[linux.git] / crypto / ecdh_helper.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2016, Intel Corporation
 * Authors: Salvatore Benedetto <[email protected]>
 */
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/string.h>
#include <crypto/ecdh.h>
#include <crypto/kpp.h>

#define ECDH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 2 * sizeof(short))

static inline u8 *ecdh_pack_data(void *dst, const void *src, size_t sz)
{
	memcpy(dst, src, sz);
	return dst + sz;
}

static inline const u8 *ecdh_unpack_data(void *dst, const void *src, size_t sz)
{
	memcpy(dst, src, sz);
	return src + sz;
}

unsigned int crypto_ecdh_key_len(const struct ecdh *params)
{
	return ECDH_KPP_SECRET_MIN_SIZE + params->key_size;
}
EXPORT_SYMBOL_GPL(crypto_ecdh_key_len);

int crypto_ecdh_encode_key(char *buf, unsigned int len,
			   const struct ecdh *params)
{
	u8 *ptr = buf;
	struct kpp_secret secret = {
		.type = CRYPTO_KPP_SECRET_TYPE_ECDH,
		.len = len
	};

	if (unlikely(!buf))
		return -EINVAL;

	if (len != crypto_ecdh_key_len(params))
		return -EINVAL;

	ptr = ecdh_pack_data(ptr, &secret, sizeof(secret));
	ptr = ecdh_pack_data(ptr, &params->curve_id, sizeof(params->curve_id));
	ptr = ecdh_pack_data(ptr, &params->key_size, sizeof(params->key_size));
	ecdh_pack_data(ptr, params->key, params->key_size);

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_ecdh_encode_key);

int crypto_ecdh_decode_key(const char *buf, unsigned int len,
			   struct ecdh *params)
{
	const u8 *ptr = buf;
	struct kpp_secret secret;

	if (unlikely(!buf || len < ECDH_KPP_SECRET_MIN_SIZE))
		return -EINVAL;

	ptr = ecdh_unpack_data(&secret, ptr, sizeof(secret));
	if (secret.type != CRYPTO_KPP_SECRET_TYPE_ECDH)
		return -EINVAL;

	ptr = ecdh_unpack_data(&params->curve_id, ptr, sizeof(params->curve_id));
	ptr = ecdh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
	if (secret.len != crypto_ecdh_key_len(params))
		return -EINVAL;

	/* Don't allocate memory. Set pointer to data
	 * within the given buffer
	 */
	params->key = (void *)ptr;

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_ecdh_decode_key);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
3c4b2390 SB	2	/*
	3	* Copyright (c) 2016, Intel Corporation
	4	* Authors: Salvatore Benedetto <[email protected]>
3c4b2390 SB	5	*/
	6	#include <linux/kernel.h>
	7	#include <linux/export.h>
	8	#include <linux/err.h>
	9	#include <linux/string.h>
	10	#include <crypto/ecdh.h>
	11	#include <crypto/kpp.h>
	12
	13	#define ECDH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 2 * sizeof(short))
	14
	15	static inline u8 ecdh_pack_data(void dst, const void *src, size_t sz)
	16	{
	17	memcpy(dst, src, sz);
	18	return dst + sz;
	19	}
	20
	21	static inline const u8 ecdh_unpack_data(void dst, const void *src, size_t sz)
	22	{
	23	memcpy(dst, src, sz);
	24	return src + sz;
	25	}
	26
6e97e08d	27	unsigned int crypto_ecdh_key_len(const struct ecdh *params)
3c4b2390 SB	28	{
	29	return ECDH_KPP_SECRET_MIN_SIZE + params->key_size;
	30	}
	31	EXPORT_SYMBOL_GPL(crypto_ecdh_key_len);
	32
	33	int crypto_ecdh_encode_key(char *buf, unsigned int len,
	34	const struct ecdh *params)
	35	{
	36	u8 *ptr = buf;
	37	struct kpp_secret secret = {
	38	.type = CRYPTO_KPP_SECRET_TYPE_ECDH,
	39	.len = len
	40	};
	41
	42	if (unlikely(!buf))
	43	return -EINVAL;
	44
	45	if (len != crypto_ecdh_key_len(params))
	46	return -EINVAL;
	47
	48	ptr = ecdh_pack_data(ptr, &secret, sizeof(secret));
	49	ptr = ecdh_pack_data(ptr, &params->curve_id, sizeof(params->curve_id));
	50	ptr = ecdh_pack_data(ptr, &params->key_size, sizeof(params->key_size));
	51	ecdh_pack_data(ptr, params->key, params->key_size);
	52
	53	return 0;
	54	}
	55	EXPORT_SYMBOL_GPL(crypto_ecdh_encode_key);
	56
	57	int crypto_ecdh_decode_key(const char *buf, unsigned int len,
	58	struct ecdh *params)
	59	{
	60	const u8 *ptr = buf;
	61	struct kpp_secret secret;
	62
	63	if (unlikely(!buf \|\| len < ECDH_KPP_SECRET_MIN_SIZE))
	64	return -EINVAL;
	65
	66	ptr = ecdh_unpack_data(&secret, ptr, sizeof(secret));
	67	if (secret.type != CRYPTO_KPP_SECRET_TYPE_ECDH)
	68	return -EINVAL;
	69
	70	ptr = ecdh_unpack_data(&params->curve_id, ptr, sizeof(params->curve_id));
	71	ptr = ecdh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
	72	if (secret.len != crypto_ecdh_key_len(params))
	73	return -EINVAL;
	74
	75	/* Don't allocate memory. Set pointer to data
	76	* within the given buffer
	77	*/
	78	params->key = (void *)ptr;
	79
	80	return 0;
	81	}
	82	EXPORT_SYMBOL_GPL(crypto_ecdh_decode_key);