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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Symmetric key ciphers.
*
* Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
*/
#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 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;
unsigned int keysize;
struct crypto_tfm base;
};
struct crypto_sync_skcipher {
struct crypto_skcipher base;
};
/**
* struct skcipher_alg - symmetric key cipher definition
* @min_keysize: Minimum key size supported by the transformation. This is the
* smallest key length supported by this transformation algorithm.
* This must be set to one of the pre-defined values as this is
* not hardware specific. Possible values for this field can be
* found via git grep "_MIN_KEY_SIZE" include/crypto/
* @max_keysize: Maximum key size supported by the transformation. This is the
* largest key length supported by this transformation algorithm.
* This must be set to one of the pre-defined values as this is
* not hardware specific. Possible values for this field can be
* found via git grep "_MAX_KEY_SIZE" include/crypto/
* @setkey: Set key for the transformation. This function is used to either
* program a supplied key into the hardware or store the key in the
* transformation context for programming it later. Note that this
* function does modify the transformation context. This function can
* be called multiple times during the existence of the transformation
* object, so one must make sure the key is properly reprogrammed into
* the hardware. This function is also responsible for checking the key
* length for validity. In case a software fallback was put in place in
* the @cra_init call, this function might need to use the fallback if
* the algorithm doesn't support all of the key sizes.
* @encrypt: Encrypt a scatterlist of blocks. This function is used to encrypt
* the supplied scatterlist containing the blocks of data. The crypto
* API consumer is responsible for aligning the entries of the
* scatterlist properly and making sure the chunks are correctly
* sized. In case a software fallback was put in place in the
* @cra_init call, this function might need to use the fallback if
* the algorithm doesn't support all of the key sizes. In case the
* key was stored in transformation context, the key might need to be
* re-programmed into the hardware in this function. This function
* shall not modify the transformation context, as this function may
* be called in parallel with the same transformation object.
* @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt
* and the conditions are exactly the same.
* @init: Initialize the cryptographic transformation object. This function
* is used to 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: Deinitialize the cryptographic transformation object. This is a
* counterpart to @init, used to remove various changes set in
* @init.
* @ivsize: IV size applicable for transformation. The consumer must provide an
* IV of exactly that size to perform the encrypt or decrypt operation.
* @chunksize: Equal to the block size except for stream ciphers such as
* CTR where it is set to the underlying block size.
* @walksize: Equal to the chunk size except in cases where the algorithm is
* considerably more efficient if it can operate on multiple chunks
* in parallel. Should be a multiple of chunksize.
* @base: Definition of a generic crypto algorithm.
*
* All fields except @ivsize are mandatory and must be filled.
*/
struct skcipher_alg {
int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keylen);
int (*encrypt)(struct skcipher_request *req);
int (*decrypt)(struct skcipher_request *req);
int (*init)(struct crypto_skcipher *tfm);
void (*exit)(struct crypto_skcipher *tfm);
unsigned int min_keysize;
unsigned int max_keysize;
unsigned int ivsize;
unsigned int chunksize;
unsigned int walksize;
struct crypto_alg base;
};
#define MAX_SYNC_SKCIPHER_REQSIZE 384
/*
* This performs a type-check against the "tfm" argument to make sure
* all users have the correct skcipher tfm for doing on-stack requests.
*/
#define SYNC_SKCIPHER_REQUEST_ON_STACK(name, tfm) \
char __##name##_desc[sizeof(struct skcipher_request) + \
MAX_SYNC_SKCIPHER_REQSIZE + \
(!(sizeof((struct crypto_sync_skcipher *)1 == \
(typeof(tfm))1))) \
] CRYPTO_MINALIGN_ATTR; \
struct skcipher_request *name = (void *)__##name##_desc
/**
* 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);
struct crypto_sync_skcipher *crypto_alloc_sync_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));
}
static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm)
{
crypto_free_skcipher(&tfm->base);
}
/**
* 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_has_skcipher2() - 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 skcipher
* @mask: specifies the mask for the skcipher
*
* Return: true when the skcipher is known to the kernel crypto API; false
* otherwise
*/
int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask);
static inline const char *crypto_skcipher_driver_name(
struct crypto_skcipher *tfm)
{
return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
}
static inline struct skcipher_alg *crypto_skcipher_alg(
struct crypto_skcipher *tfm)
{
return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
struct skcipher_alg, base);
}
static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg)
{
if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER)
return alg->base.cra_blkcipher.ivsize;
if (alg->base.cra_ablkcipher.encrypt)
return alg->base.cra_ablkcipher.ivsize;
return alg->ivsize;
}
/**
* 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;
}
static inline unsigned int crypto_sync_skcipher_ivsize(
struct crypto_sync_skcipher *tfm)
{
return crypto_skcipher_ivsize(&tfm->base);
}
static inline unsigned int crypto_skcipher_alg_chunksize(
struct skcipher_alg *alg)
{
if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER)
return alg->base.cra_blocksize;
if (alg->base.cra_ablkcipher.encrypt)
return alg->base.cra_blocksize;
return alg->chunksize;
}
stati
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