1 /* Copyright (c) 2015, Google Inc.
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.
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. */
15 #ifndef OPENSSL_HEADER_CMAC_H
16 #define OPENSSL_HEADER_CMAC_H
18 #include <openssl/base.h>
20 #if defined(__cplusplus)
27 // CMAC is a MAC based on AES-CBC and defined in
28 // https://tools.ietf.org/html/rfc4493#section-2.3.
31 // One-shot functions.
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.
36 OPENSSL_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);
40 // Incremental interface.
42 // CMAC_CTX_new allocates a fresh |CMAC_CTX| and returns it, or NULL on
44 OPENSSL_EXPORT CMAC_CTX *CMAC_CTX_new(void);
46 // CMAC_CTX_free frees a |CMAC_CTX|.
47 OPENSSL_EXPORT void CMAC_CTX_free(CMAC_CTX *ctx);
49 // CMAC_Init configures |ctx| to use the given |key| and |cipher|. The CMAC RFC
50 // only specifies the use of AES-128 thus |key_len| should be 16 and |cipher|
51 // should be |EVP_aes_128_cbc()|. However, this implementation also supports
52 // AES-256 by setting |key_len| to 32 and |cipher| to |EVP_aes_256_cbc()|. The
53 // |engine| argument is ignored.
55 // It returns one on success or zero on error.
56 OPENSSL_EXPORT int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t key_len,
57 const EVP_CIPHER *cipher, ENGINE *engine);
60 // CMAC_Reset resets |ctx| so that a fresh message can be authenticated.
61 OPENSSL_EXPORT int CMAC_Reset(CMAC_CTX *ctx);
63 // CMAC_Update processes |in_len| bytes of message from |in|. It returns one on
64 // success or zero on error.
65 OPENSSL_EXPORT int CMAC_Update(CMAC_CTX *ctx, const uint8_t *in, size_t in_len);
67 // CMAC_Final sets |*out_len| to 16 and, if |out| is not NULL, writes 16 bytes
68 // of authenticator to it. It returns one on success or zero on error.
69 OPENSSL_EXPORT int CMAC_Final(CMAC_CTX *ctx, uint8_t *out, size_t *out_len);
72 #if defined(__cplusplus)
79 BORINGSSL_MAKE_DELETER(CMAC_CTX, CMAC_CTX_free)
87 #endif // OPENSSL_HEADER_CMAC_H