ecdh.h

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/* 2020-2026 Quantum Resistant Cryptographic Solutions Corporation
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 * Written by: John G. Underhill
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 */
 
#ifndef QSC_ECDH_H
#define QSC_ECDH_H
 
#include "qsccommon.h"
 
QSC_CPLUSPLUS_ENABLED_START

 
#if defined(QSC_ECDH_S1P256)
#   define QSC_ECDH_PUBLICKEY_SIZE 64U

#   define QSC_ECDH_PRIVATEKEY_SIZE 32U

#   define QSC_ECDH_SHAREDSECRET_SIZE 32U

#   define QSC_ECDH_SEED_SIZE 32U

#   define QSC_ECDH_ALGNAME "ECDH-P256"
 
#elif defined(QSC_ECDH_S3P384)

#   define QSC_ECDH_PUBLICKEY_SIZE 96U

#   define QSC_ECDH_PRIVATEKEY_SIZE 48U

#   define QSC_ECDH_SHAREDSECRET_SIZE 48U

#   define QSC_ECDH_SEED_SIZE 48U

#   define QSC_ECDH_ALGNAME "ECDH-P384"
 
#elif defined(QSC_ECDH_S5P521)

#   define QSC_ECDH_PUBLICKEY_SIZE 132U

#   define QSC_ECDH_PRIVATEKEY_SIZE 66U

#   define QSC_ECDH_SHAREDSECRET_SIZE 66U

#   define QSC_ECDH_SEED_SIZE 66U

#   define QSC_ECDH_ALGNAME "ECDH-P521"
 
#else
#   error "No ECDH parameter set defined. Define QSC_ECDH_S1EC25519 or QSC_ECDH_S3EC448."
#endif

QSC_EXPORT_API void qsc_ecdh_public_from_private(uint8_t* publickey, const uint8_t* privatekey);

QSC_EXPORT_API bool qsc_ecdh_generate_keypair(uint8_t* publickey, uint8_t* privatekey, bool (*rng_generate)(uint8_t*, size_t));

QSC_EXPORT_API bool qsc_ecdh_generate_seeded_keypair(uint8_t* publickey, uint8_t* privatekey, const uint8_t* seed);

QSC_EXPORT_API bool qsc_ecdh_key_exchange(uint8_t* secret, const uint8_t* privatekey, const uint8_t* publickey);
 
QSC_CPLUSPLUS_ENABLED_END
 
#endif