1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (c) 2016, Intel Corporation
4 * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
6 #include <linux/kernel.h>
7 #include <linux/export.h>
9 #include <linux/string.h>
10 #include <crypto/ecdh.h>
11 #include <crypto/kpp.h>
13 #define ECDH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 2 * sizeof(short))
15 static inline u8 *ecdh_pack_data(void *dst, const void *src, size_t sz)
21 static inline const u8 *ecdh_unpack_data(void *dst, const void *src, size_t sz)
27 unsigned int crypto_ecdh_key_len(const struct ecdh *params)
29 return ECDH_KPP_SECRET_MIN_SIZE + params->key_size;
31 EXPORT_SYMBOL_GPL(crypto_ecdh_key_len);
33 int crypto_ecdh_encode_key(char *buf, unsigned int len,
34 const struct ecdh *params)
37 struct kpp_secret secret = {
38 .type = CRYPTO_KPP_SECRET_TYPE_ECDH,
45 if (len != crypto_ecdh_key_len(params))
48 ptr = ecdh_pack_data(ptr, &secret, sizeof(secret));
49 ptr = ecdh_pack_data(ptr, ¶ms->curve_id, sizeof(params->curve_id));
50 ptr = ecdh_pack_data(ptr, ¶ms->key_size, sizeof(params->key_size));
51 ecdh_pack_data(ptr, params->key, params->key_size);
55 EXPORT_SYMBOL_GPL(crypto_ecdh_encode_key);
57 int crypto_ecdh_decode_key(const char *buf, unsigned int len,
61 struct kpp_secret secret;
63 if (unlikely(!buf || len < ECDH_KPP_SECRET_MIN_SIZE))
66 ptr = ecdh_unpack_data(&secret, ptr, sizeof(secret));
67 if (secret.type != CRYPTO_KPP_SECRET_TYPE_ECDH)
70 ptr = ecdh_unpack_data(¶ms->curve_id, ptr, sizeof(params->curve_id));
71 ptr = ecdh_unpack_data(¶ms->key_size, ptr, sizeof(params->key_size));
72 if (secret.len != crypto_ecdh_key_len(params))
75 /* Don't allocate memory. Set pointer to data
76 * within the given buffer
78 params->key = (void *)ptr;
82 EXPORT_SYMBOL_GPL(crypto_ecdh_decode_key);