1/* Copyright (c) 2015, Google Inc.
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15#ifndef OPENSSL_HEADER_CMAC_H
16#define OPENSSL_HEADER_CMAC_H
17
18#include <openssl/base.h>
19
20#if defined(__cplusplus)
21extern "C" {
22#endif
23
24
25// CMAC.
26//
27// CMAC is a MAC based on AES-CBC and defined in
28// https://tools.ietf.org/html/rfc4493#section-2.3.
29
30
31// One-shot functions.
32
33// AES_CMAC calculates the 16-byte, CMAC authenticator of |in_len| bytes of
34// |in| and writes it to |out|. The |key_len| may be 16 or 32 bytes to select
35// between AES-128 and AES-256. It returns one on success or zero on error.
36OPENSSL_EXPORT int AES_CMAC(uint8_t out[16], const uint8_t *key, size_t key_len,
37 const uint8_t *in, size_t in_len);
38
39
40// Incremental interface.
41
42// CMAC_CTX_new allocates a fresh |CMAC_CTX| and returns it, or NULL on
43// error.
44OPENSSL_EXPORT CMAC_CTX *CMAC_CTX_new(void);
45
46// CMAC_CTX_free frees a |CMAC_CTX|.
47OPENSSL_EXPORT void CMAC_CTX_free(CMAC_CTX *ctx);
48
49// CMAC_CTX_copy sets |out| to be a duplicate of the current state |in|. It
50// returns one on success and zero on error.
51OPENSSL_EXPORT int CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in);
52
53// CMAC_Init configures |ctx| to use the given |key| and |cipher|. The CMAC RFC
54// only specifies the use of AES-128 thus |key_len| should be 16 and |cipher|
55// should be |EVP_aes_128_cbc()|. However, this implementation also supports
56// AES-256 by setting |key_len| to 32 and |cipher| to |EVP_aes_256_cbc()|. The
57// |engine| argument is ignored.
58//
59// It returns one on success or zero on error.
60OPENSSL_EXPORT int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t key_len,
61 const EVP_CIPHER *cipher, ENGINE *engine);
62
63
64// CMAC_Reset resets |ctx| so that a fresh message can be authenticated.
65OPENSSL_EXPORT int CMAC_Reset(CMAC_CTX *ctx);
66
67// CMAC_Update processes |in_len| bytes of message from |in|. It returns one on
68// success or zero on error.
69OPENSSL_EXPORT int CMAC_Update(CMAC_CTX *ctx, const uint8_t *in, size_t in_len);
70
71// CMAC_Final sets |*out_len| to 16 and, if |out| is not NULL, writes 16 bytes
72// of authenticator to it. It returns one on success or zero on error.
73OPENSSL_EXPORT int CMAC_Final(CMAC_CTX *ctx, uint8_t *out, size_t *out_len);
74
75
76#if defined(__cplusplus)
77} // extern C
78
79extern "C++" {
80
81BSSL_NAMESPACE_BEGIN
82
83BORINGSSL_MAKE_DELETER(CMAC_CTX, CMAC_CTX_free)
84
85BSSL_NAMESPACE_END
86
87} // extern C++
88
89#endif
90
91#endif // OPENSSL_HEADER_CMAC_H
92