generate_keypair.cpp

Voici un exemple de programme permettant de générer un bi-clef (algorithme asymétrique). Ce code est générique et permet d'utiliser tous les algorithmes présent dans la librairie. Les éléments fixés ne le sont qu'à titre d'exemple.

/* -----------------------------------------------------------------------
 *
 * Copyright (c) 2002-2005 Mr Ludovic FLAMENT <ludovic.flament@free.fr>, LIEVIN, FRANCE
 *
 * Termes :
 *
 * L'utilisation et/ou la redistribution de ce code (avec ou sans modification),
 * ainsi que de tous les composants du produit (librairies, documentation, exemples, ...)
 * est soumise aux termes de la licence qui vous est attribuée par son auteur.
 *
 * -----------------------------------------------------------------------
 */

#include <stdlib.h>
#include <stdio.h>

#include <include/ecctk-prototype.h>
#include <include/ecctk-ecc.h>

s2byte generate_keypair()
{
    s4byte  ret     = -1;

    /* set curve
     */
#ifndef ECCTK_EVALUATION
    s2byte  curve   = ECCTK_CURVE_SEC_PRIME_256;
#else
    s2byte  curve   = ECCTK_CURVE_SEC_PRIME_160;
#endif

    /* set input/output file name
     */
    s1byte  kprvfile[]  = "private_key_file",
            kpubfile[]  = "public_key_file";

    /* private key context
     */
    KPRV_CTX *kprv;
    
    /* public key context
     */
    KPUB_CTX *kpub;

    /* Initialize value for all curve in memory
     */
    ret = InitializeEcctkAll();
    if (ret != ECCTK_ECC_NO_ERROR)
    {
        fprintf(stderr, "InitializeEcctkAll failed (%d)\n", ret);
        return EXIT_FAILURE;
    }

    /* generate new private key protected by password "g-4!yAv2"
     */
    kprv = GeneratePrivateKey(curve, "g-4!yAv2");
    if (kprv == NULL)
    {
        /* remove value for all curve in memory
        */
        FreeEcctkAll();

        fprintf(stderr, "Generate private key failed\n");
        return EXIT_FAILURE;
    }

    /* compute public key from private key
     */
    kpub = GeneratePublicKey(kprv, "g-4!yAv2");
    if (kpub == NULL)
    {
        /* remove value for all curve in memory
        */
        FreeEcctkAll();
        KprvCtxFree(kprv);

        fprintf(stderr, "Generate public key failed\n");
        return EXIT_FAILURE;
    }

    /* save public key on file
     */
    ret = WriteFileKpubCtx(kpubfile, kpub);
    if (ret != ECCTK_ECC_NO_ERROR)
    {
        fprintf(stderr, "Write public key on %s failed (Error : %ld)\n", kpubfile, ret);

        /* remove value for all curve in memory
         */
        FreeEcctkAll();
        KpubCtxFree(kpub);
        KprvCtxFree(kprv);
        return EXIT_FAILURE;
    }

    /* save private key on file
     */
    ret = WriteFileKprvCtx(kprvfile, kprv);
    if (ret != ECCTK_ECC_NO_ERROR)
    {
        fprintf(stderr, "Write private key on %s failed (%ld)\n", kprvfile, ret);

        /* remove value for all curve in memory
        */
        FreeEcctkAll();
        KpubCtxFree(kpub);
        KprvCtxFree(kprv);
        return EXIT_FAILURE;
    }

    fprintf(stdout, "Generate key pair success\n");

    /* free context
     */
    KpubCtxFree(kpub);
    KprvCtxFree(kprv);

    /* remove value for all curve in memory
     */
    FreeEcctkAll();

    return EXIT_SUCCESS;
}

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