Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1005 insertions, 0 deletions

diff --git a/include/crypto/hash.h b/include/crypto/hash.h
new file mode 100644
index 000000000..b2bc1e46e
--- /dev/null
+++ b/include/crypto/hash.h
@@ -0,0 +1,1005 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Hash: Hash algorithms under the crypto API
+ * 
+ * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#ifndef _CRYPTO_HASH_H
+#define _CRYPTO_HASH_H
+
+#include <linux/crypto.h>
+#include <linux/string.h>
+
+struct crypto_ahash;
+
+/**
+ * DOC: Message Digest Algorithm Definitions
+ *
+ * These data structures define modular message digest algorithm
+ * implementations, managed via crypto_register_ahash(),
+ * crypto_register_shash(), crypto_unregister_ahash() and
+ * crypto_unregister_shash().
+ */
+
+/**
+ * struct hash_alg_common - define properties of message digest
+ * @digestsize: Size of the result of the transformation. A buffer of this size
+ *	        must be available to the @final and @finup calls, so they can
+ *	        store the resulting hash into it. For various predefined sizes,
+ *	        search include/crypto/ using
+ *	        git grep _DIGEST_SIZE include/crypto.
+ * @statesize: Size of the block for partial state of the transformation. A
+ *	       buffer of this size must be passed to the @export function as it
+ *	       will save the partial state of the transformation into it. On the
+ *	       other side, the @import function will load the state from a
+ *	       buffer of this size as well.
+ * @base: Start of data structure of cipher algorithm. The common data
+ *	  structure of crypto_alg contains information common to all ciphers.
+ *	  The hash_alg_common data structure now adds the hash-specific
+ *	  information.
+ */
+struct hash_alg_common {
+	unsigned int digestsize;
+	unsigned int statesize;
+
+	struct crypto_alg base;
+};
+
+struct ahash_request {
+	struct crypto_async_request base;
+
+	unsigned int nbytes;
+	struct scatterlist *src;
+	u8 *result;
+
+	/* This field may only be used by the ahash API code. */
+	void *priv;
+
+	void *__ctx[] CRYPTO_MINALIGN_ATTR;
+};
+
+/**
+ * struct ahash_alg - asynchronous message digest definition
+ * @init: **[mandatory]** Initialize the transformation context. Intended only to initialize the
+ *	  state of the HASH transformation at the beginning. This shall fill in
+ *	  the internal structures used during the entire duration of the whole
+ *	  transformation. No data processing happens at this point. Driver code
+ *	  implementation must not use req->result.
+ * @update: **[mandatory]** Push a chunk of data into the driver for transformation. This
+ *	   function actually pushes blocks of data from upper layers into the
+ *	   driver, which then passes those to the hardware as seen fit. This
+ *	   function must not finalize the HASH transformation by calculating the
+ *	   final message digest as this only adds more data into the
+ *	   transformation. This function shall not modify the transformation
+ *	   context, as this function may be called in parallel with the same
+ *	   transformation object. Data processing can happen synchronously
+ *	   [SHASH] or asynchronously [AHASH] at this point. Driver must not use
+ *	   req->result.
+ * @final: **[mandatory]** Retrieve result from the driver. This function finalizes the
+ *	   transformation and retrieves the resulting hash from the driver and
+ *	   pushes it back to upper layers. No data processing happens at this
+ *	   point unless hardware requires it to finish the transformation
+ *	   (then the data buffered by the device driver is processed).
+ * @finup: **[optional]** Combination of @update and @final. This function is effectively a
+ *	   combination of @update and @final calls issued in sequence. As some
+ *	   hardware cannot do @update and @final separately, this callback was
+ *	   added to allow such hardware to be used at least by IPsec. Data
+ *	   processing can happen synchronously [SHASH] or asynchronously [AHASH]
+ *	   at this point.
+ * @digest: Combination of @init and @update and @final. This function
+ *	    effectively behaves as the entire chain of operations, @init,
+ *	    @update and @final issued in sequence. Just like @finup, this was
+ *	    added for hardware which cannot do even the @finup, but can only do
+ *	    the whole transformation in one run. Data processing can happen
+ *	    synchronously [SHASH] or asynchronously [AHASH] at this point.
+ * @setkey: Set optional key used by the hashing algorithm. Intended to push
+ *	    optional key used by the hashing algorithm from upper layers into
+ *	    the driver. This function can store the key in the transformation
+ *	    context or can outright program it into the hardware. In the former
+ *	    case, one must be careful to program the key into the hardware at
+ *	    appropriate time and one must be careful that .setkey() can be
+ *	    called multiple times during the existence of the transformation
+ *	    object. Not  all hashing algorithms do implement this function as it
+ *	    is only needed for keyed message digests. SHAx/MDx/CRCx do NOT
+ *	    implement this function. HMAC(MDx)/HMAC(SHAx)/CMAC(AES) do implement
+ *	    this function. This function must be called before any other of the
+ *	    @init, @update, @final, @finup, @digest is called. No data
+ *	    processing happens at this point.
+ * @export: Export partial state of the transformation. This function dumps the
+ *	    entire state of the ongoing transformation into a provided block of
+ *	    data so it can be @import 'ed back later on. This is useful in case
+ *	    you want to save partial result of the transformation after
+ *	    processing certain amount of data and reload this partial result
+ *	    multiple times later on for multiple re-use. No data processing
+ *	    happens at this point. Driver must not use req->result.
+ * @import: Import partial state of the transformation. This function loads the
+ *	    entire state of the ongoing transformation from a provided block of
+ *	    data so the transformation can continue from this point onward. No
+ *	    data processing happens at this point. Driver must not use
+ *	    req->result.
+ * @init_tfm: Initialize the cryptographic transformation object.
+ *	      This function is called only once at the instantiation
+ *	      time, right after the transformation context was
+ *	      allocated. In case the cryptographic hardware has
+ *	      some special requirements which need to be handled
+ *	      by software, this function shall check for the precise
+ *	      requirement of the transformation and put any software
+ *	      fallbacks in place.
+ * @exit_tfm: Deinitialize the cryptographic transformation object.
+ *	      This is a counterpart to @init_tfm, used to remove
+ *	      various changes set in @init_tfm.
+ * @halg: see struct hash_alg_common
+ */
+struct ahash_alg {
+	int (*init)(struct ahash_request *req);
+	int (*update)(struct ahash_request *req);
+	int (*final)(struct ahash_request *req);
+	int (*finup)(struct ahash_request *req);
+	int (*digest)(struct ahash_request *req);
+	int (*export)(struct ahash_request *req, void *out);
+	int (*import)(struct ahash_request *req, const void *in);
+	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
+		      unsigned int keylen);
+	int (*init_tfm)(struct crypto_ahash *tfm);
+	void (*exit_tfm)(struct crypto_ahash *tfm);
+
+	struct hash_alg_common halg;
+};
+
+struct shash_desc {
+	struct crypto_shash *tfm;
+	void *__ctx[] __aligned(ARCH_SLAB_MINALIGN);
+};
+
+#define HASH_MAX_DIGESTSIZE	 64
+
+/*
+ * Worst case is hmac(sha3-224-generic).  Its context is a nested 'shash_desc'
+ * containing a 'struct sha3_state'.
+ */
+#define HASH_MAX_DESCSIZE	(sizeof(struct shash_desc) + 360)
+
+#define HASH_MAX_STATESIZE	512
+
+#define SHASH_DESC_ON_STACK(shash, ctx)					     \
+	char __##shash##_desc[sizeof(struct shash_desc) + HASH_MAX_DESCSIZE] \
+		__aligned(__alignof__(struct shash_desc));		     \
+	struct shash_desc *shash = (struct shash_desc *)__##shash##_desc
+
+/**
+ * struct shash_alg - synchronous message digest definition
+ * @init: see struct ahash_alg
+ * @update: see struct ahash_alg
+ * @final: see struct ahash_alg
+ * @finup: see struct ahash_alg
+ * @digest: see struct ahash_alg
+ * @export: see struct ahash_alg
+ * @import: see struct ahash_alg
+ * @setkey: see struct ahash_alg
+ * @init_tfm: Initialize the cryptographic transformation object.
+ *	      This function is called only once at the instantiation
+ *	      time, right after the transformation context was
+ *	      allocated. In case the cryptographic hardware has
+ *	      some special requirements which need to be handled
+ *	      by software, this function shall check for the precise
+ *	      requirement of the transformation and put any software
+ *	      fallbacks in place.
+ * @exit_tfm: Deinitialize the cryptographic transformation object.
+ *	      This is a counterpart to @init_tfm, used to remove
+ *	      various changes set in @init_tfm.
+ * @digestsize: see struct ahash_alg
+ * @statesize: see struct ahash_alg
+ * @descsize: Size of the operational state for the message digest. This state
+ * 	      size is the memory size that needs to be allocated for
+ *	      shash_desc.__ctx
+ * @base: internally used
+ */
+struct shash_alg {
+	int (*init)(struct shash_desc *desc);
+	int (*update)(struct shash_desc *desc, const u8 *data,
+		      unsigned int len);
+	int (*final)(struct shash_desc *desc, u8 *out);
+	int (*finup)(struct shash_desc *desc, const u8 *data,
+		     unsigned int len, u8 *out);
+	int (*digest)(struct shash_desc *desc, const u8 *data,
+		      unsigned int len, u8 *out);
+	int (*export)(struct shash_desc *desc, void *out);
+	int (*import)(struct shash_desc *desc, const void *in);
+	int (*setkey)(struct crypto_shash *tfm, const u8 *key,
+		      unsigned int keylen);
+	int (*init_tfm)(struct crypto_shash *tfm);
+	void (*exit_tfm)(struct crypto_shash *tfm);
+
+	unsigned int descsize;
+
+	/* These fields must match hash_alg_common. */
+	unsigned int digestsize
+		__attribute__ ((aligned(__alignof__(struct hash_alg_common))));
+	unsigned int statesize;
+
+	struct crypto_alg base;
+};
+
+struct crypto_ahash {
+	int (*init)(struct ahash_request *req);
+	int (*update)(struct ahash_request *req);
+	int (*final)(struct ahash_request *req);
+	int (*finup)(struct ahash_request *req);
+	int (*digest)(struct ahash_request *req);
+	int (*export)(struct ahash_request *req, void *out);
+	int (*import)(struct ahash_request *req, const void *in);
+	int (*setkey)(struct crypto_ahash *tfm, const u8 *key,
+		      unsigned int keylen);
+
+	unsigned int reqsize;
+	struct crypto_tfm base;
+};
+
+struct crypto_shash {
+	unsigned int descsize;
+	struct crypto_tfm base;
+};
+
+/**
+ * DOC: Asynchronous Message Digest API
+ *
+ * The asynchronous message digest API is used with the ciphers of type
+ * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto)
+ *
+ * The asynchronous cipher operation discussion provided for the
+ * CRYPTO_ALG_TYPE_SKCIPHER API applies here as well.
+ */
+
+static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
+{
+	return container_of(tfm, struct crypto_ahash, base);
+}
+
+/**
+ * crypto_alloc_ahash() - allocate ahash cipher handle
+ * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
+ *	      ahash cipher
+ * @type: specifies the type of the cipher
+ * @mask: specifies the mask for the cipher
+ *
+ * Allocate a cipher handle for an ahash. The returned struct
+ * crypto_ahash is the cipher handle that is required for any subsequent
+ * API invocation for that ahash.
+ *
+ * Return: allocated cipher handle in case of success; IS_ERR() is true in case
+ *	   of an error, PTR_ERR() returns the error code.
+ */
+struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
+					u32 mask);
+
+static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
+{
+	return &tfm->base;
+}
+
+/**
+ * crypto_free_ahash() - zeroize and free the ahash handle
+ * @tfm: cipher handle to be freed
+ *
+ * If @tfm is a NULL or error pointer, this function does nothing.
+ */
+static inline void crypto_free_ahash(struct crypto_ahash *tfm)
+{
+	crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm));
+}
+
+/**
+ * crypto_has_ahash() - Search for the availability of an ahash.
+ * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
+ *	      ahash
+ * @type: specifies the type of the ahash
+ * @mask: specifies the mask for the ahash
+ *
+ * Return: true when the ahash is known to the kernel crypto API; false
+ *	   otherwise
+ */
+int crypto_has_ahash(const char *alg_name, u32 type, u32 mask);
+
+static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm)
+{
+	return crypto_tfm_alg_name(crypto_ahash_tfm(tfm));
+}
+
+static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm)
+{
+	return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm));
+}
+
+static inline unsigned int crypto_ahash_alignmask(
+	struct crypto_ahash *tfm)
+{
+	return crypto_tfm_alg_alignmask(crypto_ahash_tfm(tfm));
+}
+
+/**
+ * crypto_ahash_blocksize() - obtain block size for cipher
+ * @tfm: cipher handle
+ *
+ * The block size for the message digest cipher referenced with the cipher
+ * handle is returned.
+ *
+ * Return: block size of cipher
+ */
+static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm)
+{
+	return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
+}
+
+static inline struct hash_alg_common *__crypto_hash_alg_common(
+	struct crypto_alg *alg)
+{
+	return container_of(alg, struct hash_alg_common, base);
+}
+
+static inline struct hash_alg_common *crypto_hash_alg_common(
+	struct crypto_ahash *tfm)
+{
+	return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg);
+}
+
+/**
+ * crypto_ahash_digestsize() - obtain message digest size
+ * @tfm: cipher handle
+ *
+ * The size for the message digest created by the message digest cipher
+ * referenced with the cipher handle is returned.
+ *
+ *
+ * Return: message digest size of cipher
+ */
+static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm)
+{
+	return crypto_hash_alg_common(tfm)->digestsize;
+}
+
+/**
+ * crypto_ahash_statesize() - obtain size of the ahash state
+ * @tfm: cipher handle
+ *
+ * Return the size of the ahash state. With the crypto_ahash_export()
+ * function, the caller can export the state into a buffer whose size is
+ * defined with this function.
+ *
+ * Return: size of the ahash state
+ */
+static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm)
+{
+	return crypto_hash_alg_common(tfm)->statesize;
+}
+
+static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm)
+{
+	return crypto_tfm_get_flags(crypto_ahash_tfm(tfm));
+}
+
+static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags)
+{
+	crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags);
+}
+
+static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags)
+{
+	crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags);
+}
+
+/**
+ * crypto_ahash_reqtfm() - obtain cipher handle from request
+ * @req: asynchronous request handle that contains the reference to the ahash
+ *	 cipher handle
+ *
+ * Return the ahash cipher handle that is registered with the asynchronous
+ * request handle ahash_request.
+ *
+ * Return: ahash cipher handle
+ */
+static inline struct crypto_ahash *crypto_ahash_reqtfm(
+	struct ahash_request *req)
+{
+	return __crypto_ahash_cast(req->base.tfm);
+}
+
+/**
+ * crypto_ahash_reqsize() - obtain size of the request data structure
+ * @tfm: cipher handle
+ *
+ * Return: size of the request data
+ */
+static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
+{
+	return tfm->reqsize;
+}
+
+static inline void *ahash_request_ctx(struct ahash_request *req)
+{
+	return req->__ctx;
+}
+
+/**
+ * crypto_ahash_setkey - set key for cipher handle
+ * @tfm: cipher handle
+ * @key: buffer holding the key
+ * @keylen: length of the key in bytes
+ *
+ * The caller provided key is set for the ahash cipher. The cipher
+ * handle must point to a keyed hash in order for this function to succeed.
+ *
+ * Return: 0 if the setting of the key was successful; < 0 if an error occurred
+ */
+int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
+			unsigned int keylen);
+
+/**
+ * crypto_ahash_finup() - update and finalize message digest
+ * @req: reference to the ahash_request handle that holds all information
+ *	 needed to perform the cipher operation
+ *
+ * This function is a "short-hand" for the function calls of
+ * crypto_ahash_update and crypto_ahash_final. The parameters have the same
+ * meaning as discussed for those separate functions.
+ *
+ * Return: see crypto_ahash_final()
+ */
+int crypto_ahash_finup(struct ahash_request *req);
+
+/**
+ * crypto_ahash_final() - calculate message digest
+ * @req: reference to the ahash_request handle that holds all information
+ *	 needed to perform the cipher operation
+ *
+ * Finalize the message digest operation and create the message digest
+ * based on all data added to the cipher handle. The message digest is placed
+ * into the output buffer registered with the ahash_request handle.
+ *
+ * Return:
+ * 0		if the message digest was successfully calculated;
+ * -EINPROGRESS	if data is feeded into hardware (DMA) or queued for later;
+ * -EBUSY	if queue is full and request should be resubmitted later;
+ * other < 0	if an error occurred
+ */
+int crypto_ahash_final(struct ahash_request *req);
+
+/**
+ * crypto_ahash_digest() - calculate message digest for a buffer
+ * @req: reference to the ahash_request handle that holds all information
+ *	 needed to perform the cipher operation
+ *
+ * This function is a "short-hand" for the function calls of crypto_ahash_init,
+ * crypto_ahash_update and crypto_ahash_final. The parameters have the same
+ * meaning as discussed for those separate three functions.
+ *
+ * Return: see crypto_ahash_final()
+ */
+int crypto_ahash_digest(struct ahash_request *req);
+
+/**
+ * crypto_ahash_export() - extract current message digest state
+ * @req: reference to the ahash_request handle whose state is exported
+ * @out: output buffer of sufficient size that can hold the hash state
+ *
+ * This function exports the hash state of the ahash_request handle into the
+ * caller-allocated output buffer out which must have sufficient size (e.g. by
+ * calling crypto_ahash_statesize()).
+ *
+ * Return: 0 if the export was successful; < 0 if an error occurred
+ */
+static inline int crypto_ahash_export(struct ahash_request *req, void *out)
+{
+	return crypto_ahash_reqtfm(req)->export(req, out);
+}
+
+/**
+ * crypto_ahash_import() - import message digest state
+ * @req: reference to ahash_request handle the state is imported into
+ * @in: buffer holding the state
+ *
+ * This function imports the hash state into the ahash_request handle from the
+ * input buffer. That buffer should have been generated with the
+ * crypto_ahash_export function.
+ *
+ * Return: 0 if the import was successful; < 0 if an error occurred
+ */
+static inline int crypto_ahash_import(struct ahash_request *req, const void *in)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
+	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+		return -ENOKEY;
+
+	return tfm->import(req, in);
+}
+
+/**
+ * crypto_ahash_init() - (re)initialize message digest handle
+ * @req: ahash_request handle that already is initialized with all necessary
+ *	 data using the ahash_request_* API functions
+ *
+ * The call (re-)initializes the message digest referenced by the ahash_request
+ * handle. Any potentially existing state created by previous operations is
+ * discarded.
+ *
+ * Return: see crypto_ahash_final()
+ */
+static inline int crypto_ahash_init(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
+	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+		return -ENOKEY;
+
+	return tfm->init(req);
+}
+
+/**
+ * crypto_ahash_update() - add data to message digest for processing
+ * @req: ahash_request handle that was previously initialized with the
+ *	 crypto_ahash_init call.
+ *
+ * Updates the message digest state of the &ahash_request handle. The input data
+ * is pointed to by the scatter/gather list registered in the &ahash_request
+ * handle
+ *
+ * Return: see crypto_ahash_final()
+ */
+static inline int crypto_ahash_update(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct crypto_alg *alg = tfm->base.__crt_alg;
+	unsigned int nbytes = req->nbytes;
+	int ret;
+
+	crypto_stats_get(alg);
+	ret = crypto_ahash_reqtfm(req)->update(req);
+	crypto_stats_ahash_update(nbytes, ret, alg);
+	return ret;
+}
+
+/**
+ * DOC: Asynchronous Hash Request Handle
+ *
+ * The &ahash_request data structure contains all pointers to data
+ * required for the asynchronous cipher operation. This includes the cipher
+ * handle (which can be used by multiple &ahash_request instances), pointer
+ * to plaintext and the message digest output buffer, asynchronous callback
+ * function, etc. It acts as a handle to the ahash_request_* API calls in a
+ * similar way as ahash handle to the crypto_ahash_* API calls.
+ */
+
+/**
+ * ahash_request_set_tfm() - update cipher handle reference in request
+ * @req: request handle to be modified
+ * @tfm: cipher handle that shall be added to the request handle
+ *
+ * Allow the caller to replace the existing ahash handle in the request
+ * data structure with a different one.
+ */
+static inline void ahash_request_set_tfm(struct ahash_request *req,
+					 struct crypto_ahash *tfm)
+{
+	req->base.tfm = crypto_ahash_tfm(tfm);
+}
+
+/**
+ * ahash_request_alloc() - allocate request data structure
+ * @tfm: cipher handle to be registered with the request
+ * @gfp: memory allocation flag that is handed to kmalloc by the API call.
+ *
+ * Allocate the request data structure that must be used with the ahash
+ * message digest API calls. During
+ * the allocation, the provided ahash handle
+ * is registered in the request data structure.
+ *
+ * Return: allocated request handle in case of success, or NULL if out of memory
+ */
+static inline struct ahash_request *ahash_request_alloc(
+	struct crypto_ahash *tfm, gfp_t gfp)
+{
+	struct ahash_request *req;
+
+	req = kmalloc(sizeof(struct ahash_request) +
+		      crypto_ahash_reqsize(tfm), gfp);
+
+	if (likely(req))
+		ahash_request_set_tfm(req, tfm);
+
+	return req;
+}
+
+/**
+ * ahash_request_free() - zeroize and free the request data structure
+ * @req: request data structure cipher handle to be freed
+ */
+static inline void ahash_request_free(struct ahash_request *req)
+{
+	kfree_sensitive(req);
+}
+
+static inline void ahash_request_zero(struct ahash_request *req)
+{
+	memzero_explicit(req, sizeof(*req) +
+			      crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));
+}
+
+static inline struct ahash_request *ahash_request_cast(
+	struct crypto_async_request *req)
+{
+	return container_of(req, struct ahash_request, base);
+}
+
+/**
+ * ahash_request_set_callback() - set asynchronous callback function
+ * @req: request handle
+ * @flags: specify zero or an ORing of the flags
+ *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
+ *	   increase the wait queue beyond the initial maximum size;
+ *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
+ * @compl: callback function pointer to be registered with the request handle
+ * @data: The data pointer refers to memory that is not used by the kernel
+ *	  crypto API, but provided to the callback function for it to use. Here,
+ *	  the caller can provide a reference to memory the callback function can
+ *	  operate on. As the callback function is invoked asynchronously to the
+ *	  related functionality, it may need to access data structures of the
+ *	  related functionality which can be referenced using this pointer. The
+ *	  callback function can access the memory via the "data" field in the
+ *	  &crypto_async_request data structure provided to the callback function.
+ *
+ * This function allows setting the callback function that is triggered once
+ * the cipher operation completes.
+ *
+ * The callback function is registered with the &ahash_request handle and
+ * must comply with the following template::
+ *
+ *	void callback_function(struct crypto_async_request *req, int error)
+ */
+static inline void ahash_request_set_callback(struct ahash_request *req,
+					      u32 flags,
+					      crypto_completion_t compl,
+					      void *data)
+{
+	req->base.complete = compl;
+	req->base.data = data;
+	req->base.flags = flags;
+}
+
+/**
+ * ahash_request_set_crypt() - set data buffers
+ * @req: ahash_request handle to be updated
+ * @src: source scatter/gather list
+ * @result: buffer that is filled with the message digest -- the caller must
+ *	    ensure that the buffer has sufficient space by, for example, calling
+ *	    crypto_ahash_digestsize()
+ * @nbytes: number of bytes to process from the source scatter/gather list
+ *
+ * By using this call, the caller references the source scatter/gather list.
+ * The source scatter/gather list points to the data the message digest is to
+ * be calculated for.
+ */
+static inline void ahash_request_set_crypt(struct ahash_request *req,
+					   struct scatterlist *src, u8 *result,
+					   unsigned int nbytes)
+{
+	req->src = src;
+	req->nbytes = nbytes;
+	req->result = result;
+}
+
+/**
+ * DOC: Synchronous Message Digest API
+ *
+ * The synchronous message digest API is used with the ciphers of type
+ * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto)
+ *
+ * The message digest API is able to maintain state information for the
+ * caller.
+ *
+ * The synchronous message digest API can store user-related context in its
+ * shash_desc request data structure.
+ */
+
+/**
+ * crypto_alloc_shash() - allocate message digest handle
+ * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
+ *	      message digest cipher
+ * @type: specifies the type of the cipher
+ * @mask: specifies the mask for the cipher
+ *
+ * Allocate a cipher handle for a message digest. The returned &struct
+ * crypto_shash is the cipher handle that is required for any subsequent
+ * API invocation for that message digest.
+ *
+ * Return: allocated cipher handle in case of success; IS_ERR() is true in case
+ *	   of an error, PTR_ERR() returns the error code.
+ */
+struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
+					u32 mask);
+
+static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
+{
+	return &tfm->base;
+}
+
+/**
+ * crypto_free_shash() - zeroize and free the message digest handle
+ * @tfm: cipher handle to be freed
+ *
+ * If @tfm is a NULL or error pointer, this function does nothing.
+ */
+static inline void crypto_free_shash(struct crypto_shash *tfm)
+{
+	crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
+}
+
+static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
+{
+	return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
+}
+
+static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm)
+{
+	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
+}
+
+static inline unsigned int crypto_shash_alignmask(
+	struct crypto_shash *tfm)
+{
+	return crypto_tfm_alg_alignmask(crypto_shash_tfm(tfm));
+}
+
+/**
+ * crypto_shash_blocksize() - obtain block size for cipher
+ * @tfm: cipher handle
+ *
+ * The block size for the message digest cipher referenced with the cipher
+ * handle is returned.
+ *
+ * Return: block size of cipher
+ */
+static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm)
+{
+	return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm));
+}
+
+static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg)
+{
+	return container_of(alg, struct shash_alg, base);
+}
+
+static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm)
+{
+	return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg);
+}
+
+/**
+ * crypto_shash_digestsize() - obtain message digest size
+ * @tfm: cipher handle
+ *
+ * The size for the message digest created by the message digest cipher
+ * referenced with the cipher handle is returned.
+ *
+ * Return: digest size of cipher
+ */
+static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm)
+{
+	return crypto_shash_alg(tfm)->digestsize;
+}
+
+static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm)
+{
+	return crypto_shash_alg(tfm)->statesize;
+}
+
+static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm)
+{
+	return crypto_tfm_get_flags(crypto_shash_tfm(tfm));
+}
+
+static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags)
+{
+	crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags);
+}
+
+static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags)
+{
+	crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags);
+}
+
+/**
+ * crypto_shash_descsize() - obtain the operational state size
+ * @tfm: cipher handle
+ *
+ * The size of the operational state the cipher needs during operation is
+ * returned for the hash referenced with the cipher handle. This size is
+ * required to calculate the memory requirements to allow the caller allocating
+ * sufficient memory for operational state.
+ *
+ * The operational state is defined with struct shash_desc where the size of
+ * that data structure is to be calculated as
+ * sizeof(struct shash_desc) + crypto_shash_descsize(alg)
+ *
+ * Return: size of the operational state
+ */
+static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
+{
+	return tfm->descsize;
+}
+
+static inline void *shash_desc_ctx(struct shash_desc *desc)
+{
+	return desc->__ctx;
+}
+
+/**
+ * crypto_shash_setkey() - set key for message digest
+ * @tfm: cipher handle
+ * @key: buffer holding the key
+ * @keylen: length of the key in bytes
+ *
+ * The caller provided key is set for the keyed message digest cipher. The
+ * cipher handle must point to a keyed message digest cipher in order for this
+ * function to succeed.
+ *
+ * Context: Any context.
+ * Return: 0 if the setting of the key was successful; < 0 if an error occurred
+ */
+int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
+			unsigned int keylen);
+
+/**
+ * crypto_shash_digest() - calculate message digest for buffer
+ * @desc: see crypto_shash_final()
+ * @data: see crypto_shash_update()
+ * @len: see crypto_shash_update()
+ * @out: see crypto_shash_final()
+ *
+ * This function is a "short-hand" for the function calls of crypto_shash_init,
+ * crypto_shash_update and crypto_shash_final. The parameters have the same
+ * meaning as discussed for those separate three functions.
+ *
+ * Context: Any context.
+ * Return: 0 if the message digest creation was successful; < 0 if an error
+ *	   occurred
+ */
+int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
+			unsigned int len, u8 *out);
+
+/**
+ * crypto_shash_tfm_digest() - calculate message digest for buffer
+ * @tfm: hash transformation object
+ * @data: see crypto_shash_update()
+ * @len: see crypto_shash_update()
+ * @out: see crypto_shash_final()
+ *
+ * This is a simplified version of crypto_shash_digest() for users who don't
+ * want to allocate their own hash descriptor (shash_desc).  Instead,
+ * crypto_shash_tfm_digest() takes a hash transformation object (crypto_shash)
+ * directly, and it allocates a hash descriptor on the stack internally.
+ * Note that this stack allocation may be fairly large.
+ *
+ * Context: Any context.
+ * Return: 0 on success; < 0 if an error occurred.
+ */
+int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
+			    unsigned int len, u8 *out);
+
+/**
+ * crypto_shash_export() - extract operational state for message digest
+ * @desc: reference to the operational state handle whose state is exported
+ * @out: output buffer of sufficient size that can hold the hash state
+ *
+ * This function exports the hash state of the operational state handle into the
+ * caller-allocated output buffer out which must have sufficient size (e.g. by
+ * calling crypto_shash_descsize).
+ *
+ * Context: Any context.
+ * Return: 0 if the export creation was successful; < 0 if an error occurred
+ */
+static inline int crypto_shash_export(struct shash_desc *desc, void *out)
+{
+	return crypto_shash_alg(desc->tfm)->export(desc, out);
+}
+
+/**
+ * crypto_shash_import() - import operational state
+ * @desc: reference to the operational state handle the state imported into
+ * @in: buffer holding the state
+ *
+ * This function imports the hash state into the operational state handle from
+ * the input buffer. That buffer should have been generated with the
+ * crypto_ahash_export function.
+ *
+ * Context: Any context.
+ * Return: 0 if the import was successful; < 0 if an error occurred
+ */
+static inline int crypto_shash_import(struct shash_desc *desc, const void *in)
+{
+	struct crypto_shash *tfm = desc->tfm;
+
+	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+		return -ENOKEY;
+
+	return crypto_shash_alg(tfm)->import(desc, in);
+}
+
+/**
+ * crypto_shash_init() - (re)initialize message digest
+ * @desc: operational state handle that is already filled
+ *
+ * The call (re-)initializes the message digest referenced by the
+ * operational state handle. Any potentially existing state created by
+ * previous operations is discarded.
+ *
+ * Context: Any context.
+ * Return: 0 if the message digest initialization was successful; < 0 if an
+ *	   error occurred
+ */
+static inline int crypto_shash_init(struct shash_desc *desc)
+{
+	struct crypto_shash *tfm = desc->tfm;
+
+	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+		return -ENOKEY;
+
+	return crypto_shash_alg(tfm)->init(desc);
+}
+
+/**
+ * crypto_shash_update() - add data to message digest for processing
+ * @desc: operational state handle that is already initialized
+ * @data: input data to be added to the message digest
+ * @len: length of the input data
+ *
+ * Updates the message digest state of the operational state handle.
+ *
+ * Context: Any context.
+ * Return: 0 if the message digest update was successful; < 0 if an error
+ *	   occurred
+ */
+int crypto_shash_update(struct shash_desc *desc, const u8 *data,
+			unsigned int len);
+
+/**
+ * crypto_shash_final() - calculate message digest
+ * @desc: operational state handle that is already filled with data
+ * @out: output buffer filled with the message digest
+ *
+ * Finalize the message digest operation and create the message digest
+ * based on all data added to the cipher handle. The message digest is placed
+ * into the output buffer. The caller must ensure that the output buffer is
+ * large enough by using crypto_shash_digestsize.
+ *
+ * Context: Any context.
+ * Return: 0 if the message digest creation was successful; < 0 if an error
+ *	   occurred
+ */
+int crypto_shash_final(struct shash_desc *desc, u8 *out);
+
+/**
+ * crypto_shash_finup() - calculate message digest of buffer
+ * @desc: see crypto_shash_final()
+ * @data: see crypto_shash_update()
+ * @len: see crypto_shash_update()
+ * @out: see crypto_shash_final()
+ *
+ * This function is a "short-hand" for the function calls of
+ * crypto_shash_update and crypto_shash_final. The parameters have the same
+ * meaning as discussed for those separate functions.
+ *
+ * Context: Any context.
+ * Return: 0 if the message digest creation was successful; < 0 if an error
+ *	   occurred
+ */
+int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
+		       unsigned int len, u8 *out);
+
+static inline void shash_desc_zero(struct shash_desc *desc)
+{
+	memzero_explicit(desc,
+			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
+}
+
+#endif	/* _CRYPTO_HASH_H */