Question

I have a problem with some source code regarding OpenSSL and Cpp. For some reason it runs fine but doesn’t open a socket! When I try to connect to it using s_client I get ‘Connect: No Error”. When I run netstat I get no open port. It should open a port on 12120. I even disabled my firewall temporarly and it didn’t help! BTW I’m using Windows 7. Thanks for your consideration! My program just says everythings fine and it starts blocking at the second *BIO_do_accept( abio );*

#include "stdio.h"
#include "string.h"

#include "openssl/bio.h"
#include "openssl/ssl.h"
#include "openssl/err.h"

int password_callback(char *buf, int size, int rwflag, void *userdata)
{
    /* For the purposes of this demonstration, the password is "dw" */

    printf("*** Callback function called\n");
    strcpy(buf, "dw");
    return 1;
}

int main()
{
    SSL_CTX *ctx;
    SSL *ssl;
    BIO *bio, *abio, *out, *sbio;

    int (*callback)(char *, int, int, void *) = &password_callback;

    printf("Secure Programming with the OpenSSL API, Part 4:\n");
    printf("Serving it up in a secure manner\n\n");

    SSL_load_error_strings();
    ERR_load_BIO_strings();
    SSL_library_init();
    ERR_load_SSL_strings();
    OpenSSL_add_all_algorithms();

    printf("Attempting to create SSL context... ");
    ctx = SSL_CTX_new( SSLv23_server_method() );
    if(ctx == NULL)
    {
        printf("Failed. Aborting.\n");
        return 0;
    }

    printf("\nLoading certificates...\n");
    SSL_CTX_set_default_passwd_cb(ctx, callback);
    if(!SSL_CTX_use_certificate_file(ctx, "certificate.pem", SSL_FILETYPE_PEM))
    {
        ERR_print_errors_fp(stdout);
        SSL_CTX_free(ctx);
        return 0;
    }
    if(!SSL_CTX_use_PrivateKey_file(ctx, "private.key", SSL_FILETYPE_PEM))
    {
        ERR_print_errors_fp(stdout);
        SSL_CTX_free(ctx);
        return 0;
    }

    printf("Attempting to create BIO object... ");
    bio = BIO_new_ssl(ctx, 0);
    if(bio == NULL)
    {
        printf("Failed. Aborting.\n");
        ERR_print_errors_fp(stdout);
        SSL_CTX_free(ctx);
        return 0;
    }

    printf("\nAttempting to set up BIO for SSL...\n");
    BIO_get_ssl(bio, &ssl);
    SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY);

    abio = BIO_new_accept("12120");
    BIO_set_accept_bios(abio, bio);

    printf("Waiting for incoming connection...\n");

    if(BIO_do_accept(abio) <= 0)
    {
        ERR_print_errors_fp(stdout);
        SSL_CTX_free(ctx);    SSL_library_init();
        BIO_free_all(bio);
        BIO_free_all(abio);
        return 0;
    }

    if(BIO_do_accept(abio) <= 0)
    {
        ERR_print_errors_fp(stdout);
        SSL_CTX_free(ctx);
        BIO_free_all(bio);
        BIO_free_all(abio);
        return 0;
    }

    out = BIO_pop(abio);

    if(BIO_do_handshake(out) <= 0)
    {
        printf("Handshake failed.\n");
        ERR_print_errors_fp(stdout);
        SSL_CTX_free(ctx);
        BIO_free_all(bio);
        BIO_free_all(abio);
        return 0;
    }

    BIO_puts(out, "Hello\n");
    BIO_flush(out);

    BIO_free_all(out);
    BIO_free_all(bio);
    BIO_free_all(abio);

    SSL_CTX_free(ctx);
}

Answer 1

What exactly are you expecting here? You should see port 12120 in LISTENING state. Your client should then be able to connect. Your server then does another accept, which will prevent it reading any I/O on the accepted port, and will ultimately block your client too. I don’t know why you are doing two accept’s in a row but it’s your code.