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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 | ||
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25 | /* Curves IDs */ |
26 | #define ECC_CURVE_NIST_P192 0x0001 | |
27 | #define ECC_CURVE_NIST_P256 0x0002 | |
703c748d | 28 | #define ECC_CURVE_NIST_P384 0x0003 |
3c4b2390 | 29 | |
8d23da22 SM |
30 | /** |
31 | * struct ecdh - define an ECDH private key | |
32 | * | |
8d23da22 SM |
33 | * @key: Private ECDH key |
34 | * @key_size: Size of the private ECDH key | |
35 | */ | |
3c4b2390 | 36 | struct ecdh { |
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37 | char *key; |
38 | unsigned short key_size; | |
39 | }; | |
40 | ||
8d23da22 SM |
41 | /** |
42 | * crypto_ecdh_key_len() - Obtain the size of the private ECDH key | |
43 | * @params: private ECDH key | |
44 | * | |
45 | * This function returns the packet ECDH key size. A caller can use that | |
46 | * with the provided ECDH private key reference to obtain the required | |
47 | * memory size to hold a packet key. | |
48 | * | |
49 | * Return: size of the key in bytes | |
50 | */ | |
6e97e08d | 51 | unsigned int crypto_ecdh_key_len(const struct ecdh *params); |
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52 | |
53 | /** | |
54 | * crypto_ecdh_encode_key() - encode the private key | |
55 | * @buf: Buffer allocated by the caller to hold the packet ECDH | |
56 | * private key. The buffer should be at least crypto_ecdh_key_len | |
57 | * bytes in size. | |
58 | * @len: Length of the packet private key buffer | |
59 | * @p: Buffer with the caller-specified private key | |
60 | * | |
61 | * The ECDH implementations operate on a packet representation of the private | |
62 | * key. | |
63 | * | |
64 | * Return: -EINVAL if buffer has insufficient size, 0 on success | |
65 | */ | |
3c4b2390 | 66 | int crypto_ecdh_encode_key(char *buf, unsigned int len, const struct ecdh *p); |
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67 | |
68 | /** | |
69 | * crypto_ecdh_decode_key() - decode a private key | |
70 | * @buf: Buffer holding a packet key that should be decoded | |
c0ca1215 | 71 | * @len: Length of the packet private key buffer |
8d23da22 | 72 | * @p: Buffer allocated by the caller that is filled with the |
c0ca1215 | 73 | * unpacked ECDH private key. |
8d23da22 SM |
74 | * |
75 | * The unpacking obtains the private key by pointing @p to the correct location | |
76 | * in @buf. Thus, both pointers refer to the same memory. | |
77 | * | |
78 | * Return: -EINVAL if buffer has insufficient size, 0 on success | |
79 | */ | |
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80 | int crypto_ecdh_decode_key(const char *buf, unsigned int len, struct ecdh *p); |
81 | ||
82 | #endif |