Password Security

When you’re dealing with user passwords, the site owner does not (or should not) want to know the actual password the user enters. A very good reason for not wanting to know the actual password is that if the database is leaked, in one way or the other, whoever gets hold of the database won’t know the passwords.


What you do instead, is to save a hash of the password. A hash is a kind of checksum, so that for a given input, you get a fixed length output value. A very simple (and useless) hash is to just add the ascii-values of each char together, taking modulo 256 of the sum.

So, when the user enters “23456” as his password, you calculate the sum of the ascii-values ( 50 + 51 + 52 + 53 + 54 ) = 260, take the modulo 256 of 260, we get “4” as the checksum, we then store the “4” in the database, instead of the “23456” string.

Username Password-Hash
Morten   4

The next time, the user comes along, we do the same calculation, and compare the results. If the result is “4”, the user gets access. If the user, by a mistake, entered “23457” we’d get the hash of “5” and we’d reject the user.

But wait a minute, the astute reader yells out, banging his fist on the table: “the password “65432” would give the exact same hash!”. And the reader would be correct. This is known as collision, and is why some hashes are good, and others are bad. In my idiot hash algorithm, it is completely trivial for someone to find a combination of letters that give “4” as the output.

Instead of a useless hash, you might use some that are considered “good”. The SHA family of hashes are generally considered the gold standard of hashes. Bitcoin, for example, uses SHA-256 to provide Proof of Work.


So, let’s say we pick SHA-1, and we store the output of that. In that case we’d get

SHA1( "23456" ) = c24d0a1968e339c3786751ab16411c2c24ce8a2e

But what if two users have the same password? Consider these two rows in the db

Username    Password-Hash
Morten      c24d0a1968e339c3786751ab16411c2c24ce8a2e
John        c24d0a1968e339c3786751ab16411c2c24ce8a2e

If I know the password of “Morten”, I also now know the password of “John”.

What you do, instead, is to add a “salt”. The salt is just a random sequence of strings that I append to the password before computing the hash. For example, with salts, we’d get

Username    Password-Hash                               Salt
Morten      ac5740fde13da84ba4a5266ce9e9b7d697e0622b    xyz
John        c96bbd1bed0ffa3f5a0098ce7ee568ce6e9d496c    abc

Now it’s not apparent that Morten and John both use “23456” as passwords, and we’re almost done….

Brute Force Attacks

In my bad hashing algorithm, it’s pretty clear that you can’t guess my password from knowing the hash value “4”. On one hand it means that other users, might easily get access to an account on the site, but on the other hand, it also means that they can’t guess the original password.

This means that even if they could get access to an account on the site using the (false) password “65432”, they probably wouldn’t be able to access the users gmail account, because it uses a different security model, and in that case the “65432” just wouldn’t work.

However, if the site uses SHA1, the chance of collision is quite low, which means that if I can find an input string that gives the same SHA1 there’s a very good chance that I found the actual original password, and if the user reused the password on other sites, I might be able to gain access to those too.

Brute force attacks don’t actually try every conceivable input, instead it uses something known as “rainbow tables”. These are tables of the most common passwords, As GPU’s improve, the number of SHA1 computations we can make in a given time increases. For example, a new NVidia GTX 1080 TI will do 11374.1 MH/s

In other words, SHA1 salted passwords are not safe, and they are certainly not safe if they occur in a rainbow table somewhere, and there is plenty of software available to accomplish this, hashcat being one.

What To Do?

If you’re reading this, you probably aren’t using either “password” or “123456” as passwords (or are you John?). Furthermore, if you are using “123456”, then you probably are also using the same password for multiple logins, and chances are your other accounts have already been breached.

Two-factor authentication goes a long way to remedy the situation; if the user logs in from a new IP (meaning outside a subnet of known verified ips), then the 2nd stage kicks in, and you need to authenticate over email or SMS. However, this doesn’t work too well if the user uses “123456” all over the place, because the attacker might already have access to your email account (especially if the email account is your username on the site).

Enforcing “good” passwords on the site is also an improvement. You don’t have to go nuts on the requirements that it has to have special chars, upper and lower case etc. The site could actually generate the password for you. This way it would be unique, and hard to guess, if the site was breached, only the site would be affected, and if the site is just a TMZ style rag, the damage would not be too bad.



Tagged ,

The Parts of an IP Camera

To understand where the IP camera market is headed, I think it’s important to understand how one of these things are put together.

Like most high tech devices, each product is really an amalgamation of parts from different manufacturers. In fact many products are the result of tight, but perhaps unappreciated, collaboration of several (sometimes competing) companies. I’d recommend listening to Freakonomics rundown of the “I, Pencil” essay (starts 7 minutes in).

So, an IP camera is not a pencil, but just like all pencil manufacturers don’t manufacture every single part of the pencil, but instead, they purchase the parts (graphite, brass, paint and so on) and every manufacturer puts the pencil together following roughly the same pattern.

And, so, when it comes to IP cameras, they too are composed of parts that are available to everyone who wants to start making cameras.

You’ll need a couple of things: A lens, a sensor, some circuitry and some code.

You’re not going to start making your own lenses or sensors, are you? Probably not, so you’ll get the lenses from a lens maker (and they may even outsource their manufacturing process even further), and the sensor from either Sony or Canon.

You’re not going to design your own CPU either (unless you’re Axis). Today, you’d be better off grabbing an ARM platform and use that to drive the sensor and interface. The other advantage is that ARM is well supported in the software world, so you’re already halfway there.

Now that you have the basics, you need to write some code to get it all working together. If you went the ARM route, it’s pretty simple to get a linux kernel running. Well.. “simple” is depends on your level of skill, but finding a few geeks who can do this shouldn’t take long. So you grab the Linux kernel, add Apache or perhaps GoAhead, you can add gStreamer too (do check the link, it is a great presentation by Axis) . The next thing you know, you have a jumble of cables and breadboards, burns on your fingers from the soldering iron, you haven’t seen your kids in 4 days and the smell is getting a little hard to stomach.

On top of that, you need to wrap this in an enclosure. There’s regulations to follow, tests that need to be carried out and so on. Then you have the nightmare of maintaining all those pieces of code, and trust me – if you wrote everything yourself, it would take even longer and be much harder to test and maintain.

What if there was a company, that could do all of the above? And just stick my name on the box? After all, my company would pick the same lens, the same sensor, the same board and the same software, so why not do it?

I have no intention of starting production of a Raspberry Pi Zero based IP camera, but I know that I can make one for ~$40 (and that’s buying all the parts retail). Not only will this thing work as an IP camera, it can work as a full fledged stand-alone VMS.

In other words, the question is: if some washed up coder in Copenhagen can build a fully functional “IP camera” for $40, I think you’re going to face a tough time if you’ve based your entire organization around selling your cheapest cameras for $250+ (they may be “even more good enough”, but who cares?).

Obviously, my camera is not going to be materially different from the other guy’s cameras. We’re all going to use the same bits and pieces, including software, even the damn protocols are going to be the same.

So, I think we’re going to see a race to the bottom in terms of prices. The cameras will look and perform almost identically across brands, use the same protocols, and be completely interchangeable, much to the chagrin of the incumbents, so the USP for the brands in this realm will have be something else.

VMS Software, perhaps…







HDR and Low Light

In the early days, the only thing that mattered was pixel count. The more pixels you could cram onto a sensor, the better. Some people noticed that the higher pixels count would decrease the performance in low light scenes (for the same sensor size), and we got to a point where you’d have ridiculously high resolutions on extremely small sensors, but you’d need to be a few miles from the sun in order to get good, sharp footage.,

There are all sorts of software tricks that you can employ to improve the appearance of the image to the casual observer, but you can’t conjure up data that just aren’t there. One trick is to use very long exposure, but that causes moving objects to get blurry, or you can do noise reduction, but that also removes actual details.

So what happened that caused the cameras to suddenly improve quite dramatically over the last couple of years? The sensor guys came up with back-illuminated sensors. Basically, the sensors got a hell of a lot better, and now we’re reaping the benefits.


Xda-Developers has a great article on the Sony IMX378 explaining BI sensors and how HDR is achieved. And of course, there’s always Wikipedia.

Competition is a wonderful thing.





A while back I got fed up with people parking their cars right in front of my driveway, and I decided to find a solution.

A camera could work, but since I am cheap, I decided to look for something a bit more… economical. A PIR sensor wouldn’t work because it triggers when there is motion, and cars and people pass by all the time, so I looked into ultrasonic sensors and eventually radars. If the distance measured drops below a pre-defined threshold and stays there, I know to run into the street, yelling and screaming.

The inspiration came from Adafruit and Andreas Spiess who has a great YouTube channel where you can get more information about ultrasonic sensors and radars (and about 1000 other things).


Basically, you can get an Arduino capable board. I hope the WiFi capable ESP8266 will work (since I have one lying around). Then get some cheap sensors from China via Alibaba and you’re ready to experiment. At the very least, it should give you some idea of the base cost of such a device.

Both Axis and Avigilon have launched commercial versions of miniature radars that can interface to your favorite VMS. Combined with a PTZ camera this might be a very interesting combination that offers a bit more smartness than the good old PIR/PTZ combo.



As with IP cameras, one of the IoT challenges is how to get your controlling device (typically a phone) to talk to the IoT device in a way that does not require opening up inbound ports on your firewall.

All communication is peer to peer, so the term, when used in the context of IoT devices, is perhaps a little misleading, after all, an exposed camera sending a video stream to a phone somewhere is also “peer to peer”. Instead, P2P might be translated to “send data from A to B, even if both A and B are behind firewalls, using a middleman C” (what the hell is up with all the A, B, C these days).

On a technical level, the P2P cameras use something called UDP hole punching, which sounds a bit onymous, but there’s really nothing sneaky about it. What happens is that A connects to C, so that C now knows the external IP address of A. Likewise, B also connects to C, and now C knows the external IP address of both A and B.

This middleman, now passes the IP address of A to B, and B to A. Next step is for A to fire a volley of UDP packets towards B, while B does the same towards A.

The firewall on A’s side sees a bunch of packets travel to B’s address, and when B’s packets arrive, the firewall thinks that the UDP packets are replies to the packets that were sent from A and let’s them through.

You could accomplish the same thing by having A go to “” and email it to B, B would then do the same. Then run scripts that send UDP packets over the network, but a STUN server automates this process.

But who controls this “middle man”? Ideally, you’d be in charge of it; you’d be able to specify your own STUN-type server in the camera interface, so that you have full control of all links in the chain. In time, perhaps the camera vendors will release a protocol description and open source modules so that you can host your own middle-man.

The problem might be that you bought a nice cheap camera in the grey market. The camera is intended for the Chinese market, but comes with a “modded” firmware that enables English menus and so on. This is obviously risky. Updating a modded firmware may be impossible and brick the camera, and the manufacturer may be less inclined to support devices that have been modded. You get what you pay for, so to speak (and this blog is free!)

The modder is selling the cameras in the western markets, but the STUN server is still pointing to a server in China. This makes sense if you are a Chinese user, but it may seem very strange that your camera “calls home” to a server in China. A non-modded camera might do the same, simply because running a STUN service is cheaper, and allows the government to eavesdrop on the traffic. If you are Chinese (I am not), you could argue that you don’t trust Amazon, Microsoft or Google because they might work with the NSA. Therefore, using your own server would be preferred.

Apart from the STUN functionality, the camera may follow direction that are sent from B to C to A. This puts a lot of responsibility in the hands of the guys maintaining this server. If it is breached, a lot of cameras will then be vulnerable.

Depending on the end user, P2P may not be appropriate at all. To some users, the cost of a breach is small, compared to the hassle of installing a fully secure system it might be worth it.

While yours truly has abandoned all attempts to appear professional over the years, the truth is that most big installations have their shit together. Unfortunately the volume of DIYers and amateurish installers who don’t really know what they are doing is much bigger (in terms of headcount, not commercial volume), and if there’s one thing we all want to do, it’s to blame someone else.

Caveat Emptor.



Dear Shanghai Bill

You can say whatever you want in the comments, and I will approve it, but I need to know who you are before I do so.




It’s very hard to differentiate between stupidity and intentional dishonesty. Yesterday, I made a mistake of posting an inaccurate portrayal of statements made by another blogger. I removed it from my blog almost immediately. But subscribers to my blog had received the post, and one reader quickly accused me of “defamation”, and told me that I was “on notice”.

Mistakes are made, I attempt to correct them as quickly and as best I can, but sometimes people just crave confrontation.

I’d like to take the opportunity to talk about true dishonesty. I’m a big fan of Dan Ariely, who studies behavioural economics. When Salty Features wanted to crowdfund a movie about dishonesty, centered around Dan’s work, I did not hesitate to sign up, and I can only recommend that you go watch (Dis)honesty (it’s on Netflix in Denmark and most other places I would imagine).

Dan and his team tries to establish a baseline for how dishonest people are, in general. The experiment is quite simple. They hand out math tasks. The more tasks are solved, them higher the reward (a few dollars). But, instead of handing the papers over for verification, they are to send them straight to a paper shredder. Then proceed to the controller’s desk, and simply state how many tasks were solved. No chance of verification.

The rigid financial theory says that there is 0% chance of being caught, so they might as well say that they solved all the tasks, and reap all the reward.

But that’s not what happens. A lot of people cheat a little bit, some not at all, and some go all in (in accordance with the rigid theory). The completely honest and completely dishonest people are outliers.

How did they know that the students cheated? The shredder was rigged. Some people might have suspected this, but even if they did, there would be no repercussions to go all in on the cheating, so some people are just naturally honest, while some use every opportunity to the fullest.

The experiment was then changed, so that instead of direct payment, the students would receive tokens, that would then be exchanged to real cash. Most people would probably assume that this made no difference at all, but as it turns out, this added abstraction of cheating = cash, increased the cheating substantially. The end result was the same, but one step was interjected that really should have mattered, but it did.

So, what if we look at the business world? Dan argues that the abstraction of money in high finance might be a contributing factor in what he describes as cheating, but it’s not just banks. As Dan’s research shows, a little bit of cheating is common – natural – even.

We can also illustrate the principle in another way:

Here’s an example of something that everyone will agree is problematic:

Company A pays B (who claims “independence”) to write about competitors of Company A.

Anyone in their right mind would say that B is hardly independent, and who would ever trust anything B has to say regarding companies in A’s domain? I know that a few would. There’s always a few. But most wouldn’t.

How about this, then:

Company A pays Company C to sign up to a service from Company D that is owned by B.

The end result is the same, but we’ve inserted a few layers of abstraction between A and B. And as Dan’s research show, there’s always a few that exploit this as far as it can go.

I highly recommend Dan’s books. And may I suggest you visit his sites too.


NSFW: Let’s talk about 2009

This motion picture article is protected under the copyright laws of the United States and other countries throughout the world. Country of first publication: United States of America. Any unauthorized exhibition, distribution, or copying of this film article or any part thereof (including soundtrack?) may result in civil liability and criminal prosecution. The story, all names, characters, and incidents portrayed in this production are fictitious. No identification with actual persons (living or deceased), places, buildings, and products is intended or should be inferred.

2009, to some people, seem like long ago. I remember it vividly. It was the nadir of the financial crisis (the great recession) and the central banks were in panic mode. Their attempts to calm the waters with lies, omissions and cover-ups had failed. Jim Cramer had had a meltdown on live TV and Jon Stewart later took him through hell, in what was a rare glimpse of honest journalism on mainstream TV. Incidentally, the show was taped down the street from where I used to live.

Today the market are at an all time high, and to most of the bankers, the year 2009 probably seems like a distant, vague memory. Not something to consider anymore. We’ve moved on etc. Other people have other reasons to distance themselves from that anno horribilis.

I don’t remember the exact date, but I was a little hung over and I had stumbled into some sort of marketing-integration-pep talk-show. At first I thought I was at a church, as I saw a man with a squeaky voice perform a very strange sermon. As the fog of yesterdays gin/tonics lifted, and I could see more clearly, I discovered that the man on stage was just getting started. What followed next, made me question my sanity.

As the man rambled on about how “we can squeeze out cost and squeeze out Verint”, he seemed to drive himself into a state of trance; as the man heard his own voice, it triggered a sort of feedback loop, that in turn caused the mouth to make even more outrageous statements. Tourrettes causes involuntary expressions of vulgarity and noises, but this was not Tourrettes. The steady flow of depravity and vulgarities was entirely voluntary and the man seemed anxious to drive himself into ever higher states of madness.

In my recollection (admittedly rather faint due to over-consumption of stimulants), I stumbled back to my hotel room, Thinking that I had just witnessed a male version of “heavy splash” in Japanese. I showered for 45 minutes. I submerged myself in scalding hot water, but I still felt dirty. I assumed that the man had received the king’s ransom in order to put on that kind of show.

While the memories from that fateful day had started to fade, they were always present in the back of my mind. I had to remind myself that we had just gone through a financial crisis that had driven people to desperation. Many years of over consumption, and debt fueled spending had come back to roost. As the tide went out, some people, it turned out, were naked.

When I recently sat outside my local watering hole, sipping a cup of detoxicating green tea, and nibbling on some gluten-free, fully organic biscuits from a farm just a few miles from Copenhagen, I ran into the same man.

It was a shocking sight. The man had gathered a following that were carrying him around town. He was wearing thick makeup, heavy rouge and pink lipstick. His disciples placed a wooden crate on the ground, and placed the man atop. He locked eyes with me, and there was a long awkward pause.

He prodded one of his lackeys with a stick, and whispered something inaudible in his ears. The lackey then cleared his throat, and proceeded to address me.

“We are not happy with how you portray things” he said. He then pulled out a scroll, and handed it to me. It was hardly legible, it had either been written by a 5 year old child, or a very old man. It stated that they were going to tell their herd about me and my evil deeds.

I was confused. In front of me stood, what would appear to be an adult male, wearing clown makeup, surrounded by a group of escapees from an asylum, announcing that he would “tell on me”.

This was the same man I had seen perform unspeakable acts of depravity just a few years ago.

I asked if his flock knew about his past, thinking that the desire bow down to their high priest would be somewhat diminished. But I also suspected that most people in the flock had never heard of the internet or google, so I genuinely wasn’t sure.

To my surprise, the clown decided to speak. He cleared his throat. His eyes rolled to the skies, and when I once again heard that squeaky voice again it all came back to me. It’s still surprising so vividly you remember things, under the right circumstances. Like hearing a long forgotten pop-song from the 80’s and remembering every detail from that summer in Spain.

But this was no summer in Spain, and the man announced that he was fed up with me bringing up his performance many years ago. He straightened and lifted his arms, palms facing the sky and proclaimed “I received no payment, I did it all for free”. There was a pause. Everyone waiting, breath baited, and then, with a deep voice (well, not that deep) he ceremonially announced: “I am clean”.

As he said those words, my biscuit fell to the ground and broke into 1 large and 4 smaller pieces and some crumbs. My jaw dropped. He had done it all for free!?! It was hard to fathom. My mind started racing. This was unexpected. Why on earth would you do what I had witnessed a few years ago, for free?!!! This was not a man who did anything for free, unless there was something to be gained later.

I later realized that the guy published some sort of periodical that people had to pay to read. It mostly contained self praise, and descriptions of what happens when completely inept people attempt to use high tech equipment. I suppose it could be thought of as a mildly entertaining break from the daily humdrum at the office and you can always call it “working”, because it is kinda, sorta, related to what you do.

I suspect that direct payment, would probably be considered prostitution and therefore illegal. Instead, as payment for his performance on that fateful day, the host of the show would instead purchase a lot of “licenses” to read the “news”.

And that, ladies and gentlemen, how you stay “clean”.


I Am Myself

Well, well, well…

This weekend I posted a piece on IPVMs crusade against Hikvision which seemed to suggest a lack of technical comprehension and perhaps – general assholery.

1 minute after posting, I receive a visit from Ghana. I have also had visitors from Mali and other nations in Africa that seemingly have a keen interest in what I have to say. Another option is that someone thinks they need to use Tor (or some other anonymizing browser) to read my blog.

This morning, I woke up to an email, asking me to ensure that the folks from some obscure blog understands that this blog is in no way, shape or form affiliated with OnSSI. A strange coincidence that writing about a sensationalist blog fucking things up, triggers a request for clarification about the independence of this one.

So let me make that absolutely clear, so that even sensationalist bloggers running fake universities, and his “associates” can understand it.

This blog, has nothing to do with OnSSI.

While I have written specifically about the mobile app OnSSI released a while ago, other people in the software development industry (not IP video), have the exact same experience. Next generation apps face an uphill battle as loyal users of the old app discover that things may have changed, and they are much more likely to post a very negative “review”, than people who will eventually benefit from the improvements. Since posts that are anchored in real experiences are dangerous to my livelihood (the blogger is using them as a vector to try and shut me down), I will remove that type of content from the blog (but I am confident that the Ghanaian visitor made a copy before reaching out to protect the innocent, so just ask him for a copy).

So, just to be clear, what you read in these posts, is the opinions and thoughts of the person Morten Tor Nielsen. I submit ideas and thoughts that are founded in a general understanding of the world as I see it.

I suppose that if you are consumed with deranged ideas about infiltration of corner shops and jiffy-lubes by the Chinese government, and your every living hour is spent on thinking about how to attract more subscribers to your rumour-mill, then this might be hard to fathom, but I work on a wide range of things (including overhauling my old Suzuki Bandit 600), and so among the exposure of incompetent asshats (from my humble computer here in Copenhagen), jot about a lot of things.

If you follow my blog, you’ll know that I have been working on micro-PC‘s, I have set up Axis cameras to provide health state information, I have done a lot of GPU work (yes, for OnSSI) and many other things. I have called out BS here, and here, and here  and many other places. I have mused over how companies can improve and what danger signs to look for. I have critiqued buzz-word-driven development (as a response to VR goggles being passed out at a convention). The list goes on…

You have to be senile, demented or sociopathic to think that this blog would somehow reflect the “thoughts” of a company. So if you suffer from any of the 3, and that’s the reason you contact OnSSI rather than writing a comment refuting claims, then you’re excused.

If not, you’re just a sad, over-extended sphincter.

But I think you (and everyone else) know that already.

In Defence of Hikvision

Look at this nonsense!

Brian Karas reported on March 2 that he was hearing from multiple Hikvision security camera and DVR users who suddenly were locked out of their devices and had new “system” user accounts added without their permission.

Karas said the devices in question all were set up to be remotely accessible over the Internet, and were running with the default credentials (12345). Karas noted that there don’t appear to be any Hikvision devices sought out by the Mirai worm — the now open-source malware that is being used to enslave IoT devices in a botnet for launching crippling online attacks (in contrast, Dahua’s products are hugely represented in the list of systems being sought out by the Mirai worm.)

[I cut out some text from here (I’ll tell you why)]

According to Karas, Hikvision has not acknowledged an unpatched backdoor or any other equivalent weakness in its product. But on Mar. 2, the company issued a reminder to its integrator partners about the need to be updated to the latest firmware.

OK, so Brian hears that people who a) expose their IP cameras directly to the internet, and b) are using default admin credentials “suddenly were locked out of their devices”. My God, what kind of evil genius hacker is behind this, and there were new “system” user accounts!!?!

This must be the Chinese government’s work. Only a government organisation would be able to crack into IP devices with default passwords that are directly exposed to the internet.

When people got their shit “hacked”…. actually, let’s not call it hacked. Someone logged in, as admin, and changed things, so, not hacking. Someone had done something similar to mirai (which will take any script kiddie 30 minutes to write up, but Karas and Krebs pretend to not understand that). Hikvision sees this, and then reminds people to update their firmware, and as the new firmware does not allow default passwords (as far as I can tell), it seems prudent advice, and what you ought to do.

Krebs seems to want to play a part in all this “dangerous Hikvision camera” bullshit, so instead of posting a meaningful timeline, he spices things up, and injects this little tidbit (which I removed above to ensure a comprehensible timeline).

In addition, a programmer who has long written and distributed custom firmware for Hikvision devices claims he’s found a backdoor in “many popular Hikvision products that makes it possible to gain full admin access to the device,” wrote the user “Montecrypto” on the IoT forum IPcamtalk on Mar. 5. “Hikvision gets two weeks to come forward, acknowledge, and explain why the backdoor is there and when it is going to be removed. I sent them an email. If nothing changes, I will publish all details on March 20th, along with the firmware that disables the backdoor.”

OK, so on the 2nd the n00bs at IPVM and their subscribers are “hacked” by a genius hacker, who is able to guess the password and add new accounts, and then on the 5th, a guy who re-compiles the hikvision firmware discovers a vulnerability. In fact, he tells John Honovich that Hikvision has been very responsive in fixing the issue!! This seems to get lost somewhere between the sensationalist blogs (I think, because I am banned from IPVM).

How the hell do you make a connection between morons who exposes their cameras with default admin credentials, and someone discovering a bug in the validation of a reset packet (I guess that is the vulnerability, because I don’t know the details). You make that connection, if you think it will bring in more subscribers, and by extension, more filthy lucre.

Full disclosure: I am not paid in any way shape or form by Hikvision or any camera manufacturer for that matter. I receive no payment from this blog either, the ads you might see are put there by wordpress that hosts the blog, as compensation for hosting and traffic cost (and profit I guess), but I receive exactly $0.