linux/net/bluetooth/ecdh_helper.c

/*
 * ECDH helper functions - KPP wrappings
 *
 * Copyright (C) 2017 Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
 * CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
 * COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
 * SOFTWARE IS DISCLAIMED.
 */
#include "ecdh_helper.h"

#include <linux/scatterlist.h>
#include <crypto/ecdh.h>

static inline void swap_digits(u64 *in, u64 *out, unsigned int ndigits)
{ … }

/* compute_ecdh_secret() - function assumes that the private key was
 *                         already set.
 * @tfm:          KPP tfm handle allocated with crypto_alloc_kpp().
 * @public_key:   pair's ecc public key.
 * secret:        memory where the ecdh computed shared secret will be saved.
 *
 * Return: zero on success; error code in case of error.
 */
int compute_ecdh_secret(struct crypto_kpp *tfm, const u8 public_key[64],
			u8 secret[32])
{ … }

/* set_ecdh_privkey() - set or generate ecc private key.
 *
 * Function generates an ecc private key in the crypto subsystem when receiving
 * a NULL private key or sets the received key when not NULL.
 *
 * @tfm:           KPP tfm handle allocated with crypto_alloc_kpp().
 * @private_key:   user's ecc private key. When not NULL, the key is expected
 *                 in little endian format.
 *
 * Return: zero on success; error code in case of error.
 */
int set_ecdh_privkey(struct crypto_kpp *tfm, const u8 private_key[32])
{ … }

/* generate_ecdh_public_key() - function assumes that the private key was
 *                              already set.
 *
 * @tfm:          KPP tfm handle allocated with crypto_alloc_kpp().
 * @public_key:   memory where the computed ecc public key will be saved.
 *
 * Return: zero on success; error code in case of error.
 */
int generate_ecdh_public_key(struct crypto_kpp *tfm, u8 public_key[64])
{ … }

/* generate_ecdh_keys() - generate ecc key pair.
 *
 * @tfm:          KPP tfm handle allocated with crypto_alloc_kpp().
 * @public_key:   memory where the computed ecc public key will be saved.
 *
 * Return: zero on success; error code in case of error.
 */
int generate_ecdh_keys(struct crypto_kpp *tfm, u8 public_key[64])
{ … }