OpenSSL::SSL::Session#to_der

static VALUE ossl_ssl_session_to_der(VALUE self)
{
    SSL_SESSION *ctx;
    unsigned char *p;
    int len;
    VALUE str;

    GetSSLSession(self, ctx);
    len = i2d_SSL_SESSION(ctx, NULL);
    if (len <= 0) {
        ossl_raise(eSSLSession, "i2d_SSL_SESSION");
    }

    str = rb_str_new(0, len);
    p = (unsigned char *)RSTRING_PTR(str);
    i2d_SSL_SESSION(ctx, &p);
    ossl_str_adjust(str, p);
    return str;
}