Error de obtención en EVP_OpenInit () de OpenSSL EVP api para descifrado RSA, en C

Question

Dec 06, 2011, 02:05 PM

openssl encryption public-key-encryption c rsa

Error de obtención en EVP_OpenInit () de OpenSSL EVP api para descifrado RSA, en C

Me enfrento a un problema en el descifrado de RSA usando OpenSSL Library (EVP api). Aquí está mi código para la generación de claves

#include <stdio.h>
#include <openssl/evp.h>
#include <openssl/rsa.h>
#include <openssl/bio.h>
#include <openssl/pem.h>

#define SECFILE "sec.pem"
#define PUBFILE "pub.pem"

int main()
{

    EVP_PKEY_CTX *ctx;
    EVP_PKEY *pkey = NULL;
    ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA, NULL);
    FILE *fp;

    if (!ctx)
    {
        /* Error occurred */
        perror("Error in CTX \n");

    }
    if (EVP_PKEY_keygen_init(ctx) <= 0)
    {
        /* Error */
        perror("Error in EVP_PKEY_keygen_init \n");
    }
    if (EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, 2048) <= 0)
    {
        /* Error */
        perror("Error in EVP_PKEY_CTX_set_rsa_keygen_bits \n");
    }
    /* Generate key */
    if (EVP_PKEY_keygen(ctx, &pkey) <= 0)
    {   
        /* Error */
        perror("Error in EVP_PKEY_keygen \n");

    }


    fp = fopen(SECFILE, "w");
    PEM_write_PrivateKey(fp, pkey, NULL,NULL, 0,0, NULL);
    fclose(fp);

    fp = fopen(PUBFILE, "w");
    PEM_write_PUBKEY(fp,pkey);
    fclose(fp);


    return 0;
}

Para el cifrado:

Usé esteenlac

Para descifrar:

   int do_evp_open(FILE *rsa_pkey_file, FILE *in_file, FILE *out_file) 
{ 
    int retval = 0; 
    RSA *rsa_pkey = NULL; 
    EVP_PKEY *pkey = EVP_PKEY_new(); 
    EVP_CIPHER_CTX ctx; 
    unsigned char buffer[4096]; 
    unsigned char buffer_out[4096 + EVP_MAX_IV_LENGTH]; 
    size_t len; 
    int len_out; 
    unsigned char *ek; 
    int eklen ; 
    uint32_t eklen_n; 
    unsigned char iv[EVP_MAX_IV_LENGTH] = {122,205,106,192,4,183,69,176,84,28,214,226,220,140,86,174}; 


    /// Read RSA Private Key 
    if (PEM_read_RSAPrivateKey(rsa_pkey_file, &rsa_pkey, NULL, NULL) == NULL) 
    { 
        fprintf(stderr, "Error loading RSA Private Key File.\n"); 
        ERR_print_errors_fp(stderr); 
        retval = -2; 
        goto out; 
    } 


    /// Assign RSA key to EVP key
    if (!EVP_PKEY_assign_RSA(pkey, rsa_pkey)) 
    { 
        fprintf(stderr, "EVP_PKEY_assign_RSA: failed.\n"); 
        retval = -3; 
        goto out; 
    }

    EVP_CIPHER_CTX_init(&ctx); 

    ek = malloc( EVP_PKEY_size(pkey)); 



    if (!EVP_OpenInit(&ctx, EVP_aes_128_cbc(), ek, eklen, iv,pkey)) 
    { 
        fprintf(stderr, "EVP_OpenInit: failed.\n"); 
       ERR_print_errors_fp(stderr); /// Prints error of occured in Openssl  
        retval = -3; 
        goto out_free; 
    } 




    while ((len = fread(buffer, 1, sizeof buffer, in_file)) > 0) 
    { 
        if (!EVP_OpenUpdate(&ctx, buffer_out, &len_out, buffer, len)) 
        { 
            fprintf(stderr, "EVP_OpenUpdate: failed.\n"); 
            retval = 3; 
            goto out_free; 
        } 

        if (fwrite(buffer_out, len_out, 1, out_file) != 1) 
        { 
            perror("output file"); 
            retval = -5; 
            goto out_free; 
        } 
    } 

    if (ferror(in_file)) 
    { 
        perror("input file"); 
        retval = -4; 
        goto out_free; 
    } 

    if (!EVP_OpenFinal(&ctx, buffer_out, &len_out)) 
    { 
        fprintf(stderr, "EVP_OpenFinal: failed.\n"); 
        retval = - 3; 
        goto out_free; 
    } 

    if (fwrite(buffer_out, len_out, 1, out_file) != 1) 
    { 
        perror("output file"); 
        retval = -5; 
        goto out_free; 
    } 

    out_free: 
    EVP_PKEY_free(pkey); 
    free(ek); 

    out: 
    return retval; 
}

Mis claves privadas y públicas son:

El error que recibo mientras EVP_OpenInit es:

140004942804648:error:0407106B:lib(4):func(113):reason(107):rsa_pk1.c:190: 140004942804648:error:04065072:lib(4):func(101):reason(114):rsa_eay.c:594

Cualquier ayuda sería apreciada. Gracias Pawan