About Tor and Multi-Protocol Port Numbers.

On a past occasion I had tried to write on Facebook – of all places – that each computer, and therefore each IP Number, has seemingly arbitrary Port Numbers that it receives packets to, primarily to prevent most connection attempts from being futile. I.e., I was stating that there is an official, assigned port number, for most types of protocol that devices communicate with over the Internet. Yes, There Are Many More types of protocols, than just those for HTTP (80), HTTPS (443), POP, SMTP, IMAP, etc..

But this proclamation of mine just serves to remind, that no matter how hard we try to convey the truth, we only end up with approximations.

It’s possible for one server-program to listen on one port number, and to accept requests for a number of protocols – all on the same port number.

One example where this happens, is with proxy-servers. Typically, they might be listening for HTTP connections, let’s say on port 8118. But then the next question people might ask when setting up their browsers could be: ‘I like sending my regular HTML text through a proxy, let’s say to filter it, but I must also forward my HTTPS requests through a proxy – or not – And one might not want to send all the browser’s data through a single SOCKS5 port, just so that the proxy-server can do some differentiation. Therefore, where should I tell my browser to forward my HTTPS traffic?’

And in most cases, the answer would be through port 8118 again .  And that’s because a typical HTTP proxy, reacts to an HTTPS request, via a CONNECT instruction, which means that it treats the encrypted data as gibberish, and then either lets it through or not so. It’s not strictly necessary for a proxy server to analyze traffic, in order to be able to forward it. Yet, there can exist some HTTP proxies, whose feature just to accept a CONNECT command has been disabled. But you can in some cases just try them out.

Another example of this would be the “Tor” anonymizing network. Its standard port number has been 9050 for some time, but a Tor node simply listens on this one port number, regardless of whether that’s to accept connections from Tor nodes someplace else on the Internet, or whether that’s to accept an outbound connection from a local proxy-server – i.e. from another program on the same computer. With Tor specifically, If in doubt, you’d simply try to fire a connection at it and see what happens, via its only listening port. But for the most part, Tor likes a SOCKS5 connection going out.

Now there has been the issue, that certain firewalls will specifically block requests to connect to port 9050 on outside machines. And so some Tor nodes have been instructed to listen on some other port number, for incoming connections. But in order to get that to work, a kind of quiet agreement has been reached between Tor users, as to which port number they’re hijacking – that port number now being one officially assigned to an existing, other protocol.

So was I half-right, or half-wrong? I was trying to state basic knowledge, which might still be taken as a first-order approximation of the real world.

Dirk

 

I have received my Flexible Keyboard today.

Today I have received my “Delicol Foldable Flexible Waterproof Keyboard” (USB 2.0), which I ordered on Amazon.ca as this item below:

https://www.amazon.ca/gp/product/B00FGSB71W/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Even though with most items I do verify very thoroughly, that they work, this was one item not having a high priority with me. I just felt I’d like to have one like this, even though I don’t need to use it right away. And so I may not test this one right away.

One check which I did with it however, was to see whether it’s the kind of flexible product, that passes as thin, very thin, extremely thin, etc.. Some sellers might claim that theirs is also a thin, foldable item, even though theirs might simply be a rather thick, bendable appliance. And what I find is that this keyboard at least passes the test, that I can actually fold it over twice, without having to exert dangerous force. It complies quite easily.

As to whether it’s compatible with my Linux machines, while being stated as Windows 7 and OSX -compatible, is a non-issue for me. I find that this type of device will work under Linux, if it works at all, and I don’t have any Mac. And the fact that it works under Windows 7, which I also have, I’ll take at face-value. It’s important though, that even my oldest, Linux boxes have USB 2 Ports specifically, which they do, and which work at USB 2 speeds.

Dirk

 

A design anachronism within WordPress.

This blog is being hosted by the “WordPress.org” Content Management System (configured for one user) (:1). Yesterday I lost a night’s sleep, trying to figure out why this software was having problems. Tonight, it’s still a little early, for my night’s sleep to start.

Here’s the problem. If we follow the documentation to set up this software, it tries to create a configuration by which the personal contents of a Blog are stored in Linux folder ‘/srv/www’ .  This is a tad confusing, because according to other documentation, it could be setting this up in folder ‘/var/lib/wordpress/wp-content’. At the same time, the components of the page which display, that belong to WordPress and its CGI scripts, are set up in ‘/usr/share/wordpress’. The user is given rough guidelines, as to how he can set up his Apache server, to have an Alias according to his configuration file, which points to the General Location from a URL, which is a Parent URL to the one, whose Alias points to the Personal Folders on the hard drive, the latter located under ‘/srv/www’ when the initial confusion is solved.

What can happen next is that the page seems to display in a not-so-neat way, until the owner tries to upload a photo or something, at which point he finds that his browser can no longer even view that file, getting a ‘403-Forbidden’ error. What’s confusing about this situation, is that the user is likely to look very intensely at the configuration file which defines the Virtual Host, or which defines this set of URL-Aliases, as the probable cause fw Apache is not giving access to the browser, to the content folder. This turns into a waste of time, because aside from some semantic quibbles, there’s really no error there.

What happens is that in the Apache configuration folder, there is  a Main Configuration File named ‘/etc/apache2/apache2.conf’ .  It’s located right next to the files, which tell Apache to create the aliases specific to each Web-site the user has. Under modern versions of Apache, this main config file allows the server – and thus all the pages – to access anything under ‘/usr/share’ and under ‘/var/www’ by default, but explicitly forbids any of the other config files, from accessing other folders, especially ‘/srv’ .  This has been put as a security measure, to prevent hijacked Web-sites from doing extensive damage on the host machine. That same config file can easily be edited, to include ‘/srv’ as one of the allowed folders.

But, because none of the troubleshooting attention goes there, it can take time to find this problem. As I wrote, I lost a night’s sleep over this mere annoyance. Once access has been granted to all Apache’s hosted sites, to access ‘/srv’ as well potentially – still according to their own config files – we also see that the page itself displays in its full style and splendor, and that uploaded photos now download to the browser.

There’s a deeper problem with this sort of bug. It can undermine the confidence the user has, in the ability of the provider of the software to program well. I have in fact heard of WordPress, and yet initially, based on the errors I was getting, was not getting a good first impression of it. And the fact that the Style which my Blog displays in, has elements of my personal preferences in it, which were not accessible at first, also made the pages ‘look ugly’ at first, again undermining how well WordPress might be programmed, according to my first experience with it.

This happens often in computing.

And, it also happened too often in my past, that I eventually solved such issues, but that I never left a detailed account to myself, about how I had solved them. Now that I have a micro-Blog, I can rectify this last point.

BTW, Finally WordPress does come across as good software, very functional. And the fact that the software is very functional is confirmed more strongly, by the fact that it was at first even able to display my Blog partially, in spite of not being able to access half its folders.

It’s deprecated under Linux, to store Web content under ‘/srv/www’ !

Dirk

Edit 01/18/2016  1:)  It was only after having installed WordPress.org, and having started my Blog, that I also learned that this package is different from WordPress.com .  But this initial gap in my knowledge is of course also tied to the fact, that with the .org product, users “need to get their hands dirty, to make it work”.

 

Beginning of Blog

logo-dirk_testHello.

I’m a single, 51-year old man, who is unemployed, but essentially financially independent. I live by myself, and have decided that at this stage of my life, I’ll want to keep doing so. Even though I’d be willing to go on dates with single Women, in fact there are few girlfriends who’d be willing to accept even these terms. I’m speaking from experience. And so my future may become one of celibacy, which I’m willing to endure, with only my computers, and certain personal Friends, for company.

I’ve never blogged before, but have decided that rather than to try rewinding my story to my distant past, I should just jump in and write about events in my life as they happen.

My life usually revolves around my computers these days, but maybe also around photography, around gadgets, around food, and around some select Health Subjects. I go to a drop-in center.

All in all I’d say I’m contented, but also suffer from moments of anxiety, which I seem to be able to manage.

I have to add that I’m an atheist, but not one with a capital ‘A’. Atheists with a capital ‘A’ are the kind that feel, that the only crime they can commit is to get caught. I believe in doing the right thing, in observing moral standards etc., but not because of any fear of eternal punishment after my death. I think that when I die, I’ll simply cease to exist.

Sure, There Is more to life than that, but actually to explain my many viewpoints would take some time. One of my viewpoints is that I must respect other people, even if they don’t have the same opinions as I do, about God, about Ideology, about sexual orientation. And I feel that while material reality is highly important, it’s also important to keep in mind, that sometimes a question can be looked at from different directions, and that doing so can lead people to unexpected realizations. In that regard, I actually have an open mind.

And yet the reader may find that most of my future blogging, should I choose to continue with it, will revolve around material issues in my life, such as what the caveats are of using a specific gadget I bought, of AI, and of sundry other subjects that tend towards the technological.

Dirk