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
15struct 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 */
32struct 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}
70struct hash_alg_common HASH_ALG_COMMON;
71
72struct 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 */
158struct 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
175struct 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 */
225struct 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
252struct 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
259struct 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
274static 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 */
293struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
294 u32 mask);
295
296struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *tfm);
297
298static 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 */
309static inline void crypto_free_ahash(struct crypto_ahash *tfm)
310{
311 crypto_destroy_tfm(mem: 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 */
324int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
325
326static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
327{
328 return crypto_tfm_alg_name(tfm: crypto_ahash_tfm(tfm));
329}
330
331static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
332{
333 return crypto_tfm_alg_driver_name(tfm: 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 */
345static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
346{
347 return crypto_tfm_alg_blocksize(tfm: crypto_ahash_tfm(tfm));
348}
349
350static 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
356static inline struct hash_alg_common *crypto_hash_alg_common(
357 struct crypto_ahash *tfm)
358{
359 return __crypto_hash_alg_common(alg: 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 */
372static 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 */
387static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
388{
389 return tfm->statesize;
390}
391
392static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
393{
394 return crypto_tfm_get_flags(tfm: crypto_ahash_tfm(tfm));
395}
396
397static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
398{
399 crypto_tfm_set_flags(tfm: crypto_ahash_tfm(tfm), flags);
400}
401
402static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
403{
404 crypto_tfm_clear_flags(tfm: 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 */
417static inline struct crypto_ahash *crypto_ahash_reqtfm(
418 struct ahash_request *req)
419{
420 return __crypto_ahash_cast(tfm: 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 */
429static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
430{
431 return tfm->reqsize;
432}
433
434static 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 */
450int 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 */
464int 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 */
481int 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 */
494int 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 */
507int 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 */
520int 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 */
533int 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 */
546int 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 */
567static 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 */
585static 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(size: sizeof(struct ahash_request) +
591 crypto_ahash_reqsize(tfm), flags: 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 */
603static inline void ahash_request_free(struct ahash_request *req)
604{
605 kfree_sensitive(objp: req);
606}
607
608static inline void ahash_request_zero(struct ahash_request *req)
609{
610 memzero_explicit(s: req, count: sizeof(*req) +
611 crypto_ahash_reqsize(tfm: crypto_ahash_reqtfm(req)));
612}
613
614static 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 */
645static 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 */
668static 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 */
704struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
705 u32 mask);
706
707struct crypto_shash *crypto_clone_shash(struct crypto_shash *tfm);
708
709int crypto_has_shash(const char *alg_name, u32 type, u32 mask);
710
711static 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 */
722static inline void crypto_free_shash(struct crypto_shash *tfm)
723{
724 crypto_destroy_tfm(mem: tfm, tfm: crypto_shash_tfm(tfm));
725}
726
727static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
728{
729 return crypto_tfm_alg_name(tfm: crypto_shash_tfm(tfm));
730}
731
732static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
733{
734 return crypto_tfm_alg_driver_name(tfm: 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 */
746static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
747{
748 return crypto_tfm_alg_blocksize(tfm: crypto_shash_tfm(tfm));
749}
750
751static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
752{
753 return container_of(alg, struct shash_alg, base);
754}
755
756static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
757{
758 return __crypto_shash_alg(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 */
770static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
771{
772 return crypto_shash_alg(tfm)->digestsize;
773}
774
775static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
776{
777 return crypto_shash_alg(tfm)->statesize;
778}
779
780static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
781{
782 return crypto_tfm_get_flags(tfm: crypto_shash_tfm(tfm));
783}
784
785static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
786{
787 crypto_tfm_set_flags(tfm: crypto_shash_tfm(tfm), flags);
788}
789
790static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
791{
792 crypto_tfm_clear_flags(tfm: 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 */
810static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
811{
812 return tfm->descsize;
813}
814
815static 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 */
833int 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 */
851int 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 */
870int 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 */
885int 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 */
899int 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 */
913static 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 */
935int 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 */
952int 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 */
969int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
970 unsigned int len, u8 *out);
971
972static inline void shash_desc_zero(struct shash_desc *desc)
973{
974 memzero_explicit(s: desc,
975 count: sizeof(*desc) + crypto_shash_descsize(tfm: desc->tfm));
976}
977
978#endif /* _CRYPTO_HASH_H */
979

source code of linux/include/crypto/hash.h