/* SPDX-License-Identifier: GPL-2.0-or-later *//* * ECDH params to be used with kpp API * * Copyright (c) 2016, Intel Corporation * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com> */#ifndef _CRYPTO_ECDH_#define _CRYPTO_ECDH_ /** * DOC: ECDH Helper Functions * * To use ECDH with the KPP cipher API, the following data structure and * functions should be used. * * The ECC curves known to the ECDH implementation are specified in this * header file. * * To use ECDH with KPP, the following functions should be used to operate on * an ECDH private key. The packet private key that can be set with * the KPP API function call of crypto_kpp_set_secret. */ /* Curves IDs */#define ECC_CURVE_NIST_P192	0x0001#define ECC_CURVE_NIST_P256	0x0002#define ECC_CURVE_NIST_P384	0x0003#define ECC_CURVE_NIST_P521	0x0004 /** * struct ecdh - define an ECDH private key * * @key:	Private ECDH key * @key_size:	Size of the private ECDH key */struct ecdh {	char *key;	unsigned short key_size;}; /** * crypto_ecdh_key_len() - Obtain the size of the private ECDH key * @params:	private ECDH key * * This function returns the packet ECDH key size. A caller can use that * with the provided ECDH private key reference to obtain the required * memory size to hold a packet key. * * Return: size of the key in bytes */unsigned int crypto_ecdh_key_len(const struct ecdh *params); /** * crypto_ecdh_encode_key() - encode the private key * @buf:	Buffer allocated by the caller to hold the packet ECDH *		private key. The buffer should be at least crypto_ecdh_key_len *		bytes in size. * @len:	Length of the packet private key buffer * @p:		Buffer with the caller-specified private key * * The ECDH implementations operate on a packet representation of the private * key. * * Return:	-EINVAL if buffer has insufficient size, 0 on success */int crypto_ecdh_encode_key(char *buf, unsigned int len, const struct ecdh *p); /** * crypto_ecdh_decode_key() - decode a private key * @buf:	Buffer holding a packet key that should be decoded * @len:	Length of the packet private key buffer * @p:		Buffer allocated by the caller that is filled with the *		unpacked ECDH private key. * * The unpacking obtains the private key by pointing @p to the correct location * in @buf. Thus, both pointers refer to the same memory. * * Return:	-EINVAL if buffer has insufficient size, 0 on success */int crypto_ecdh_decode_key(const char *buf, unsigned int len, struct ecdh *p); #endif