c - 当我试图做 ssl_connect() 返回 0 和 ssl_get_error 返回 5

Question

下面是正在使用它的代码。

/* ---------------------------------------------------------- *
    * These function calls initialize openssl for correct work.  *
    * ---------------------------------------------------------- */
    OpenSSL_add_all_algorithms();
    ERR_load_BIO_strings();
    ERR_load_crypto_strings();
    SSL_load_error_strings();

    /* ---------------------------------------------------------- *
    * Create the Input/Output BIO's.                             *
    * ---------------------------------------------------------- */
    certbio = BIO_new(BIO_s_file());
    outbio = BIO_new_fp(stdout, BIO_NOCLOSE);

    /* ---------------------------------------------------------- *
    * initialize SSL library and register algorithms             *
    * ---------------------------------------------------------- */
    if (SSL_library_init() < 0)
    {
        BIO_printf(outbio, "Could not initialize the OpenSSL library !\n");
    }
    /* ---------------------------------------------------------- *
    * Set SSLv2 client hello, also announce SSLv3 and TLSv1      *
    * ---------------------------------------------------------- */
    method = TLSv1_client_method();

    /* ---------------------------------------------------------- *
    * Try to create a new SSL context                            *
    * ---------------------------------------------------------- */
    if ((ctx = SSL_CTX_new(method)) == NULL)
    {
        BIO_printf(outbio, "Unable to create a new SSL context structure.\n");
    }

    /* Create new SSL connection state object */
    ssl = SSL_new(ctx);

    /* Make the underlying TCP socket connection */
    server = openconnection(ip_addr);
    if (server != 0)
    {
        printf("Successfully made the TCP connection");
    }

    /* Attach the SSL session to the socket descriptor */
    SSL_set_fd(ssl, server);

    /**
     * SSL_connect - initiate the TLS/SSL handshake with an TLS/SSL server 
     * Try to SSL-connect here, returns 1 for success
     */
    err_status = SSL_connect(ssl);
    if(err_status != 1)
    {
        err_status = SSL_get_error(ssl, err_status);
        printf("SYSTEM:SSL_SOCKET:Could not build SSL session: %d %s\n", err_status,strerror(errno));
    }
    else
    {
        BIO_printf(outbio, "Successfully enabled SSL/TLS session");
    }

    /* Get the remote certificate into the X509 structure    */
    cert = SSL_get_peer_certificate(ssl);
    if (cert == NULL)
    {
        BIO_printf(outbio, "Error: Could not get a certificate");
    }
    else
    {
        BIO_printf(outbio, "Retrieved the server's certificate");
    }

    /* ---------------------------------------------------------- *
    * extract various certificate information                    *
    * -----------------------------------------------------------*/
    certname = X509_NAME_new();
    certname = X509_get_subject_name(cert);

    /* ---------------------------------------------------------- *
    * display the cert subject here                              *
    * -----------------------------------------------------------*/
    BIO_printf(outbio, "Displaying the certificate subject data:\n");
    X509_NAME_print_ex(outbio, certname, 0, 0);
    BIO_printf(outbio, "\n");

    SSL_free(ssl);
    close(server);
    X509_free(cert);
    SSL_CTX_free(ctx);
    BIO_printf(outbio, "Finished SSL/TLS connection with server");