xref: /linux/include/crypto/hash.h (revision 122333d6bd229af279cdb35d1b874b71b3b9ccfb)
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 	int (*init)(struct ahash_request *req);
254 	int (*update)(struct ahash_request *req);
255 	int (*final)(struct ahash_request *req);
256 	int (*finup)(struct ahash_request *req);
257 	int (*digest)(struct ahash_request *req);
258 	int (*export)(struct ahash_request *req, void *out);
259 	int (*import)(struct ahash_request *req, const void *in);
260 	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
261 		      unsigned int keylen);
262 
263 	unsigned int reqsize;
264 	struct crypto_tfm base;
265 };
266 
267 struct crypto_shash {
268 	unsigned int descsize;
269 	struct crypto_tfm base;
270 };
271 
272 /**
273  * DOC: Asynchronous Message Digest API
274  *
275  * The asynchronous message digest API is used with the ciphers of type
276  * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
277  *
278  * The asynchronous cipher operation discussion provided for the
279  * CRYPTO_ALG_TYPE_SKCIPHER API applies here as well.
280  */
281 
282 static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
283 {
284 	return container_of(tfm, struct crypto_ahash, base);
285 }
286 
287 /**
288  * crypto_alloc_ahash() - allocate ahash cipher handle
289  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
290  *	      ahash cipher
291  * @type: specifies the type of the cipher
292  * @mask: specifies the mask for the cipher
293  *
294  * Allocate a cipher handle for an ahash. The returned struct
295  * crypto_ahash is the cipher handle that is required for any subsequent
296  * API invocation for that ahash.
297  *
298  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
299  *	   of an error, PTR_ERR() returns the error code.
300  */
301 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
302 					u32 mask);
303 
304 struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *tfm);
305 
306 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
307 {
308 	return &tfm->base;
309 }
310 
311 /**
312  * crypto_free_ahash() - zeroize and free the ahash handle
313  * @tfm: cipher handle to be freed
314  *
315  * If @tfm is a NULL or error pointer, this function does nothing.
316  */
317 static inline void crypto_free_ahash(struct crypto_ahash *tfm)
318 {
319 	crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm));
320 }
321 
322 /**
323  * crypto_has_ahash() - Search for the availability of an ahash.
324  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
325  *	      ahash
326  * @type: specifies the type of the ahash
327  * @mask: specifies the mask for the ahash
328  *
329  * Return: true when the ahash is known to the kernel crypto API; false
330  *	   otherwise
331  */
332 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
333 
334 static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
335 {
336 	return crypto_tfm_alg_name(crypto_ahash_tfm(tfm));
337 }
338 
339 static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
340 {
341 	return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm));
342 }
343 
344 static inline unsigned int crypto_ahash_alignmask(
345 	struct crypto_ahash *tfm)
346 {
347 	return crypto_tfm_alg_alignmask(crypto_ahash_tfm(tfm));
348 }
349 
350 /**
351  * crypto_ahash_blocksize() - obtain block size for cipher
352  * @tfm: cipher handle
353  *
354  * The block size for the message digest cipher referenced with the cipher
355  * handle is returned.
356  *
357  * Return: block size of cipher
358  */
359 static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
360 {
361 	return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
362 }
363 
364 static inline struct hash_alg_common *__crypto_hash_alg_common(
365 	struct crypto_alg *alg)
366 {
367 	return container_of(alg, struct hash_alg_common, base);
368 }
369 
370 static inline struct hash_alg_common *crypto_hash_alg_common(
371 	struct crypto_ahash *tfm)
372 {
373 	return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg);
374 }
375 
376 /**
377  * crypto_ahash_digestsize() - obtain message digest size
378  * @tfm: cipher handle
379  *
380  * The size for the message digest created by the message digest cipher
381  * referenced with the cipher handle is returned.
382  *
383  *
384  * Return: message digest size of cipher
385  */
386 static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
387 {
388 	return crypto_hash_alg_common(tfm)->digestsize;
389 }
390 
391 /**
392  * crypto_ahash_statesize() - obtain size of the ahash state
393  * @tfm: cipher handle
394  *
395  * Return the size of the ahash state. With the crypto_ahash_export()
396  * function, the caller can export the state into a buffer whose size is
397  * defined with this function.
398  *
399  * Return: size of the ahash state
400  */
401 static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
402 {
403 	return crypto_hash_alg_common(tfm)->statesize;
404 }
405 
406 static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
407 {
408 	return crypto_tfm_get_flags(crypto_ahash_tfm(tfm));
409 }
410 
411 static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
412 {
413 	crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags);
414 }
415 
416 static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
417 {
418 	crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags);
419 }
420 
421 /**
422  * crypto_ahash_reqtfm() - obtain cipher handle from request
423  * @req: asynchronous request handle that contains the reference to the ahash
424  *	 cipher handle
425  *
426  * Return the ahash cipher handle that is registered with the asynchronous
427  * request handle ahash_request.
428  *
429  * Return: ahash cipher handle
430  */
431 static inline struct crypto_ahash *crypto_ahash_reqtfm(
432 	struct ahash_request *req)
433 {
434 	return __crypto_ahash_cast(req->base.tfm);
435 }
436 
437 /**
438  * crypto_ahash_reqsize() - obtain size of the request data structure
439  * @tfm: cipher handle
440  *
441  * Return: size of the request data
442  */
443 static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
444 {
445 	return tfm->reqsize;
446 }
447 
448 static inline void *ahash_request_ctx(struct ahash_request *req)
449 {
450 	return req->__ctx;
451 }
452 
453 /**
454  * crypto_ahash_setkey - set key for cipher handle
455  * @tfm: cipher handle
456  * @key: buffer holding the key
457  * @keylen: length of the key in bytes
458  *
459  * The caller provided key is set for the ahash cipher. The cipher
460  * handle must point to a keyed hash in order for this function to succeed.
461  *
462  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
463  */
464 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
465 			unsigned int keylen);
466 
467 /**
468  * crypto_ahash_finup() - update and finalize message digest
469  * @req: reference to the ahash_request handle that holds all information
470  *	 needed to perform the cipher operation
471  *
472  * This function is a "short-hand" for the function calls of
473  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
474  * meaning as discussed for those separate functions.
475  *
476  * Return: see crypto_ahash_final()
477  */
478 int crypto_ahash_finup(struct ahash_request *req);
479 
480 /**
481  * crypto_ahash_final() - calculate message digest
482  * @req: reference to the ahash_request handle that holds all information
483  *	 needed to perform the cipher operation
484  *
485  * Finalize the message digest operation and create the message digest
486  * based on all data added to the cipher handle. The message digest is placed
487  * into the output buffer registered with the ahash_request handle.
488  *
489  * Return:
490  * 0		if the message digest was successfully calculated;
491  * -EINPROGRESS	if data is fed into hardware (DMA) or queued for later;
492  * -EBUSY	if queue is full and request should be resubmitted later;
493  * other < 0	if an error occurred
494  */
495 int crypto_ahash_final(struct ahash_request *req);
496 
497 /**
498  * crypto_ahash_digest() - calculate message digest for a buffer
499  * @req: reference to the ahash_request handle that holds all information
500  *	 needed to perform the cipher operation
501  *
502  * This function is a "short-hand" for the function calls of crypto_ahash_init,
503  * crypto_ahash_update and crypto_ahash_final. The parameters have the same
504  * meaning as discussed for those separate three functions.
505  *
506  * Return: see crypto_ahash_final()
507  */
508 int crypto_ahash_digest(struct ahash_request *req);
509 
510 /**
511  * crypto_ahash_export() - extract current message digest state
512  * @req: reference to the ahash_request handle whose state is exported
513  * @out: output buffer of sufficient size that can hold the hash state
514  *
515  * This function exports the hash state of the ahash_request handle into the
516  * caller-allocated output buffer out which must have sufficient size (e.g. by
517  * calling crypto_ahash_statesize()).
518  *
519  * Return: 0 if the export was successful; < 0 if an error occurred
520  */
521 static inline int crypto_ahash_export(struct ahash_request *req, void *out)
522 {
523 	return crypto_ahash_reqtfm(req)->export(req, out);
524 }
525 
526 /**
527  * crypto_ahash_import() - import message digest state
528  * @req: reference to ahash_request handle the state is imported into
529  * @in: buffer holding the state
530  *
531  * This function imports the hash state into the ahash_request handle from the
532  * input buffer. That buffer should have been generated with the
533  * crypto_ahash_export function.
534  *
535  * Return: 0 if the import was successful; < 0 if an error occurred
536  */
537 static inline int crypto_ahash_import(struct ahash_request *req, const void *in)
538 {
539 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
540 
541 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
542 		return -ENOKEY;
543 
544 	return tfm->import(req, in);
545 }
546 
547 /**
548  * crypto_ahash_init() - (re)initialize message digest handle
549  * @req: ahash_request handle that already is initialized with all necessary
550  *	 data using the ahash_request_* API functions
551  *
552  * The call (re-)initializes the message digest referenced by the ahash_request
553  * handle. Any potentially existing state created by previous operations is
554  * discarded.
555  *
556  * Return: see crypto_ahash_final()
557  */
558 static inline int crypto_ahash_init(struct ahash_request *req)
559 {
560 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
561 
562 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
563 		return -ENOKEY;
564 
565 	return tfm->init(req);
566 }
567 
568 static inline struct crypto_istat_hash *hash_get_stat(
569 	struct hash_alg_common *alg)
570 {
571 #ifdef CONFIG_CRYPTO_STATS
572 	return &alg->stat;
573 #else
574 	return NULL;
575 #endif
576 }
577 
578 static inline int crypto_hash_errstat(struct hash_alg_common *alg, int err)
579 {
580 	if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
581 		return err;
582 
583 	if (err && err != -EINPROGRESS && err != -EBUSY)
584 		atomic64_inc(&hash_get_stat(alg)->err_cnt);
585 
586 	return err;
587 }
588 
589 /**
590  * crypto_ahash_update() - add data to message digest for processing
591  * @req: ahash_request handle that was previously initialized with the
592  *	 crypto_ahash_init call.
593  *
594  * Updates the message digest state of the &ahash_request handle. The input data
595  * is pointed to by the scatter/gather list registered in the &ahash_request
596  * handle
597  *
598  * Return: see crypto_ahash_final()
599  */
600 static inline int crypto_ahash_update(struct ahash_request *req)
601 {
602 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
603 	struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
604 
605 	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
606 		atomic64_add(req->nbytes, &hash_get_stat(alg)->hash_tlen);
607 
608 	return crypto_hash_errstat(alg, tfm->update(req));
609 }
610 
611 /**
612  * DOC: Asynchronous Hash Request Handle
613  *
614  * The &ahash_request data structure contains all pointers to data
615  * required for the asynchronous cipher operation. This includes the cipher
616  * handle (which can be used by multiple &ahash_request instances), pointer
617  * to plaintext and the message digest output buffer, asynchronous callback
618  * function, etc. It acts as a handle to the ahash_request_* API calls in a
619  * similar way as ahash handle to the crypto_ahash_* API calls.
620  */
621 
622 /**
623  * ahash_request_set_tfm() - update cipher handle reference in request
624  * @req: request handle to be modified
625  * @tfm: cipher handle that shall be added to the request handle
626  *
627  * Allow the caller to replace the existing ahash handle in the request
628  * data structure with a different one.
629  */
630 static inline void ahash_request_set_tfm(struct ahash_request *req,
631 					 struct crypto_ahash *tfm)
632 {
633 	req->base.tfm = crypto_ahash_tfm(tfm);
634 }
635 
636 /**
637  * ahash_request_alloc() - allocate request data structure
638  * @tfm: cipher handle to be registered with the request
639  * @gfp: memory allocation flag that is handed to kmalloc by the API call.
640  *
641  * Allocate the request data structure that must be used with the ahash
642  * message digest API calls. During
643  * the allocation, the provided ahash handle
644  * is registered in the request data structure.
645  *
646  * Return: allocated request handle in case of success, or NULL if out of memory
647  */
648 static inline struct ahash_request *ahash_request_alloc(
649 	struct crypto_ahash *tfm, gfp_t gfp)
650 {
651 	struct ahash_request *req;
652 
653 	req = kmalloc(sizeof(struct ahash_request) +
654 		      crypto_ahash_reqsize(tfm), gfp);
655 
656 	if (likely(req))
657 		ahash_request_set_tfm(req, tfm);
658 
659 	return req;
660 }
661 
662 /**
663  * ahash_request_free() - zeroize and free the request data structure
664  * @req: request data structure cipher handle to be freed
665  */
666 static inline void ahash_request_free(struct ahash_request *req)
667 {
668 	kfree_sensitive(req);
669 }
670 
671 static inline void ahash_request_zero(struct ahash_request *req)
672 {
673 	memzero_explicit(req, sizeof(*req) +
674 			      crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));
675 }
676 
677 static inline struct ahash_request *ahash_request_cast(
678 	struct crypto_async_request *req)
679 {
680 	return container_of(req, struct ahash_request, base);
681 }
682 
683 /**
684  * ahash_request_set_callback() - set asynchronous callback function
685  * @req: request handle
686  * @flags: specify zero or an ORing of the flags
687  *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
688  *	   increase the wait queue beyond the initial maximum size;
689  *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
690  * @compl: callback function pointer to be registered with the request handle
691  * @data: The data pointer refers to memory that is not used by the kernel
692  *	  crypto API, but provided to the callback function for it to use. Here,
693  *	  the caller can provide a reference to memory the callback function can
694  *	  operate on. As the callback function is invoked asynchronously to the
695  *	  related functionality, it may need to access data structures of the
696  *	  related functionality which can be referenced using this pointer. The
697  *	  callback function can access the memory via the "data" field in the
698  *	  &crypto_async_request data structure provided to the callback function.
699  *
700  * This function allows setting the callback function that is triggered once
701  * the cipher operation completes.
702  *
703  * The callback function is registered with the &ahash_request handle and
704  * must comply with the following template::
705  *
706  *	void callback_function(struct crypto_async_request *req, int error)
707  */
708 static inline void ahash_request_set_callback(struct ahash_request *req,
709 					      u32 flags,
710 					      crypto_completion_t compl,
711 					      void *data)
712 {
713 	req->base.complete = compl;
714 	req->base.data = data;
715 	req->base.flags = flags;
716 }
717 
718 /**
719  * ahash_request_set_crypt() - set data buffers
720  * @req: ahash_request handle to be updated
721  * @src: source scatter/gather list
722  * @result: buffer that is filled with the message digest -- the caller must
723  *	    ensure that the buffer has sufficient space by, for example, calling
724  *	    crypto_ahash_digestsize()
725  * @nbytes: number of bytes to process from the source scatter/gather list
726  *
727  * By using this call, the caller references the source scatter/gather list.
728  * The source scatter/gather list points to the data the message digest is to
729  * be calculated for.
730  */
731 static inline void ahash_request_set_crypt(struct ahash_request *req,
732 					   struct scatterlist *src, u8 *result,
733 					   unsigned int nbytes)
734 {
735 	req->src = src;
736 	req->nbytes = nbytes;
737 	req->result = result;
738 }
739 
740 /**
741  * DOC: Synchronous Message Digest API
742  *
743  * The synchronous message digest API is used with the ciphers of type
744  * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
745  *
746  * The message digest API is able to maintain state information for the
747  * caller.
748  *
749  * The synchronous message digest API can store user-related context in its
750  * shash_desc request data structure.
751  */
752 
753 /**
754  * crypto_alloc_shash() - allocate message digest handle
755  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
756  *	      message digest cipher
757  * @type: specifies the type of the cipher
758  * @mask: specifies the mask for the cipher
759  *
760  * Allocate a cipher handle for a message digest. The returned &struct
761  * crypto_shash is the cipher handle that is required for any subsequent
762  * API invocation for that message digest.
763  *
764  * Return: allocated cipher handle in case of success; IS_ERR() is true in case
765  *	   of an error, PTR_ERR() returns the error code.
766  */
767 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
768 					u32 mask);
769 
770 struct crypto_shash *crypto_clone_shash(struct crypto_shash *tfm);
771 
772 int crypto_has_shash(const char *alg_name, u32 type, u32 mask);
773 
774 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
775 {
776 	return &tfm->base;
777 }
778 
779 /**
780  * crypto_free_shash() - zeroize and free the message digest handle
781  * @tfm: cipher handle to be freed
782  *
783  * If @tfm is a NULL or error pointer, this function does nothing.
784  */
785 static inline void crypto_free_shash(struct crypto_shash *tfm)
786 {
787 	crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
788 }
789 
790 static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
791 {
792 	return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
793 }
794 
795 static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
796 {
797 	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
798 }
799 
800 static inline unsigned int crypto_shash_alignmask(
801 	struct crypto_shash *tfm)
802 {
803 	return crypto_tfm_alg_alignmask(crypto_shash_tfm(tfm));
804 }
805 
806 /**
807  * crypto_shash_blocksize() - obtain block size for cipher
808  * @tfm: cipher handle
809  *
810  * The block size for the message digest cipher referenced with the cipher
811  * handle is returned.
812  *
813  * Return: block size of cipher
814  */
815 static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
816 {
817 	return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm));
818 }
819 
820 static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
821 {
822 	return container_of(alg, struct shash_alg, base);
823 }
824 
825 static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
826 {
827 	return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg);
828 }
829 
830 /**
831  * crypto_shash_digestsize() - obtain message digest size
832  * @tfm: cipher handle
833  *
834  * The size for the message digest created by the message digest cipher
835  * referenced with the cipher handle is returned.
836  *
837  * Return: digest size of cipher
838  */
839 static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
840 {
841 	return crypto_shash_alg(tfm)->digestsize;
842 }
843 
844 static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
845 {
846 	return crypto_shash_alg(tfm)->statesize;
847 }
848 
849 static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
850 {
851 	return crypto_tfm_get_flags(crypto_shash_tfm(tfm));
852 }
853 
854 static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
855 {
856 	crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags);
857 }
858 
859 static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
860 {
861 	crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags);
862 }
863 
864 /**
865  * crypto_shash_descsize() - obtain the operational state size
866  * @tfm: cipher handle
867  *
868  * The size of the operational state the cipher needs during operation is
869  * returned for the hash referenced with the cipher handle. This size is
870  * required to calculate the memory requirements to allow the caller allocating
871  * sufficient memory for operational state.
872  *
873  * The operational state is defined with struct shash_desc where the size of
874  * that data structure is to be calculated as
875  * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
876  *
877  * Return: size of the operational state
878  */
879 static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
880 {
881 	return tfm->descsize;
882 }
883 
884 static inline void *shash_desc_ctx(struct shash_desc *desc)
885 {
886 	return desc->__ctx;
887 }
888 
889 /**
890  * crypto_shash_setkey() - set key for message digest
891  * @tfm: cipher handle
892  * @key: buffer holding the key
893  * @keylen: length of the key in bytes
894  *
895  * The caller provided key is set for the keyed message digest cipher. The
896  * cipher handle must point to a keyed message digest cipher in order for this
897  * function to succeed.
898  *
899  * Context: Any context.
900  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
901  */
902 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
903 			unsigned int keylen);
904 
905 /**
906  * crypto_shash_digest() - calculate message digest for buffer
907  * @desc: see crypto_shash_final()
908  * @data: see crypto_shash_update()
909  * @len: see crypto_shash_update()
910  * @out: see crypto_shash_final()
911  *
912  * This function is a "short-hand" for the function calls of crypto_shash_init,
913  * crypto_shash_update and crypto_shash_final. The parameters have the same
914  * meaning as discussed for those separate three functions.
915  *
916  * Context: Any context.
917  * Return: 0 if the message digest creation was successful; < 0 if an error
918  *	   occurred
919  */
920 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
921 			unsigned int len, u8 *out);
922 
923 /**
924  * crypto_shash_tfm_digest() - calculate message digest for buffer
925  * @tfm: hash transformation object
926  * @data: see crypto_shash_update()
927  * @len: see crypto_shash_update()
928  * @out: see crypto_shash_final()
929  *
930  * This is a simplified version of crypto_shash_digest() for users who don't
931  * want to allocate their own hash descriptor (shash_desc).  Instead,
932  * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
933  * directly, and it allocates a hash descriptor on the stack internally.
934  * Note that this stack allocation may be fairly large.
935  *
936  * Context: Any context.
937  * Return: 0 on success; < 0 if an error occurred.
938  */
939 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
940 			    unsigned int len, u8 *out);
941 
942 /**
943  * crypto_shash_export() - extract operational state for message digest
944  * @desc: reference to the operational state handle whose state is exported
945  * @out: output buffer of sufficient size that can hold the hash state
946  *
947  * This function exports the hash state of the operational state handle into the
948  * caller-allocated output buffer out which must have sufficient size (e.g. by
949  * calling crypto_shash_descsize).
950  *
951  * Context: Any context.
952  * Return: 0 if the export creation was successful; < 0 if an error occurred
953  */
954 static inline int crypto_shash_export(struct shash_desc *desc, void *out)
955 {
956 	return crypto_shash_alg(desc->tfm)->export(desc, out);
957 }
958 
959 /**
960  * crypto_shash_import() - import operational state
961  * @desc: reference to the operational state handle the state imported into
962  * @in: buffer holding the state
963  *
964  * This function imports the hash state into the operational state handle from
965  * the input buffer. That buffer should have been generated with the
966  * crypto_ahash_export function.
967  *
968  * Context: Any context.
969  * Return: 0 if the import was successful; < 0 if an error occurred
970  */
971 static inline int crypto_shash_import(struct shash_desc *desc, const void *in)
972 {
973 	struct crypto_shash *tfm = desc->tfm;
974 
975 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
976 		return -ENOKEY;
977 
978 	return crypto_shash_alg(tfm)->import(desc, in);
979 }
980 
981 /**
982  * crypto_shash_init() - (re)initialize message digest
983  * @desc: operational state handle that is already filled
984  *
985  * The call (re-)initializes the message digest referenced by the
986  * operational state handle. Any potentially existing state created by
987  * previous operations is discarded.
988  *
989  * Context: Any context.
990  * Return: 0 if the message digest initialization was successful; < 0 if an
991  *	   error occurred
992  */
993 static inline int crypto_shash_init(struct shash_desc *desc)
994 {
995 	struct crypto_shash *tfm = desc->tfm;
996 
997 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
998 		return -ENOKEY;
999 
1000 	return crypto_shash_alg(tfm)->init(desc);
1001 }
1002 
1003 /**
1004  * crypto_shash_update() - add data to message digest for processing
1005  * @desc: operational state handle that is already initialized
1006  * @data: input data to be added to the message digest
1007  * @len: length of the input data
1008  *
1009  * Updates the message digest state of the operational state handle.
1010  *
1011  * Context: Any context.
1012  * Return: 0 if the message digest update was successful; < 0 if an error
1013  *	   occurred
1014  */
1015 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
1016 			unsigned int len);
1017 
1018 /**
1019  * crypto_shash_final() - calculate message digest
1020  * @desc: operational state handle that is already filled with data
1021  * @out: output buffer filled with the message digest
1022  *
1023  * Finalize the message digest operation and create the message digest
1024  * based on all data added to the cipher handle. The message digest is placed
1025  * into the output buffer. The caller must ensure that the output buffer is
1026  * large enough by using crypto_shash_digestsize.
1027  *
1028  * Context: Any context.
1029  * Return: 0 if the message digest creation was successful; < 0 if an error
1030  *	   occurred
1031  */
1032 int crypto_shash_final(struct shash_desc *desc, u8 *out);
1033 
1034 /**
1035  * crypto_shash_finup() - calculate message digest of buffer
1036  * @desc: see crypto_shash_final()
1037  * @data: see crypto_shash_update()
1038  * @len: see crypto_shash_update()
1039  * @out: see crypto_shash_final()
1040  *
1041  * This function is a "short-hand" for the function calls of
1042  * crypto_shash_update and crypto_shash_final. The parameters have the same
1043  * meaning as discussed for those separate functions.
1044  *
1045  * Context: Any context.
1046  * Return: 0 if the message digest creation was successful; < 0 if an error
1047  *	   occurred
1048  */
1049 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
1050 		       unsigned int len, u8 *out);
1051 
1052 static inline void shash_desc_zero(struct shash_desc *desc)
1053 {
1054 	memzero_explicit(desc,
1055 			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
1056 }
1057 
1058 #endif	/* _CRYPTO_HASH_H */
1059