sign_stream.cpp

Voici un exemple de programme permettant de signer un buffer mémoire (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-hash.h>
#include <include/ecctk-ecc.h>

s2byte sign_stream()
{
    s4byte  ret     = -1;

    /* set algo
     */
    s2byte  algo    = ECCTK_ECC_ALGO_ECDSA;

    /* set hashalgorithm
     */
    s2byte  hash_algo = ECCTK_HASH_ALGO_SHA160;

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

    /* set memory buffer to sign
     */
    u1byte  in[] = "Elliptic Curve Cryptographic ToolKit";

    /* set size of memory buffer
     */
    s4byte  in_size = sizeof(in);

    /* private key context
     */
    KPRV_CTX *kprv;

    /* signature context
     */
    SIGN_CTX *sign;

    /* read private key on file (protected by password : "mypassword")
     */
    kprv = ReadFileKprvCtx(kprvfile);
    if (kprv == NULL)
    {
        fprintf(stderr, "Read private key on %s failed\n", kprvfile);
        return EXIT_FAILURE;
    }

    /* 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;
    }

    switch (algo)
    {
    case ECCTK_ECC_ALGO_ECDSA:
        sign = SignStreamEcdsa(in, in_size, hash_algo, kprv, "mypassword");
        break;
    case ECCTK_ECC_ALGO_ECNR:
        sign = SignStreamEcnr(in, in_size, hash_algo, kprv, "mypassword");
        break;
    default:
        sign = NULL;
        break;
    }

    if (sign == NULL)
    {
        fprintf(stderr, "Sign stream failed\n");

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

        KprvCtxFree(kprv);
        return EXIT_FAILURE;
    }

    /* write signature context on file
     */
    ret = WriteFileSignCtx(signfile, sign);
    if (ret != ECCTK_ECC_NO_ERROR)
    {
        fprintf(stderr, "Write signature context on file %s failed (Error : %ld)\n", signfile, ret);
        
        /* remove value for all curve in memory
        */
        FreeEcctkAll();

        KprvCtxFree(kprv);
        SignCtxFree(sign);
        return EXIT_FAILURE;
    }

    /* free context
     */
    KprvCtxFree(kprv);
    SignCtxFree(sign);

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

    fprintf(stdout, "Sign stream success\n");
    return EXIT_SUCCESS;
}

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