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 * @descsize: Size of the operational state for the message digest. This state
216 * size is the memory size that needs to be allocated for
217 * shash_desc.__ctx
218 * @halg: see struct hash_alg_common
219 * @HASH_ALG_COMMON: see struct hash_alg_common
220 */
221struct shash_alg {
222 int (*init)(struct shash_desc *desc);
223 int (*update)(struct shash_desc *desc, const u8 *data,
224 unsigned int len);
225 int (*final)(struct shash_desc *desc, u8 *out);
226 int (*finup)(struct shash_desc *desc, const u8 *data,
227 unsigned int len, u8 *out);
228 int (*digest)(struct shash_desc *desc, const u8 *data,
229 unsigned int len, u8 *out);
230 int (*export)(struct shash_desc *desc, void *out);
231 int (*import)(struct shash_desc *desc, const void *in);
232 int (*setkey)(struct crypto_shash *tfm, const u8 *key,
233 unsigned int keylen);
234 int (*init_tfm)(struct crypto_shash *tfm);
235 void (*exit_tfm)(struct crypto_shash *tfm);
236 int (*clone_tfm)(struct crypto_shash *dst, struct crypto_shash *src);
237
238 unsigned int descsize;
239
240 union {
241 struct HASH_ALG_COMMON;
242 struct hash_alg_common halg;
243 };
244};
245#undef HASH_ALG_COMMON
246#undef HASH_ALG_COMMON_STAT
247
248struct crypto_ahash {
249 bool using_shash; /* Underlying algorithm is shash, not ahash */
250 unsigned int statesize;
251 unsigned int reqsize;
252 struct crypto_tfm base;
253};
254
255struct crypto_shash {
256 unsigned int descsize;
257 struct crypto_tfm base;
258};
259
260/**
261 * DOC: Asynchronous Message Digest API
262 *
263 * The asynchronous message digest API is used with the ciphers of type
264 * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
265 *
266 * The asynchronous cipher operation discussion provided for the
267 * CRYPTO_ALG_TYPE_SKCIPHER API applies here as well.
268 */
269
270static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
271{
272 return container_of(tfm, struct crypto_ahash, base);
273}
274
275/**
276 * crypto_alloc_ahash() - allocate ahash cipher handle
277 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
278 * ahash cipher
279 * @type: specifies the type of the cipher
280 * @mask: specifies the mask for the cipher
281 *
282 * Allocate a cipher handle for an ahash. The returned struct
283 * crypto_ahash is the cipher handle that is required for any subsequent
284 * API invocation for that ahash.
285 *
286 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
287 * of an error, PTR_ERR() returns the error code.
288 */
289struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
290 u32 mask);
291
292struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *tfm);
293
294static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
295{
296 return &tfm->base;
297}
298
299/**
300 * crypto_free_ahash() - zeroize and free the ahash handle
301 * @tfm: cipher handle to be freed
302 *
303 * If @tfm is a NULL or error pointer, this function does nothing.
304 */
305static inline void crypto_free_ahash(struct crypto_ahash *tfm)
306{
307 crypto_destroy_tfm(mem: tfm, tfm: crypto_ahash_tfm(tfm));
308}
309
310/**
311 * crypto_has_ahash() - Search for the availability of an ahash.
312 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
313 * ahash
314 * @type: specifies the type of the ahash
315 * @mask: specifies the mask for the ahash
316 *
317 * Return: true when the ahash is known to the kernel crypto API; false
318 * otherwise
319 */
320int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
321
322static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
323{
324 return crypto_tfm_alg_name(tfm: crypto_ahash_tfm(tfm));
325}
326
327static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
328{
329 return crypto_tfm_alg_driver_name(tfm: crypto_ahash_tfm(tfm));
330}
331
332/**
333 * crypto_ahash_blocksize() - obtain block size for cipher
334 * @tfm: cipher handle
335 *
336 * The block size for the message digest cipher referenced with the cipher
337 * handle is returned.
338 *
339 * Return: block size of cipher
340 */
341static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
342{
343 return crypto_tfm_alg_blocksize(tfm: crypto_ahash_tfm(tfm));
344}
345
346static inline struct hash_alg_common *__crypto_hash_alg_common(
347 struct crypto_alg *alg)
348{
349 return container_of(alg, struct hash_alg_common, base);
350}
351
352static inline struct hash_alg_common *crypto_hash_alg_common(
353 struct crypto_ahash *tfm)
354{
355 return __crypto_hash_alg_common(alg: crypto_ahash_tfm(tfm)->__crt_alg);
356}
357
358/**
359 * crypto_ahash_digestsize() - obtain message digest size
360 * @tfm: cipher handle
361 *
362 * The size for the message digest created by the message digest cipher
363 * referenced with the cipher handle is returned.
364 *
365 *
366 * Return: message digest size of cipher
367 */
368static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
369{
370 return crypto_hash_alg_common(tfm)->digestsize;
371}
372
373/**
374 * crypto_ahash_statesize() - obtain size of the ahash state
375 * @tfm: cipher handle
376 *
377 * Return the size of the ahash state. With the crypto_ahash_export()
378 * function, the caller can export the state into a buffer whose size is
379 * defined with this function.
380 *
381 * Return: size of the ahash state
382 */
383static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
384{
385 return tfm->statesize;
386}
387
388static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
389{
390 return crypto_tfm_get_flags(tfm: crypto_ahash_tfm(tfm));
391}
392
393static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
394{
395 crypto_tfm_set_flags(tfm: crypto_ahash_tfm(tfm), flags);
396}
397
398static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
399{
400 crypto_tfm_clear_flags(tfm: crypto_ahash_tfm(tfm), flags);
401}
402
403/**
404 * crypto_ahash_reqtfm() - obtain cipher handle from request
405 * @req: asynchronous request handle that contains the reference to the ahash
406 * cipher handle
407 *
408 * Return the ahash cipher handle that is registered with the asynchronous
409 * request handle ahash_request.
410 *
411 * Return: ahash cipher handle
412 */
413static inline struct crypto_ahash *crypto_ahash_reqtfm(
414 struct ahash_request *req)
415{
416 return __crypto_ahash_cast(tfm: req->base.tfm);
417}
418
419/**
420 * crypto_ahash_reqsize() - obtain size of the request data structure
421 * @tfm: cipher handle
422 *
423 * Return: size of the request data
424 */
425static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
426{
427 return tfm->reqsize;
428}
429
430static inline void *ahash_request_ctx(struct ahash_request *req)
431{
432 return req->__ctx;
433}
434
435/**
436 * crypto_ahash_setkey - set key for cipher handle
437 * @tfm: cipher handle
438 * @key: buffer holding the key
439 * @keylen: length of the key in bytes
440 *
441 * The caller provided key is set for the ahash cipher. The cipher
442 * handle must point to a keyed hash in order for this function to succeed.
443 *
444 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
445 */
446int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
447 unsigned int keylen);
448
449/**
450 * crypto_ahash_finup() - update and finalize message digest
451 * @req: reference to the ahash_request handle that holds all information
452 * needed to perform the cipher operation
453 *
454 * This function is a "short-hand" for the function calls of
455 * crypto_ahash_update and crypto_ahash_final. The parameters have the same
456 * meaning as discussed for those separate functions.
457 *
458 * Return: see crypto_ahash_final()
459 */
460int crypto_ahash_finup(struct ahash_request *req);
461
462/**
463 * crypto_ahash_final() - calculate message digest
464 * @req: reference to the ahash_request handle that holds all information
465 * needed to perform the cipher operation
466 *
467 * Finalize the message digest operation and create the message digest
468 * based on all data added to the cipher handle. The message digest is placed
469 * into the output buffer registered with the ahash_request handle.
470 *
471 * Return:
472 * 0 if the message digest was successfully calculated;
473 * -EINPROGRESS if data is fed into hardware (DMA) or queued for later;
474 * -EBUSY if queue is full and request should be resubmitted later;
475 * other < 0 if an error occurred
476 */
477int crypto_ahash_final(struct ahash_request *req);
478
479/**
480 * crypto_ahash_digest() - calculate message digest for a buffer
481 * @req: reference to the ahash_request handle that holds all information
482 * needed to perform the cipher operation
483 *
484 * This function is a "short-hand" for the function calls of crypto_ahash_init,
485 * crypto_ahash_update and crypto_ahash_final. The parameters have the same
486 * meaning as discussed for those separate three functions.
487 *
488 * Return: see crypto_ahash_final()
489 */
490int crypto_ahash_digest(struct ahash_request *req);
491
492/**
493 * crypto_ahash_export() - extract current message digest state
494 * @req: reference to the ahash_request handle whose state is exported
495 * @out: output buffer of sufficient size that can hold the hash state
496 *
497 * This function exports the hash state of the ahash_request handle into the
498 * caller-allocated output buffer out which must have sufficient size (e.g. by
499 * calling crypto_ahash_statesize()).
500 *
501 * Return: 0 if the export was successful; < 0 if an error occurred
502 */
503int crypto_ahash_export(struct ahash_request *req, void *out);
504
505/**
506 * crypto_ahash_import() - import message digest state
507 * @req: reference to ahash_request handle the state is imported into
508 * @in: buffer holding the state
509 *
510 * This function imports the hash state into the ahash_request handle from the
511 * input buffer. That buffer should have been generated with the
512 * crypto_ahash_export function.
513 *
514 * Return: 0 if the import was successful; < 0 if an error occurred
515 */
516int crypto_ahash_import(struct ahash_request *req, const void *in);
517
518/**
519 * crypto_ahash_init() - (re)initialize message digest handle
520 * @req: ahash_request handle that already is initialized with all necessary
521 * data using the ahash_request_* API functions
522 *
523 * The call (re-)initializes the message digest referenced by the ahash_request
524 * handle. Any potentially existing state created by previous operations is
525 * discarded.
526 *
527 * Return: see crypto_ahash_final()
528 */
529int crypto_ahash_init(struct ahash_request *req);
530
531/**
532 * crypto_ahash_update() - add data to message digest for processing
533 * @req: ahash_request handle that was previously initialized with the
534 * crypto_ahash_init call.
535 *
536 * Updates the message digest state of the &ahash_request handle. The input data
537 * is pointed to by the scatter/gather list registered in the &ahash_request
538 * handle
539 *
540 * Return: see crypto_ahash_final()
541 */
542int crypto_ahash_update(struct ahash_request *req);
543
544/**
545 * DOC: Asynchronous Hash Request Handle
546 *
547 * The &ahash_request data structure contains all pointers to data
548 * required for the asynchronous cipher operation. This includes the cipher
549 * handle (which can be used by multiple &ahash_request instances), pointer
550 * to plaintext and the message digest output buffer, asynchronous callback
551 * function, etc. It acts as a handle to the ahash_request_* API calls in a
552 * similar way as ahash handle to the crypto_ahash_* API calls.
553 */
554
555/**
556 * ahash_request_set_tfm() - update cipher handle reference in request
557 * @req: request handle to be modified
558 * @tfm: cipher handle that shall be added to the request handle
559 *
560 * Allow the caller to replace the existing ahash handle in the request
561 * data structure with a different one.
562 */
563static inline void ahash_request_set_tfm(struct ahash_request *req,
564 struct crypto_ahash *tfm)
565{
566 req->base.tfm = crypto_ahash_tfm(tfm);
567}
568
569/**
570 * ahash_request_alloc() - allocate request data structure
571 * @tfm: cipher handle to be registered with the request
572 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
573 *
574 * Allocate the request data structure that must be used with the ahash
575 * message digest API calls. During
576 * the allocation, the provided ahash handle
577 * is registered in the request data structure.
578 *
579 * Return: allocated request handle in case of success, or NULL if out of memory
580 */
581static inline struct ahash_request *ahash_request_alloc(
582 struct crypto_ahash *tfm, gfp_t gfp)
583{
584 struct ahash_request *req;
585
586 req = kmalloc(size: sizeof(struct ahash_request) +
587 crypto_ahash_reqsize(tfm), flags: gfp);
588
589 if (likely(req))
590 ahash_request_set_tfm(req, tfm);
591
592 return req;
593}
594
595/**
596 * ahash_request_free() - zeroize and free the request data structure
597 * @req: request data structure cipher handle to be freed
598 */
599static inline void ahash_request_free(struct ahash_request *req)
600{
601 kfree_sensitive(objp: req);
602}
603
604static inline void ahash_request_zero(struct ahash_request *req)
605{
606 memzero_explicit(s: req, count: sizeof(*req) +
607 crypto_ahash_reqsize(tfm: crypto_ahash_reqtfm(req)));
608}
609
610static inline struct ahash_request *ahash_request_cast(
611 struct crypto_async_request *req)
612{
613 return container_of(req, struct ahash_request, base);
614}
615
616/**
617 * ahash_request_set_callback() - set asynchronous callback function
618 * @req: request handle
619 * @flags: specify zero or an ORing of the flags
620 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
621 * increase the wait queue beyond the initial maximum size;
622 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
623 * @compl: callback function pointer to be registered with the request handle
624 * @data: The data pointer refers to memory that is not used by the kernel
625 * crypto API, but provided to the callback function for it to use. Here,
626 * the caller can provide a reference to memory the callback function can
627 * operate on. As the callback function is invoked asynchronously to the
628 * related functionality, it may need to access data structures of the
629 * related functionality which can be referenced using this pointer. The
630 * callback function can access the memory via the "data" field in the
631 * &crypto_async_request data structure provided to the callback function.
632 *
633 * This function allows setting the callback function that is triggered once
634 * the cipher operation completes.
635 *
636 * The callback function is registered with the &ahash_request handle and
637 * must comply with the following template::
638 *
639 * void callback_function(struct crypto_async_request *req, int error)
640 */
641static inline void ahash_request_set_callback(struct ahash_request *req,
642 u32 flags,
643 crypto_completion_t compl,
644 void *data)
645{
646 req->base.complete = compl;
647 req->base.data = data;
648 req->base.flags = flags;
649}
650
651/**
652 * ahash_request_set_crypt() - set data buffers
653 * @req: ahash_request handle to be updated
654 * @src: source scatter/gather list
655 * @result: buffer that is filled with the message digest -- the caller must
656 * ensure that the buffer has sufficient space by, for example, calling
657 * crypto_ahash_digestsize()
658 * @nbytes: number of bytes to process from the source scatter/gather list
659 *
660 * By using this call, the caller references the source scatter/gather list.
661 * The source scatter/gather list points to the data the message digest is to
662 * be calculated for.
663 */
664static inline void ahash_request_set_crypt(struct ahash_request *req,
665 struct scatterlist *src, u8 *result,
666 unsigned int nbytes)
667{
668 req->src = src;
669 req->nbytes = nbytes;
670 req->result = result;
671}
672
673/**
674 * DOC: Synchronous Message Digest API
675 *
676 * The synchronous message digest API is used with the ciphers of type
677 * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
678 *
679 * The message digest API is able to maintain state information for the
680 * caller.
681 *
682 * The synchronous message digest API can store user-related context in its
683 * shash_desc request data structure.
684 */
685
686/**
687 * crypto_alloc_shash() - allocate message digest handle
688 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
689 * message digest cipher
690 * @type: specifies the type of the cipher
691 * @mask: specifies the mask for the cipher
692 *
693 * Allocate a cipher handle for a message digest. The returned &struct
694 * crypto_shash is the cipher handle that is required for any subsequent
695 * API invocation for that message digest.
696 *
697 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
698 * of an error, PTR_ERR() returns the error code.
699 */
700struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
701 u32 mask);
702
703struct crypto_shash *crypto_clone_shash(struct crypto_shash *tfm);
704
705int crypto_has_shash(const char *alg_name, u32 type, u32 mask);
706
707static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
708{
709 return &tfm->base;
710}
711
712/**
713 * crypto_free_shash() - zeroize and free the message digest handle
714 * @tfm: cipher handle to be freed
715 *
716 * If @tfm is a NULL or error pointer, this function does nothing.
717 */
718static inline void crypto_free_shash(struct crypto_shash *tfm)
719{
720 crypto_destroy_tfm(mem: tfm, tfm: crypto_shash_tfm(tfm));
721}
722
723static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
724{
725 return crypto_tfm_alg_name(tfm: crypto_shash_tfm(tfm));
726}
727
728static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
729{
730 return crypto_tfm_alg_driver_name(tfm: crypto_shash_tfm(tfm));
731}
732
733/**
734 * crypto_shash_blocksize() - obtain block size for cipher
735 * @tfm: cipher handle
736 *
737 * The block size for the message digest cipher referenced with the cipher
738 * handle is returned.
739 *
740 * Return: block size of cipher
741 */
742static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
743{
744 return crypto_tfm_alg_blocksize(tfm: crypto_shash_tfm(tfm));
745}
746
747static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
748{
749 return container_of(alg, struct shash_alg, base);
750}
751
752static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
753{
754 return __crypto_shash_alg(alg: crypto_shash_tfm(tfm)->__crt_alg);
755}
756
757/**
758 * crypto_shash_digestsize() - obtain message digest size
759 * @tfm: cipher handle
760 *
761 * The size for the message digest created by the message digest cipher
762 * referenced with the cipher handle is returned.
763 *
764 * Return: digest size of cipher
765 */
766static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
767{
768 return crypto_shash_alg(tfm)->digestsize;
769}
770
771static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
772{
773 return crypto_shash_alg(tfm)->statesize;
774}
775
776static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
777{
778 return crypto_tfm_get_flags(tfm: crypto_shash_tfm(tfm));
779}
780
781static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
782{
783 crypto_tfm_set_flags(tfm: crypto_shash_tfm(tfm), flags);
784}
785
786static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
787{
788 crypto_tfm_clear_flags(tfm: crypto_shash_tfm(tfm), flags);
789}
790
791/**
792 * crypto_shash_descsize() - obtain the operational state size
793 * @tfm: cipher handle
794 *
795 * The size of the operational state the cipher needs during operation is
796 * returned for the hash referenced with the cipher handle. This size is
797 * required to calculate the memory requirements to allow the caller allocating
798 * sufficient memory for operational state.
799 *
800 * The operational state is defined with struct shash_desc where the size of
801 * that data structure is to be calculated as
802 * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
803 *
804 * Return: size of the operational state
805 */
806static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
807{
808 return tfm->descsize;
809}
810
811static inline void *shash_desc_ctx(struct shash_desc *desc)
812{
813 return desc->__ctx;
814}
815
816/**
817 * crypto_shash_setkey() - set key for message digest
818 * @tfm: cipher handle
819 * @key: buffer holding the key
820 * @keylen: length of the key in bytes
821 *
822 * The caller provided key is set for the keyed message digest cipher. The
823 * cipher handle must point to a keyed message digest cipher in order for this
824 * function to succeed.
825 *
826 * Context: Any context.
827 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
828 */
829int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
830 unsigned int keylen);
831
832/**
833 * crypto_shash_digest() - calculate message digest for buffer
834 * @desc: see crypto_shash_final()
835 * @data: see crypto_shash_update()
836 * @len: see crypto_shash_update()
837 * @out: see crypto_shash_final()
838 *
839 * This function is a "short-hand" for the function calls of crypto_shash_init,
840 * crypto_shash_update and crypto_shash_final. The parameters have the same
841 * meaning as discussed for those separate three functions.
842 *
843 * Context: Any context.
844 * Return: 0 if the message digest creation was successful; < 0 if an error
845 * occurred
846 */
847int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
848 unsigned int len, u8 *out);
849
850/**
851 * crypto_shash_tfm_digest() - calculate message digest for buffer
852 * @tfm: hash transformation object
853 * @data: see crypto_shash_update()
854 * @len: see crypto_shash_update()
855 * @out: see crypto_shash_final()
856 *
857 * This is a simplified version of crypto_shash_digest() for users who don't
858 * want to allocate their own hash descriptor (shash_desc). Instead,
859 * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
860 * directly, and it allocates a hash descriptor on the stack internally.
861 * Note that this stack allocation may be fairly large.
862 *
863 * Context: Any context.
864 * Return: 0 on success; < 0 if an error occurred.
865 */
866int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
867 unsigned int len, u8 *out);
868
869/**
870 * crypto_shash_export() - extract operational state for message digest
871 * @desc: reference to the operational state handle whose state is exported
872 * @out: output buffer of sufficient size that can hold the hash state
873 *
874 * This function exports the hash state of the operational state handle into the
875 * caller-allocated output buffer out which must have sufficient size (e.g. by
876 * calling crypto_shash_descsize).
877 *
878 * Context: Any context.
879 * Return: 0 if the export creation was successful; < 0 if an error occurred
880 */
881int crypto_shash_export(struct shash_desc *desc, void *out);
882
883/**
884 * crypto_shash_import() - import operational state
885 * @desc: reference to the operational state handle the state imported into
886 * @in: buffer holding the state
887 *
888 * This function imports the hash state into the operational state handle from
889 * the input buffer. That buffer should have been generated with the
890 * crypto_ahash_export function.
891 *
892 * Context: Any context.
893 * Return: 0 if the import was successful; < 0 if an error occurred
894 */
895int crypto_shash_import(struct shash_desc *desc, const void *in);
896
897/**
898 * crypto_shash_init() - (re)initialize message digest
899 * @desc: operational state handle that is already filled
900 *
901 * The call (re-)initializes the message digest referenced by the
902 * operational state handle. Any potentially existing state created by
903 * previous operations is discarded.
904 *
905 * Context: Any context.
906 * Return: 0 if the message digest initialization was successful; < 0 if an
907 * error occurred
908 */
909static inline int crypto_shash_init(struct shash_desc *desc)
910{
911 struct crypto_shash *tfm = desc->tfm;
912
913 if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
914 return -ENOKEY;
915
916 return crypto_shash_alg(tfm)->init(desc);
917}
918
919/**
920 * crypto_shash_update() - add data to message digest for processing
921 * @desc: operational state handle that is already initialized
922 * @data: input data to be added to the message digest
923 * @len: length of the input data
924 *
925 * Updates the message digest state of the operational state handle.
926 *
927 * Context: Any context.
928 * Return: 0 if the message digest update was successful; < 0 if an error
929 * occurred
930 */
931int crypto_shash_update(struct shash_desc *desc, const u8 *data,
932 unsigned int len);
933
934/**
935 * crypto_shash_final() - calculate message digest
936 * @desc: operational state handle that is already filled with data
937 * @out: output buffer filled with the message digest
938 *
939 * Finalize the message digest operation and create the message digest
940 * based on all data added to the cipher handle. The message digest is placed
941 * into the output buffer. The caller must ensure that the output buffer is
942 * large enough by using crypto_shash_digestsize.
943 *
944 * Context: Any context.
945 * Return: 0 if the message digest creation was successful; < 0 if an error
946 * occurred
947 */
948int crypto_shash_final(struct shash_desc *desc, u8 *out);
949
950/**
951 * crypto_shash_finup() - calculate message digest of buffer
952 * @desc: see crypto_shash_final()
953 * @data: see crypto_shash_update()
954 * @len: see crypto_shash_update()
955 * @out: see crypto_shash_final()
956 *
957 * This function is a "short-hand" for the function calls of
958 * crypto_shash_update and crypto_shash_final. The parameters have the same
959 * meaning as discussed for those separate functions.
960 *
961 * Context: Any context.
962 * Return: 0 if the message digest creation was successful; < 0 if an error
963 * occurred
964 */
965int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
966 unsigned int len, u8 *out);
967
968static inline void shash_desc_zero(struct shash_desc *desc)
969{
970 memzero_explicit(s: desc,
971 count: sizeof(*desc) + crypto_shash_descsize(tfm: desc->tfm));
972}
973
974#endif /* _CRYPTO_HASH_H */
975

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