[mirror_ubuntu-hirsute-kernel.git] / include / crypto / ecdh.h

/* 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

/**
 * struct ecdh - define an ECDH private key
 *
 * @curve_id:	ECC curve the key is based on.
 * @key:	Private ECDH key
 * @key_size:	Size of the private ECDH key
 */
struct ecdh {
	unsigned short curve_id;
	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
Commit	Line	Data
2874c5fd	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
3c4b2390 SB	2	/*
	3	* ECDH params to be used with kpp API
	4	*
	5	* Copyright (c) 2016, Intel Corporation
	6	* Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
3c4b2390 SB	7	*/
	8	#ifndef _CRYPTO_ECDH_
	9	#define _CRYPTO_ECDH_
	10
8d23da22 SM	11	/**
	12	* DOC: ECDH Helper Functions
	13	*
	14	* To use ECDH with the KPP cipher API, the following data structure and
	15	* functions should be used.
	16	*
	17	* The ECC curves known to the ECDH implementation are specified in this
	18	* header file.
	19	*
	20	* To use ECDH with KPP, the following functions should be used to operate on
	21	* an ECDH private key. The packet private key that can be set with
	22	* the KPP API function call of crypto_kpp_set_secret.
	23	*/
	24
3c4b2390 SB	25	/* Curves IDs */
	26	#define ECC_CURVE_NIST_P192 0x0001
	27	#define ECC_CURVE_NIST_P256 0x0002
	28
8d23da22 SM	29	/**
	30	* struct ecdh - define an ECDH private key
	31	*
	32	* @curve_id: ECC curve the key is based on.
	33	* @key: Private ECDH key
	34	* @key_size: Size of the private ECDH key
	35	*/
3c4b2390 SB	36	struct ecdh {
	37	unsigned short curve_id;
	38	char *key;
	39	unsigned short key_size;
	40	};
	41
8d23da22 SM	42	/**
	43	* crypto_ecdh_key_len() - Obtain the size of the private ECDH key
	44	* @params: private ECDH key
	45	*
	46	* This function returns the packet ECDH key size. A caller can use that
	47	* with the provided ECDH private key reference to obtain the required
	48	* memory size to hold a packet key.
	49	*
	50	* Return: size of the key in bytes
	51	*/
6e97e08d	52	unsigned int crypto_ecdh_key_len(const struct ecdh *params);
8d23da22 SM	53
	54	/**
	55	* crypto_ecdh_encode_key() - encode the private key
	56	* @buf: Buffer allocated by the caller to hold the packet ECDH
	57	* private key. The buffer should be at least crypto_ecdh_key_len
	58	* bytes in size.
	59	* @len: Length of the packet private key buffer
	60	* @p: Buffer with the caller-specified private key
	61	*
	62	* The ECDH implementations operate on a packet representation of the private
	63	* key.
	64	*
	65	* Return: -EINVAL if buffer has insufficient size, 0 on success
	66	*/
3c4b2390	67	int crypto_ecdh_encode_key(char buf, unsigned int len, const struct ecdh p);
8d23da22 SM	68
	69	/**
	70	* crypto_ecdh_decode_key() - decode a private key
	71	* @buf: Buffer holding a packet key that should be decoded
c0ca1215	72	* @len: Length of the packet private key buffer
8d23da22	73	* @p: Buffer allocated by the caller that is filled with the
c0ca1215	74	* unpacked ECDH private key.
8d23da22 SM	75	*
	76	* The unpacking obtains the private key by pointing @p to the correct location
	77	* in @buf. Thus, both pointers refer to the same memory.
	78	*
	79	* Return: -EINVAL if buffer has insufficient size, 0 on success
	80	*/
3c4b2390 SB	81	int crypto_ecdh_decode_key(const char buf, unsigned int len, struct ecdh p);
	82
	83	#endif