diff options
Diffstat (limited to 'include/crypto')
| -rw-r--r-- | include/crypto/hash.h | 492 | ||||
| -rw-r--r-- | include/crypto/if_alg.h | 1 | ||||
| -rw-r--r-- | include/crypto/rng.h | 80 |
3 files changed, 573 insertions, 0 deletions
diff --git a/include/crypto/hash.h b/include/crypto/hash.h index 74b13ec1ebd4..98abda9ed3aa 100644 --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -17,6 +17,32 @@ 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; @@ -37,6 +63,63 @@ struct ahash_request { void *__ctx[] CRYPTO_MINALIGN_ATTR; }; +/** + * struct ahash_alg - asynchronous message digest definition + * @init: Initialize the transformation context. Intended only to initialize the + * state of the HASH transformation at the begining. This shall fill in + * the internal structures used during the entire duration of the whole + * transformation. No data processing happens at this point. + * @update: 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. + * @final: 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. + * @finup: 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. + * @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. + * @halg: see struct hash_alg_common + */ struct ahash_alg { int (*init)(struct ahash_request *req); int (*update)(struct ahash_request *req); @@ -63,6 +146,23 @@ struct shash_desc { crypto_shash_descsize(ctx)] CRYPTO_MINALIGN_ATTR; \ 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 + * @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, @@ -107,11 +207,35 @@ struct crypto_shash { 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_ABLKCIPHER 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); @@ -120,6 +244,10 @@ 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 + */ static inline void crypto_free_ahash(struct crypto_ahash *tfm) { crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm)); @@ -143,6 +271,16 @@ static inline struct hash_alg_common *crypto_hash_alg_common( 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; @@ -168,12 +306,32 @@ 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 the size of the ahash state size. 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_reqsize(struct crypto_ahash *tfm) { return tfm->reqsize; @@ -184,38 +342,166 @@ 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_shash_final. The parameters have the same + * meaning as discussed for those separate functions. + * + * Return: 0 if the message digest creation was successful; < 0 if an error + * occurred + */ 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 creation was successful; < 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: 0 if the message digest creation was successful; < 0 if an error + * occurred + */ 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_reqsize). + * + * 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) { return crypto_ahash_reqtfm(req)->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: 0 if the message digest initialization was successful; < 0 if an + * error occurred + */ static inline int crypto_ahash_init(struct ahash_request *req) { return crypto_ahash_reqtfm(req)->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: 0 if the message digest update was successful; < 0 if an error + * occurred + */ static inline int crypto_ahash_update(struct ahash_request *req) { return crypto_ahash_reqtfm(req)->update(req); } +/** + * 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; IS_ERR() is true in case + * of an error, PTR_ERR() returns the error code. + */ static inline struct ahash_request *ahash_request_alloc( struct crypto_ahash *tfm, gfp_t gfp) { @@ -230,6 +516,10 @@ static inline struct ahash_request *ahash_request_alloc( 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) { kzfree(req); @@ -241,6 +531,31 @@ static inline struct ahash_request *ahash_request_cast( 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, @@ -251,6 +566,19 @@ static inline void ahash_request_set_callback(struct ahash_request *req, 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) @@ -260,6 +588,33 @@ static inline void ahash_request_set_crypt(struct ahash_request *req, 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 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); @@ -268,6 +623,10 @@ 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 + */ static inline void crypto_free_shash(struct crypto_shash *tfm) { crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm)); @@ -279,6 +638,15 @@ static inline unsigned int crypto_shash_alignmask( 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)); @@ -294,6 +662,15 @@ 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; @@ -319,6 +696,21 @@ 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; @@ -329,29 +721,129 @@ 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. + * + * 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. + * + * 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_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). + * + * 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. + * + * 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) { return crypto_shash_alg(desc->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. + * + * Return: 0 if the message digest initialization was successful; < 0 if an + * error occurred + */ static inline int crypto_shash_init(struct shash_desc *desc) { return crypto_shash_alg(desc->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. + * + * 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. + * + * 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. + * + * 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); diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h index d61c11170213..cd62bf4289e9 100644 --- a/include/crypto/if_alg.h +++ b/include/crypto/if_alg.h @@ -42,6 +42,7 @@ struct af_alg_completion { struct af_alg_control { struct af_alg_iv *iv; int op; + unsigned int aead_assoclen; }; struct af_alg_type { diff --git a/include/crypto/rng.h b/include/crypto/rng.h index c93f9b917925..a16fb10142bf 100644 --- a/include/crypto/rng.h +++ b/include/crypto/rng.h @@ -20,11 +20,38 @@ extern struct crypto_rng *crypto_default_rng; int crypto_get_default_rng(void); void crypto_put_default_rng(void); +/** + * DOC: Random number generator API + * + * The random number generator API is used with the ciphers of type + * CRYPTO_ALG_TYPE_RNG (listed as type "rng" in /proc/crypto) + */ + static inline struct crypto_rng *__crypto_rng_cast(struct crypto_tfm *tfm) { return (struct crypto_rng *)tfm; } +/** + * crypto_alloc_rng() -- allocate RNG 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 random number generator. The returned struct + * crypto_rng is the cipher handle that is required for any subsequent + * API invocation for that random number generator. + * + * For all random number generators, this call creates a new private copy of + * the random number generator that does not share a state with other + * instances. The only exception is the "krng" random number generator which + * is a kernel crypto API use case for the get_random_bytes() function of the + * /dev/random driver. + * + * Return: allocated cipher handle in case of success; IS_ERR() is true in case + * of an error, PTR_ERR() returns the error code. + */ static inline struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask) { @@ -40,6 +67,14 @@ static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm) return &tfm->base; } +/** + * crypto_rng_alg - obtain name of RNG + * @tfm: cipher handle + * + * Return the generic name (cra_name) of the initialized random number generator + * + * Return: generic name string + */ static inline struct rng_alg *crypto_rng_alg(struct crypto_rng *tfm) { return &crypto_rng_tfm(tfm)->__crt_alg->cra_rng; @@ -50,23 +85,68 @@ static inline struct rng_tfm *crypto_rng_crt(struct crypto_rng *tfm) return &crypto_rng_tfm(tfm)->crt_rng; } +/** + * crypto_free_rng() - zeroize and free RNG handle + * @tfm: cipher handle to be freed + */ static inline void crypto_free_rng(struct crypto_rng *tfm) { crypto_free_tfm(crypto_rng_tfm(tfm)); } +/** + * crypto_rng_get_bytes() - get random number + * @tfm: cipher handle + * @rdata: output buffer holding the random numbers + * @dlen: length of the output buffer + * + * This function fills the caller-allocated buffer with random numbers using the + * random number generator referenced by the cipher handle. + * + * Return: > 0 function was successful and returns the number of generated + * bytes; < 0 if an error occurred + */ static inline int crypto_rng_get_bytes(struct crypto_rng *tfm, u8 *rdata, unsigned int dlen) { return crypto_rng_crt(tfm)->rng_gen_random(tfm, rdata, dlen); } +/** + * crypto_rng_reset() - re-initialize the RNG + * @tfm: cipher handle + * @seed: seed input data + * @slen: length of the seed input data + * + * The reset function completely re-initializes the random number generator + * referenced by the cipher handle by clearing the current state. The new state + * is initialized with the caller provided seed or automatically, depending + * on the random number generator type (the ANSI X9.31 RNG requires + * caller-provided seed, the SP800-90A DRBGs perform an automatic seeding). + * The seed is provided as a parameter to this function call. The provided seed + * should have the length of the seed size defined for the random number + * generator as defined by crypto_rng_seedsize. + * + * Return: 0 if the setting of the key was successful; < 0 if an error occurred + */ static inline int crypto_rng_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen) { return crypto_rng_crt(tfm)->rng_reset(tfm, seed, slen); } +/** + * crypto_rng_seedsize() - obtain seed size of RNG + * @tfm: cipher handle + * + * The function returns the seed size for the random number generator + * referenced by the cipher handle. This value may be zero if the random + * number generator does not implement or require a reseeding. For example, + * the SP800-90A DRBGs implement an automated reseeding after reaching a + * pre-defined threshold. + * + * Return: seed size for the random number generator + */ static inline int crypto_rng_seedsize(struct crypto_rng *tfm) { return crypto_rng_alg(tfm)->seedsize; |