rcs.h

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/*
 * 2025 Quantum Resistant Cryptographic Solutions Corporation
 * All Rights Reserved.
 *
 * NOTICE: This software and all accompanying materials are the exclusive 
 * property of Quantum Resistant Cryptographic Solutions Corporation (QRCS).
 * The intellectual and technical concepts contained within this implementation 
 * are proprietary to QRCS and its authorized licensors and are protected under 
 * applicable U.S. and international copyright, patent, and trade secret laws.
 *
 * CRYPTOGRAPHIC STANDARDS:
 * - This software includes implementations of cryptographic algorithms such as 
 *   SHA3, AES, and others. These algorithms are public domain or standardized 
 *   by organizations such as NIST and are NOT the property of QRCS.
 * - However, all source code, optimizations, and implementations in this library 
 *   are original works of QRCS and are protected under this license.
 *
 * RESTRICTIONS:
 * - Redistribution, modification, or unauthorized distribution of this software, 
 *   in whole or in part, is strictly prohibited.
 * - This software is provided for non-commercial, educational, and research 
 *   purposes only. Commercial use in any form is expressly forbidden.
 * - Licensing and authorized distribution are solely at the discretion of QRCS.
 * - Any use of this software implies acceptance of these restrictions.
 *
 * DISCLAIMER:
 * This software is provided "as is," without warranty of any kind, express or 
 * implied, including but not limited to warranties of merchantability or fitness 
 * for a particular purpose. QRCS disclaims all liability for any direct, indirect, 
 * incidental, or consequential damages resulting from the use or misuse of this software.
 *
 * FULL LICENSE:
 * This software is subject to the **Quantum Resistant Cryptographic Solutions 
 * Proprietary License (QRCS-PL)**. The complete license terms are included 
 * in the LICENSE.txt file distributed with this software.
 *
 * Written by: John G. Underhill
 * Contact: john.underhill@protonmail.com
 */
 
#ifndef QSC_RCS_H
#define QSC_RCS_H
 
#include "common.h"
#include "sha3.h"
#if defined(QSC_SYSTEM_AESNI_ENABLED)
#   include "intrinsics.h"
#   include <immintrin.h>
#endif
 
QSC_CPLUSPLUS_ENABLED_START

 
/***********************************
*    USER CONFIGURABLE SETTINGS    *
***********************************/

#if !defined(QSC_RCS_AUTHENTICATED)
#   define QSC_RCS_AUTHENTICATED
#endif
 
/* Enable one of the authentication options: 
   a 24 round KMAC, a reduced rounds KMAC, or the QMAC post quantum GMAC function */
#if defined(QSC_RCS_AUTHENTICATED)
// * \def QSC_RCS_AUTH_KMACR24
// * \brief Sets the authentication mode to standard KMAC-R24.
// * Remove this definition to enable the reduced rounds version using KMAC-R12.
// */
//# define QSC_RCS_AUTH_KMACR24

// * \def QSC_RCS_AUTH_KMACR12
// * \brief Enables the reduced rounds KMAC-R12 implementation.
// */
//# define QSC_RCS_AUTH_KMACR12

 #  define QSC_RCS_AUTH_QMAC
#endif
 
/* The default authentication MAC */
#if defined(QSC_RCS_AUTHENTICATED)
#   if !defined(QSC_RCS_AUTH_KMACR24) && !defined(QSC_RCS_AUTH_KMACR12) && !defined(QSC_RCS_AUTH_QMAC)
#       define QSC_RCS_AUTH_KMACR24
#   endif
#endif
 
#if defined(QSC_RCS_AUTH_QMAC)
#   include "qmac.h"
#endif
 
/***********************************
*     RCS CONSTANTS AND SIZES      *
***********************************/

#define QSC_RCS_BLOCK_SIZE 32ULL

#define QSC_RCS256_KEY_SIZE 32ULL

#define QSC_RCS256_MAC_SIZE 32ULL

#define QSC_RCS512_KEY_SIZE 64ULL
 
#if defined(QSC_RCS_AUTH_QMAC)
#define QSC_RCS512_MAC_SIZE 32ULL
#else
#define QSC_RCS512_MAC_SIZE 64ULL
#endif

#define QSC_RCS_NONCE_SIZE 32ULL

typedef enum
{
    RCS256 = 0x01,    
    RCS512 = 0x02,    
} rcs_cipher_type;

QSC_EXPORT_API typedef struct
{
    const uint8_t* key;      
    size_t keylen;            
    uint8_t* nonce;            
    const uint8_t* info;    
    size_t infolen;          
} qsc_rcs_keyparams;

QSC_EXPORT_API typedef struct
{
    rcs_cipher_type ctype;              
#if defined(QSC_SYSTEM_AESNI_ENABLED)
    __m128i roundkeys[62];             
#   if defined(QSC_SYSTEM_HAS_AVX512)
        __m512i roundkeysw[31];         
#   endif
#else
    uint32_t roundkeys[248];           
#endif
    size_t roundkeylen;                  
    size_t rounds;                        
#if defined(QSC_RCS_AUTH_QMAC)
    qsc_qmac_state kstate;              
#else
    qsc_keccak_state kstate;          
#endif
    uint8_t nonce[QSC_RCS_NONCE_SIZE];   
    uint64_t counter;                    
    bool encrypt;                        
} qsc_rcs_state;

QSC_EXPORT_API void qsc_rcs_dispose(qsc_rcs_state* ctx);

QSC_EXPORT_API void qsc_rcs_initialize(qsc_rcs_state* ctx, const qsc_rcs_keyparams* keyparams, bool encryption);

QSC_EXPORT_API void qsc_rcs_set_associated(qsc_rcs_state* ctx, const uint8_t* data, size_t length);

QSC_EXPORT_API void qsc_rcs_store_nonce(const qsc_rcs_state* ctx, uint8_t nonce[QSC_RCS_NONCE_SIZE]);

QSC_EXPORT_API bool qsc_rcs_transform(qsc_rcs_state* ctx, uint8_t* output, const uint8_t* input, size_t length);

QSC_EXPORT_API bool qsc_rcs_extended_transform(qsc_rcs_state* ctx, uint8_t* output, const uint8_t* input, size_t length, bool finalize);
 
QSC_CPLUSPLUS_ENABLED_END
 
#endif