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) 21 extern "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. 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); 38 39 40 // Incremental interface. 41 42 // CMAC_CTX_new allocates a fresh |CMAC_CTX| and returns it, or NULL on 43 // error. 44 OPENSSL_EXPORT CMAC_CTX *CMAC_CTX_new(void); 45 46 // CMAC_CTX_free frees a |CMAC_CTX|. 47 OPENSSL_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. 51 OPENSSL_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. 60 OPENSSL_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. 65 OPENSSL_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. 69 OPENSSL_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. 73 OPENSSL_EXPORT int CMAC_Final(CMAC_CTX *ctx, uint8_t *out, size_t *out_len); 74 75 76 #if defined(__cplusplus) 77 } // extern C 78 79 extern "C++" { 80 81 BSSL_NAMESPACE_BEGIN 82 83 BORINGSSL_MAKE_DELETER(CMAC_CTX, CMAC_CTX_free) 84 85 BSSL_NAMESPACE_END 86 87 } // extern C++ 88 89 #endif 90 91 #endif // OPENSSL_HEADER_CMAC_H 92