/* * Symmetric key ciphers. * * Copyright (c) 2007-2015 Herbert Xu * * 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 #include #include /** * 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; 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 #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 /** * 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 * * If @tfm is a NULL or error pointer, this function does nothing. */ 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; } static inline unsigned int crypto_skcipher_alg_walksize( 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->walksize; } /** * crypto_skcipher_chunksize() - obtain chunk size * @tfm: cipher handle * * The block size is set to one for ciphers such as CTR. However, * you still need to provide incremental updates in multiples of * the underlying block size as the IV does not have sub-block * granularity. This is known in this API as the chunk size. * * Return: chunk size in bytes */ static inline unsigned int crypto_skcipher_chunksize( struct crypto_skcipher *tfm) { return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm)); } /** * crypto_skcipher_walksize() - obtain walk size * @tfm: cipher handle * * In some cases, algorithms can only perform optimally when operating on * multiple blocks in parallel. This is reflected by the walksize, which * must be a multiple of the chunksize (or equal if the concern does not * apply) * * Return: walk size in bytes */ static inline unsigned int crypto_skcipher_walksize( struct crypto_skcipher *tfm) { return crypto_skcipher_alg_walksize(crypto_skcipher_alg(tfm)); } /** * 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_sync_skcipher_blocksize( struct crypto_sync_skcipher *tfm) { return crypto_skcipher_blocksize(&tfm->base); } 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); } static inline u32 crypto_sync_skcipher_get_flags( struct crypto_sync_skcipher *tfm) { return crypto_skcipher_get_flags(&tfm->base); } static inline void crypto_sync_skcipher_set_flags( struct crypto_sync_skcipher *tfm, u32 flags) { crypto_skcipher_set_flags(&tfm->base, flags); } static inline void crypto_sync_skcipher_clear_flags( struct crypto_sync_skcipher *tfm, u32 flags) { crypto_skcipher_clear_flags(&tfm->base, 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); } static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm, const u8 *key, unsigned int keylen) { return crypto_skcipher_setkey(&tfm->base, key, keylen); } static inline unsigned int crypto_skcipher_default_keysize( struct crypto_skcipher *tfm) { return tfm->keysize; } /** * 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); } static inline struct crypto_sync_skcipher *crypto_sync_skcipher_reqtfm( struct skcipher_request *req) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); return container_of(tfm, struct crypto_sync_skcipher, base); } /** * 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); if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) return -ENOKEY; 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); if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) return -ENOKEY; 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 void skcipher_request_set_sync_tfm(struct skcipher_request *req, struct crypto_sync_skcipher *tfm) { skcipher_request_set_tfm(req, &tfm->base); } 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, or NULL if out of memory */ 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); } static inline void skcipher_request_zero(struct skcipher_request *req) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm)); } /** * 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 */