text: /* Copyright (c) 2015, Google Inc.
   *
   * Permission to use, copy, modify, and/or distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
   * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
   * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
   * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
  
  #ifndef OPENSSL_HEADER_CMAC_H
  #define OPENSSL_HEADER_CMAC_H
  
  #include "CCryptoBoringSSL_base.h"
  
  #if defined(__cplusplus)
  extern "C" {
  #endif
  
  
  // CMAC.
  //
  // CMAC is a MAC based on AES-CBC and defined in
  // https://tools.ietf.org/html/rfc4493#section-2.3.
  
  
  // One-shot functions.
  
  // AES_CMAC calculates the 16-byte, CMAC authenticator of |in_len| bytes of
  // |in| and writes it to |out|. The |key_len| may be 16 or 32 bytes to select
  // between AES-128 and AES-256. It returns one on success or zero on error.
  OPENSSL_EXPORT int AES_CMAC(uint8_t out[16], const uint8_t *key, size_t key_len,
                              const uint8_t *in, size_t in_len);
  
  
  // Incremental interface.
  
  // CMAC_CTX_new allocates a fresh |CMAC_CTX| and returns it, or NULL on
  // error.
  OPENSSL_EXPORT CMAC_CTX *CMAC_CTX_new(void);
  
  // CMAC_CTX_free frees a |CMAC_CTX|.
  OPENSSL_EXPORT void CMAC_CTX_free(CMAC_CTX *ctx);
  
  // CMAC_CTX_copy sets |out| to be a duplicate of the current state |in|. It
  // returns one on success and zero on error.
  OPENSSL_EXPORT int CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in);
  
  // CMAC_Init configures |ctx| to use the given |key| and |cipher|. The CMAC RFC
  // only specifies the use of AES-128 thus |key_len| should be 16 and |cipher|
  // should be |EVP_aes_128_cbc()|. However, this implementation also supports
  // AES-256 by setting |key_len| to 32 and |cipher| to |EVP_aes_256_cbc()|. The
  // |engine| argument is ignored.
  //
  // It returns one on success or zero on error.
  OPENSSL_EXPORT int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t key_len,
                               const EVP_CIPHER *cipher, ENGINE *engine);
  
  
  // CMAC_Reset resets |ctx| so that a fresh message can be authenticated.
  OPENSSL_EXPORT int CMAC_Reset(CMAC_CTX *ctx);
  
  // CMAC_Update processes |in_len| bytes of message from |in|. It returns one on
  // success or zero on error.
  OPENSSL_EXPORT int CMAC_Update(CMAC_CTX *ctx, const uint8_t *in, size_t in_len);
  
  // CMAC_Final sets |*out_len| to 16 and, if |out| is not NULL, writes 16 bytes
  // of authenticator to it. It returns one on success or zero on error.
  OPENSSL_EXPORT int CMAC_Final(CMAC_CTX *ctx, uint8_t *out, size_t *out_len);
  
  
  #if defined(__cplusplus)
  }  // extern C
  
  extern "C++" {
  
  BSSL_NAMESPACE_BEGIN
  
  BORINGSSL_MAKE_DELETER(CMAC_CTX, CMAC_CTX_free)
  
  BSSL_NAMESPACE_END
  
  }  // extern C++
  
  #endif
  
  #endif  // OPENSSL_HEADER_CMAC_H
  