https://github.com/torvalds/linux
Tip revision: a38297e3fb012ddfa7ce0321a7e5a8daeb1872b6 authored by Linus Torvalds on 12 May 2024, 21:12:29 UTC
Linux 6.9
Linux 6.9
Tip revision: a38297e
crypto.h
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Scatterlist Cryptographic API.
*
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
* Copyright (c) 2002 David S. Miller (davem@redhat.com)
* Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
*
* Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
* and Nettle, by Niels Möller.
*/
#ifndef _LINUX_CRYPTO_H
#define _LINUX_CRYPTO_H
#include <linux/completion.h>
#include <linux/refcount.h>
#include <linux/slab.h>
#include <linux/types.h>
/*
* Algorithm masks and types.
*/
#define CRYPTO_ALG_TYPE_MASK 0x0000000f
#define CRYPTO_ALG_TYPE_CIPHER 0x00000001
#define CRYPTO_ALG_TYPE_COMPRESS 0x00000002
#define CRYPTO_ALG_TYPE_AEAD 0x00000003
#define CRYPTO_ALG_TYPE_LSKCIPHER 0x00000004
#define CRYPTO_ALG_TYPE_SKCIPHER 0x00000005
#define CRYPTO_ALG_TYPE_AKCIPHER 0x00000006
#define CRYPTO_ALG_TYPE_SIG 0x00000007
#define CRYPTO_ALG_TYPE_KPP 0x00000008
#define CRYPTO_ALG_TYPE_ACOMPRESS 0x0000000a
#define CRYPTO_ALG_TYPE_SCOMPRESS 0x0000000b
#define CRYPTO_ALG_TYPE_RNG 0x0000000c
#define CRYPTO_ALG_TYPE_HASH 0x0000000e
#define CRYPTO_ALG_TYPE_SHASH 0x0000000e
#define CRYPTO_ALG_TYPE_AHASH 0x0000000f
#define CRYPTO_ALG_TYPE_ACOMPRESS_MASK 0x0000000e
#define CRYPTO_ALG_LARVAL 0x00000010
#define CRYPTO_ALG_DEAD 0x00000020
#define CRYPTO_ALG_DYING 0x00000040
#define CRYPTO_ALG_ASYNC 0x00000080
/*
* Set if the algorithm (or an algorithm which it uses) requires another
* algorithm of the same type to handle corner cases.
*/
#define CRYPTO_ALG_NEED_FALLBACK 0x00000100
/*
* Set if the algorithm has passed automated run-time testing. Note that
* if there is no run-time testing for a given algorithm it is considered
* to have passed.
*/
#define CRYPTO_ALG_TESTED 0x00000400
/*
* Set if the algorithm is an instance that is built from templates.
*/
#define CRYPTO_ALG_INSTANCE 0x00000800
/* Set this bit if the algorithm provided is hardware accelerated but
* not available to userspace via instruction set or so.
*/
#define CRYPTO_ALG_KERN_DRIVER_ONLY 0x00001000
/*
* Mark a cipher as a service implementation only usable by another
* cipher and never by a normal user of the kernel crypto API
*/
#define CRYPTO_ALG_INTERNAL 0x00002000
/*
* Set if the algorithm has a ->setkey() method but can be used without
* calling it first, i.e. there is a default key.
*/
#define CRYPTO_ALG_OPTIONAL_KEY 0x00004000
/*
* Don't trigger module loading
*/
#define CRYPTO_NOLOAD 0x00008000
/*
* The algorithm may allocate memory during request processing, i.e. during
* encryption, decryption, or hashing. Users can request an algorithm with this
* flag unset if they can't handle memory allocation failures.
*
* This flag is currently only implemented for algorithms of type "skcipher",
* "aead", "ahash", "shash", and "cipher". Algorithms of other types might not
* have this flag set even if they allocate memory.
*
* In some edge cases, algorithms can allocate memory regardless of this flag.
* To avoid these cases, users must obey the following usage constraints:
* skcipher:
* - The IV buffer and all scatterlist elements must be aligned to the
* algorithm's alignmask.
* - If the data were to be divided into chunks of size
* crypto_skcipher_walksize() (with any remainder going at the end), no
* chunk can cross a page boundary or a scatterlist element boundary.
* aead:
* - The IV buffer and all scatterlist elements must be aligned to the
* algorithm's alignmask.
* - The first scatterlist element must contain all the associated data,
* and its pages must be !PageHighMem.
* - If the plaintext/ciphertext were to be divided into chunks of size
* crypto_aead_walksize() (with the remainder going at the end), no chunk
* can cross a page boundary or a scatterlist element boundary.
* ahash:
* - crypto_ahash_finup() must not be used unless the algorithm implements
* ->finup() natively.
*/
#define CRYPTO_ALG_ALLOCATES_MEMORY 0x00010000
/*
* Mark an algorithm as a service implementation only usable by a
* template and never by a normal user of the kernel crypto API.
* This is intended to be used by algorithms that are themselves
* not FIPS-approved but may instead be used to implement parts of
* a FIPS-approved algorithm (e.g., dh vs. ffdhe2048(dh)).
*/
#define CRYPTO_ALG_FIPS_INTERNAL 0x00020000
/*
* Transform masks and values (for crt_flags).
*/
#define CRYPTO_TFM_NEED_KEY 0x00000001
#define CRYPTO_TFM_REQ_MASK 0x000fff00
#define CRYPTO_TFM_REQ_FORBID_WEAK_KEYS 0x00000100
#define CRYPTO_TFM_REQ_MAY_SLEEP 0x00000200
#define CRYPTO_TFM_REQ_MAY_BACKLOG 0x00000400
/*
* Miscellaneous stuff.
*/
#define CRYPTO_MAX_ALG_NAME 128
/*
* The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual
* declaration) is used to ensure that the crypto_tfm context structure is
* aligned correctly for the given architecture so that there are no alignment
* faults for C data types. On architectures that support non-cache coherent
* DMA, such as ARM or arm64, it also takes into account the minimal alignment
* that is required to ensure that the context struct member does not share any
* cachelines with the rest of the struct. This is needed to ensure that cache
* maintenance for non-coherent DMA (cache invalidation in particular) does not
* affect data that may be accessed by the CPU concurrently.
*/
#define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN
#define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
struct crypto_tfm;
struct crypto_type;
struct module;
typedef void (*crypto_completion_t)(void *req, int err);
/**
* DOC: Block Cipher Context Data Structures
*
* These data structures define the operating context for each block cipher
* type.
*/
struct crypto_async_request {
struct list_head list;
crypto_completion_t complete;
void *data;
struct crypto_tfm *tfm;
u32 flags;
};
/**
* DOC: Block Cipher Algorithm Definitions
*
* These data structures define modular crypto algorithm implementations,
* managed via crypto_register_alg() and crypto_unregister_alg().
*/
/**
* struct cipher_alg - single-block symmetric ciphers definition
* @cia_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/
* @cia_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/
* @cia_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.
* @cia_encrypt: Encrypt a single block. This function is used to encrypt a
* single block of data, which must be @cra_blocksize big. This
* always operates on a full @cra_blocksize and it is not possible
* to encrypt a block of smaller size. The supplied buffers must
* therefore also be at least of @cra_blocksize size. Both the
* input and output buffers are always aligned to @cra_alignmask.
* In case either of the input or output buffer supplied by user
* of the crypto API is not aligned to @cra_alignmask, the crypto
* API will re-align the buffers. The re-alignment means that a
* new buffer will be allocated, the data will be copied into the
* new buffer, then the processing will happen on the new buffer,
* then the data will be copied back into the original buffer and
* finally the new buffer will be freed. 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.
* @cia_decrypt: Decrypt a single block. This is a reverse counterpart to
* @cia_encrypt, and the conditions are exactly the same.
*
* All fields are mandatory and must be filled.
*/
struct cipher_alg {
unsigned int cia_min_keysize;
unsigned int cia_max_keysize;
int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key,
unsigned int keylen);
void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
};
/**
* struct compress_alg - compression/decompression algorithm
* @coa_compress: Compress a buffer of specified length, storing the resulting
* data in the specified buffer. Return the length of the
* compressed data in dlen.
* @coa_decompress: Decompress the source buffer, storing the uncompressed
* data in the specified buffer. The length of the data is
* returned in dlen.
*
* All fields are mandatory.
*/
struct compress_alg {
int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen);
int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen);
};
#define cra_cipher cra_u.cipher
#define cra_compress cra_u.compress
/**
* struct crypto_alg - definition of a cryptograpic cipher algorithm
* @cra_flags: Flags describing this transformation. See include/linux/crypto.h
* CRYPTO_ALG_* flags for the flags which go in here. Those are
* used for fine-tuning the description of the transformation
* algorithm.
* @cra_blocksize: Minimum block size of this transformation. The size in bytes
* of the smallest possible unit which can be transformed with
* this algorithm. The users must respect this value.
* In case of HASH transformation, it is possible for a smaller
* block than @cra_blocksize to be passed to the crypto API for
* transformation, in case of any other transformation type, an
* error will be returned upon any attempt to transform smaller
* than @cra_blocksize chunks.
* @cra_ctxsize: Size of the operational context of the transformation. This
* value informs the kernel crypto API about the memory size
* needed to be allocated for the transformation context.
* @cra_alignmask: For cipher, skcipher, lskcipher, and aead algorithms this is
* 1 less than the alignment, in bytes, that the algorithm
* implementation requires for input and output buffers. When
* the crypto API is invoked with buffers that are not aligned
* to this alignment, the crypto API automatically utilizes
* appropriately aligned temporary buffers to comply with what
* the algorithm needs. (For scatterlists this happens only if
* the algorithm uses the skcipher_walk helper functions.) This
* misalignment handling carries a performance penalty, so it is
* preferred that algorithms do not set a nonzero alignmask.
* Also, crypto API users may wish to allocate buffers aligned
* to the alignmask of the algorithm being used, in order to
* avoid the API having to realign them. Note: the alignmask is
* not supported for hash algorithms and is always 0 for them.
* @cra_priority: Priority of this transformation implementation. In case
* multiple transformations with same @cra_name are available to
* the Crypto API, the kernel will use the one with highest
* @cra_priority.
* @cra_name: Generic name (usable by multiple implementations) of the
* transformation algorithm. This is the name of the transformation
* itself. This field is used by the kernel when looking up the
* providers of particular transformation.
* @cra_driver_name: Unique name of the transformation provider. This is the
* name of the provider of the transformation. This can be any
* arbitrary value, but in the usual case, this contains the
* name of the chip or provider and the name of the
* transformation algorithm.
* @cra_type: Type of the cryptographic transformation. This is a pointer to
* struct crypto_type, which implements callbacks common for all
* transformation types. There are multiple options, such as
* &crypto_skcipher_type, &crypto_ahash_type, &crypto_rng_type.
* This field might be empty. In that case, there are no common
* callbacks. This is the case for: cipher, compress, shash.
* @cra_u: Callbacks implementing the transformation. This is a union of
* multiple structures. Depending on the type of transformation selected
* by @cra_type and @cra_flags above, the associated structure must be
* filled with callbacks. This field might be empty. This is the case
* for ahash, shash.
* @cra_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.
* @cra_exit: Deinitialize the cryptographic transformation object. This is a
* counterpart to @cra_init, used to remove various changes set in
* @cra_init.
* @cra_u.cipher: Union member which contains a single-block symmetric cipher
* definition. See @struct @cipher_alg.
* @cra_u.compress: Union member which contains a (de)compression algorithm.
* See @struct @compress_alg.
* @cra_module: Owner of this transformation implementation. Set to THIS_MODULE
* @cra_list: internally used
* @cra_users: internally used
* @cra_refcnt: internally used
* @cra_destroy: internally used
*
* The struct crypto_alg describes a generic Crypto API algorithm and is common
* for all of the transformations. Any variable not documented here shall not
* be used by a cipher implementation as it is internal to the Crypto API.
*/
struct crypto_alg {
struct list_head cra_list;
struct list_head cra_users;
u32 cra_flags;
unsigned int cra_blocksize;
unsigned int cra_ctxsize;
unsigned int cra_alignmask;
int cra_priority;
refcount_t cra_refcnt;
char cra_name[CRYPTO_MAX_ALG_NAME];
char cra_driver_name[CRYPTO_MAX_ALG_NAME];
const struct crypto_type *cra_type;
union {
struct cipher_alg cipher;
struct compress_alg compress;
} cra_u;
int (*cra_init)(struct crypto_tfm *tfm);
void (*cra_exit)(struct crypto_tfm *tfm);
void (*cra_destroy)(struct crypto_alg *alg);
struct module *cra_module;
} CRYPTO_MINALIGN_ATTR;
/*
* A helper struct for waiting for completion of async crypto ops
*/
struct crypto_wait {
struct completion completion;
int err;
};
/*
* Macro for declaring a crypto op async wait object on stack
*/
#define DECLARE_CRYPTO_WAIT(_wait) \
struct crypto_wait _wait = { \
COMPLETION_INITIALIZER_ONSTACK((_wait).completion), 0 }
/*
* Async ops completion helper functioons
*/
void crypto_req_done(void *req, int err);
static inline int crypto_wait_req(int err, struct crypto_wait *wait)
{
switch (err) {
case -EINPROGRESS:
case -EBUSY:
wait_for_completion(&wait->completion);
reinit_completion(&wait->completion);
err = wait->err;
break;
}
return err;
}
static inline void crypto_init_wait(struct crypto_wait *wait)
{
init_completion(&wait->completion);
}
/*
* Algorithm query interface.
*/
int crypto_has_alg(const char *name, u32 type, u32 mask);
/*
* Transforms: user-instantiated objects which encapsulate algorithms
* and core processing logic. Managed via crypto_alloc_*() and
* crypto_free_*(), as well as the various helpers below.
*/
struct crypto_tfm {
refcount_t refcnt;
u32 crt_flags;
int node;
void (*exit)(struct crypto_tfm *tfm);
struct crypto_alg *__crt_alg;
void *__crt_ctx[] CRYPTO_MINALIGN_ATTR;
};
struct crypto_comp {
struct crypto_tfm base;
};
/*
* Transform user interface.
*/
struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask);
void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm);
static inline void crypto_free_tfm(struct crypto_tfm *tfm)
{
return crypto_destroy_tfm(tfm, tfm);
}
/*
* Transform helpers which query the underlying algorithm.
*/
static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
{
return tfm->__crt_alg->cra_name;
}
static inline const char *crypto_tfm_alg_driver_name(struct crypto_tfm *tfm)
{
return tfm->__crt_alg->cra_driver_name;
}
static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
{
return tfm->__crt_alg->cra_blocksize;
}
static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
{
return tfm->__crt_alg->cra_alignmask;
}
static inline u32 crypto_tfm_get_flags(struct crypto_tfm *tfm)
{
return tfm->crt_flags;
}
static inline void crypto_tfm_set_flags(struct crypto_tfm *tfm, u32 flags)
{
tfm->crt_flags |= flags;
}
static inline void crypto_tfm_clear_flags(struct crypto_tfm *tfm, u32 flags)
{
tfm->crt_flags &= ~flags;
}
static inline unsigned int crypto_tfm_ctx_alignment(void)
{
struct crypto_tfm *tfm;
return __alignof__(tfm->__crt_ctx);
}
static inline struct crypto_comp *__crypto_comp_cast(struct crypto_tfm *tfm)
{
return (struct crypto_comp *)tfm;
}
static inline struct crypto_comp *crypto_alloc_comp(const char *alg_name,
u32 type, u32 mask)
{
type &= ~CRYPTO_ALG_TYPE_MASK;
type |= CRYPTO_ALG_TYPE_COMPRESS;
mask |= CRYPTO_ALG_TYPE_MASK;
return __crypto_comp_cast(crypto_alloc_base(alg_name, type, mask));
}
static inline struct crypto_tfm *crypto_comp_tfm(struct crypto_comp *tfm)
{
return &tfm->base;
}
static inline void crypto_free_comp(struct crypto_comp *tfm)
{
crypto_free_tfm(crypto_comp_tfm(tfm));
}
static inline int crypto_has_comp(const char *alg_name, u32 type, u32 mask)
{
type &= ~CRYPTO_ALG_TYPE_MASK;
type |= CRYPTO_ALG_TYPE_COMPRESS;
mask |= CRYPTO_ALG_TYPE_MASK;
return crypto_has_alg(alg_name, type, mask);
}
static inline const char *crypto_comp_name(struct crypto_comp *tfm)
{
return crypto_tfm_alg_name(crypto_comp_tfm(tfm));
}
int crypto_comp_compress(struct crypto_comp *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen);
int crypto_comp_decompress(struct crypto_comp *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen);
#endif /* _LINUX_CRYPTO_H */