * crypto_free_ahash() - zeroize and free the ahash handle
275  * @tfm: cipher handle to be freed
276  */
277 static inline void crypto_free_ahash(struct crypto_ahash *tfm)
278 {
279 	crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm));
280 }
281 
282 /**
283  * crypto_has_ahash() - Search for the availability of an ahash.
284  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
285  *	      ahash
286  * @type: specifies the type of the ahash
287  * @mask: specifies the mask for the ahash
288  *
289  * Return: true when the ahash is known to the kernel crypto API; false
290  *	   otherwise
291  */
292 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
293 
294 static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
295 {
296 	return crypto_tfm_alg_name(crypto_ahash_tfm(tfm));
297 }
298 
299 static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
300 {
301 	return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm));
302 }
303 
304 static inline unsigned int crypto_ahash_alignmask(
305 	struct crypto_ahash *tfm)
306 {
307 	return crypto_tfm_alg_alignmask(crypto_ahash_tfm(tfm));
308 }
309 
310 /**
311  * crypto_ahash_blocksize() - obtain block size for cipher
312  * @tfm: cipher handle
313  *
314  * The block size for the message digest cipher referenced with the cipher
315  * handle is returned.
316  *
317  * Return: block size of cipher
318  */
319 static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
320 {
321 	return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
322 }
323 
324 static inline struct hash_alg_common *__crypto_hash_alg_common(
325 	struct crypto_alg *alg)
326 {
327 	return container_of(alg, struct hash_alg_common, base);
328 }
329 
330 static inline struct hash_alg_common *crypto_hash_alg_common(
331 	struct crypto_ahash *tfm)
332 {
333 	return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg);
334 }
335 
336 /**
337  * crypto_ahash_digestsize() - obtain message digest size
338  * @tfm: cipher handle
339  *
340  * The size for the message digest created by the message digest cipher
341  * referenced with the cipher handle is returned.
342  *
343  *
344  * Return: message digest size of cipher
345  */
346 static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
347 {
348 	return crypto_hash_alg_common(tfm)->digestsize;
349 }
350 
351 /**
352  * crypto_ahash_statesize() - obtain size of the ahash state
353  * @tfm: cipher handle
354  *
355  * Return the size of the ahash state. With the crypto_ahash_export()
356  * function, the caller can export the state into a buffer whose size is
357  * defined with this function.
358  *
359  * Return: size of the ahash state
360  */
361 static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
362 {
363 	return crypto_hash_alg_common(tfm)->statesize;
364 }
365 
366 static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
367 {
368 	return crypto_tfm_get_flags(crypto_ahash_tfm(tfm));
369 }
370 
371 static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
372 {
373 	crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags);
374 }
375 
376 static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
377 {
378 	crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags);
379 }
380 
381 /**
382  * crypto_ahash_reqtfm() - obtain cipher handle from request
383  * @req: asynchronous request handle that contains the reference to the ahash
384  *	 cipher handle
385  *
386  * Return the ahash cipher handle that is registered with the asynchronous
387  * request handle ahash_request.
388  *
389  * Return: ahash cipher handle
390  */
391 static inline struct crypto_ahash *crypto_ahash_reqtfm(
392 	struct ahash_request *req)
393 {
394 	return __crypto_ahash_cast(req->base.tfm);
395 }
396 
397 /**
398  * crypto_ahash_reqsize() - obtain size of the request data structure
399  * @tfm: cipher handle
400  *
401  * Return: size of the request data
402  */
403 static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
404 {
405 	return tfm->reqsize;
406 }
407 
408 static inline void *ahash_request_ctx(struct ahash_request *req)
409 {
410 	return req->__ctx;
411 }
412 
413 /**
414  * crypto_ahash_setkey - set key for cipher handle
415  * @tfm: cipher handle
416  * @key: buffer holding the key
417  * @keylen: length of the key in bytes
418  *
419  * The caller provided key is set for the ahash cipher. The cipher
420  * handle must point to a keyed hash in order for this function to succeed.
421  *
422  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
423  */
424 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
425 			unsigned int keylen);
426 
427 /**
428  * crypto_ahash_finup() - update and finalize message digest
429  * @req: reference to the ahash_request handle that holds all information
430  *	 needed to perform the cipher operation
431  *
432  * This function is a "short-hand" for the function calls of
433  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
434  * meaning as discussed for those separate functions.
435  *
436  * Return: see crypto_ahash_final()
437  */
438 int crypto_ahash_finup(struct ahash_request *req);
439 
440 /**
441  * crypto_ahash_final() - calculate message digest
442  * @req: reference to the ahash_request handle that holds all information
443  *	 needed to perform the cipher operation
444  *
445  * Finalize the message digest operation and create the message digest
446  * based on all data added to the cipher handle. The message digest is placed
447  * into the output buffer registered with the ahash_request handle.
448  *
449  * Return:
450  * 0		if the message digest was successfully calculated;
451  * -EINPROGRESS	if data is feeded into hardware (DMA) or queued for later;
452  * -EBUSY	if queue is full and request should be resubmitted later;
453  * other < 0	if an error occurred
454  */
455 int crypto_ahash_final(struct ahash_request *req);
456 
457 /**
458  * crypto_ahash_digest() - calculate message digest for a buffer
459  * @req: reference to the ahash_request handle that holds all information
460  *	 needed to perform the cipher operation
461  *
462  * This function is a "short-hand" for the function calls of crypto_ahash_init,
463  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
464  * meaning as discussed for those separate three functions.
465  *
466  * Return: see crypto_ahash_final()
467  */
468 int crypto_ahash_digest(struct ahash_request *req);
469 
470 /**
471  * crypto_ahash_export() - extract current message digest state
472  * @req: reference to the ahash_request handle whose state is exported
473  * @out: output buffer of sufficient size that can hold the hash state
474  *
475  * This function exports the hash state of the ahash_request handle into the
476  * caller-allocated output buffer out which must have sufficient size (e.g. by
477  * calling crypto_ahash_statesize()).
478  *
479  * Return: 0 if the export was successful; < 0 if an error occurred
480  */
481 static inline int crypto_ahash_export(struct ahash_request *req, void *out)
482 {
483 	return crypto_ahash_reqtfm(req)->export(req, out);
484 }
485 
486 /**
487  * crypto_ahash_import() - import message digest state
488  * @req: reference to ahash_request handle the state is imported into
489  * @in: buffer holding the state
490  *
491  * This function imports the hash state into the ahash_request handle from the
492  * input buffer. That buffer should have been generated with the
493  * crypto_ahash_export function.
494  *
495  * Return: 0 if the import was successful; < 0 if an error occurred
496  */
497 static inline int crypto_ahash_import(struct ahash_request *req, const void *in)
498 {
499 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
500 
501 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
502 		return -ENOKEY;
503 
504 	return tfm->import(req, in);
505 }
506 
507 /**
508  * crypto_ahash_init() - (re)initialize message digest handle
509  * @req: ahash_request handle that already is initialized with all necessary
510  *	 data using the ahash_request_* API functions
511  *
512  * The call (re-)initializes the message digest referenced by the ahash_request
513  * handle. Any potentially existing state created by previous operations is
514  * discarded.
515  *
516  * Return: see crypto_ahash_final()
517  */
518 static inline int crypto_ahash_init(struct ahash_request *req)
519 {
520 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
521 
522 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
523 		return -ENOKEY;
524 
525 	return tfm->init(req);
526 }
527 
528 /**
529  * crypto_ahash_update() - add data to message digest for processing
530  * @req: ahash_request handle that was previously initialized with the
531  *	 crypto_ahash_init call.
532  *
533  * Updates the message digest state of the &ahash_request handle. The input data
534  * is pointed to by the scatter/gather list registered in the &ahash_request
535  * handle
536  *
537  * Return: see crypto_ahash_final()
538  */
539 static inline int crypto_ahash_update(struct ahash_request *req)
540 {
541 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
542 	struct crypto_alg *alg = tfm->base.__crt_alg;
543 	unsigned int nbytes = req->nbytes;
544 	int ret;
545 
546 	crypto_stats_get(alg);
547 	ret = crypto_ahash_reqtfm(req)->update(req);
548 	crypto_stats_ahash_update(nbytes, ret, alg);
549 	return ret;
550 }
551 
552 /**
553  * DOC: Asynchronous Hash Request Handle
554  *
555  * The &ahash_request data structure contains all pointers to data
556  * required for the asynchronous cipher operation. This includes the cipher
557  * handle (which can be used by multiple &ahash_request instances), pointer
558  * to plaintext and the message digest output buffer, asynchronous callback
559  * function, etc. It acts as a handle to the ahash_request_* API calls in a
560  * similar way as ahash handle to the crypto_ahash_* API calls.
561  */
562 
563 /**
564  * ahash_request_set_tfm() - update cipher handle reference in request
565  * @req: request handle to be modified
566  * @tfm: cipher handle that shall be added to the request handle
567  *
568  * Allow the caller to replace the existing ahash handle in the request
569  * data structure with a different one.
570  */
571 static inline void ahash_request_set_tfm(struct ahash_request *req,
572 					 struct crypto_ahash *tfm)
573 {
574 	req->base.tfm = crypto_ahash_tfm(tfm);
575 }
576 
577 /**
578  * ahash_request_alloc() - allocate request data structure
579  * @tfm: cipher handle to be registered with the request
580  * @gfp: memory allocation flag that is handed to kmalloc by the API call.
581  *
582  * Allocate the request data structure that must be used with the ahash
583  * message digest API calls. During
584  * the allocation, the provided ahash handle
585  * is registered in the request data structure.
586  *
587  * Return: allocated request handle in case of success, or NULL if out of memory
588  */
589 static inline struct ahash_request *ahash_request_alloc(
590 	struct crypto_ahash *tfm, gfp_t gfp)
591 {
592 	struct ahash_request *req;
593 
594 	req = kmalloc(sizeof(struct ahash_request) +
595 		      crypto_ahash_reqsize(tfm), gfp);
596 
597 	if (likely(req))
598 		ahash_request_set_tfm(req, tfm);
599 
600 	return req;
601 }
602 
603 /**
604  * ahash_request_free() - zeroize and free the request data structure
605  * @req: request data structure cipher handle to be freed
606  */
607 static inline void ahash_request_free(struct ahash_request *req)
608 {
609 	kzfree(req);
610 }
611 
612 static inline void ahash_request_zero(struct ahash_request *req)
613 {
614 	memzero_explicit(req, sizeof(*req) +
615 			      crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));
616 }
617 
618 static inline struct ahash_request *ahash_request_cast(
619 	struct crypto_async_request *req)
620 {
621 	return container_of(req, struct ahash_request, base);
622 }
623 
624 /**
625  * ahash_request_set_callback() - set asynchronous callback function
626  * @req: request handle
627  * @flags: specify zero or an ORing of the flags
628  *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
629  *	   increase the wait queue beyond the initial maximum size;
630  *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
631  * @compl: callback function pointer to be registered with the request handle
632  * @data: The data pointer refers to memory that is not used by the kernel
633  *	  crypto API, but provided to the callback function for it to use. Here,
634  *	  the caller can provide a reference to memory the callback function can
635  *	  operate on. As the callback function is invoked asynchronously to the
636  *	  related functionality, it may need to access data structures of the
637  *	  related functionality which can be referenced using this pointer. The
638  *	  callback function can access the memory via the "data" field in the
639  *	  &crypto_async_request data structure provided to the callback function.
640  *
641  * This function allows setting the callback function that is triggered once
642  * the cipher operation completes.
643  *
644  * The callback function is registered with the &ahash_request handle and
645  * must comply with the following template::
646  *
647  *	void callback_function(struct crypto_async_request *req, int error)
648  */
649 static inline void ahash_request_set_callback(struct ahash_request *req,
650 					      u32 flags,
651 					      crypto_completion_t compl,
652 					      void *data)
653 {
654 	req->base.complete = compl;
655 	req->base.data = data;
656 	req->base.flags = flags;
657 }
658 
659 /**
660  * ahash_request_set_crypt() - set data buffers
661  * @req: ahash_request handle to be updated
662  * @src: source scatter/gather list
663  * @result: buffer that is filled with the message digest -- the caller must
664  *	    ensure that the buffer has sufficient space by, for example, calling
665  *	    crypto_ahash_digestsize()
666  * @nbytes: number of bytes to process from the source scatter/gather list
667  *
668  * By using this call, the caller references the source scatter/gather list.
669  * The source scatter/gather list points to the data the message digest is to
670  * be calculated for.
671  */
672 static inline void ahash_request_set_crypt(struct ahash_request *req,
673 					   struct scatterlist *src, u8 *result,
674 					   unsigned int nbytes)
675 {
676 	req->src = src;
677 	req->nbytes = nbytes;
678 	req->result = result;
679 }
680 
681 /**
682  * DOC: Synchronous Message Digest API
683  *
684  * The synchronous message digest API is used with the ciphers of type
685  * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
686  *
687  * The message digest API is able to maintain state information for the
688  * caller.
689  *
690  * The synchronous message digest API can store user-related context in in its
691  * shash_desc request data structure.
692  */
693 
694 /**
695  * crypto_alloc_shash() - allocate message digest handle
696  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
697  *	      message digest cipher
698  * @type: specifies the type of the cipher
699  * @mask: specifies the mask for the cipher
700  *
701  * Allocate a cipher handle for a message digest. The returned &struct
702  * crypto_shash is the cipher handle that is required for any subsequent
703  * API invocation for that message digest.
704  *
705  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
706  *	   of an error, PTR_ERR() returns the error code.
707  */
708 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
709 					u32 mask);
710 
711 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
712 {
713 	return &tfm->base;
714 }
715 
716 /**
717  * crypto_free_shash() - zeroize and free the message digest handle
718  * @tfm: cipher handle to be freed
719  */
720 static inline void crypto_free_shash(struct crypto_shash *tfm)
721 {
722 	crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
723 }
724 
725 static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
726 {
727 	return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
728 }
729 
730 static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
731 {
732 	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
733 }
734 
735 static inline unsigned int crypto_shash_alignmask(
736 	struct crypto_shash *tfm)
737 {
738 	return crypto_tfm_alg_alignmask(crypto_shash_tfm(tfm));
739 }
740 
741 /**
742  * crypto_shash_blocksize() - obtain block size for cipher
743  * @tfm: cipher handle
744  *
745  * The block size for the message digest cipher referenced with the cipher
746  * handle is returned.
747  *
748  * Return: block size of cipher
749  */
750 static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
751 {
752 	return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm));
753 }
754 
755 static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
756 {
757 	return container_of(alg, struct shash_alg, base);
758 }
759 
760 static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
761 {
762 	return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg);
763 }
764 
765 /**
766  * crypto_shash_digestsize() - obtain message digest size
767  * @tfm: cipher handle
768  *
769  * The size for the message digest created by the message digest cipher
770  * referenced with the cipher handle is returned.
771  *
772  * Return: digest size of cipher
773  */
774 static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
775 {
776 	return crypto_shash_alg(tfm)->digestsize;
777 }
778 
779 static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
780 {
781 	return crypto_shash_alg(tfm)->statesize;
782 }
783 
784 static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
785 {
786 	return crypto_tfm_get_flags(crypto_shash_tfm(tfm));
787 }
788 
789 static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
790 {
791 	crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags);
792 }
793 
794 static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
795 {
796 	crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags);
797 }
798 
799 /**
800  * crypto_shash_descsize() - obtain the operational state size
801  * @tfm: cipher handle
802  *
803  * The size of the operational state the cipher needs during operation is
804  * returned for the hash referenced with the cipher handle. This size is
805  * required to calculate the memory requirements to allow the caller allocating
806  * sufficient memory for operational state.
807  *
808  * The operational state is defined with struct shash_desc where the size of
809  * that data structure is to be calculated as
810  * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
811  *
812  * Return: size of the operational state
813  */
814 static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
815 {
816 	return tfm->descsize;
817 }
818 
819 static inline void *shash_desc_ctx(struct shash_desc *desc)
820 {
821 	return desc->__ctx;
822 }
823 
824 /**
825  * crypto_shash_setkey() - set key for message digest
826  * @tfm: cipher handle
827  * @key: buffer holding the key
828  * @keylen: length of the key in bytes
829  *
830  * The caller provided key is set for the keyed message digest cipher. The
831  * cipher handle must point to a keyed message digest cipher in order for this
832  * function to succeed.
833  *
834  * Context: Any context.
835  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
836  */
837 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
838 			unsigned int keylen);
839 
840 /**
841  * crypto_shash_digest() - calculate message digest for buffer
842  * @desc: see crypto_shash_final()
843  * @data: see crypto_shash_update()
844  * @len: see crypto_shash_update()
845  * @out: see crypto_shash_final()
846  *
847  * This function is a "short-hand" for the function calls of crypto_shash_init,
848  * crypto_shash_update and crypto_shash_final. The parameters have the same
849  * meaning as discussed for those separate three functions.
850  *
851  * Context: Any context.
852  * Return: 0 if the message digest creation was successful; < 0 if an error
853  *	   occurred
854  */
855 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
856 			unsigned int len, u8 *out);
857 
858 /**
859  * crypto_shash_tfm_digest() - calculate message digest for buffer
860  * @tfm: hash transformation object
861  * @data: see crypto_shash_update()
862  * @len: see crypto_shash_update()
863  * @out: see crypto_shash_final()
864  *
865  * This is a simplified version of crypto_shash_digest() for users who don't
866  * want to allocate their own hash descriptor (shash_desc).  Instead,
867  * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
868  * directly, and it allocates a hash descriptor on the stack internally.
869  * Note that this stack allocation may be fairly large.
870  *
871  * Context: Any context.
872  * Return: 0 on success; < 0 if an error occurred.
873  */
874 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
875 			    unsigned int len, u8 *out);
876 
877 /**
878  * crypto_shash_export() - extract operational state for message digest
879  * @desc: reference to the operational state handle whose state is exported
880  * @out: output buffer of sufficient size that can hold the hash state
881  *
882  * This function exports the hash state of the operational state handle into the
883  * caller-allocated output buffer out which must have sufficient size (e.g. by
884  * calling crypto_shash_descsize).
885  *
886  * Context: Any context.
887  * Return: 0 if the export creation was successful; < 0 if an error occurred
888  */
889 static inline int crypto_shash_export(struct shash_desc *desc, void *out)
890 {
891 	return crypto_shash_alg(desc->tfm)->export(desc, out);
892 }
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 static inline int crypto_shash_import(struct shash_desc *desc, const void *in)
907 {
908 	struct crypto_shash *tfm = desc->tfm;
909 
910 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
911 		return -ENOKEY;
912 
913 	return crypto_shash_alg(tfm)->import(desc, in);
914 }
915 
916 /**
917  * crypto_shash_init() - (re)initialize message digest
918  * @desc: operational state handle that is already filled
919  *
920  * The call (re-)initializes the message digest referenced by the
921  * operational state handle. Any potentially existing state created by
922  * previous operations is discarded.
923  *
924  * Context: Any context.
925  * Return: 0 if the message digest initialization was successful; < 0 if an
926  *	   error occurred
927  */
928 static inline int crypto_shash_init(struct shash_desc *desc)
929 {
930 	struct crypto_shash *tfm = desc->tfm;
931 
932 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
933 		return -ENOKEY;
934 
935 	return crypto_shash_alg(tfm)->init(desc);
936 }
937 
938 /**
939  * crypto_shash_update() - add data to message digest for processing
940  * @desc: operational state handle that is already initialized
941  * @data: input data to be added to the message digest
942  * @len: length of the input data
943  *
944  * Updates the message digest state of the operational state handle.
945  *
946  * Context: Any context.
947  * Return: 0 if the message digest update was successful; < 0 if an error
948  *	   occurred
949  */
950 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
951 			unsigned int len);
952 
953 /**
954  * crypto_shash_final() - calculate message digest
955  * @desc: operational state handle that is already filled with data
956  * @out: output buffer filled with the message digest
957  *
958  * Finalize the message digest operation and create the message digest
959  * based on all data added to the cipher handle. The message digest is placed
960  * into the output buffer. The caller must ensure that the output buffer is
961  * large enough by using crypto_shash_digestsize.
962  *
963  * Context: Any context.
964  * Return: 0 if the message digest creation was successful; < 0 if an error
965  *	   occurred
966  */
967 int crypto_shash_final(struct shash_desc *desc, u8 *out);
968 
969 /**
970  * crypto_shash_finup() - calculate message digest of buffer
971  * @desc: see crypto_shash_final()
972  * @data: see crypto_shash_update()
973  * @len: see crypto_shash_update()
974  * @out: see crypto_shash_final()
975  *
976  * This function is a "short-hand" for the function calls of
977  * crypto_shash_update and crypto_shash_final. The parameters have the same
978  * meaning as discussed for those separate functions.
979  *
980  * Context: Any context.
981  * Return: 0 if the message digest creation was successful; < 0 if an error
982  *	   occurred
983  */
984 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
985 		       unsigned int len, u8 *out);
986 
987 static inline void shash_desc_zero(struct shash_desc *desc)
988 {
989 	memzero_explicit(desc,
990 			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
991 }
992 
993 #endif	/* _CRYPTO_HASH_H */
994