Come generare CSR (Certificate Signing Request) utilizzando C ++ e openssl [closed]

Sono nuovo di openssl. Sto cercando di implementare il programma per generare CSR usando openssl e c ++. Devo implementare i seguenti comandi usando C ++.

openssl req -new -newkey rsa: 1024 -nodes -keyout key.pem -out x509Req.pem.

Ho provato un codice di esempio dal tutorial link

bool gen_X509Req()
{
int             ret = 0;
RSA             *r = NULL;
BIGNUM          *bne = NULL;

int             nVersion = 1;
int             bits = 2048;
unsigned long   e = RSA_F4;

X509_REQ        *x509_req = NULL;
X509_NAME       *x509_name = NULL;
EVP_PKEY        *pKey = NULL;
RSA             *tem = NULL;
BIO             *out = NULL, *bio_err = NULL;

const char      *szCountry = "CA";
const char      *szProvince = "BC";
const char      *szCity = "Vancouver";
const char      *szOrganization = "Dynamsoft";
const char      *szCommon = "localhost";

const char      *szPath = "x509Req.pem";

// 1. generate rsa key
bne = BN_new();
ret = BN_set_word(bne,e);
if(ret != 1){
    goto free_all;
}

r = RSA_new();
ret = RSA_generate_key_ex(r, bits, bne, NULL);
if(ret != 1){
    goto free_all;
}

// 2. set version of x509 req
x509_req = X509_REQ_new();
ret = X509_REQ_set_version(x509_req, nVersion);
if (ret != 1){
    goto free_all;
}

// 3. set subject of x509 req
x509_name = X509_REQ_get_subject_name(x509_req);

ret = X509_NAME_add_entry_by_txt(x509_name,"C", MBSTRING_ASC, (const unsigned char*)szCountry, -1, -1, 0);
if (ret != 1){
    goto free_all;
}

ret = X509_NAME_add_entry_by_txt(x509_name,"ST", MBSTRING_ASC, (const unsigned char*)szProvince, -1, -1, 0);
if (ret != 1){
    goto free_all;
}

ret = X509_NAME_add_entry_by_txt(x509_name,"L", MBSTRING_ASC, (const unsigned char*)szCity, -1, -1, 0);
if (ret != 1){
    goto free_all;
}   

ret = X509_NAME_add_entry_by_txt(x509_name,"O", MBSTRING_ASC, (const unsigned char*)szOrganization, -1, -1, 0);
if (ret != 1){
    goto free_all;
}

ret = X509_NAME_add_entry_by_txt(x509_name,"CN", MBSTRING_ASC, (const unsigned char*)szCommon, -1, -1, 0);
if (ret != 1){
    goto free_all;
}

// 4. set public key of x509 req
pKey = EVP_PKEY_new();
EVP_PKEY_assign_RSA(pKey, r);
r = NULL;   // will be free rsa when EVP_PKEY_free(pKey)

ret = X509_REQ_set_pubkey(x509_req, pKey);
if (ret != 1){
    goto free_all;
}

// 5. set sign key of x509 req
ret = X509_REQ_sign(x509_req, pKey, EVP_sha1());    // return x509_req->signature->length
if (ret <= 0){
    goto free_all;
}

out = BIO_new_file(szPath,"w");
ret = PEM_write_bio_X509_REQ(out, x509_req);

// 6. free
 free_all:
X509_REQ_free(x509_req);
BIO_free_all(out);

EVP_PKEY_free(pKey);
BN_free(bne);

return (ret == 1); 
 }

È in grado di creare il file x509Req.pem, ma quando lo apro in linux con file aperto, mostra l'errore "Impossibile visualizzare 'x509Req.pem' Motivo: dati non riconosciuti o non supportati." Qualcuno potrebbe dirmi come risolvere questo errore o altri tutorial per generare CSR usando c ++ e openssl.

Grazie in anticipo.