xref: /linux/include/crypto/hash.h (revision 79997eda0d31bc68203c95ecb978773ee6ce7a1f)
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  * @digestsize: see struct ahash_alg
216  * @statesize: see struct ahash_alg
217  * @descsize: Size of the operational state for the message digest. This state
218  * 	      size is the memory size that needs to be allocated for
219  *	      shash_desc.__ctx
220  * @stat: Statistics for hash algorithm.
221  * @base: internally used
222  * @halg: see struct hash_alg_common
223  * @HASH_ALG_COMMON: see struct hash_alg_common
224  */
225 struct shash_alg {
226 	int (*init)(struct shash_desc *desc);
227 	int (*update)(struct shash_desc *desc, const u8 *data,
228 		      unsigned int len);
229 	int (*final)(struct shash_desc *desc, u8 *out);
230 	int (*finup)(struct shash_desc *desc, const u8 *data,
231 		     unsigned int len, u8 *out);
232 	int (*digest)(struct shash_desc *desc, const u8 *data,
233 		      unsigned int len, u8 *out);
234 	int (*export)(struct shash_desc *desc, void *out);
235 	int (*import)(struct shash_desc *desc, const void *in);
236 	int (*setkey)(struct crypto_shash *tfm, const u8 *key,
237 		      unsigned int keylen);
238 	int (*init_tfm)(struct crypto_shash *tfm);
239 	void (*exit_tfm)(struct crypto_shash *tfm);
240 	int (*clone_tfm)(struct crypto_shash *dst, struct crypto_shash *src);
241 
242 	unsigned int descsize;
243 
244 	union {
245 		struct HASH_ALG_COMMON;
246 		struct hash_alg_common halg;
247 	};
248 };
249 #undef HASH_ALG_COMMON
250 #undef HASH_ALG_COMMON_STAT
251 
252 struct crypto_ahash {
253 	bool using_shash; /* Underlying algorithm is shash, not ahash */
254 	unsigned int statesize;
255 	unsigned int reqsize;
256 	struct crypto_tfm base;
257 };
258 
259 struct crypto_shash {
260 	unsigned int descsize;
261 	struct crypto_tfm base;
262 };
263 
264 /**
265  * DOC: Asynchronous Message Digest API
266  *
267  * The asynchronous message digest API is used with the ciphers of type
268  * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
269  *
270  * The asynchronous cipher operation discussion provided for the
271  * CRYPTO_ALG_TYPE_SKCIPHER API applies here as well.
272  */
273 
274 static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
275 {
276 	return container_of(tfm, struct crypto_ahash, base);
277 }
278 
279 /**
280  * crypto_alloc_ahash() - allocate ahash cipher handle
281  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
282  *	      ahash cipher
283  * @type: specifies the type of the cipher
284  * @mask: specifies the mask for the cipher
285  *
286  * Allocate a cipher handle for an ahash. The returned struct
287  * crypto_ahash is the cipher handle that is required for any subsequent
288  * API invocation for that ahash.
289  *
290  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
291  *	   of an error, PTR_ERR() returns the error code.
292  */
293 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
294 					u32 mask);
295 
296 struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *tfm);
297 
298 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
299 {
300 	return &tfm->base;
301 }
302 
303 /**
304  * crypto_free_ahash() - zeroize and free the ahash handle
305  * @tfm: cipher handle to be freed
306  *
307  * If @tfm is a NULL or error pointer, this function does nothing.
308  */
309 static inline void crypto_free_ahash(struct crypto_ahash *tfm)
310 {
311 	crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm));
312 }
313 
314 /**
315  * crypto_has_ahash() - Search for the availability of an ahash.
316  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
317  *	      ahash
318  * @type: specifies the type of the ahash
319  * @mask: specifies the mask for the ahash
320  *
321  * Return: true when the ahash is known to the kernel crypto API; false
322  *	   otherwise
323  */
324 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
325 
326 static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
327 {
328 	return crypto_tfm_alg_name(crypto_ahash_tfm(tfm));
329 }
330 
331 static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
332 {
333 	return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm));
334 }
335 
336 /**
337  * crypto_ahash_blocksize() - obtain block size for cipher
338  * @tfm: cipher handle
339  *
340  * The block size for the message digest cipher referenced with the cipher
341  * handle is returned.
342  *
343  * Return: block size of cipher
344  */
345 static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
346 {
347 	return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
348 }
349 
350 static inline struct hash_alg_common *__crypto_hash_alg_common(
351 	struct crypto_alg *alg)
352 {
353 	return container_of(alg, struct hash_alg_common, base);
354 }
355 
356 static inline struct hash_alg_common *crypto_hash_alg_common(
357 	struct crypto_ahash *tfm)
358 {
359 	return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg);
360 }
361 
362 /**
363  * crypto_ahash_digestsize() - obtain message digest size
364  * @tfm: cipher handle
365  *
366  * The size for the message digest created by the message digest cipher
367  * referenced with the cipher handle is returned.
368  *
369  *
370  * Return: message digest size of cipher
371  */
372 static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
373 {
374 	return crypto_hash_alg_common(tfm)->digestsize;
375 }
376 
377 /**
378  * crypto_ahash_statesize() - obtain size of the ahash state
379  * @tfm: cipher handle
380  *
381  * Return the size of the ahash state. With the crypto_ahash_export()
382  * function, the caller can export the state into a buffer whose size is
383  * defined with this function.
384  *
385  * Return: size of the ahash state
386  */
387 static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
388 {
389 	return tfm->statesize;
390 }
391 
392 static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
393 {
394 	return crypto_tfm_get_flags(crypto_ahash_tfm(tfm));
395 }
396 
397 static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
398 {
399 	crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags);
400 }
401 
402 static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
403 {
404 	crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags);
405 }
406 
407 /**
408  * crypto_ahash_reqtfm() - obtain cipher handle from request
409  * @req: asynchronous request handle that contains the reference to the ahash
410  *	 cipher handle
411  *
412  * Return the ahash cipher handle that is registered with the asynchronous
413  * request handle ahash_request.
414  *
415  * Return: ahash cipher handle
416  */
417 static inline struct crypto_ahash *crypto_ahash_reqtfm(
418 	struct ahash_request *req)
419 {
420 	return __crypto_ahash_cast(req->base.tfm);
421 }
422 
423 /**
424  * crypto_ahash_reqsize() - obtain size of the request data structure
425  * @tfm: cipher handle
426  *
427  * Return: size of the request data
428  */
429 static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
430 {
431 	return tfm->reqsize;
432 }
433 
434 static inline void *ahash_request_ctx(struct ahash_request *req)
435 {
436 	return req->__ctx;
437 }
438 
439 /**
440  * crypto_ahash_setkey - set key for cipher handle
441  * @tfm: cipher handle
442  * @key: buffer holding the key
443  * @keylen: length of the key in bytes
444  *
445  * The caller provided key is set for the ahash cipher. The cipher
446  * handle must point to a keyed hash in order for this function to succeed.
447  *
448  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
449  */
450 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
451 			unsigned int keylen);
452 
453 /**
454  * crypto_ahash_finup() - update and finalize message digest
455  * @req: reference to the ahash_request handle that holds all information
456  *	 needed to perform the cipher operation
457  *
458  * This function is a "short-hand" for the function calls of
459  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
460  * meaning as discussed for those separate functions.
461  *
462  * Return: see crypto_ahash_final()
463  */
464 int crypto_ahash_finup(struct ahash_request *req);
465 
466 /**
467  * crypto_ahash_final() - calculate message digest
468  * @req: reference to the ahash_request handle that holds all information
469  *	 needed to perform the cipher operation
470  *
471  * Finalize the message digest operation and create the message digest
472  * based on all data added to the cipher handle. The message digest is placed
473  * into the output buffer registered with the ahash_request handle.
474  *
475  * Return:
476  * 0		if the message digest was successfully calculated;
477  * -EINPROGRESS	if data is fed into hardware (DMA) or queued for later;
478  * -EBUSY	if queue is full and request should be resubmitted later;
479  * other < 0	if an error occurred
480  */
481 int crypto_ahash_final(struct ahash_request *req);
482 
483 /**
484  * crypto_ahash_digest() - calculate message digest for a buffer
485  * @req: reference to the ahash_request handle that holds all information
486  *	 needed to perform the cipher operation
487  *
488  * This function is a "short-hand" for the function calls of crypto_ahash_init,
489  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
490  * meaning as discussed for those separate three functions.
491  *
492  * Return: see crypto_ahash_final()
493  */
494 int crypto_ahash_digest(struct ahash_request *req);
495 
496 /**
497  * crypto_ahash_export() - extract current message digest state
498  * @req: reference to the ahash_request handle whose state is exported
499  * @out: output buffer of sufficient size that can hold the hash state
500  *
501  * This function exports the hash state of the ahash_request handle into the
502  * caller-allocated output buffer out which must have sufficient size (e.g. by
503  * calling crypto_ahash_statesize()).
504  *
505  * Return: 0 if the export was successful; < 0 if an error occurred
506  */
507 int crypto_ahash_export(struct ahash_request *req, void *out);
508 
509 /**
510  * crypto_ahash_import() - import message digest state
511  * @req: reference to ahash_request handle the state is imported into
512  * @in: buffer holding the state
513  *
514  * This function imports the hash state into the ahash_request handle from the
515  * input buffer. That buffer should have been generated with the
516  * crypto_ahash_export function.
517  *
518  * Return: 0 if the import was successful; < 0 if an error occurred
519  */
520 int crypto_ahash_import(struct ahash_request *req, const void *in);
521 
522 /**
523  * crypto_ahash_init() - (re)initialize message digest handle
524  * @req: ahash_request handle that already is initialized with all necessary
525  *	 data using the ahash_request_* API functions
526  *
527  * The call (re-)initializes the message digest referenced by the ahash_request
528  * handle. Any potentially existing state created by previous operations is
529  * discarded.
530  *
531  * Return: see crypto_ahash_final()
532  */
533 int crypto_ahash_init(struct ahash_request *req);
534 
535 /**
536  * crypto_ahash_update() - add data to message digest for processing
537  * @req: ahash_request handle that was previously initialized with the
538  *	 crypto_ahash_init call.
539  *
540  * Updates the message digest state of the &ahash_request handle. The input data
541  * is pointed to by the scatter/gather list registered in the &ahash_request
542  * handle
543  *
544  * Return: see crypto_ahash_final()
545  */
546 int crypto_ahash_update(struct ahash_request *req);
547 
548 /**
549  * DOC: Asynchronous Hash Request Handle
550  *
551  * The &ahash_request data structure contains all pointers to data
552  * required for the asynchronous cipher operation. This includes the cipher
553  * handle (which can be used by multiple &ahash_request instances), pointer
554  * to plaintext and the message digest output buffer, asynchronous callback
555  * function, etc. It acts as a handle to the ahash_request_* API calls in a
556  * similar way as ahash handle to the crypto_ahash_* API calls.
557  */
558 
559 /**
560  * ahash_request_set_tfm() - update cipher handle reference in request
561  * @req: request handle to be modified
562  * @tfm: cipher handle that shall be added to the request handle
563  *
564  * Allow the caller to replace the existing ahash handle in the request
565  * data structure with a different one.
566  */
567 static inline void ahash_request_set_tfm(struct ahash_request *req,
568 					 struct crypto_ahash *tfm)
569 {
570 	req->base.tfm = crypto_ahash_tfm(tfm);
571 }
572 
573 /**
574  * ahash_request_alloc() - allocate request data structure
575  * @tfm: cipher handle to be registered with the request
576  * @gfp: memory allocation flag that is handed to kmalloc by the API call.
577  *
578  * Allocate the request data structure that must be used with the ahash
579  * message digest API calls. During
580  * the allocation, the provided ahash handle
581  * is registered in the request data structure.
582  *
583  * Return: allocated request handle in case of success, or NULL if out of memory
584  */
585 static inline struct ahash_request *ahash_request_alloc(
586 	struct crypto_ahash *tfm, gfp_t gfp)
587 {
588 	struct ahash_request *req;
589 
590 	req = kmalloc(sizeof(struct ahash_request) +
591 		      crypto_ahash_reqsize(tfm), gfp);
592 
593 	if (likely(req))
594 		ahash_request_set_tfm(req, tfm);
595 
596 	return req;
597 }
598 
599 /**
600  * ahash_request_free() - zeroize and free the request data structure
601  * @req: request data structure cipher handle to be freed
602  */
603 static inline void ahash_request_free(struct ahash_request *req)
604 {
605 	kfree_sensitive(req);
606 }
607 
608 static inline void ahash_request_zero(struct ahash_request *req)
609 {
610 	memzero_explicit(req, sizeof(*req) +
611 			      crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));
612 }
613 
614 static inline struct ahash_request *ahash_request_cast(
615 	struct crypto_async_request *req)
616 {
617 	return container_of(req, struct ahash_request, base);
618 }
619 
620 /**
621  * ahash_request_set_callback() - set asynchronous callback function
622  * @req: request handle
623  * @flags: specify zero or an ORing of the flags
624  *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
625  *	   increase the wait queue beyond the initial maximum size;
626  *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
627  * @compl: callback function pointer to be registered with the request handle
628  * @data: The data pointer refers to memory that is not used by the kernel
629  *	  crypto API, but provided to the callback function for it to use. Here,
630  *	  the caller can provide a reference to memory the callback function can
631  *	  operate on. As the callback function is invoked asynchronously to the
632  *	  related functionality, it may need to access data structures of the
633  *	  related functionality which can be referenced using this pointer. The
634  *	  callback function can access the memory via the "data" field in the
635  *	  &crypto_async_request data structure provided to the callback function.
636  *
637  * This function allows setting the callback function that is triggered once
638  * the cipher operation completes.
639  *
640  * The callback function is registered with the &ahash_request handle and
641  * must comply with the following template::
642  *
643  *	void callback_function(struct crypto_async_request *req, int error)
644  */
645 static inline void ahash_request_set_callback(struct ahash_request *req,
646 					      u32 flags,
647 					      crypto_completion_t compl,
648 					      void *data)
649 {
650 	req->base.complete = compl;
651 	req->base.data = data;
652 	req->base.flags = flags;
653 }
654 
655 /**
656  * ahash_request_set_crypt() - set data buffers
657  * @req: ahash_request handle to be updated
658  * @src: source scatter/gather list
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 scatter/gather list
663  *
664  * By using this call, the caller references the source scatter/gather list.
665  * The source scatter/gather list points to the data the message digest is to
666  * be calculated for.
667  */
668 static inline void ahash_request_set_crypt(struct ahash_request *req,
669 					   struct scatterlist *src, u8 *result,
670 					   unsigned int nbytes)
671 {
672 	req->src = src;
673 	req->nbytes = nbytes;
674 	req->result = result;
675 }
676 
677 /**
678  * DOC: Synchronous Message Digest API
679  *
680  * The synchronous message digest API is used with the ciphers of type
681  * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
682  *
683  * The message digest API is able to maintain state information for the
684  * caller.
685  *
686  * The synchronous message digest API can store user-related context in its
687  * shash_desc request data structure.
688  */
689 
690 /**
691  * crypto_alloc_shash() - allocate message digest handle
692  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
693  *	      message digest cipher
694  * @type: specifies the type of the cipher
695  * @mask: specifies the mask for the cipher
696  *
697  * Allocate a cipher handle for a message digest. The returned &struct
698  * crypto_shash is the cipher handle that is required for any subsequent
699  * API invocation for that message digest.
700  *
701  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
702  *	   of an error, PTR_ERR() returns the error code.
703  */
704 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
705 					u32 mask);
706 
707 struct crypto_shash *crypto_clone_shash(struct crypto_shash *tfm);
708 
709 int crypto_has_shash(const char *alg_name, u32 type, 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  * If @tfm is a NULL or error pointer, this function does nothing.
721  */
722 static inline void crypto_free_shash(struct crypto_shash *tfm)
723 {
724 	crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
725 }
726 
727 static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
728 {
729 	return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
730 }
731 
732 static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
733 {
734 	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
735 }
736 
737 /**
738  * crypto_shash_blocksize() - obtain block size for cipher
739  * @tfm: cipher handle
740  *
741  * The block size for the message digest cipher referenced with the cipher
742  * handle is returned.
743  *
744  * Return: block size of cipher
745  */
746 static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
747 {
748 	return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm));
749 }
750 
751 static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
752 {
753 	return container_of(alg, struct shash_alg, base);
754 }
755 
756 static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
757 {
758 	return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg);
759 }
760 
761 /**
762  * crypto_shash_digestsize() - obtain message digest size
763  * @tfm: cipher handle
764  *
765  * The size for the message digest created by the message digest cipher
766  * referenced with the cipher handle is returned.
767  *
768  * Return: digest size of cipher
769  */
770 static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
771 {
772 	return crypto_shash_alg(tfm)->digestsize;
773 }
774 
775 static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
776 {
777 	return crypto_shash_alg(tfm)->statesize;
778 }
779 
780 static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
781 {
782 	return crypto_tfm_get_flags(crypto_shash_tfm(tfm));
783 }
784 
785 static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
786 {
787 	crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags);
788 }
789 
790 static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
791 {
792 	crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags);
793 }
794 
795 /**
796  * crypto_shash_descsize() - obtain the operational state size
797  * @tfm: cipher handle
798  *
799  * The size of the operational state the cipher needs during operation is
800  * returned for the hash referenced with the cipher handle. This size is
801  * required to calculate the memory requirements to allow the caller allocating
802  * sufficient memory for operational state.
803  *
804  * The operational state is defined with struct shash_desc where the size of
805  * that data structure is to be calculated as
806  * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
807  *
808  * Return: size of the operational state
809  */
810 static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
811 {
812 	return tfm->descsize;
813 }
814 
815 static inline void *shash_desc_ctx(struct shash_desc *desc)
816 {
817 	return desc->__ctx;
818 }
819 
820 /**
821  * crypto_shash_setkey() - set key for message digest
822  * @tfm: cipher handle
823  * @key: buffer holding the key
824  * @keylen: length of the key in bytes
825  *
826  * The caller provided key is set for the keyed message digest cipher. The
827  * cipher handle must point to a keyed message digest cipher in order for this
828  * function to succeed.
829  *
830  * Context: Any context.
831  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
832  */
833 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
834 			unsigned int keylen);
835 
836 /**
837  * crypto_shash_digest() - calculate message digest for buffer
838  * @desc: see crypto_shash_final()
839  * @data: see crypto_shash_update()
840  * @len: see crypto_shash_update()
841  * @out: see crypto_shash_final()
842  *
843  * This function is a "short-hand" for the function calls of crypto_shash_init,
844  * crypto_shash_update and crypto_shash_final. The parameters have the same
845  * meaning as discussed for those separate three functions.
846  *
847  * Context: Any context.
848  * Return: 0 if the message digest creation was successful; < 0 if an error
849  *	   occurred
850  */
851 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
852 			unsigned int len, u8 *out);
853 
854 /**
855  * crypto_shash_tfm_digest() - calculate message digest for buffer
856  * @tfm: hash transformation object
857  * @data: see crypto_shash_update()
858  * @len: see crypto_shash_update()
859  * @out: see crypto_shash_final()
860  *
861  * This is a simplified version of crypto_shash_digest() for users who don't
862  * want to allocate their own hash descriptor (shash_desc).  Instead,
863  * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
864  * directly, and it allocates a hash descriptor on the stack internally.
865  * Note that this stack allocation may be fairly large.
866  *
867  * Context: Any context.
868  * Return: 0 on success; < 0 if an error occurred.
869  */
870 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
871 			    unsigned int len, u8 *out);
872 
873 /**
874  * crypto_shash_export() - extract operational state for message digest
875  * @desc: reference to the operational state handle whose state is exported
876  * @out: output buffer of sufficient size that can hold the hash state
877  *
878  * This function exports the hash state of the operational state handle into the
879  * caller-allocated output buffer out which must have sufficient size (e.g. by
880  * calling crypto_shash_descsize).
881  *
882  * Context: Any context.
883  * Return: 0 if the export creation was successful; < 0 if an error occurred
884  */
885 int crypto_shash_export(struct shash_desc *desc, void *out);
886 
887 /**
888  * crypto_shash_import() - import operational state
889  * @desc: reference to the operational state handle the state imported into
890  * @in: buffer holding the state
891  *
892  * This function imports the hash state into the operational state handle from
893  * the input buffer. That buffer should have been generated with the
894  * crypto_ahash_export function.
895  *
896  * Context: Any context.
897  * Return: 0 if the import was successful; < 0 if an error occurred
898  */
899 int crypto_shash_import(struct shash_desc *desc, const void *in);
900 
901 /**
902  * crypto_shash_init() - (re)initialize message digest
903  * @desc: operational state handle that is already filled
904  *
905  * The call (re-)initializes the message digest referenced by the
906  * operational state handle. Any potentially existing state created by
907  * previous operations is discarded.
908  *
909  * Context: Any context.
910  * Return: 0 if the message digest initialization was successful; < 0 if an
911  *	   error occurred
912  */
913 static inline int crypto_shash_init(struct shash_desc *desc)
914 {
915 	struct crypto_shash *tfm = desc->tfm;
916 
917 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
918 		return -ENOKEY;
919 
920 	return crypto_shash_alg(tfm)->init(desc);
921 }
922 
923 /**
924  * crypto_shash_update() - add data to message digest for processing
925  * @desc: operational state handle that is already initialized
926  * @data: input data to be added to the message digest
927  * @len: length of the input data
928  *
929  * Updates the message digest state of the operational state handle.
930  *
931  * Context: Any context.
932  * Return: 0 if the message digest update was successful; < 0 if an error
933  *	   occurred
934  */
935 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
936 			unsigned int len);
937 
938 /**
939  * crypto_shash_final() - calculate message digest
940  * @desc: operational state handle that is already filled with data
941  * @out: output buffer filled with the message digest
942  *
943  * Finalize the message digest operation and create the message digest
944  * based on all data added to the cipher handle. The message digest is placed
945  * into the output buffer. The caller must ensure that the output buffer is
946  * large enough by using crypto_shash_digestsize.
947  *
948  * Context: Any context.
949  * Return: 0 if the message digest creation was successful; < 0 if an error
950  *	   occurred
951  */
952 int crypto_shash_final(struct shash_desc *desc, u8 *out);
953 
954 /**
955  * crypto_shash_finup() - calculate message digest of buffer
956  * @desc: see crypto_shash_final()
957  * @data: see crypto_shash_update()
958  * @len: see crypto_shash_update()
959  * @out: see crypto_shash_final()
960  *
961  * This function is a "short-hand" for the function calls of
962  * crypto_shash_update and crypto_shash_final. The parameters have the same
963  * meaning as discussed for those separate functions.
964  *
965  * Context: Any context.
966  * Return: 0 if the message digest creation was successful; < 0 if an error
967  *	   occurred
968  */
969 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
970 		       unsigned int len, u8 *out);
971 
972 static inline void shash_desc_zero(struct shash_desc *desc)
973 {
974 	memzero_explicit(desc,
975 			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
976 }
977 
978 #endif	/* _CRYPTO_HASH_H */
979