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Diffstat (limited to 'include/crypto/kpp.h')
| -rw-r--r-- | include/crypto/kpp.h | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/include/crypto/kpp.h b/include/crypto/kpp.h new file mode 100644 index 000000000..1a34630fc --- /dev/null +++ b/include/crypto/kpp.h @@ -0,0 +1,352 @@ +/* + * Key-agreement Protocol Primitives (KPP) + * + * Copyright (c) 2016, Intel Corporation + * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com> + * + * 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_KPP_ +#define _CRYPTO_KPP_ +#include <linux/crypto.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 + * + * @base: Common crypto API algorithm data structure + */ +struct crypto_kpp { + 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. + * + * @reqsize: Request context size required by algorithm + * implementation + * @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); + + unsigned int reqsize; + 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); + +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 crypto_kpp_alg(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) +{ + kzfree(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) +{ + struct kpp_alg *alg = crypto_kpp_alg(tfm); + + return alg->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); + struct kpp_alg *alg = crypto_kpp_alg(tfm); + + return alg->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); + struct kpp_alg *alg = crypto_kpp_alg(tfm); + + return alg->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 |