1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 * Hash: Hash algorithms under the crypto API
5 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
11 #include <linux/atomic.h>
12 #include <linux/crypto.h>
13 #include <linux/string.h>
18 * DOC: Message Digest Algorithm Definitions
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().
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
32 struct crypto_istat_hash {
38 #ifdef CONFIG_CRYPTO_STATS
39 #define HASH_ALG_COMMON_STAT struct crypto_istat_hash stat;
41 #define HASH_ALG_COMMON_STAT
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
62 #define HASH_ALG_COMMON { \
63 HASH_ALG_COMMON_STAT \
65 unsigned int digestsize; \
66 unsigned int statesize; \
68 struct crypto_alg base; \
70 struct hash_alg_common HASH_ALG_COMMON;
72 struct ahash_request {
73 struct crypto_async_request base;
76 struct scatterlist *src;
79 /* This field may only be used by the ahash API code. */
82 void *__ctx[] CRYPTO_MINALIGN_ATTR;
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
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]
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
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
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);
172 struct hash_alg_common halg;
176 struct crypto_shash *tfm;
177 void *__ctx[] __aligned(ARCH_SLAB_MINALIGN);
180 #define HASH_MAX_DIGESTSIZE 64
183 * Worst case is hmac(sha3-224-generic). Its context is a nested 'shash_desc'
184 * containing a 'struct sha3_state'.
186 #define HASH_MAX_DESCSIZE (sizeof(struct shash_desc) + 360)
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
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
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
226 int (*init)(struct shash_desc *desc);
227 int (*update)(struct shash_desc *desc, const u8 *data,
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);
242 unsigned int descsize;
245 struct HASH_ALG_COMMON;
246 struct hash_alg_common halg;
249 #undef HASH_ALG_COMMON
250 #undef HASH_ALG_COMMON_STAT
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);
263 unsigned int statesize;
264 unsigned int reqsize;
265 struct crypto_tfm base;
268 struct crypto_shash {
269 unsigned int descsize;
270 struct crypto_tfm base;
274 * DOC: Asynchronous Message Digest API
276 * The asynchronous message digest API is used with the ciphers of type
277 * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
279 * The asynchronous cipher operation discussion provided for the
280 * CRYPTO_ALG_TYPE_SKCIPHER API applies here as well.
283 static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
285 return container_of(tfm, struct crypto_ahash, base);
289 * crypto_alloc_ahash() - allocate ahash cipher handle
290 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
292 * @type: specifies the type of the cipher
293 * @mask: specifies the mask for the cipher
295 * Allocate a cipher handle for an ahash. The returned struct
296 * crypto_ahash is the cipher handle that is required for any subsequent
297 * API invocation for that ahash.
299 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
300 * of an error, PTR_ERR() returns the error code.
302 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
305 struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *tfm);
307 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
313 * crypto_free_ahash() - zeroize and free the ahash handle
314 * @tfm: cipher handle to be freed
316 * If @tfm is a NULL or error pointer, this function does nothing.
318 static inline void crypto_free_ahash(struct crypto_ahash *tfm)
320 crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm));
324 * crypto_has_ahash() - Search for the availability of an ahash.
325 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
327 * @type: specifies the type of the ahash
328 * @mask: specifies the mask for the ahash
330 * Return: true when the ahash is known to the kernel crypto API; false
333 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
335 static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
337 return crypto_tfm_alg_name(crypto_ahash_tfm(tfm));
340 static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
342 return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm));
345 static inline unsigned int crypto_ahash_alignmask(
346 struct crypto_ahash *tfm)
348 return crypto_tfm_alg_alignmask(crypto_ahash_tfm(tfm));
352 * crypto_ahash_blocksize() - obtain block size for cipher
353 * @tfm: cipher handle
355 * The block size for the message digest cipher referenced with the cipher
356 * handle is returned.
358 * Return: block size of cipher
360 static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
362 return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
365 static inline struct hash_alg_common *__crypto_hash_alg_common(
366 struct crypto_alg *alg)
368 return container_of(alg, struct hash_alg_common, base);
371 static inline struct hash_alg_common *crypto_hash_alg_common(
372 struct crypto_ahash *tfm)
374 return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg);
378 * crypto_ahash_digestsize() - obtain message digest size
379 * @tfm: cipher handle
381 * The size for the message digest created by the message digest cipher
382 * referenced with the cipher handle is returned.
385 * Return: message digest size of cipher
387 static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
389 return crypto_hash_alg_common(tfm)->digestsize;
393 * crypto_ahash_statesize() - obtain size of the ahash state
394 * @tfm: cipher handle
396 * Return the size of the ahash state. With the crypto_ahash_export()
397 * function, the caller can export the state into a buffer whose size is
398 * defined with this function.
400 * Return: size of the ahash state
402 static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
404 return tfm->statesize;
407 static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
409 return crypto_tfm_get_flags(crypto_ahash_tfm(tfm));
412 static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
414 crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags);
417 static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
419 crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags);
423 * crypto_ahash_reqtfm() - obtain cipher handle from request
424 * @req: asynchronous request handle that contains the reference to the ahash
427 * Return the ahash cipher handle that is registered with the asynchronous
428 * request handle ahash_request.
430 * Return: ahash cipher handle
432 static inline struct crypto_ahash *crypto_ahash_reqtfm(
433 struct ahash_request *req)
435 return __crypto_ahash_cast(req->base.tfm);
439 * crypto_ahash_reqsize() - obtain size of the request data structure
440 * @tfm: cipher handle
442 * Return: size of the request data
444 static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
449 static inline void *ahash_request_ctx(struct ahash_request *req)
455 * crypto_ahash_setkey - set key for cipher handle
456 * @tfm: cipher handle
457 * @key: buffer holding the key
458 * @keylen: length of the key in bytes
460 * The caller provided key is set for the ahash cipher. The cipher
461 * handle must point to a keyed hash in order for this function to succeed.
463 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
465 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
466 unsigned int keylen);
469 * crypto_ahash_finup() - update and finalize message digest
470 * @req: reference to the ahash_request handle that holds all information
471 * needed to perform the cipher operation
473 * This function is a "short-hand" for the function calls of
474 * crypto_ahash_update and crypto_ahash_final. The parameters have the same
475 * meaning as discussed for those separate functions.
477 * Return: see crypto_ahash_final()
479 int crypto_ahash_finup(struct ahash_request *req);
482 * crypto_ahash_final() - calculate message digest
483 * @req: reference to the ahash_request handle that holds all information
484 * needed to perform the cipher operation
486 * Finalize the message digest operation and create the message digest
487 * based on all data added to the cipher handle. The message digest is placed
488 * into the output buffer registered with the ahash_request handle.
491 * 0 if the message digest was successfully calculated;
492 * -EINPROGRESS if data is fed into hardware (DMA) or queued for later;
493 * -EBUSY if queue is full and request should be resubmitted later;
494 * other < 0 if an error occurred
496 int crypto_ahash_final(struct ahash_request *req);
499 * crypto_ahash_digest() - calculate message digest for a buffer
500 * @req: reference to the ahash_request handle that holds all information
501 * needed to perform the cipher operation
503 * This function is a "short-hand" for the function calls of crypto_ahash_init,
504 * crypto_ahash_update and crypto_ahash_final. The parameters have the same
505 * meaning as discussed for those separate three functions.
507 * Return: see crypto_ahash_final()
509 int crypto_ahash_digest(struct ahash_request *req);
512 * crypto_ahash_export() - extract current message digest state
513 * @req: reference to the ahash_request handle whose state is exported
514 * @out: output buffer of sufficient size that can hold the hash state
516 * This function exports the hash state of the ahash_request handle into the
517 * caller-allocated output buffer out which must have sufficient size (e.g. by
518 * calling crypto_ahash_statesize()).
520 * Return: 0 if the export was successful; < 0 if an error occurred
522 static inline int crypto_ahash_export(struct ahash_request *req, void *out)
524 return crypto_ahash_reqtfm(req)->export(req, out);
528 * crypto_ahash_import() - import message digest state
529 * @req: reference to ahash_request handle the state is imported into
530 * @in: buffer holding the state
532 * This function imports the hash state into the ahash_request handle from the
533 * input buffer. That buffer should have been generated with the
534 * crypto_ahash_export function.
536 * Return: 0 if the import was successful; < 0 if an error occurred
538 static inline int crypto_ahash_import(struct ahash_request *req, const void *in)
540 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
542 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
545 return tfm->import(req, in);
549 * crypto_ahash_init() - (re)initialize message digest handle
550 * @req: ahash_request handle that already is initialized with all necessary
551 * data using the ahash_request_* API functions
553 * The call (re-)initializes the message digest referenced by the ahash_request
554 * handle. Any potentially existing state created by previous operations is
557 * Return: see crypto_ahash_final()
559 static inline int crypto_ahash_init(struct ahash_request *req)
561 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
563 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
566 return tfm->init(req);
569 static inline struct crypto_istat_hash *hash_get_stat(
570 struct hash_alg_common *alg)
572 #ifdef CONFIG_CRYPTO_STATS
579 static inline int crypto_hash_errstat(struct hash_alg_common *alg, int err)
581 if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
584 if (err && err != -EINPROGRESS && err != -EBUSY)
585 atomic64_inc(&hash_get_stat(alg)->err_cnt);
591 * crypto_ahash_update() - add data to message digest for processing
592 * @req: ahash_request handle that was previously initialized with the
593 * crypto_ahash_init call.
595 * Updates the message digest state of the &ahash_request handle. The input data
596 * is pointed to by the scatter/gather list registered in the &ahash_request
599 * Return: see crypto_ahash_final()
601 static inline int crypto_ahash_update(struct ahash_request *req)
603 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
604 struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
606 if (IS_ENABLED(CONFIG_CRYPTO_STATS))
607 atomic64_add(req->nbytes, &hash_get_stat(alg)->hash_tlen);
609 return crypto_hash_errstat(alg, tfm->update(req));
613 * DOC: Asynchronous Hash Request Handle
615 * The &ahash_request data structure contains all pointers to data
616 * required for the asynchronous cipher operation. This includes the cipher
617 * handle (which can be used by multiple &ahash_request instances), pointer
618 * to plaintext and the message digest output buffer, asynchronous callback
619 * function, etc. It acts as a handle to the ahash_request_* API calls in a
620 * similar way as ahash handle to the crypto_ahash_* API calls.
624 * ahash_request_set_tfm() - update cipher handle reference in request
625 * @req: request handle to be modified
626 * @tfm: cipher handle that shall be added to the request handle
628 * Allow the caller to replace the existing ahash handle in the request
629 * data structure with a different one.
631 static inline void ahash_request_set_tfm(struct ahash_request *req,
632 struct crypto_ahash *tfm)
634 req->base.tfm = crypto_ahash_tfm(tfm);
638 * ahash_request_alloc() - allocate request data structure
639 * @tfm: cipher handle to be registered with the request
640 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
642 * Allocate the request data structure that must be used with the ahash
643 * message digest API calls. During
644 * the allocation, the provided ahash handle
645 * is registered in the request data structure.
647 * Return: allocated request handle in case of success, or NULL if out of memory
649 static inline struct ahash_request *ahash_request_alloc(
650 struct crypto_ahash *tfm, gfp_t gfp)
652 struct ahash_request *req;
654 req = kmalloc(sizeof(struct ahash_request) +
655 crypto_ahash_reqsize(tfm), gfp);
658 ahash_request_set_tfm(req, tfm);
664 * ahash_request_free() - zeroize and free the request data structure
665 * @req: request data structure cipher handle to be freed
667 static inline void ahash_request_free(struct ahash_request *req)
669 kfree_sensitive(req);
672 static inline void ahash_request_zero(struct ahash_request *req)
674 memzero_explicit(req, sizeof(*req) +
675 crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));
678 static inline struct ahash_request *ahash_request_cast(
679 struct crypto_async_request *req)
681 return container_of(req, struct ahash_request, base);
685 * ahash_request_set_callback() - set asynchronous callback function
686 * @req: request handle
687 * @flags: specify zero or an ORing of the flags
688 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
689 * increase the wait queue beyond the initial maximum size;
690 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
691 * @compl: callback function pointer to be registered with the request handle
692 * @data: The data pointer refers to memory that is not used by the kernel
693 * crypto API, but provided to the callback function for it to use. Here,
694 * the caller can provide a reference to memory the callback function can
695 * operate on. As the callback function is invoked asynchronously to the
696 * related functionality, it may need to access data structures of the
697 * related functionality which can be referenced using this pointer. The
698 * callback function can access the memory via the "data" field in the
699 * &crypto_async_request data structure provided to the callback function.
701 * This function allows setting the callback function that is triggered once
702 * the cipher operation completes.
704 * The callback function is registered with the &ahash_request handle and
705 * must comply with the following template::
707 * void callback_function(struct crypto_async_request *req, int error)
709 static inline void ahash_request_set_callback(struct ahash_request *req,
711 crypto_completion_t compl,
714 req->base.complete = compl;
715 req->base.data = data;
716 req->base.flags = flags;
720 * ahash_request_set_crypt() - set data buffers
721 * @req: ahash_request handle to be updated
722 * @src: source scatter/gather list
723 * @result: buffer that is filled with the message digest -- the caller must
724 * ensure that the buffer has sufficient space by, for example, calling
725 * crypto_ahash_digestsize()
726 * @nbytes: number of bytes to process from the source scatter/gather list
728 * By using this call, the caller references the source scatter/gather list.
729 * The source scatter/gather list points to the data the message digest is to
732 static inline void ahash_request_set_crypt(struct ahash_request *req,
733 struct scatterlist *src, u8 *result,
737 req->nbytes = nbytes;
738 req->result = result;
742 * DOC: Synchronous Message Digest API
744 * The synchronous message digest API is used with the ciphers of type
745 * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
747 * The message digest API is able to maintain state information for the
750 * The synchronous message digest API can store user-related context in its
751 * shash_desc request data structure.
755 * crypto_alloc_shash() - allocate message digest handle
756 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
757 * message digest cipher
758 * @type: specifies the type of the cipher
759 * @mask: specifies the mask for the cipher
761 * Allocate a cipher handle for a message digest. The returned &struct
762 * crypto_shash is the cipher handle that is required for any subsequent
763 * API invocation for that message digest.
765 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
766 * of an error, PTR_ERR() returns the error code.
768 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
771 struct crypto_shash *crypto_clone_shash(struct crypto_shash *tfm);
773 int crypto_has_shash(const char *alg_name, u32 type, u32 mask);
775 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
781 * crypto_free_shash() - zeroize and free the message digest handle
782 * @tfm: cipher handle to be freed
784 * If @tfm is a NULL or error pointer, this function does nothing.
786 static inline void crypto_free_shash(struct crypto_shash *tfm)
788 crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
791 static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
793 return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
796 static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
798 return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
801 static inline unsigned int crypto_shash_alignmask(
802 struct crypto_shash *tfm)
804 return crypto_tfm_alg_alignmask(crypto_shash_tfm(tfm));
808 * crypto_shash_blocksize() - obtain block size for cipher
809 * @tfm: cipher handle
811 * The block size for the message digest cipher referenced with the cipher
812 * handle is returned.
814 * Return: block size of cipher
816 static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
818 return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm));
821 static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
823 return container_of(alg, struct shash_alg, base);
826 static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
828 return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg);
832 * crypto_shash_digestsize() - obtain message digest size
833 * @tfm: cipher handle
835 * The size for the message digest created by the message digest cipher
836 * referenced with the cipher handle is returned.
838 * Return: digest size of cipher
840 static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
842 return crypto_shash_alg(tfm)->digestsize;
845 static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
847 return crypto_shash_alg(tfm)->statesize;
850 static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
852 return crypto_tfm_get_flags(crypto_shash_tfm(tfm));
855 static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
857 crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags);
860 static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
862 crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags);
866 * crypto_shash_descsize() - obtain the operational state size
867 * @tfm: cipher handle
869 * The size of the operational state the cipher needs during operation is
870 * returned for the hash referenced with the cipher handle. This size is
871 * required to calculate the memory requirements to allow the caller allocating
872 * sufficient memory for operational state.
874 * The operational state is defined with struct shash_desc where the size of
875 * that data structure is to be calculated as
876 * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
878 * Return: size of the operational state
880 static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
882 return tfm->descsize;
885 static inline void *shash_desc_ctx(struct shash_desc *desc)
891 * crypto_shash_setkey() - set key for message digest
892 * @tfm: cipher handle
893 * @key: buffer holding the key
894 * @keylen: length of the key in bytes
896 * The caller provided key is set for the keyed message digest cipher. The
897 * cipher handle must point to a keyed message digest cipher in order for this
898 * function to succeed.
900 * Context: Any context.
901 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
903 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
904 unsigned int keylen);
907 * crypto_shash_digest() - calculate message digest for buffer
908 * @desc: see crypto_shash_final()
909 * @data: see crypto_shash_update()
910 * @len: see crypto_shash_update()
911 * @out: see crypto_shash_final()
913 * This function is a "short-hand" for the function calls of crypto_shash_init,
914 * crypto_shash_update and crypto_shash_final. The parameters have the same
915 * meaning as discussed for those separate three functions.
917 * Context: Any context.
918 * Return: 0 if the message digest creation was successful; < 0 if an error
921 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
922 unsigned int len, u8 *out);
925 * crypto_shash_tfm_digest() - calculate message digest for buffer
926 * @tfm: hash transformation object
927 * @data: see crypto_shash_update()
928 * @len: see crypto_shash_update()
929 * @out: see crypto_shash_final()
931 * This is a simplified version of crypto_shash_digest() for users who don't
932 * want to allocate their own hash descriptor (shash_desc). Instead,
933 * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
934 * directly, and it allocates a hash descriptor on the stack internally.
935 * Note that this stack allocation may be fairly large.
937 * Context: Any context.
938 * Return: 0 on success; < 0 if an error occurred.
940 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
941 unsigned int len, u8 *out);
944 * crypto_shash_export() - extract operational state for message digest
945 * @desc: reference to the operational state handle whose state is exported
946 * @out: output buffer of sufficient size that can hold the hash state
948 * This function exports the hash state of the operational state handle into the
949 * caller-allocated output buffer out which must have sufficient size (e.g. by
950 * calling crypto_shash_descsize).
952 * Context: Any context.
953 * Return: 0 if the export creation was successful; < 0 if an error occurred
955 static inline int crypto_shash_export(struct shash_desc *desc, void *out)
957 return crypto_shash_alg(desc->tfm)->export(desc, out);
961 * crypto_shash_import() - import operational state
962 * @desc: reference to the operational state handle the state imported into
963 * @in: buffer holding the state
965 * This function imports the hash state into the operational state handle from
966 * the input buffer. That buffer should have been generated with the
967 * crypto_ahash_export function.
969 * Context: Any context.
970 * Return: 0 if the import was successful; < 0 if an error occurred
972 static inline int crypto_shash_import(struct shash_desc *desc, const void *in)
974 struct crypto_shash *tfm = desc->tfm;
976 if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
979 return crypto_shash_alg(tfm)->import(desc, in);
983 * crypto_shash_init() - (re)initialize message digest
984 * @desc: operational state handle that is already filled
986 * The call (re-)initializes the message digest referenced by the
987 * operational state handle. Any potentially existing state created by
988 * previous operations is discarded.
990 * Context: Any context.
991 * Return: 0 if the message digest initialization was successful; < 0 if an
994 static inline int crypto_shash_init(struct shash_desc *desc)
996 struct crypto_shash *tfm = desc->tfm;
998 if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
1001 return crypto_shash_alg(tfm)->init(desc);
1005 * crypto_shash_update() - add data to message digest for processing
1006 * @desc: operational state handle that is already initialized
1007 * @data: input data to be added to the message digest
1008 * @len: length of the input data
1010 * Updates the message digest state of the operational state handle.
1012 * Context: Any context.
1013 * Return: 0 if the message digest update was successful; < 0 if an error
1016 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
1020 * crypto_shash_final() - calculate message digest
1021 * @desc: operational state handle that is already filled with data
1022 * @out: output buffer filled with the message digest
1024 * Finalize the message digest operation and create the message digest
1025 * based on all data added to the cipher handle. The message digest is placed
1026 * into the output buffer. The caller must ensure that the output buffer is
1027 * large enough by using crypto_shash_digestsize.
1029 * Context: Any context.
1030 * Return: 0 if the message digest creation was successful; < 0 if an error
1033 int crypto_shash_final(struct shash_desc *desc, u8 *out);
1036 * crypto_shash_finup() - calculate message digest of buffer
1037 * @desc: see crypto_shash_final()
1038 * @data: see crypto_shash_update()
1039 * @len: see crypto_shash_update()
1040 * @out: see crypto_shash_final()
1042 * This function is a "short-hand" for the function calls of
1043 * crypto_shash_update and crypto_shash_final. The parameters have the same
1044 * meaning as discussed for those separate functions.
1046 * Context: Any context.
1047 * Return: 0 if the message digest creation was successful; < 0 if an error
1050 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
1051 unsigned int len, u8 *out);
1053 static inline void shash_desc_zero(struct shash_desc *desc)
1055 memzero_explicit(desc,
1056 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
1059 #endif /* _CRYPTO_HASH_H */