ref: 127dfcfefaec2397cb462ef797befd0b3611864e
dir: /third_party/boringssl/src/include/openssl/hmac.h/
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#ifndef OPENSSL_HEADER_HMAC_H
#define OPENSSL_HEADER_HMAC_H
#include <openssl/base.h>
#include <openssl/digest.h>
#if defined(__cplusplus)
extern "C" {
#endif
// HMAC contains functions for constructing PRFs from Merkle–Damgård hash
// functions using HMAC.
// One-shot operation.
// HMAC calculates the HMAC of |data_len| bytes of |data|, using the given key
// and hash function, and writes the result to |out|. On entry, |out| must
// contain at least |EVP_MD_size| bytes of space. The actual length of the
// result is written to |*out_len|. An output size of |EVP_MAX_MD_SIZE| will
// always be large enough. It returns |out| or NULL on error.
OPENSSL_EXPORT uint8_t *HMAC(const EVP_MD *evp_md, const void *key,
size_t key_len, const uint8_t *data,
size_t data_len, uint8_t *out,
unsigned int *out_len);
// Incremental operation.
// HMAC_CTX_init initialises |ctx| for use in an HMAC operation. It's assumed
// that HMAC_CTX objects will be allocated on the stack thus no allocation
// function is provided.
OPENSSL_EXPORT void HMAC_CTX_init(HMAC_CTX *ctx);
// HMAC_CTX_new allocates and initialises a new |HMAC_CTX| and returns it, or
// NULL on allocation failure. The caller must use |HMAC_CTX_free| to release
// the resulting object.
OPENSSL_EXPORT HMAC_CTX *HMAC_CTX_new(void);
// HMAC_CTX_cleanup frees data owned by |ctx|. It does not free |ctx| itself.
OPENSSL_EXPORT void HMAC_CTX_cleanup(HMAC_CTX *ctx);
// HMAC_CTX_free calls |HMAC_CTX_cleanup| and then frees |ctx| itself.
OPENSSL_EXPORT void HMAC_CTX_free(HMAC_CTX *ctx);
// HMAC_Init_ex sets up an initialised |HMAC_CTX| to use |md| as the hash
// function and |key| as the key. For a non-initial call, |md| may be NULL, in
// which case the previous hash function will be used. If the hash function has
// not changed and |key| is NULL, |ctx| reuses the previous key. It returns one
// on success or zero on allocation failure.
//
// WARNING: NULL and empty keys are ambiguous on non-initial calls. Passing NULL
// |key| but repeating the previous |md| reuses the previous key rather than the
// empty key.
OPENSSL_EXPORT int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, size_t key_len,
const EVP_MD *md, ENGINE *impl);
// HMAC_Update hashes |data_len| bytes from |data| into the current HMAC
// operation in |ctx|. It returns one.
OPENSSL_EXPORT int HMAC_Update(HMAC_CTX *ctx, const uint8_t *data,
size_t data_len);
// HMAC_Final completes the HMAC operation in |ctx| and writes the result to
// |out| and the sets |*out_len| to the length of the result. On entry, |out|
// must contain at least |HMAC_size| bytes of space. An output size of
// |EVP_MAX_MD_SIZE| will always be large enough. It returns one on success or
// zero on allocation failure.
OPENSSL_EXPORT int HMAC_Final(HMAC_CTX *ctx, uint8_t *out,
unsigned int *out_len);
// Utility functions.
// HMAC_size returns the size, in bytes, of the HMAC that will be produced by
// |ctx|. On entry, |ctx| must have been setup with |HMAC_Init_ex|.
OPENSSL_EXPORT size_t HMAC_size(const HMAC_CTX *ctx);
// HMAC_CTX_copy_ex sets |dest| equal to |src|. On entry, |dest| must have been
// initialised by calling |HMAC_CTX_init|. It returns one on success and zero
// on error.
OPENSSL_EXPORT int HMAC_CTX_copy_ex(HMAC_CTX *dest, const HMAC_CTX *src);
// HMAC_CTX_reset calls |HMAC_CTX_cleanup| followed by |HMAC_CTX_init|.
OPENSSL_EXPORT void HMAC_CTX_reset(HMAC_CTX *ctx);
// Deprecated functions.
OPENSSL_EXPORT int HMAC_Init(HMAC_CTX *ctx, const void *key, int key_len,
const EVP_MD *md);
// HMAC_CTX_copy calls |HMAC_CTX_init| on |dest| and then sets it equal to
// |src|. On entry, |dest| must /not/ be initialised for an operation with
// |HMAC_Init_ex|. It returns one on success and zero on error.
OPENSSL_EXPORT int HMAC_CTX_copy(HMAC_CTX *dest, const HMAC_CTX *src);
// Private functions
struct hmac_ctx_st {
const EVP_MD *md;
EVP_MD_CTX md_ctx;
EVP_MD_CTX i_ctx;
EVP_MD_CTX o_ctx;
} /* HMAC_CTX */;
#if defined(__cplusplus)
} // extern C
#if !defined(BORINGSSL_NO_CXX)
extern "C++" {
BSSL_NAMESPACE_BEGIN
BORINGSSL_MAKE_DELETER(HMAC_CTX, HMAC_CTX_free)
using ScopedHMAC_CTX =
internal::StackAllocated<HMAC_CTX, void, HMAC_CTX_init, HMAC_CTX_cleanup>;
BSSL_NAMESPACE_END
} // extern C++
#endif
#endif
#endif // OPENSSL_HEADER_HMAC_H