/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Key-agreement Protocol Primitives (KPP) * * Copyright (c) 2016, Intel Corporation * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com> */ #ifndef _CRYPTO_KPP_ #define _CRYPTO_KPP_ #include <linux/atomic.h> #include <linux/container_of.h> #include <linux/crypto.h> #include <linux/slab.h> /** * struct kpp_request * * @base: Common attributes for async crypto requests * @src: Source data * @dst: Destination data * @src_len: Size of the input buffer * @dst_len: Size of the output buffer. It needs to be at least * as big as the expected result depending on the operation * After operation it will be updated with the actual size of the * result. In case of error where the dst sgl size was insufficient, * it will be updated to the size required for the operation. * @__ctx: Start of private context data */ struct kpp_request { struct crypto_async_request base; struct scatterlist *src; struct scatterlist *dst; unsigned int src_len; unsigned int dst_len; void *__ctx[] CRYPTO_MINALIGN_ATTR; }; /** * struct crypto_kpp - user-instantiated object which encapsulate * algorithms and core processing logic * * @reqsize: Request context size required by algorithm * implementation * @base: Common crypto API algorithm data structure */ struct crypto_kpp { unsigned int reqsize; struct crypto_tfm base; }; /** * struct kpp_alg - generic key-agreement protocol primitives * * @set_secret: Function invokes the protocol specific function to * store the secret private key along with parameters. * The implementation knows how to decode the buffer * @generate_public_key: Function generate the public key to be sent to the * counterpart. In case of error, where output is not big * enough req->dst_len will be updated to the size * required * @compute_shared_secret: Function compute the shared secret as defined by * the algorithm. The result is given back to the user. * In case of error, where output is not big enough, * req->dst_len will be updated to the size required * @max_size: Function returns the size of the output buffer * @init: Initialize the object. This is called only once at * instantiation time. In case the cryptographic hardware * needs to be initialized. Software fallback should be * put in place here. * @exit: Undo everything @init did. * * @base: Common crypto API algorithm data structure */ struct kpp_alg { int (*set_secret)(struct crypto_kpp *tfm, const void *buffer, unsigned int len); int (*generate_public_key)(struct kpp_request *req); int (*compute_shared_secret)(struct kpp_request *req); unsigned int (*max_size)(struct crypto_kpp *tfm); int (*init)(struct crypto_kpp *tfm); void (*exit)(struct crypto_kpp *tfm); struct crypto_alg base; }; /** * DOC: Generic Key-agreement Protocol Primitives API * * The KPP API is used with the algorithm type * CRYPTO_ALG_TYPE_KPP (listed as type "kpp" in /proc/crypto) */ /** * crypto_alloc_kpp() - allocate KPP tfm handle * @alg_name: is the name of the kpp algorithm (e.g. "dh", "ecdh") * @type: specifies the type of the algorithm * @mask: specifies the mask for the algorithm * * Allocate a handle for kpp algorithm. The returned struct crypto_kpp * is required for any following API invocation * * Return: allocated handle in case of success; IS_ERR() is true in case of * an error, PTR_ERR() returns the error code. */ struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask); int crypto_has_kpp(const char *alg_name, u32 type, u32 mask); static inline struct crypto_tfm *crypto_kpp_tfm(struct crypto_kpp *tfm) { return &tfm->base; } static inline struct kpp_alg *__crypto_kpp_alg(struct crypto_alg *alg) { return container_of(alg, struct kpp_alg, base); } static inline struct crypto_kpp *__crypto_kpp_tfm(struct crypto_tfm *tfm) { return container_of(tfm, struct crypto_kpp, base); } static inline struct kpp_alg *crypto_kpp_alg(struct crypto_kpp *tfm) { return __crypto_kpp_alg(crypto_kpp_tfm(tfm)->__crt_alg); } static inline unsigned int crypto_kpp_reqsize(struct crypto_kpp *tfm) { return tfm->reqsize; } static inline void kpp_request_set_tfm(struct kpp_request *req, struct crypto_kpp *tfm) { req->base.tfm = crypto_kpp_tfm(tfm); } static inline struct crypto_kpp *crypto_kpp_reqtfm(struct kpp_request *req) { return __crypto_kpp_tfm(req->base.tfm); } static inline u32 crypto_kpp_get_flags(struct crypto_kpp *tfm) { return crypto_tfm_get_flags(crypto_kpp_tfm(tfm)); } static inline void crypto_kpp_set_flags(struct crypto_kpp *tfm, u32 flags) { crypto_tfm_set_flags(crypto_kpp_tfm(tfm), flags); } /** * crypto_free_kpp() - free KPP tfm handle * * @tfm: KPP tfm handle allocated with crypto_alloc_kpp() * * If @tfm is a NULL or error pointer, this function does nothing. */ static inline void crypto_free_kpp(struct crypto_kpp *tfm) { crypto_destroy_tfm(tfm, crypto_kpp_tfm(tfm)); } /** * kpp_request_alloc() - allocates kpp request * * @tfm: KPP tfm handle allocated with crypto_alloc_kpp() * @gfp: allocation flags * * Return: allocated handle in case of success or NULL in case of an error. */ static inline struct kpp_request *kpp_request_alloc(struct crypto_kpp *tfm, gfp_t gfp) { struct kpp_request *req; req = kmalloc(sizeof(*req) + crypto_kpp_reqsize(tfm), gfp); if (likely(req)) kpp_request_set_tfm(req, tfm); return req; } /** * kpp_request_free() - zeroize and free kpp request * * @req: request to free */ static inline void kpp_request_free(struct kpp_request *req) { kfree_sensitive(req); } /** * kpp_request_set_callback() - Sets an asynchronous callback. * * Callback will be called when an asynchronous operation on a given * request is finished. * * @req: request that the callback will be set for * @flgs: specify for instance if the operation may backlog * @cmpl: callback which will be called * @data: private data used by the caller */ static inline void kpp_request_set_callback(struct kpp_request *req, u32 flgs, crypto_completion_t cmpl, void *data) { req->base.complete = cmpl; req->base.data = data; req->base.flags = flgs; } /** * kpp_request_set_input() - Sets input buffer * * Sets parameters required by generate_public_key * * @req: kpp request * @input: ptr to input scatter list * @input_len: size of the input scatter list */ static inline void kpp_request_set_input(struct kpp_request *req, struct scatterlist *input, unsigned int input_len) { req->src = input; req->src_len = input_len; } /** * kpp_request_set_output() - Sets output buffer * * Sets parameters required by kpp operation * * @req: kpp request * @output: ptr to output scatter list * @output_len: size of the output scatter list */ static inline void kpp_request_set_output(struct kpp_request *req, struct scatterlist *output, unsigned int output_len) { req->dst = output; req->dst_len = output_len; } enum { CRYPTO_KPP_SECRET_TYPE_UNKNOWN, CRYPTO_KPP_SECRET_TYPE_DH, CRYPTO_KPP_SECRET_TYPE_ECDH, }; /** * struct kpp_secret - small header for packing secret buffer * * @type: define type of secret. Each kpp type will define its own * @len: specify the len of the secret, include the header, that * follows the struct */ struct kpp_secret { unsigned short type; unsigned short len; }; /** * crypto_kpp_set_secret() - Invoke kpp operation * * Function invokes the specific kpp operation for a given alg. * * @tfm: tfm handle * @buffer: Buffer holding the packet representation of the private * key. The structure of the packet key depends on the particular * KPP implementation. Packing and unpacking helpers are provided * for ECDH and DH (see the respective header files for those * implementations). * @len: Length of the packet private key buffer. * * Return: zero on success; error code in case of error */ static inline int crypto_kpp_set_secret(struct crypto_kpp *tfm, const void *buffer, unsigned int len) { return crypto_kpp_alg(tfm)->set_secret(tfm, buffer, len); } /** * crypto_kpp_generate_public_key() - Invoke kpp operation * * Function invokes the specific kpp operation for generating the public part * for a given kpp algorithm. * * To generate a private key, the caller should use a random number generator. * The output of the requested length serves as the private key. * * @req: kpp key request * * Return: zero on success; error code in case of error */ static inline int crypto_kpp_generate_public_key(struct kpp_request *req) { struct crypto_kpp *tfm = crypto_kpp_reqtfm(req); return crypto_kpp_alg(tfm)->generate_public_key(req); } /** * crypto_kpp_compute_shared_secret() - Invoke kpp operation * * Function invokes the specific kpp operation for computing the shared secret * for a given kpp algorithm. * * @req: kpp key request * * Return: zero on success; error code in case of error */ static inline int crypto_kpp_compute_shared_secret(struct kpp_request *req) { struct crypto_kpp *tfm = crypto_kpp_reqtfm(req); return crypto_kpp_alg(tfm)->compute_shared_secret(req); } /** * crypto_kpp_maxsize() - Get len for output buffer * * Function returns the output buffer size required for a given key. * Function assumes that the key is already set in the transformation. If this * function is called without a setkey or with a failed setkey, you will end up * in a NULL dereference. * * @tfm: KPP tfm handle allocated with crypto_alloc_kpp() */ static inline unsigned int crypto_kpp_maxsize(struct crypto_kpp *tfm) { struct kpp_alg *alg = crypto_kpp_alg(tfm); return alg->max_size(tfm); } #endif
