xref: /linux/include/crypto/hash.h (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
1 /*
2  * Hash: Hash algorithms under the crypto API
3  *
4  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  *
11  */
12 
13 #ifndef _CRYPTO_HASH_H
14 #define _CRYPTO_HASH_H
15 
16 #include <linux/crypto.h>
17 #include <linux/string.h>
18 
19 struct crypto_ahash;
20 
21 /**
22  * DOC: Message Digest Algorithm Definitions
23  *
24  * These data structures define modular message digest algorithm
25  * implementations, managed via crypto_register_ahash(),
26  * crypto_register_shash(), crypto_unregister_ahash() and
27  * crypto_unregister_shash().
28  */
29 
30 /**
31  * struct hash_alg_common - define properties of message digest
32  * @digestsize: Size of the result of the transformation. A buffer of this size
33  *	        must be available to the @final and @finup calls, so they can
34  *	        store the resulting hash into it. For various predefined sizes,
35  *	        search include/crypto/ using
36  *	        git grep _DIGEST_SIZE include/crypto.
37  * @statesize: Size of the block for partial state of the transformation. A
38  *	       buffer of this size must be passed to the @export function as it
39  *	       will save the partial state of the transformation into it. On the
40  *	       other side, the @import function will load the state from a
41  *	       buffer of this size as well.
42  * @base: Start of data structure of cipher algorithm. The common data
43  *	  structure of crypto_alg contains information common to all ciphers.
44  *	  The hash_alg_common data structure now adds the hash-specific
45  *	  information.
46  */
47 struct hash_alg_common {
48 	unsigned int digestsize;
49 	unsigned int statesize;
50 
51 	struct crypto_alg base;
52 };
53 
54 struct ahash_request {
55 	struct crypto_async_request base;
56 
57 	unsigned int nbytes;
58 	struct scatterlist *src;
59 	u8 *result;
60 
61 	/* This field may only be used by the ahash API code. */
62 	void *priv;
63 
64 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
65 };
66 
67 #define AHASH_REQUEST_ON_STACK(name, ahash) \
68 	char __##name##_desc[sizeof(struct ahash_request) + \
69 		crypto_ahash_reqsize(ahash)] CRYPTO_MINALIGN_ATTR; \
70 	struct ahash_request *name = (void *)__##name##_desc
71 
72 /**
73  * struct ahash_alg - asynchronous message digest definition
74  * @init: Initialize the transformation context. Intended only to initialize the
75  *	  state of the HASH transformation at the beginning. This shall fill in
76  *	  the internal structures used during the entire duration of the whole
77  *	  transformation. No data processing happens at this point.
78  *	  Note: mandatory.
79  * @update: Push a chunk of data into the driver for transformation. This
80  *	   function actually pushes blocks of data from upper layers into the
81  *	   driver, which then passes those to the hardware as seen fit. This
82  *	   function must not finalize the HASH transformation by calculating the
83  *	   final message digest as this only adds more data into the
84  *	   transformation. This function shall not modify the transformation
85  *	   context, as this function may be called in parallel with the same
86  *	   transformation object. Data processing can happen synchronously
87  *	   [SHASH] or asynchronously [AHASH] at this point.
88  *	   Note: mandatory.
89  * @final: Retrieve result from the driver. This function finalizes the
90  *	   transformation and retrieves the resulting hash from the driver and
91  *	   pushes it back to upper layers. No data processing happens at this
92  *	   point unless hardware requires it to finish the transformation
93  *	   (then the data buffered by the device driver is processed).
94  *	   Note: mandatory.
95  * @finup: Combination of @update and @final. This function is effectively a
96  *	   combination of @update and @final calls issued in sequence. As some
97  *	   hardware cannot do @update and @final separately, this callback was
98  *	   added to allow such hardware to be used at least by IPsec. Data
99  *	   processing can happen synchronously [SHASH] or asynchronously [AHASH]
100  *	   at this point.
101  *	   Note: optional.
102  * @digest: Combination of @init and @update and @final. This function
103  *	    effectively behaves as the entire chain of operations, @init,
104  *	    @update and @final issued in sequence. Just like @finup, this was
105  *	    added for hardware which cannot do even the @finup, but can only do
106  *	    the whole transformation in one run. Data processing can happen
107  *	    synchronously [SHASH] or asynchronously [AHASH] at this point.
108  * @setkey: Set optional key used by the hashing algorithm. Intended to push
109  *	    optional key used by the hashing algorithm from upper layers into
110  *	    the driver. This function can store the key in the transformation
111  *	    context or can outright program it into the hardware. In the former
112  *	    case, one must be careful to program the key into the hardware at
113  *	    appropriate time and one must be careful that .setkey() can be
114  *	    called multiple times during the existence of the transformation
115  *	    object. Not  all hashing algorithms do implement this function as it
116  *	    is only needed for keyed message digests. SHAx/MDx/CRCx do NOT
117  *	    implement this function. HMAC(MDx)/HMAC(SHAx)/CMAC(AES) do implement
118  *	    this function. This function must be called before any other of the
119  *	    @init, @update, @final, @finup, @digest is called. No data
120  *	    processing happens at this point.
121  * @export: Export partial state of the transformation. This function dumps the
122  *	    entire state of the ongoing transformation into a provided block of
123  *	    data so it can be @import 'ed back later on. This is useful in case
124  *	    you want to save partial result of the transformation after
125  *	    processing certain amount of data and reload this partial result
126  *	    multiple times later on for multiple re-use. No data processing
127  *	    happens at this point.
128  * @import: Import partial state of the transformation. This function loads the
129  *	    entire state of the ongoing transformation from a provided block of
130  *	    data so the transformation can continue from this point onward. No
131  *	    data processing happens at this point.
132  * @halg: see struct hash_alg_common
133  */
134 struct ahash_alg {
135 	int (*init)(struct ahash_request *req);
136 	int (*update)(struct ahash_request *req);
137 	int (*final)(struct ahash_request *req);
138 	int (*finup)(struct ahash_request *req);
139 	int (*digest)(struct ahash_request *req);
140 	int (*export)(struct ahash_request *req, void *out);
141 	int (*import)(struct ahash_request *req, const void *in);
142 	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
143 		      unsigned int keylen);
144 
145 	struct hash_alg_common halg;
146 };
147 
148 struct shash_desc {
149 	struct crypto_shash *tfm;
150 	u32 flags;
151 
152 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
153 };
154 
155 #define SHASH_DESC_ON_STACK(shash, ctx)				  \
156 	char __##shash##_desc[sizeof(struct shash_desc) +	  \
157 		crypto_shash_descsize(ctx)] CRYPTO_MINALIGN_ATTR; \
158 	struct shash_desc *shash = (struct shash_desc *)__##shash##_desc
159 
160 /**
161  * struct shash_alg - synchronous message digest definition
162  * @init: see struct ahash_alg
163  * @update: see struct ahash_alg
164  * @final: see struct ahash_alg
165  * @finup: see struct ahash_alg
166  * @digest: see struct ahash_alg
167  * @export: see struct ahash_alg
168  * @import: see struct ahash_alg
169  * @setkey: see struct ahash_alg
170  * @digestsize: see struct ahash_alg
171  * @statesize: see struct ahash_alg
172  * @descsize: Size of the operational state for the message digest. This state
173  * 	      size is the memory size that needs to be allocated for
174  *	      shash_desc.__ctx
175  * @base: internally used
176  */
177 struct shash_alg {
178 	int (*init)(struct shash_desc *desc);
179 	int (*update)(struct shash_desc *desc, const u8 *data,
180 		      unsigned int len);
181 	int (*final)(struct shash_desc *desc, u8 *out);
182 	int (*finup)(struct shash_desc *desc, const u8 *data,
183 		     unsigned int len, u8 *out);
184 	int (*digest)(struct shash_desc *desc, const u8 *data,
185 		      unsigned int len, u8 *out);
186 	int (*export)(struct shash_desc *desc, void *out);
187 	int (*import)(struct shash_desc *desc, const void *in);
188 	int (*setkey)(struct crypto_shash *tfm, const u8 *key,
189 		      unsigned int keylen);
190 
191 	unsigned int descsize;
192 
193 	/* These fields must match hash_alg_common. */
194 	unsigned int digestsize
195 		__attribute__ ((aligned(__alignof__(struct hash_alg_common))));
196 	unsigned int statesize;
197 
198 	struct crypto_alg base;
199 };
200 
201 struct crypto_ahash {
202 	int (*init)(struct ahash_request *req);
203 	int (*update)(struct ahash_request *req);
204 	int (*final)(struct ahash_request *req);
205 	int (*finup)(struct ahash_request *req);
206 	int (*digest)(struct ahash_request *req);
207 	int (*export)(struct ahash_request *req, void *out);
208 	int (*import)(struct ahash_request *req, const void *in);
209 	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
210 		      unsigned int keylen);
211 
212 	unsigned int reqsize;
213 	bool has_setkey;
214 	struct crypto_tfm base;
215 };
216 
217 struct crypto_shash {
218 	unsigned int descsize;
219 	struct crypto_tfm base;
220 };
221 
222 /**
223  * DOC: Asynchronous Message Digest API
224  *
225  * The asynchronous message digest API is used with the ciphers of type
226  * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
227  *
228  * The asynchronous cipher operation discussion provided for the
229  * CRYPTO_ALG_TYPE_ABLKCIPHER API applies here as well.
230  */
231 
232 static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
233 {
234 	return container_of(tfm, struct crypto_ahash, base);
235 }
236 
237 /**
238  * crypto_alloc_ahash() - allocate ahash cipher handle
239  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
240  *	      ahash cipher
241  * @type: specifies the type of the cipher
242  * @mask: specifies the mask for the cipher
243  *
244  * Allocate a cipher handle for an ahash. The returned struct
245  * crypto_ahash is the cipher handle that is required for any subsequent
246  * API invocation for that ahash.
247  *
248  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
249  *	   of an error, PTR_ERR() returns the error code.
250  */
251 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
252 					u32 mask);
253 
254 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
255 {
256 	return &tfm->base;
257 }
258 
259 /**
260  * crypto_free_ahash() - zeroize and free the ahash handle
261  * @tfm: cipher handle to be freed
262  */
263 static inline void crypto_free_ahash(struct crypto_ahash *tfm)
264 {
265 	crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm));
266 }
267 
268 /**
269  * crypto_has_ahash() - Search for the availability of an ahash.
270  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
271  *	      ahash
272  * @type: specifies the type of the ahash
273  * @mask: specifies the mask for the ahash
274  *
275  * Return: true when the ahash is known to the kernel crypto API; false
276  *	   otherwise
277  */
278 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
279 
280 static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
281 {
282 	return crypto_tfm_alg_name(crypto_ahash_tfm(tfm));
283 }
284 
285 static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
286 {
287 	return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm));
288 }
289 
290 static inline unsigned int crypto_ahash_alignmask(
291 	struct crypto_ahash *tfm)
292 {
293 	return crypto_tfm_alg_alignmask(crypto_ahash_tfm(tfm));
294 }
295 
296 /**
297  * crypto_ahash_blocksize() - obtain block size for cipher
298  * @tfm: cipher handle
299  *
300  * The block size for the message digest cipher referenced with the cipher
301  * handle is returned.
302  *
303  * Return: block size of cipher
304  */
305 static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
306 {
307 	return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
308 }
309 
310 static inline struct hash_alg_common *__crypto_hash_alg_common(
311 	struct crypto_alg *alg)
312 {
313 	return container_of(alg, struct hash_alg_common, base);
314 }
315 
316 static inline struct hash_alg_common *crypto_hash_alg_common(
317 	struct crypto_ahash *tfm)
318 {
319 	return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg);
320 }
321 
322 /**
323  * crypto_ahash_digestsize() - obtain message digest size
324  * @tfm: cipher handle
325  *
326  * The size for the message digest created by the message digest cipher
327  * referenced with the cipher handle is returned.
328  *
329  *
330  * Return: message digest size of cipher
331  */
332 static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
333 {
334 	return crypto_hash_alg_common(tfm)->digestsize;
335 }
336 
337 /**
338  * crypto_ahash_statesize() - obtain size of the ahash state
339  * @tfm: cipher handle
340  *
341  * Return the size of the ahash state. With the crypto_ahash_export()
342  * function, the caller can export the state into a buffer whose size is
343  * defined with this function.
344  *
345  * Return: size of the ahash state
346  */
347 static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
348 {
349 	return crypto_hash_alg_common(tfm)->statesize;
350 }
351 
352 static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
353 {
354 	return crypto_tfm_get_flags(crypto_ahash_tfm(tfm));
355 }
356 
357 static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
358 {
359 	crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags);
360 }
361 
362 static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
363 {
364 	crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags);
365 }
366 
367 /**
368  * crypto_ahash_reqtfm() - obtain cipher handle from request
369  * @req: asynchronous request handle that contains the reference to the ahash
370  *	 cipher handle
371  *
372  * Return the ahash cipher handle that is registered with the asynchronous
373  * request handle ahash_request.
374  *
375  * Return: ahash cipher handle
376  */
377 static inline struct crypto_ahash *crypto_ahash_reqtfm(
378 	struct ahash_request *req)
379 {
380 	return __crypto_ahash_cast(req->base.tfm);
381 }
382 
383 /**
384  * crypto_ahash_reqsize() - obtain size of the request data structure
385  * @tfm: cipher handle
386  *
387  * Return: size of the request data
388  */
389 static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
390 {
391 	return tfm->reqsize;
392 }
393 
394 static inline void *ahash_request_ctx(struct ahash_request *req)
395 {
396 	return req->__ctx;
397 }
398 
399 /**
400  * crypto_ahash_setkey - set key for cipher handle
401  * @tfm: cipher handle
402  * @key: buffer holding the key
403  * @keylen: length of the key in bytes
404  *
405  * The caller provided key is set for the ahash cipher. The cipher
406  * handle must point to a keyed hash in order for this function to succeed.
407  *
408  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
409  */
410 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
411 			unsigned int keylen);
412 
413 static inline bool crypto_ahash_has_setkey(struct crypto_ahash *tfm)
414 {
415 	return tfm->has_setkey;
416 }
417 
418 /**
419  * crypto_ahash_finup() - update and finalize message digest
420  * @req: reference to the ahash_request handle that holds all information
421  *	 needed to perform the cipher operation
422  *
423  * This function is a "short-hand" for the function calls of
424  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
425  * meaning as discussed for those separate functions.
426  *
427  * Return: see crypto_ahash_final()
428  */
429 int crypto_ahash_finup(struct ahash_request *req);
430 
431 /**
432  * crypto_ahash_final() - calculate message digest
433  * @req: reference to the ahash_request handle that holds all information
434  *	 needed to perform the cipher operation
435  *
436  * Finalize the message digest operation and create the message digest
437  * based on all data added to the cipher handle. The message digest is placed
438  * into the output buffer registered with the ahash_request handle.
439  *
440  * Return:
441  * 0		if the message digest was successfully calculated;
442  * -EINPROGRESS	if data is feeded into hardware (DMA) or queued for later;
443  * -EBUSY	if queue is full and request should be resubmitted later;
444  * other < 0	if an error occurred
445  */
446 int crypto_ahash_final(struct ahash_request *req);
447 
448 /**
449  * crypto_ahash_digest() - calculate message digest for a buffer
450  * @req: reference to the ahash_request handle that holds all information
451  *	 needed to perform the cipher operation
452  *
453  * This function is a "short-hand" for the function calls of crypto_ahash_init,
454  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
455  * meaning as discussed for those separate three functions.
456  *
457  * Return: see crypto_ahash_final()
458  */
459 int crypto_ahash_digest(struct ahash_request *req);
460 
461 /**
462  * crypto_ahash_export() - extract current message digest state
463  * @req: reference to the ahash_request handle whose state is exported
464  * @out: output buffer of sufficient size that can hold the hash state
465  *
466  * This function exports the hash state of the ahash_request handle into the
467  * caller-allocated output buffer out which must have sufficient size (e.g. by
468  * calling crypto_ahash_statesize()).
469  *
470  * Return: 0 if the export was successful; < 0 if an error occurred
471  */
472 static inline int crypto_ahash_export(struct ahash_request *req, void *out)
473 {
474 	return crypto_ahash_reqtfm(req)->export(req, out);
475 }
476 
477 /**
478  * crypto_ahash_import() - import message digest state
479  * @req: reference to ahash_request handle the state is imported into
480  * @in: buffer holding the state
481  *
482  * This function imports the hash state into the ahash_request handle from the
483  * input buffer. That buffer should have been generated with the
484  * crypto_ahash_export function.
485  *
486  * Return: 0 if the import was successful; < 0 if an error occurred
487  */
488 static inline int crypto_ahash_import(struct ahash_request *req, const void *in)
489 {
490 	return crypto_ahash_reqtfm(req)->import(req, in);
491 }
492 
493 /**
494  * crypto_ahash_init() - (re)initialize message digest handle
495  * @req: ahash_request handle that already is initialized with all necessary
496  *	 data using the ahash_request_* API functions
497  *
498  * The call (re-)initializes the message digest referenced by the ahash_request
499  * handle. Any potentially existing state created by previous operations is
500  * discarded.
501  *
502  * Return: see crypto_ahash_final()
503  */
504 static inline int crypto_ahash_init(struct ahash_request *req)
505 {
506 	return crypto_ahash_reqtfm(req)->init(req);
507 }
508 
509 /**
510  * crypto_ahash_update() - add data to message digest for processing
511  * @req: ahash_request handle that was previously initialized with the
512  *	 crypto_ahash_init call.
513  *
514  * Updates the message digest state of the &ahash_request handle. The input data
515  * is pointed to by the scatter/gather list registered in the &ahash_request
516  * handle
517  *
518  * Return: see crypto_ahash_final()
519  */
520 static inline int crypto_ahash_update(struct ahash_request *req)
521 {
522 	return crypto_ahash_reqtfm(req)->update(req);
523 }
524 
525 /**
526  * DOC: Asynchronous Hash Request Handle
527  *
528  * The &ahash_request data structure contains all pointers to data
529  * required for the asynchronous cipher operation. This includes the cipher
530  * handle (which can be used by multiple &ahash_request instances), pointer
531  * to plaintext and the message digest output buffer, asynchronous callback
532  * function, etc. It acts as a handle to the ahash_request_* API calls in a
533  * similar way as ahash handle to the crypto_ahash_* API calls.
534  */
535 
536 /**
537  * ahash_request_set_tfm() - update cipher handle reference in request
538  * @req: request handle to be modified
539  * @tfm: cipher handle that shall be added to the request handle
540  *
541  * Allow the caller to replace the existing ahash handle in the request
542  * data structure with a different one.
543  */
544 static inline void ahash_request_set_tfm(struct ahash_request *req,
545 					 struct crypto_ahash *tfm)
546 {
547 	req->base.tfm = crypto_ahash_tfm(tfm);
548 }
549 
550 /**
551  * ahash_request_alloc() - allocate request data structure
552  * @tfm: cipher handle to be registered with the request
553  * @gfp: memory allocation flag that is handed to kmalloc by the API call.
554  *
555  * Allocate the request data structure that must be used with the ahash
556  * message digest API calls. During
557  * the allocation, the provided ahash handle
558  * is registered in the request data structure.
559  *
560  * Return: allocated request handle in case of success, or NULL if out of memory
561  */
562 static inline struct ahash_request *ahash_request_alloc(
563 	struct crypto_ahash *tfm, gfp_t gfp)
564 {
565 	struct ahash_request *req;
566 
567 	req = kmalloc(sizeof(struct ahash_request) +
568 		      crypto_ahash_reqsize(tfm), gfp);
569 
570 	if (likely(req))
571 		ahash_request_set_tfm(req, tfm);
572 
573 	return req;
574 }
575 
576 /**
577  * ahash_request_free() - zeroize and free the request data structure
578  * @req: request data structure cipher handle to be freed
579  */
580 static inline void ahash_request_free(struct ahash_request *req)
581 {
582 	kzfree(req);
583 }
584 
585 static inline void ahash_request_zero(struct ahash_request *req)
586 {
587 	memzero_explicit(req, sizeof(*req) +
588 			      crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));
589 }
590 
591 static inline struct ahash_request *ahash_request_cast(
592 	struct crypto_async_request *req)
593 {
594 	return container_of(req, struct ahash_request, base);
595 }
596 
597 /**
598  * ahash_request_set_callback() - set asynchronous callback function
599  * @req: request handle
600  * @flags: specify zero or an ORing of the flags
601  *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
602  *	   increase the wait queue beyond the initial maximum size;
603  *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
604  * @compl: callback function pointer to be registered with the request handle
605  * @data: The data pointer refers to memory that is not used by the kernel
606  *	  crypto API, but provided to the callback function for it to use. Here,
607  *	  the caller can provide a reference to memory the callback function can
608  *	  operate on. As the callback function is invoked asynchronously to the
609  *	  related functionality, it may need to access data structures of the
610  *	  related functionality which can be referenced using this pointer. The
611  *	  callback function can access the memory via the "data" field in the
612  *	  &crypto_async_request data structure provided to the callback function.
613  *
614  * This function allows setting the callback function that is triggered once
615  * the cipher operation completes.
616  *
617  * The callback function is registered with the &ahash_request handle and
618  * must comply with the following template::
619  *
620  *	void callback_function(struct crypto_async_request *req, int error)
621  */
622 static inline void ahash_request_set_callback(struct ahash_request *req,
623 					      u32 flags,
624 					      crypto_completion_t compl,
625 					      void *data)
626 {
627 	req->base.complete = compl;
628 	req->base.data = data;
629 	req->base.flags = flags;
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 }
653 
654 /**
655  * DOC: Synchronous Message Digest API
656  *
657  * The synchronous message digest API is used with the ciphers of type
658  * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
659  *
660  * The message digest API is able to maintain state information for the
661  * caller.
662  *
663  * The synchronous message digest API can store user-related context in in its
664  * shash_desc request data structure.
665  */
666 
667 /**
668  * crypto_alloc_shash() - allocate message digest handle
669  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
670  *	      message digest cipher
671  * @type: specifies the type of the cipher
672  * @mask: specifies the mask for the cipher
673  *
674  * Allocate a cipher handle for a message digest. The returned &struct
675  * crypto_shash is the cipher handle that is required for any subsequent
676  * API invocation for that message digest.
677  *
678  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
679  *	   of an error, PTR_ERR() returns the error code.
680  */
681 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
682 					u32 mask);
683 
684 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
685 {
686 	return &tfm->base;
687 }
688 
689 /**
690  * crypto_free_shash() - zeroize and free the message digest handle
691  * @tfm: cipher handle to be freed
692  */
693 static inline void crypto_free_shash(struct crypto_shash *tfm)
694 {
695 	crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
696 }
697 
698 static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
699 {
700 	return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
701 }
702 
703 static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
704 {
705 	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
706 }
707 
708 static inline unsigned int crypto_shash_alignmask(
709 	struct crypto_shash *tfm)
710 {
711 	return crypto_tfm_alg_alignmask(crypto_shash_tfm(tfm));
712 }
713 
714 /**
715  * crypto_shash_blocksize() - obtain block size for cipher
716  * @tfm: cipher handle
717  *
718  * The block size for the message digest cipher referenced with the cipher
719  * handle is returned.
720  *
721  * Return: block size of cipher
722  */
723 static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
724 {
725 	return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm));
726 }
727 
728 static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
729 {
730 	return container_of(alg, struct shash_alg, base);
731 }
732 
733 static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
734 {
735 	return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg);
736 }
737 
738 /**
739  * crypto_shash_digestsize() - obtain message digest size
740  * @tfm: cipher handle
741  *
742  * The size for the message digest created by the message digest cipher
743  * referenced with the cipher handle is returned.
744  *
745  * Return: digest size of cipher
746  */
747 static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
748 {
749 	return crypto_shash_alg(tfm)->digestsize;
750 }
751 
752 static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
753 {
754 	return crypto_shash_alg(tfm)->statesize;
755 }
756 
757 static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
758 {
759 	return crypto_tfm_get_flags(crypto_shash_tfm(tfm));
760 }
761 
762 static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
763 {
764 	crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags);
765 }
766 
767 static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
768 {
769 	crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags);
770 }
771 
772 /**
773  * crypto_shash_descsize() - obtain the operational state size
774  * @tfm: cipher handle
775  *
776  * The size of the operational state the cipher needs during operation is
777  * returned for the hash referenced with the cipher handle. This size is
778  * required to calculate the memory requirements to allow the caller allocating
779  * sufficient memory for operational state.
780  *
781  * The operational state is defined with struct shash_desc where the size of
782  * that data structure is to be calculated as
783  * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
784  *
785  * Return: size of the operational state
786  */
787 static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
788 {
789 	return tfm->descsize;
790 }
791 
792 static inline void *shash_desc_ctx(struct shash_desc *desc)
793 {
794 	return desc->__ctx;
795 }
796 
797 /**
798  * crypto_shash_setkey() - set key for message digest
799  * @tfm: cipher handle
800  * @key: buffer holding the key
801  * @keylen: length of the key in bytes
802  *
803  * The caller provided key is set for the keyed message digest cipher. The
804  * cipher handle must point to a keyed message digest cipher in order for this
805  * function to succeed.
806  *
807  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
808  */
809 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
810 			unsigned int keylen);
811 
812 /**
813  * crypto_shash_digest() - calculate message digest for buffer
814  * @desc: see crypto_shash_final()
815  * @data: see crypto_shash_update()
816  * @len: see crypto_shash_update()
817  * @out: see crypto_shash_final()
818  *
819  * This function is a "short-hand" for the function calls of crypto_shash_init,
820  * crypto_shash_update and crypto_shash_final. The parameters have the same
821  * meaning as discussed for those separate three functions.
822  *
823  * Return: 0 if the message digest creation was successful; < 0 if an error
824  *	   occurred
825  */
826 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
827 			unsigned int len, u8 *out);
828 
829 /**
830  * crypto_shash_export() - extract operational state for message digest
831  * @desc: reference to the operational state handle whose state is exported
832  * @out: output buffer of sufficient size that can hold the hash state
833  *
834  * This function exports the hash state of the operational state handle into the
835  * caller-allocated output buffer out which must have sufficient size (e.g. by
836  * calling crypto_shash_descsize).
837  *
838  * Return: 0 if the export creation was successful; < 0 if an error occurred
839  */
840 static inline int crypto_shash_export(struct shash_desc *desc, void *out)
841 {
842 	return crypto_shash_alg(desc->tfm)->export(desc, out);
843 }
844 
845 /**
846  * crypto_shash_import() - import operational state
847  * @desc: reference to the operational state handle the state imported into
848  * @in: buffer holding the state
849  *
850  * This function imports the hash state into the operational state handle from
851  * the input buffer. That buffer should have been generated with the
852  * crypto_ahash_export function.
853  *
854  * Return: 0 if the import was successful; < 0 if an error occurred
855  */
856 static inline int crypto_shash_import(struct shash_desc *desc, const void *in)
857 {
858 	return crypto_shash_alg(desc->tfm)->import(desc, in);
859 }
860 
861 /**
862  * crypto_shash_init() - (re)initialize message digest
863  * @desc: operational state handle that is already filled
864  *
865  * The call (re-)initializes the message digest referenced by the
866  * operational state handle. Any potentially existing state created by
867  * previous operations is discarded.
868  *
869  * Return: 0 if the message digest initialization was successful; < 0 if an
870  *	   error occurred
871  */
872 static inline int crypto_shash_init(struct shash_desc *desc)
873 {
874 	return crypto_shash_alg(desc->tfm)->init(desc);
875 }
876 
877 /**
878  * crypto_shash_update() - add data to message digest for processing
879  * @desc: operational state handle that is already initialized
880  * @data: input data to be added to the message digest
881  * @len: length of the input data
882  *
883  * Updates the message digest state of the operational state handle.
884  *
885  * Return: 0 if the message digest update was successful; < 0 if an error
886  *	   occurred
887  */
888 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
889 			unsigned int len);
890 
891 /**
892  * crypto_shash_final() - calculate message digest
893  * @desc: operational state handle that is already filled with data
894  * @out: output buffer filled with the message digest
895  *
896  * Finalize the message digest operation and create the message digest
897  * based on all data added to the cipher handle. The message digest is placed
898  * into the output buffer. The caller must ensure that the output buffer is
899  * large enough by using crypto_shash_digestsize.
900  *
901  * Return: 0 if the message digest creation was successful; < 0 if an error
902  *	   occurred
903  */
904 int crypto_shash_final(struct shash_desc *desc, u8 *out);
905 
906 /**
907  * crypto_shash_finup() - calculate message digest of buffer
908  * @desc: see crypto_shash_final()
909  * @data: see crypto_shash_update()
910  * @len: see crypto_shash_update()
911  * @out: see crypto_shash_final()
912  *
913  * This function is a "short-hand" for the function calls of
914  * crypto_shash_update and crypto_shash_final. The parameters have the same
915  * meaning as discussed for those separate functions.
916  *
917  * Return: 0 if the message digest creation was successful; < 0 if an error
918  *	   occurred
919  */
920 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
921 		       unsigned int len, u8 *out);
922 
923 static inline void shash_desc_zero(struct shash_desc *desc)
924 {
925 	memzero_explicit(desc,
926 			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
927 }
928 
929 #endif	/* _CRYPTO_HASH_H */
930