[mirror_ubuntu-jammy-kernel.git] / include / crypto / dh.h

/*
 * Diffie-Hellman secret to be used with kpp API along with helper functions
 *
 * 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_DH_
#define _CRYPTO_DH_

/**
 * DOC: DH Helper Functions
 *
 * To use DH with the KPP cipher API, the following data structure and
 * functions should be used.
 *
 * To use DH with KPP, the following functions should be used to operate on
 * a DH private key. The packet private key that can be set with
 * the KPP API function call of crypto_kpp_set_secret.
 */

/**
 * struct dh - define a DH private key
 *
 * @key:	Private DH key
 * @p:		Diffie-Hellman parameter P
 * @q:		Diffie-Hellman parameter Q
 * @g:		Diffie-Hellman generator G
 * @key_size:	Size of the private DH key
 * @p_size:	Size of DH parameter P
 * @q_size:	Size of DH parameter Q
 * @g_size:	Size of DH generator G
 */
struct dh {
	void *key;
	void *p;
	void *q;
	void *g;
	unsigned int key_size;
	unsigned int p_size;
	unsigned int q_size;
	unsigned int g_size;
};

/**
 * crypto_dh_key_len() - Obtain the size of the private DH key
 * @params:	private DH key
 *
 * This function returns the packet DH key size. A caller can use that
 * with the provided DH private key reference to obtain the required
 * memory size to hold a packet key.
 *
 * Return: size of the key in bytes
 */
unsigned int crypto_dh_key_len(const struct dh *params);

/**
 * crypto_dh_encode_key() - encode the private key
 * @buf:	Buffer allocated by the caller to hold the packet DH
 *		private key. The buffer should be at least crypto_dh_key_len
 *		bytes in size.
 * @len:	Length of the packet private key buffer
 * @params:	Buffer with the caller-specified private key
 *
 * The DH implementations operate on a packet representation of the private
 * key.
 *
 * Return:	-EINVAL if buffer has insufficient size, 0 on success
 */
int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params);

/**
 * crypto_dh_decode_key() - decode a private key
 * @buf:	Buffer holding a packet key that should be decoded
 * @len:	Length of the packet private key buffer
 * @params:	Buffer allocated by the caller that is filled with the
 *		unpacked DH 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_dh_decode_key(const char *buf, unsigned int len, struct dh *params);

#endif
Commit	Line	Data
802c7f1c SB	1	/*
	2	* Diffie-Hellman secret to be used with kpp API along with helper functions
	3	*
	4	* Copyright (c) 2016, Intel Corporation
	5	* Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify it
	8	* under the terms of the GNU General Public License as published by the Free
	9	* Software Foundation; either version 2 of the License, or (at your option)
	10	* any later version.
	11	*
	12	*/
	13	#ifndef _CRYPTO_DH_
	14	#define _CRYPTO_DH_
	15
8d23da22 SM	16	/**
	17	* DOC: DH Helper Functions
	18	*
	19	* To use DH with the KPP cipher API, the following data structure and
	20	* functions should be used.
	21	*
	22	* To use DH with KPP, the following functions should be used to operate on
	23	* a DH private key. The packet private key that can be set with
	24	* the KPP API function call of crypto_kpp_set_secret.
	25	*/
	26
	27	/**
	28	* struct dh - define a DH private key
	29	*
	30	* @key: Private DH key
	31	* @p: Diffie-Hellman parameter P
e3fe0ae1	32	* @q: Diffie-Hellman parameter Q
8d23da22 SM	33	* @g: Diffie-Hellman generator G
	34	* @key_size: Size of the private DH key
	35	* @p_size: Size of DH parameter P
e3fe0ae1	36	* @q_size: Size of DH parameter Q
8d23da22 SM	37	* @g_size: Size of DH generator G
8d23da22 SM	38	*/
802c7f1c SB	39	struct dh {
	40	void *key;
	41	void *p;
e3fe0ae1	42	void *q;
802c7f1c SB	43	void *g;
	44	unsigned int key_size;
	45	unsigned int p_size;
e3fe0ae1	46	unsigned int q_size;
802c7f1c SB	47	unsigned int g_size;
	48	};
	49
8d23da22 SM	50	/**
	51	* crypto_dh_key_len() - Obtain the size of the private DH key
	52	* @params: private DH key
	53	*
	54	* This function returns the packet DH key size. A caller can use that
	55	* with the provided DH private key reference to obtain the required
	56	* memory size to hold a packet key.
	57	*
	58	* Return: size of the key in bytes
	59	*/
5b3f3a8b	60	unsigned int crypto_dh_key_len(const struct dh *params);
8d23da22 SM	61
	62	/**
	63	* crypto_dh_encode_key() - encode the private key
	64	* @buf: Buffer allocated by the caller to hold the packet DH
	65	* private key. The buffer should be at least crypto_dh_key_len
	66	* bytes in size.
	67	* @len: Length of the packet private key buffer
	68	* @params: Buffer with the caller-specified private key
	69	*
	70	* The DH implementations operate on a packet representation of the private
	71	* key.
	72	*
	73	* Return: -EINVAL if buffer has insufficient size, 0 on success
	74	*/
802c7f1c	75	int crypto_dh_encode_key(char buf, unsigned int len, const struct dh params);
8d23da22 SM	76
	77	/**
	78	* crypto_dh_decode_key() - decode a private key
	79	* @buf: Buffer holding a packet key that should be decoded
c0ca1215	80	* @len: Length of the packet private key buffer
8d23da22	81	* @params: Buffer allocated by the caller that is filled with the
c0ca1215	82	* unpacked DH private key.
8d23da22 SM	83	*
	84	* The unpacking obtains the private key by pointing @p to the correct location
	85	* in @buf. Thus, both pointers refer to the same memory.
	86	*
	87	* Return: -EINVAL if buffer has insufficient size, 0 on success
	88	*/
802c7f1c SB	89	int crypto_dh_decode_key(const char buf, unsigned int len, struct dh params);
	90
	91	#endif