eddsa.c

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/**
 * @file eddsa.c
 * @brief EdDSA (Edwards-Curve Digital Signature Algorithm)
 *
 * @section License
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * Copyright (C) 2010-2024 Oryx Embedded SARL. All rights reserved.
 *
 * This file is part of CycloneCRYPTO Open.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * @author Oryx Embedded SARL (www.oryx-embedded.com)
 * @version 2.4.4
 **/
 
//Switch to the appropriate trace level
#define TRACE_LEVEL CRYPTO_TRACE_LEVEL
 
//Dependencies
#include "core/crypto.h"
#include "ecc/eddsa.h"
#include "mpi/mpi.h"
#include "debug.h"
 
//Check crypto library configuration
#if (ED25519_SUPPORT == ENABLED || ED448_SUPPORT == ENABLED)
 
 
/**
 * @brief Initialize an EdDSA public key
 * @param[in] key Pointer to the EdDSA public key to initialize
 **/
 
void eddsaInitPublicKey(EddsaPublicKey *key)
{
   //Initialize multiple precision integer
   mpiInit(&key->q);
}
 
 
/**
 * @brief Release an EdDSA public key
 * @param[in] key Pointer to the EdDSA public key to free
 **/
 
void eddsaFreePublicKey(EddsaPublicKey *key)
{
   //Free multiple precision integer
   mpiFree(&key->q);
}
 
 
/**
 * @brief Initialize an EdDSA private key
 * @param[in] key Pointer to the EdDSA private key to initialize
 **/
 
void eddsaInitPrivateKey(EddsaPrivateKey *key)
{
   //Initialize multiple precision integers
   mpiInit(&key->d);
   mpiInit(&key->q);
 
   //Initialize private key slot
   key->slot = -1;
}
 
 
/**
 * @brief Release an EdDSA private key
 * @param[in] key Pointer to the EdDSA public key to free
 **/
 
void eddsaFreePrivateKey(EddsaPrivateKey *key)
{
   //Free multiple precision integers
   mpiFree(&key->d);
   mpiFree(&key->q);
}
 
 
/**
 * @brief EdDSA key pair generation
 * @param[in] prngAlgo PRNG algorithm
 * @param[in] prngContext Pointer to the PRNG context
 * @param[in] curveInfo Elliptic curve parameters
 * @param[out] privateKey EdDSA private key
 * @param[out] publicKey EdDSA public key
 * @return Error code
 **/
 
error_t eddsaGenerateKeyPair(const PrngAlgo *prngAlgo, void *prngContext,
   const EcCurveInfo *curveInfo, EddsaPrivateKey *privateKey,
   EddsaPublicKey *publicKey)
{
   error_t error;
 
   //Generate a private key
   error = eddsaGeneratePrivateKey(prngAlgo, prngContext, curveInfo,
      privateKey);
 
   //Check status code
   if(!error)
   {
      //Derive the public key from the private key
      error = eddsaGeneratePublicKey(curveInfo, privateKey, publicKey);
   }
 
   //Return status code
   return error;
}
 
 
/**
 * @brief EdDSA private key generation
 * @param[in] prngAlgo PRNG algorithm
 * @param[in] prngContext Pointer to the PRNG context
 * @param[in] curveInfo Elliptic curve parameters
 * @param[out] privateKey EdDSA private key
 * @return Error code
 **/
 
error_t eddsaGeneratePrivateKey(const PrngAlgo *prngAlgo, void *prngContext,
   const EcCurveInfo *curveInfo, EddsaPrivateKey *privateKey)
{
   error_t error;
 
#if (ED25519_SUPPORT == ENABLED)
   //Ed25519 algorithm?
   if(curveInfo == ED25519_CURVE)
   {
      uint8_t rawPrivateKey[ED25519_PRIVATE_KEY_LEN];
 
      //Generate an Ed25519 private key
      error = ed25519GeneratePrivateKey(prngAlgo, prngContext, rawPrivateKey);
 
      //Check status code
      if(!error)
      {
         //Import the Ed25519 private key
         error = mpiImport(&privateKey->d, rawPrivateKey, ED25519_PRIVATE_KEY_LEN,
            MPI_FORMAT_LITTLE_ENDIAN);
      }
   }
   else
#endif
#if (ED448_SUPPORT == ENABLED)
   //Ed448 algorithm?
   if(curveInfo == ED448_CURVE)
   {
      uint8_t rawPrivateKey[ED448_PRIVATE_KEY_LEN];
 
      //Generate an Ed448 private key
      error = ed448GeneratePrivateKey(prngAlgo, prngContext, rawPrivateKey);
 
      //Check status code
      if(!error)
      {
         //Import the Ed448 private key
         error = mpiImport(&privateKey->d, rawPrivateKey, ED448_PRIVATE_KEY_LEN,
            MPI_FORMAT_LITTLE_ENDIAN);
      }
   }
   else
#endif
   //Unknown algorithm?
   {
      //Report an error
      error = ERROR_INVALID_PARAMETER;
   }
 
   //Return status code
   return error;
}
 
 
/**
 * @brief Derive the public key from an EdDSA private key
 * @param[in] curveInfo Elliptic curve parameters
 * @param[in] privateKey EdDSA private key
 * @param[out] publicKey EdDSA public key
 * @return Error code
 **/
 
error_t eddsaGeneratePublicKey(const EcCurveInfo *curveInfo,
   const EddsaPrivateKey *privateKey, EddsaPublicKey *publicKey)
{
   error_t error;
 
#if (ED25519_SUPPORT == ENABLED)
   //Ed25519 algorithm?
   if(curveInfo == ED25519_CURVE)
   {
      uint8_t rawPrivateKey[ED25519_PRIVATE_KEY_LEN];
      uint8_t rawPublicKey[ED25519_PUBLIC_KEY_LEN];
 
      //Export the Ed25519 private key
      error = mpiExport(&privateKey->d, rawPrivateKey, ED25519_PRIVATE_KEY_LEN,
         MPI_FORMAT_LITTLE_ENDIAN);
 
      //Check status code
      if(!error)
      {
         //Derive the public key from the private key
         error = ed25519GeneratePublicKey(rawPrivateKey, rawPublicKey);
      }
 
      //Check status code
      if(!error)
      {
         //Import the Ed25519 public key
         error = mpiImport(&publicKey->q, rawPublicKey, ED25519_PUBLIC_KEY_LEN,
            MPI_FORMAT_LITTLE_ENDIAN);
      }
   }
   else
#endif
#if (ED448_SUPPORT == ENABLED)
   //Ed448 algorithm?
   if(curveInfo == ED448_CURVE)
   {
      uint8_t rawPrivateKey[ED448_PRIVATE_KEY_LEN];
      uint8_t rawPublicKey[ED448_PUBLIC_KEY_LEN];
 
      //Export the Ed448 private key
      error = mpiExport(&privateKey->d, rawPrivateKey, ED448_PRIVATE_KEY_LEN,
         MPI_FORMAT_LITTLE_ENDIAN);
 
      //Check status code
      if(!error)
      {
         //Derive the public key from the private key
         error = ed448GeneratePublicKey(rawPrivateKey, rawPublicKey);
      }
 
      //Check status code
      if(!error)
      {
         //Import the Ed448 public key
         error = mpiImport(&publicKey->q, rawPublicKey, ED448_PUBLIC_KEY_LEN,
            MPI_FORMAT_LITTLE_ENDIAN);
      }
   }
   else
#endif
   //Unknown algorithm?
   {
      //Report an error
      error = ERROR_INVALID_PARAMETER;
   }
 
   //Return status code
   return error;
}
 
#endif