include/crypto/skcipher.h - arm/linux - Git at Google

 /*
  * Symmetric key ciphers.
  *
  * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * Software Foundation; either version 2 of the License, or (at your option)
  * any later version.
  *
  */

 #ifndef _CRYPTO_SKCIPHER_H
 #define _CRYPTO_SKCIPHER_H

 #include <linux/crypto.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>

 /**
  *	struct skcipher_request - Symmetric key cipher request
  *	@cryptlen: Number of bytes to encrypt or decrypt
  *	@iv: Initialisation Vector
  *	@src: Source SG list
  *	@dst: Destination SG list
  *	@base: Underlying async request request
  *	@__ctx: Start of private context data
  */
 struct skcipher_request {
 	unsigned int cryptlen;

 	u8 *iv;

 	struct scatterlist *src;
 	struct scatterlist *dst;

 	struct crypto_async_request base;

 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
 };

 /**
  *	struct skcipher_givcrypt_request - Crypto request with IV generation
  *	@seq: Sequence number for IV generation
  *	@giv: Space for generated IV
  *	@creq: The crypto request itself
  */
 struct skcipher_givcrypt_request {
 	u64 seq;
 	u8 *giv;

 	struct ablkcipher_request creq;
 };

 struct crypto_skcipher {
 	int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
 	              unsigned int keylen);
 	int (*encrypt)(struct skcipher_request *req);
 	int (*decrypt)(struct skcipher_request *req);

 	unsigned int ivsize;
 	unsigned int reqsize;

 	struct crypto_tfm base;
 };

 #define SKCIPHER_REQUEST_ON_STACK(name, tfm) \
 	char __##name##_desc[sizeof(struct skcipher_request) + \
 		crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
 	struct skcipher_request *name = (void *)__##name##_desc

 static inline struct crypto_ablkcipher *skcipher_givcrypt_reqtfm(
 	struct skcipher_givcrypt_request *req)
 {
 	return crypto_ablkcipher_reqtfm(&req->creq);
 }

 static inline int crypto_skcipher_givencrypt(
 	struct skcipher_givcrypt_request *req)
 {
 	struct ablkcipher_tfm *crt =
 		crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
 	return crt->givencrypt(req);
 };

 static inline int crypto_skcipher_givdecrypt(
 	struct skcipher_givcrypt_request *req)
 {
 	struct ablkcipher_tfm *crt =
 		crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
 	return crt->givdecrypt(req);
 };

 static inline void skcipher_givcrypt_set_tfm(
 	struct skcipher_givcrypt_request *req, struct crypto_ablkcipher *tfm)
 {
 	req->creq.base.tfm = crypto_ablkcipher_tfm(tfm);
 }

 static inline struct skcipher_givcrypt_request *skcipher_givcrypt_cast(
 	struct crypto_async_request *req)
 {
 	return container_of(ablkcipher_request_cast(req),
 			    struct skcipher_givcrypt_request, creq);
 }

 static inline struct skcipher_givcrypt_request *skcipher_givcrypt_alloc(
 	struct crypto_ablkcipher *tfm, gfp_t gfp)
 {
 	struct skcipher_givcrypt_request *req;

 	req = kmalloc(sizeof(struct skcipher_givcrypt_request) +
 		      crypto_ablkcipher_reqsize(tfm), gfp);

 	if (likely(req))
 		skcipher_givcrypt_set_tfm(req, tfm);

 	return req;
 }

 static inline void skcipher_givcrypt_free(struct skcipher_givcrypt_request *req)
 {
 	kfree(req);
 }

 static inline void skcipher_givcrypt_set_callback(
 	struct skcipher_givcrypt_request *req, u32 flags,
 	crypto_completion_t compl, void *data)
 {
 	ablkcipher_request_set_callback(&req->creq, flags, compl, data);
 }

 static inline void skcipher_givcrypt_set_crypt(
 	struct skcipher_givcrypt_request *req,
 	struct scatterlist *src, struct scatterlist *dst,
 	unsigned int nbytes, void *iv)
 {
 	ablkcipher_request_set_crypt(&req->creq, src, dst, nbytes, iv);
 }

 static inline void skcipher_givcrypt_set_giv(
 	struct skcipher_givcrypt_request *req, u8 *giv, u64 seq)
 {
 	req->giv = giv;
 	req->seq = seq;
 }

 /**
  * DOC: Symmetric Key Cipher API
  *
  * Symmetric key cipher API is used with the ciphers of type
  * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
  *
  * Asynchronous cipher operations imply that the function invocation for a
  * cipher request returns immediately before the completion of the operation.
  * The cipher request is scheduled as a separate kernel thread and therefore
  * load-balanced on the different CPUs via the process scheduler. To allow
  * the kernel crypto API to inform the caller about the completion of a cipher
  * request, the caller must provide a callback function. That function is
  * invoked with the cipher handle when the request completes.
  *
  * To support the asynchronous operation, additional information than just the
  * cipher handle must be supplied to the kernel crypto API. That additional
  * information is given by filling in the skcipher_request data structure.
  *
  * For the symmetric key cipher API, the state is maintained with the tfm
  * cipher handle. A single tfm can be used across multiple calls and in
  * parallel. For asynchronous block cipher calls, context data supplied and
  * only used by the caller can be referenced the request data structure in
  * addition to the IV used for the cipher request. The maintenance of such
  * state information would be important for a crypto driver implementer to
  * have, because when calling the callback function upon completion of the
  * cipher operation, that callback function may need some information about
  * which operation just finished if it invoked multiple in parallel. This
  * state information is unused by the kernel crypto API.
  */

 static inline struct crypto_skcipher *__crypto_skcipher_cast(
 	struct crypto_tfm *tfm)
 {
 	return container_of(tfm, struct crypto_skcipher, base);
 }

 /**
  * crypto_alloc_skcipher() - allocate symmetric key cipher handle
  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
  *	      skcipher cipher
  * @type: specifies the type of the cipher
  * @mask: specifies the mask for the cipher
  *
  * Allocate a cipher handle for an skcipher. The returned struct
  * crypto_skcipher is the cipher handle that is required for any subsequent
  * API invocation for that skcipher.
  *
  * 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_skcipher *crypto_alloc_skcipher(const char *alg_name,
 					      u32 type, u32 mask);

 static inline struct crypto_tfm *crypto_skcipher_tfm(
 	struct crypto_skcipher *tfm)
 {
 	return &tfm->base;
 }

 /**
  * crypto_free_skcipher() - zeroize and free cipher handle
  * @tfm: cipher handle to be freed
  */
 static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
 {
 	crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
 }

 /**
  * crypto_has_skcipher() - Search for the availability of an skcipher.
  * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
  *	      skcipher
  * @type: specifies the type of the cipher
  * @mask: specifies the mask for the cipher
  *
  * Return: true when the skcipher is known to the kernel crypto API; false
  *	   otherwise
  */
 static inline int crypto_has_skcipher(const char *alg_name, u32 type,
 					u32 mask)
 {
 	return crypto_has_alg(alg_name, crypto_skcipher_type(type),
 			      crypto_skcipher_mask(mask));
 }

 /**
  * crypto_skcipher_ivsize() - obtain IV size
  * @tfm: cipher handle
  *
  * The size of the IV for the skcipher referenced by the cipher handle is
  * returned. This IV size may be zero if the cipher does not need an IV.
  *
  * Return: IV size in bytes
  */
 static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
 {
 	return tfm->ivsize;
 }

 /**
  * crypto_skcipher_blocksize() - obtain block size of cipher
  * @tfm: cipher handle
  *
  * The block size for the skcipher referenced with the cipher handle is
  * returned. The caller may use that information to allocate appropriate
  * memory for the data returned by the encryption or decryption operation
  *
  * Return: block size of cipher
  */
 static inline unsigned int crypto_skcipher_blocksize(
 	struct crypto_skcipher *tfm)
 {
 	return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
 }

 static inline unsigned int crypto_skcipher_alignmask(
 	struct crypto_skcipher *tfm)
 {
 	return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
 }

 static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
 {
 	return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
 }

 static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
 					       u32 flags)
 {
 	crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
 }

 static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
 						 u32 flags)
 {
 	crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
 }

 /**
  * crypto_skcipher_setkey() - set key for cipher
  * @tfm: cipher handle
  * @key: buffer holding the key
  * @keylen: length of the key in bytes
  *
  * The caller provided key is set for the skcipher referenced by the cipher
  * handle.
  *
  * Note, the key length determines the cipher type. Many block ciphers implement
  * different cipher modes depending on the key size, such as AES-128 vs AES-192
  * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
  * is performed.
  *
  * Return: 0 if the setting of the key was successful; < 0 if an error occurred
  */
 static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
 					 const u8 *key, unsigned int keylen)
 {
 	return tfm->setkey(tfm, key, keylen);
 }

 /**
  * crypto_skcipher_reqtfm() - obtain cipher handle from request
  * @req: skcipher_request out of which the cipher handle is to be obtained
  *
  * Return the crypto_skcipher handle when furnishing an skcipher_request
  * data structure.
  *
  * Return: crypto_skcipher handle
  */
 static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
 	struct skcipher_request *req)
 {
 	return __crypto_skcipher_cast(req->base.tfm);
 }

 /**
  * crypto_skcipher_encrypt() - encrypt plaintext
  * @req: reference to the skcipher_request handle that holds all information
  *	 needed to perform the cipher operation
  *
  * Encrypt plaintext data using the skcipher_request handle. That data
  * structure and how it is filled with data is discussed with the
  * skcipher_request_* functions.
  *
  * Return: 0 if the cipher operation was successful; < 0 if an error occurred
  */
 static inline int crypto_skcipher_encrypt(struct skcipher_request *req)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

 	return tfm->encrypt(req);
 }

 /**
  * crypto_skcipher_decrypt() - decrypt ciphertext
  * @req: reference to the skcipher_request handle that holds all information
  *	 needed to perform the cipher operation
  *
  * Decrypt ciphertext data using the skcipher_request handle. That data
  * structure and how it is filled with data is discussed with the
  * skcipher_request_* functions.
  *
  * Return: 0 if the cipher operation was successful; < 0 if an error occurred
  */
 static inline int crypto_skcipher_decrypt(struct skcipher_request *req)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

 	return tfm->decrypt(req);
 }

 /**
  * DOC: Symmetric Key Cipher Request Handle
  *
  * The skcipher_request data structure contains all pointers to data
  * required for the symmetric key cipher operation. This includes the cipher
  * handle (which can be used by multiple skcipher_request instances), pointer
  * to plaintext and ciphertext, asynchronous callback function, etc. It acts
  * as a handle to the skcipher_request_* API calls in a similar way as
  * skcipher handle to the crypto_skcipher_* API calls.
  */

 /**
  * crypto_skcipher_reqsize() - obtain size of the request data structure
  * @tfm: cipher handle
  *
  * Return: number of bytes
  */
 static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
 {
 	return tfm->reqsize;
 }

 /**
  * skcipher_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 skcipher handle in the request
  * data structure with a different one.
  */
 static inline void skcipher_request_set_tfm(struct skcipher_request *req,
 					    struct crypto_skcipher *tfm)
 {
 	req->base.tfm = crypto_skcipher_tfm(tfm);
 }

 static inline struct skcipher_request *skcipher_request_cast(
 	struct crypto_async_request *req)
 {
 	return container_of(req, struct skcipher_request, base);
 }

 /**
  * skcipher_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 skcipher
  * encrypt and decrypt API calls. During the allocation, the provided skcipher
  * handle is registered in the request data structure.
  *
  * Return: allocated request handle in case of success; IS_ERR() is true in case
  *	   of an error, PTR_ERR() returns the error code.
  */
 static inline struct skcipher_request *skcipher_request_alloc(
 	struct crypto_skcipher *tfm, gfp_t gfp)
 {
 	struct skcipher_request *req;

 	req = kmalloc(sizeof(struct skcipher_request) +
 		      crypto_skcipher_reqsize(tfm), gfp);

 	if (likely(req))
 		skcipher_request_set_tfm(req, tfm);

 	return req;
 }

 /**
  * skcipher_request_free() - zeroize and free request data structure
  * @req: request data structure cipher handle to be freed
  */
 static inline void skcipher_request_free(struct skcipher_request *req)
 {
 	kzfree(req);
 }

 /**
  * skcipher_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 skcipher_request handle and
  * must comply with the following template
  *
  *	void callback_function(struct crypto_async_request *req, int error)
  */
 static inline void skcipher_request_set_callback(struct skcipher_request *req,
 						 u32 flags,
 						 crypto_completion_t compl,
 						 void *data)
 {
 	req->base.complete = compl;
 	req->base.data = data;
 	req->base.flags = flags;
 }

 /**
  * skcipher_request_set_crypt() - set data buffers
  * @req: request handle
  * @src: source scatter / gather list
  * @dst: destination scatter / gather list
  * @cryptlen: number of bytes to process from @src
  * @iv: IV for the cipher operation which must comply with the IV size defined
  *      by crypto_skcipher_ivsize
  *
  * This function allows setting of the source data and destination data
  * scatter / gather lists.
  *
  * For encryption, the source is treated as the plaintext and the
  * destination is the ciphertext. For a decryption operation, the use is
  * reversed - the source is the ciphertext and the destination is the plaintext.
  */
 static inline void skcipher_request_set_crypt(
 	struct skcipher_request *req,
 	struct scatterlist *src, struct scatterlist *dst,
 	unsigned int cryptlen, void *iv)
 {
 	req->src = src;
 	req->dst = dst;
 	req->cryptlen = cryptlen;
 	req->iv = iv;
 }

 #endif	/* _CRYPTO_SKCIPHER_H */
	/*
	* Symmetric key ciphers.
	*
	* Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the Free
	* Software Foundation; either version 2 of the License, or (at your option)
	* any later version.
	*
	*/

	#ifndef _CRYPTO_SKCIPHER_H
	#define _CRYPTO_SKCIPHER_H

	#include <linux/crypto.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>

	/**
	* struct skcipher_request - Symmetric key cipher request
	* @cryptlen: Number of bytes to encrypt or decrypt
	* @iv: Initialisation Vector
	* @src: Source SG list
	* @dst: Destination SG list
	* @base: Underlying async request request
	* @__ctx: Start of private context data
	*/
	struct skcipher_request {
	unsigned int cryptlen;

	u8 *iv;

	struct scatterlist *src;
	struct scatterlist *dst;

	struct crypto_async_request base;

	void *__ctx[] CRYPTO_MINALIGN_ATTR;
	};

	/**
	* struct skcipher_givcrypt_request - Crypto request with IV generation
	* @seq: Sequence number for IV generation
	* @giv: Space for generated IV
	* @creq: The crypto request itself
	*/
	struct skcipher_givcrypt_request {
	u64 seq;
	u8 *giv;

	struct ablkcipher_request creq;
	};

	struct crypto_skcipher {
	int (setkey)(struct crypto_skcipher tfm, const u8 *key,
	unsigned int keylen);
	int (encrypt)(struct skcipher_request req);
	int (decrypt)(struct skcipher_request req);

	unsigned int ivsize;
	unsigned int reqsize;

	struct crypto_tfm base;
	};

	#define SKCIPHER_REQUEST_ON_STACK(name, tfm) \
	char __##name##_desc[sizeof(struct skcipher_request) + \
	crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
	struct skcipher_request name = (void )__##name##_desc

	static inline struct crypto_ablkcipher *skcipher_givcrypt_reqtfm(
	struct skcipher_givcrypt_request *req)
	{
	return crypto_ablkcipher_reqtfm(&req->creq);
	}

	static inline int crypto_skcipher_givencrypt(
	struct skcipher_givcrypt_request *req)
	{
	struct ablkcipher_tfm *crt =
	crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
	return crt->givencrypt(req);
	};

	static inline int crypto_skcipher_givdecrypt(
	struct skcipher_givcrypt_request *req)
	{
	struct ablkcipher_tfm *crt =
	crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
	return crt->givdecrypt(req);
	};

	static inline void skcipher_givcrypt_set_tfm(
	struct skcipher_givcrypt_request req, struct crypto_ablkcipher tfm)
	{
	req->creq.base.tfm = crypto_ablkcipher_tfm(tfm);
	}

	static inline struct skcipher_givcrypt_request *skcipher_givcrypt_cast(
	struct crypto_async_request *req)
	{
	return container_of(ablkcipher_request_cast(req),
	struct skcipher_givcrypt_request, creq);
	}

	static inline struct skcipher_givcrypt_request *skcipher_givcrypt_alloc(
	struct crypto_ablkcipher *tfm, gfp_t gfp)
	{
	struct skcipher_givcrypt_request *req;

	req = kmalloc(sizeof(struct skcipher_givcrypt_request) +
	crypto_ablkcipher_reqsize(tfm), gfp);

	if (likely(req))
	skcipher_givcrypt_set_tfm(req, tfm);

	return req;
	}

	static inline void skcipher_givcrypt_free(struct skcipher_givcrypt_request *req)
	{
	kfree(req);
	}

	static inline void skcipher_givcrypt_set_callback(
	struct skcipher_givcrypt_request *req, u32 flags,
	crypto_completion_t compl, void *data)
	{
	ablkcipher_request_set_callback(&req->creq, flags, compl, data);
	}

	static inline void skcipher_givcrypt_set_crypt(
	struct skcipher_givcrypt_request *req,
	struct scatterlist src, struct scatterlist dst,
	unsigned int nbytes, void *iv)
	{
	ablkcipher_request_set_crypt(&req->creq, src, dst, nbytes, iv);
	}

	static inline void skcipher_givcrypt_set_giv(
	struct skcipher_givcrypt_request req, u8 giv, u64 seq)
	{
	req->giv = giv;
	req->seq = seq;
	}

	/**
	* DOC: Symmetric Key Cipher API
	*
	* Symmetric key cipher API is used with the ciphers of type
	* CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
	*
	* Asynchronous cipher operations imply that the function invocation for a
	* cipher request returns immediately before the completion of the operation.
	* The cipher request is scheduled as a separate kernel thread and therefore
	* load-balanced on the different CPUs via the process scheduler. To allow
	* the kernel crypto API to inform the caller about the completion of a cipher
	* request, the caller must provide a callback function. That function is
	* invoked with the cipher handle when the request completes.
	*
	* To support the asynchronous operation, additional information than just the
	* cipher handle must be supplied to the kernel crypto API. That additional
	* information is given by filling in the skcipher_request data structure.
	*
	* For the symmetric key cipher API, the state is maintained with the tfm
	* cipher handle. A single tfm can be used across multiple calls and in
	* parallel. For asynchronous block cipher calls, context data supplied and
	* only used by the caller can be referenced the request data structure in
	* addition to the IV used for the cipher request. The maintenance of such
	* state information would be important for a crypto driver implementer to
	* have, because when calling the callback function upon completion of the
	* cipher operation, that callback function may need some information about
	* which operation just finished if it invoked multiple in parallel. This
	* state information is unused by the kernel crypto API.
	*/

	static inline struct crypto_skcipher *__crypto_skcipher_cast(
	struct crypto_tfm *tfm)
	{
	return container_of(tfm, struct crypto_skcipher, base);
	}

	/**
	* crypto_alloc_skcipher() - allocate symmetric key cipher handle
	* @alg_name: is the cra_name / name or cra_driver_name / driver name of the
	* skcipher cipher
	* @type: specifies the type of the cipher
	* @mask: specifies the mask for the cipher
	*
	* Allocate a cipher handle for an skcipher. The returned struct
	* crypto_skcipher is the cipher handle that is required for any subsequent
	* API invocation for that skcipher.
	*
	* 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_skcipher crypto_alloc_skcipher(const char alg_name,
	u32 type, u32 mask);

	static inline struct crypto_tfm *crypto_skcipher_tfm(
	struct crypto_skcipher *tfm)
	{
	return &tfm->base;
	}

	/**
	* crypto_free_skcipher() - zeroize and free cipher handle
	* @tfm: cipher handle to be freed
	*/
	static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
	{
	crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
	}

	/**
	* crypto_has_skcipher() - Search for the availability of an skcipher.
	* @alg_name: is the cra_name / name or cra_driver_name / driver name of the
	* skcipher
	* @type: specifies the type of the cipher
	* @mask: specifies the mask for the cipher
	*
	* Return: true when the skcipher is known to the kernel crypto API; false
	* otherwise
	*/
	static inline int crypto_has_skcipher(const char *alg_name, u32 type,
	u32 mask)
	{
	return crypto_has_alg(alg_name, crypto_skcipher_type(type),
	crypto_skcipher_mask(mask));
	}

	/**
	* crypto_skcipher_ivsize() - obtain IV size
	* @tfm: cipher handle
	*
	* The size of the IV for the skcipher referenced by the cipher handle is
	* returned. This IV size may be zero if the cipher does not need an IV.
	*
	* Return: IV size in bytes
	*/
	static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
	{
	return tfm->ivsize;
	}

	/**
	* crypto_skcipher_blocksize() - obtain block size of cipher
	* @tfm: cipher handle
	*
	* The block size for the skcipher referenced with the cipher handle is
	* returned. The caller may use that information to allocate appropriate
	* memory for the data returned by the encryption or decryption operation
	*
	* Return: block size of cipher
	*/
	static inline unsigned int crypto_skcipher_blocksize(
	struct crypto_skcipher *tfm)
	{
	return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
	}

	static inline unsigned int crypto_skcipher_alignmask(
	struct crypto_skcipher *tfm)
	{
	return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
	}

	static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
	{
	return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
	}

	static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
	u32 flags)
	{
	crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
	}

	static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
	u32 flags)
	{
	crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
	}

	/**
	* crypto_skcipher_setkey() - set key for cipher
	* @tfm: cipher handle
	* @key: buffer holding the key
	* @keylen: length of the key in bytes
	*
	* The caller provided key is set for the skcipher referenced by the cipher
	* handle.
	*
	* Note, the key length determines the cipher type. Many block ciphers implement
	* different cipher modes depending on the key size, such as AES-128 vs AES-192
	* vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
	* is performed.
	*
	* Return: 0 if the setting of the key was successful; < 0 if an error occurred
	*/
	static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
	const u8 *key, unsigned int keylen)
	{
	return tfm->setkey(tfm, key, keylen);
	}

	/**
	* crypto_skcipher_reqtfm() - obtain cipher handle from request
	* @req: skcipher_request out of which the cipher handle is to be obtained
	*
	* Return the crypto_skcipher handle when furnishing an skcipher_request
	* data structure.
	*
	* Return: crypto_skcipher handle
	*/
	static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
	struct skcipher_request *req)
	{
	return __crypto_skcipher_cast(req->base.tfm);
	}

	/**
	* crypto_skcipher_encrypt() - encrypt plaintext
	* @req: reference to the skcipher_request handle that holds all information
	* needed to perform the cipher operation
	*
	* Encrypt plaintext data using the skcipher_request handle. That data
	* structure and how it is filled with data is discussed with the
	* skcipher_request_* functions.
	*
	* Return: 0 if the cipher operation was successful; < 0 if an error occurred
	*/
	static inline int crypto_skcipher_encrypt(struct skcipher_request *req)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	return tfm->encrypt(req);
	}

	/**
	* crypto_skcipher_decrypt() - decrypt ciphertext
	* @req: reference to the skcipher_request handle that holds all information
	* needed to perform the cipher operation
	*
	* Decrypt ciphertext data using the skcipher_request handle. That data
	* structure and how it is filled with data is discussed with the
	* skcipher_request_* functions.
	*
	* Return: 0 if the cipher operation was successful; < 0 if an error occurred
	*/
	static inline int crypto_skcipher_decrypt(struct skcipher_request *req)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	return tfm->decrypt(req);
	}

	/**
	* DOC: Symmetric Key Cipher Request Handle
	*
	* The skcipher_request data structure contains all pointers to data
	* required for the symmetric key cipher operation. This includes the cipher
	* handle (which can be used by multiple skcipher_request instances), pointer
	* to plaintext and ciphertext, asynchronous callback function, etc. It acts
	* as a handle to the skcipher_request_* API calls in a similar way as
	* skcipher handle to the crypto_skcipher_* API calls.
	*/

	/**
	* crypto_skcipher_reqsize() - obtain size of the request data structure
	* @tfm: cipher handle
	*
	* Return: number of bytes
	*/
	static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
	{
	return tfm->reqsize;
	}

	/**
	* skcipher_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 skcipher handle in the request
	* data structure with a different one.
	*/
	static inline void skcipher_request_set_tfm(struct skcipher_request *req,
	struct crypto_skcipher *tfm)
	{
	req->base.tfm = crypto_skcipher_tfm(tfm);
	}

	static inline struct skcipher_request *skcipher_request_cast(
	struct crypto_async_request *req)
	{
	return container_of(req, struct skcipher_request, base);
	}

	/**
	* skcipher_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 skcipher
	* encrypt and decrypt API calls. During the allocation, the provided skcipher
	* handle is registered in the request data structure.
	*
	* Return: allocated request handle in case of success; IS_ERR() is true in case
	* of an error, PTR_ERR() returns the error code.
	*/
	static inline struct skcipher_request *skcipher_request_alloc(
	struct crypto_skcipher *tfm, gfp_t gfp)
	{
	struct skcipher_request *req;

	req = kmalloc(sizeof(struct skcipher_request) +
	crypto_skcipher_reqsize(tfm), gfp);

	if (likely(req))
	skcipher_request_set_tfm(req, tfm);

	return req;
	}

	/**
	* skcipher_request_free() - zeroize and free request data structure
	* @req: request data structure cipher handle to be freed
	*/
	static inline void skcipher_request_free(struct skcipher_request *req)
	{
	kzfree(req);
	}

	/**
	* skcipher_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 skcipher_request handle and
	* must comply with the following template
	*
	* void callback_function(struct crypto_async_request *req, int error)
	*/
	static inline void skcipher_request_set_callback(struct skcipher_request *req,
	u32 flags,
	crypto_completion_t compl,
	void *data)
	{
	req->base.complete = compl;
	req->base.data = data;
	req->base.flags = flags;
	}

	/**
	* skcipher_request_set_crypt() - set data buffers
	* @req: request handle
	* @src: source scatter / gather list
	* @dst: destination scatter / gather list
	* @cryptlen: number of bytes to process from @src
	* @iv: IV for the cipher operation which must comply with the IV size defined
	* by crypto_skcipher_ivsize
	*
	* This function allows setting of the source data and destination data
	* scatter / gather lists.
	*
	* For encryption, the source is treated as the plaintext and the
	* destination is the ciphertext. For a decryption operation, the use is
	* reversed - the source is the ciphertext and the destination is the plaintext.
	*/
	static inline void skcipher_request_set_crypt(
	struct skcipher_request *req,
	struct scatterlist src, struct scatterlist dst,
	unsigned int cryptlen, void *iv)
	{
	req->src = src;
	req->dst = dst;
	req->cryptlen = cryptlen;
	req->iv = iv;
	}

	#endif /* _CRYPTO_SKCIPHER_H */