lc_symhmac.h

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/*
 * Copyright (C) 2022 - 2024, Stephan Mueller <smueller@chronox.de>
 *
 * License: see LICENSE file in root directory
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
 * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR 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 NOT ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */
 
#ifndef LC_SYMHMAC_H
#define LC_SYMHMAC_H
 
#include "lc_aead.h"
#include "lc_sym.h"
#include "lc_hmac.h"
#include "lc_memset_secure.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
struct lc_sh_cryptor {
        struct lc_sym_ctx sym;
        struct lc_hmac_ctx auth_ctx;
};
 
#define LC_SH_STATE_SIZE(sym, hash)                                            \
        (LC_SYM_STATE_SIZE(sym) + LC_HMAC_STATE_SIZE(hash))
#define LC_SH_CTX_SIZE(sym, hash)                                              \
        (sizeof(struct lc_aead) + sizeof(struct lc_sh_cryptor) +               \
         LC_SH_STATE_SIZE(sym, hash))
 
/* AES-CBC with HMAC based AEAD-algorithm */
extern const struct lc_aead *lc_symhmac_aead;
 
#define _LC_SH_SET_CTX(name, symalgo, hash)                                    \
        _LC_SYM_SET_CTX((&name->sym), symalgo, name,                           \
                        (sizeof(struct lc_sh_cryptor)));                       \
        _LC_HMAC_SET_CTX(                                                      \
                (&name->auth_ctx), hash, name,                                 \
                (sizeof(struct lc_sh_cryptor) + LC_SYM_STATE_SIZE(symalgo)))
 
#define LC_SH_SET_CTX(name, sym, hash)                                         \
        LC_AEAD_CTX(name, lc_symhmac_aead);                                    \
        _LC_SH_SET_CTX(((struct lc_sh_cryptor *)name->aead_state), sym, hash)
 
int lc_sh_alloc(const struct lc_sym *sym, const struct lc_hash *hash,
                struct lc_aead_ctx **ctx);
 
#define LC_SH_CTX_ON_STACK(name, sym, hash)                                         \
        _Pragma("GCC diagnostic push")                                              \
                _Pragma("GCC diagnostic ignored \"-Wvla\"") _Pragma(                \
                        "GCC diagnostic ignored \"-Wdeclaration-after-statement\"") \
                        LC_ALIGNED_BUFFER(name##_ctx_buf,                           \
                                          LC_SH_CTX_SIZE(sym, hash),                \
                                          LC_HASH_COMMON_ALIGNMENT);                \
        struct lc_aead_ctx *name = (struct lc_aead_ctx *)name##_ctx_buf;            \
        LC_SH_SET_CTX(name, sym, hash);                                             \
        lc_aead_zero(name);                                                         \
        _Pragma("GCC diagnostic pop")
 
#ifdef __cplusplus
}
#endif
 
#endif /* LC_SYMHMAC_H */