lc_hmac_drbg.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_HMAC_DRBG_H
#define LC_HMAC_DRBG_H
 
#include "lc_drbg.h"
#include "lc_hmac.h"
#include "lc_rng.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
#if !defined(LC_DRBG_HMAC_STATELEN) || !defined(LC_DRBG_HMAC_BLOCKLEN) ||      \
        !defined(LC_DRBG_HMAC_CORE)
#error "Do not include this header file directly! Use lc_hmac_drbg_<hashtype>.h"
#endif
 
struct lc_drbg_hmac_state {
        struct lc_hmac_ctx hmac_ctx; /* Cipher handle - HMAC_MAX_STATE_SIZE */
        uint8_t *V; /* internal state 10.1.1.1 1a) - DRBG_STATELEN */
        uint8_t *C; /* static value 10.1.1.1 1b) - DRBG_STATELEN */
        unsigned int seeded : 1;
};
 
#define LC_DRBG_HMAC_STATE_SIZE(x)                                             \
        (2 * LC_DRBG_HMAC_STATELEN + LC_HMAC_STATE_SIZE(x))
#define LC_DRBG_HMAC_CTX_SIZE(x)                                               \
        (LC_DRBG_HMAC_STATE_SIZE(x) + sizeof(struct lc_drbg_hmac_state) +      \
         sizeof(struct lc_rng))
 
#define _LC_DRBG_HMAC_SET_CTX(name, ctx, offset)                               \
        _LC_HMAC_SET_CTX((&(name)->hmac_ctx), LC_DRBG_HMAC_CORE, ctx, offset); \
        (name)->V = (uint8_t *)((uint8_t *)ctx + offset +                      \
                                LC_HMAC_STATE_SIZE(LC_DRBG_HMAC_CORE));        \
        (name)->C = (uint8_t *)((uint8_t *)ctx + offset +                      \
                                LC_HMAC_STATE_SIZE(LC_DRBG_HMAC_CORE) +        \
                                LC_DRBG_HMAC_STATELEN);                        \
        (name)->seeded = 0
 
#define LC_DRBG_HMAC_SET_CTX(name)                                             \
        _LC_DRBG_HMAC_SET_CTX(name, name, sizeof(struct lc_drbg_hmac_state))
 
extern const struct lc_rng *lc_hmac_drbg;
 
#define LC_DRBG_HMAC_RNG_CTX(name)                                             \
        LC_RNG_CTX(name, lc_hmac_drbg);                                        \
        LC_DRBG_HMAC_SET_CTX((struct lc_drbg_hmac_state *)name->rng_state);    \
        lc_hmac_drbg->zero(name->rng_state)
 
#define LC_DRBG_HMAC_CTX_ON_STACK(name)                                             \
        _Pragma("GCC diagnostic push")                                              \
                _Pragma("GCC diagnostic ignored \"-Wvla\"") _Pragma(                \
                        "GCC diagnostic ignored \"-Wdeclaration-after-statement\"") \
                        LC_ALIGNED_BUFFER(                                          \
                                name##_ctx_buf,                                     \
                                LC_DRBG_HMAC_CTX_SIZE(LC_DRBG_HMAC_CORE),           \
                                LC_HASH_COMMON_ALIGNMENT);                          \
        struct lc_rng_ctx *name = (struct lc_rng_ctx *)name##_ctx_buf;              \
        LC_DRBG_HMAC_RNG_CTX(name);                                                 \
        _Pragma("GCC diagnostic pop")
 
int lc_drbg_hmac_alloc(struct lc_rng_ctx **drbg);
 
int lc_drbg_hmac_healthcheck_sanity(struct lc_rng_ctx *drbg);
 
#ifdef __cplusplus
}
#endif
 
#endif /* LC_HMAC_DRBG_H */