This is a new tool that developers can add to their toolbelt. AjaxProxy.com transparently permits the use of HTTP proxies from JavaScript Ajax requests. It also bypasses CORS restrictions, to help with accessing services not designed for direct consumption from client-side JavaScript.

AjaxProxy.com

What is it

If you need to use a HTTP Proxy with Ajax, this polyfill library will allow you to specify a HTTP proxy to be used with Ajax requests. This could be useful to ensure that your Ajax requests come from a fixed IP address.

Quickstart

Step 1;

Add the library AjaxProxy.js from the following URL

<script src=”https://www.ajaxproxy.com/js/ajaxproxy.js”><script>

Step 2;

Before any Ajax requests are made, call 

ajaxProxy.init();

Step 3:

Define your Proxy server as follows;

ajaxProxy.proxy.url = “http://<your proxy>”;

ajaxProxy.proxy.credentials.username = “<proxy username>”;

ajaxProxy.proxy.credentials.password = “<proxy password>”;

Step 4:

If you are using JQuery, then modify your $.Ajax to add 

headers: ajaxProxy.proxyHeaders()

Such as like follows;

$.ajax({

    type: “GET”,

    url: “https://ICANHAZIP.COM&#8221;,

    headers: ajaxProxy.proxyHeaders(),

    dataType: “text”

}).done (function (data) {

    console.log(data);

});

If you are using plain XHR requests, then add xhr.addProxyHeaders(); 

Such as shown below;

var xhr = new XMLHttpRequest();

xhr.onreadystatechange = function() {

    if (this.readyState === 4 && this.status === 200) {

       console.log(this.responseText);

    }

};

xhr.open(“GET”, “https://ICANHAZIP.COM&#8221;, true);

xhr.addProxyHeaders();

xhr.send();

Step 5:

If you run your code, then the request should be proxied through your proxy server.

Under the hood. 

What is happening? In effect, this goes through two levels of proxies, first your request is sent to an AWS Lambda function, which checks for the following http request headers;

X-target : The destination URL

X-proxy : The proxy HTTP Address

X-proxy-username: The proxy username

X-proxy-password: The proxy password

Please note that if your proxy is limited by IP address, then this technique will not work, since the egress IP for the AWS Lambda function is dynamic. You will need a proxy that is either open (not advised), or restricted by username and password.

The AWS Lambda function will then make a connection to your proxy server, and supply it with the original destination URL, and will pass through other common headers such as the Content-Type and Authorization headers. 

Additional security

Using the technique above, your proxy username and password will be visible to anyone who can view the source of your website. If you have an intranet, and trust your users, then this may be fine, however, we do recommend taking the following security step;

You can encrypt your proxy username and password by calling:

ajaxProxy.Encrypt(“password”);

Which will return a string such as follows

:ENCRYPTED:H20n0hTqmOduBYNOatwApO1almPAr/ue

You can pass this string in place of the username and/or password and the script will do the decryption under the hood. 

There is no public method to reverse this encryption, so it is not possible for an attacker to reverse engineer your password without stealing our private keys, which we keep secret. 

Additions / Requests

This library has been offered for free, it was developed for internal use, but we are offering it to the public out of goodwill and public service. Please do not abuse this service, we will throttle requests from excessive usage.

If you would like an addition to this software, or need help with your specific application, then we may be able to help. However, nothing in this life is for free, so we do invite you to sponsor this project, if you would like an addition or change made to it.

We can supply source code if required, under NDA, please contact us for more information. 

If you want to change the default behaviour of AJAX across your website, perhaps you want to make sure that every AJAX called is logged before executing, or that it is somehow audited for security before being called, you can use interceptor scripts in Javascript that override the default functionality of the XMLHttpRequest object that is behind every AJAX call, even if a library like JQuery is used ontop of it.

So, for instance, if you wanted to catch the body of all POST requests sent via AJAX, you could do this;

(function(send) {
    XMLHttpRequest.prototype.send = function(body) {
        var info="send data\r\n"+body;
        alert(info);
        send.call(this, body);
    };
})(XMLHttpRequest.prototype.send);

Or, if you wanted to change the destination of all AJAX requests such that all communications are sent via a logging service first, then you could do this;

(function(open) {
    XMLHttpRequest.prototype.open = function(verb,url,async,user,password) {      
        open.call(this, verb,"https://somewhere.com/log",async,user,password);
	this.setRequestHeader("X-Original-URL", url);
    };
})(XMLHttpRequest.prototype.open);

Where somewhere.com/log is obviously fictitious.

Hope this is useful to somebody!

NuGet is the de-facto package manager for .NET, and as perhaps a major oversight, the Car Registration API was never available via a NuGet Package.

We’ve put this live today, here: https://www.nuget.org/packages/LicensePlateAPI/ and here is are the steps to use it;

Install the following three NuGet Packages

Install-Package LicensePlateAPI 
Install-Package System.ServiceModel.Primitives
Install-Package System.ServiceModel.Http

Then, assuming you’ve already opened an account, here is some sample code;

var client = LicensePlateAPI.API.GetClient();
var car = client.CheckAsync("{LICENSE PLATE}", "{USERNAME}").Result;
Console.WriteLine(car.vehicleJson);

Where evidently {LICENSE PLATE} and {USERNAME} are placeholders. “CheckAsync” checks for UK license plates, but you can change this to any country by using CheckUSAAsync or Check<Country>Async.

Enjoy!

Slovenia is a European country with a population of 2.081 Million, and a total of 1.118 million passenger cars registered, giving a car ownership rate of just over 53%. If your business operates in the automotive industry in Slovenia, then being able to streamline the customer onboarding experience by allowing your user enter a license plate, rather than selecting a make / model can both speed up the user intake. The API also reveals information about the vehicle’s insurer, which may not be known to third parties.

Car registration plates in Slovenia use the /CheckSlovenia  endpoint and return the following information:

• Make / Model
• Region
• Insurer
• Insurance policy number
• Representative image

Latency warning: This particular request may take over 10 seconds to complete.

Sample Registration Number: 

LJ-20-SUN

Sample Json:

{
“Description”: “Ford (D) Mustang 2,3 EcoBoost Avt.”,
“CarMake”: {
“CurrentTextValue”: “Ford (D)”
},
“CarModel”: {
“CurrentTextValue”: “Mustang 2,3 EcoBoost Avt.”
},
“MakeDescription”: {
“CurrentTextValue”: “Ford (D)”
},
“ModelDescription”: {
“CurrentTextValue”: “Mustang 2,3 EcoBoost Avt.”
},
“Insurer”: “Zavarovalnica Sava d.d.”,
“InsurancePolicy”: “000671-4716157”,
“Code”: “MBKECO11”,
“Category”: “Osebno vozilo”,
“Region”: “Ljubljana”,
“ImageUrl”: “http://registrskatablica.si/image.aspx/@Rm9yZCAoRCkgTXVzdGFuZyAyLDMgRWNvQm9vc3QgQXZ0Lg==&#8221;
}

Sign up for 10 free requests to this API today, via http://www.registrskatablica.si/

If you are still using Visual Studio 2013, you may notice that today, the Package Manager Console will have stopped working, any attempt to install a new package will give an error like

The source at nuget.org [https://www.nuget.org/api/v2/] is unreachable. Falling back to NuGet Local Cache at C:\Users\you\AppData\Local\NuGet\Cache

This is because NUGET has withdrawn support for TLS 1.1, and VS 2013 will use TLS 1.1 by default.

To Fix this, type this into the PM console:

[Net.ServicePointManager]::SecurityProtocol=[Net.ServicePointManager]::SecurityProtocol-bOR [Net.SecurityProtocolType]::Tls12

If you’ve written a Windows service, and you need to update it, perhaps with a bug fix, you’ll find that the process is very cumbersome, you need to stop the service, uninstall it, pull your changes, install it again, configure the service, then start the service.

This procedure, although not difficult, can eat away 15 minutes of development time on every update, and slows the fix/release cycle.

This is where I created a windows batch file, that does these steps in sequence, to save lots of time.

@echo off
REM – ADMIN ACCESS IS REQUIRED
REM – MAKE SURE LATEST CHANGES ARE CHECKED IN TO GIT, THIS CODE WILL UNDO UNCOMMITTED CHANGES.
net stop “My Service”
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\installutil /u MyService.exe
git stash save –keep-index –include-untracked
git pull
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\installutil MyService.exe
SC failure “My Service” actions=restart/60000/restart/60000/restart/60000 reset=86400
net start “My Service”

The SC command may not be applicable to you, but this tells the service to restart in the event of a failure.

Hope this helps someone!

You want to create a dynamic video, from a collection of images – Here is where FFMpeg is a great tool to use with C#

So, as a pre-requisite, you’ll need to download FFMpeg and put it in a folder, I’m calling it “C:\FFmpeg\” – but you can put it anywhere. I’m also assuming you have a collection of images in c:\input, and you want the output video in C:\out-video\out.mp4 – all these paths can be changed.

If you’ve seem my earlier example of capturing video from a webcam and saving to a video, this approach is more elegant, since it doesn’t involve chopping the header off the bitmap array, and swapping the red and blue channels, however, this solution is for Windows only, it’s not cross platform.

I used the FFMediaToolkit Nuget package, and also System.Drawing.Common

FFmpegLoader.FFmpegPath =
	@"C:\FFmpeg\";

var settings = new VideoEncoderSettings(width: 960, height: 544, framerate: 30, codec: VideoCodec.H264);
settings.EncoderPreset = EncoderPreset.Fast;
settings.CRF = 17;
var file = MediaBuilder.CreateContainer(@"C:\out-video\out.mp4").WithVideo(settings).Create();
var files = Directory.GetFiles(@"C:\Input\");
foreach (var inputFile in files)
{
	var binInputFile = File.ReadAllBytes(inputFile);
	var memInput = new MemoryStream(binInputFile);
	var bitmap = Bitmap.FromStream(memInput) as Bitmap;
	var rect = new System.Drawing.Rectangle(System.Drawing.Point.Empty, bitmap.Size);
	var bitLock = bitmap.LockBits(rect, ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
	var bitmapData = ImageData.FromPointer(bitLock.Scan0, ImagePixelFormat.Bgr24, bitmap.Size);
	file.Video.AddFrame(bitmapData); // Encode the frame
	bitmap.UnlockBits(bitLock);

	
}

file.Dispose();

So, what this does, is create a container video of a given size and framerate, and codec. (H264), then adds the images one by one. The container is hard-coded to 960×544, but you should base this on the maximum size of the images in your image folder instead.

The images need to be decompressed, from jpeg to Bitmap, then from Bitmap to ImageData, which is an array of BGR24 structures.

Hope this helps someone!

In northern Ireland, the over 40s should now go through the community pharmacy network to determine what pharmacies are administering the vaccine.

There is a useful web interface here: http://www.healthandcareni.net/pharmacy_rota/Covid_Vaccination_Pharmacies.html that allows you search for nearby pharmacies, but the process is quite frustrating, in that you have to click on 10-20 different pharmacies, before you find one that has slots available.

This tool allows you to search most of the the Northern Ireland pharmacy network in one go, to check for vacancies.

It’s available open source here: https://github.com/infiniteloopltd/NiCovid and I do welcome anyone to adapt this tool to something more user friendly.

It uses the SimplyBook booking system, which is used by most smaller pharmacies in northern ireland. Larger operations like boots use their own system, so this doesn’t cover other booking systems.

Technically, it extracts the list of pharmacies using the Simplybook service, and obtains a CRSF token from each site, once obtained, it makes a request to first check for services then for available days.

The date range is hardcoded, but it searches up to august 8th, I’m sure this can be changed easily.

Hope this helps someone!

If you are looking to automate some SEO / SERP processing in Google, it’s not long before you look to see how to automate the Google search API, and in this case, I’m using C#

Don’t even attempt to screen-scrape google, they will spot very quickly, and you’ll have wasted time doing HTML parsing for nothing, use the official API.

Now, the official API has one huge caveat, it is only useful for searching within a set number of specified sites. This means you can’t use it to determine, is my website in position #1 for keyword “Y”, but it can be used to check what pages of your site, or a competitor’s site are indexed.

This caveat rules out 99% of standard use cases, so feel free to close the page now, if it rules out your case. – Although I have seen that it is possible to include an entire Top Level Domain in the Custom search engine, like “*.es” (spain)

So, step 1 is to create a custom search engine, you do this from https://cse.google.com, and when it is created, copy the “cx” parameter, you will need this later

Step 2, go to https://developers.google.com/custom-search/v1/introduction/?apix=true and then press “Get A Key”, you’ll need this in step 3

Step 3, build up a URL as follows;

https://customsearch.googleapis.com/customsearch/v1?cx=…&key=…&q=&#8230;.&start=0

Where cx and key are from step 1 and 2 above respectively.

Q is the search query

Start is a number from 0 to 90 Which represents the start position in the search results. You cannot return more than 100 results using this API.

To request, you just use some code like this

var apiUrl =
"https://customsearch.googleapis.com/customsearch/v1?cx=....&key=...&q=" +
                        searchTerm + "&start=" + start;
var response = http.Request(apiUrl);
var jResponse = JObject.Parse(response);

And hopefully that helps someone!

TL;DR; here is the Github repo: https://github.com/infiniteloopltd/Zip

First off, if you’re just looking to unzip a zip file, please stop reading, and look at System.IO.Compression instead, however, if you want to write some code in C# to repair a damaged Zip file, or to find a performant way to decompress one file out of a larger zip file, then perhaps this approach may be useful.

So, from Wikipedia, you can get the header format for a Zip file; which repeats for every zip entry (compressed file)

I only wanted a few fields out of these, so I wrote code to extract them as follows;

eader = BitConverter.ToInt32(zipData.Skip(offset).Take(4).ToArray());
if (header != 0x04034b50)
{
	IsValid = false;
	return; // Zip header invalid
}
GeneralPurposeBitFlag = BitConverter.ToInt16(zipData.Skip(offset + 6).Take(2).ToArray());
var compressionMethod = BitConverter.ToInt16(zipData.Skip(offset + 8).Take(2).ToArray());
CompressionMethod = (CompressionMethodEnum) compressionMethod;
CompressedDataSize = BitConverter.ToInt32(zipData.Skip(offset + 18).Take(4).ToArray());
UncompressedDataSize = BitConverter.ToInt32(zipData.Skip(offset + 22).Take(4).ToArray());
CRC = BitConverter.ToInt32(zipData.Skip(offset + 14).Take(4).ToArray());
var fileNameLength = BitConverter.ToInt16(zipData.Skip(offset + 26).Take(2).ToArray());
FileName = Encoding.UTF8.GetString(zipData.Skip(offset + 30).Take(fileNameLength).ToArray());
var extraFieldLength = BitConverter.ToInt16(zipData.Skip(offset + 28).Take(2).ToArray());
ExtraField = zipData.Skip(offset + 30 + fileNameLength).Take(extraFieldLength).ToArray();
var dataStartIndex = offset + 30 + fileNameLength + extraFieldLength;
var bCompressed = zipData.Skip(dataStartIndex).Take(CompressedDataSize).ToArray();
Decompressed = CompressionMethod == CompressionMethodEnum.None ? bCompressed : Deflate(bCompressed);
NextOffset = dataStartIndex + CompressedDataSize;

This rather dense piece of code extracts relevant data from the zip entry header. It also determines if the zip entry is compressed, or left as-is, because with a very small file, then compression can actually increase the file size.

public enum CompressionMethodEnum
{
            None = 0,
            Deflate = 8
}

This is the enum I used, 0 for no compression, and 8 for deflate.

Now, if the zip entry is actually compressed, then you really have to revert to some code in .NET to decompress it:

private static byte[] Deflate(byte[] rawData)
{ 
	var memCompress = new MemoryStream(rawData);
	Stream csStream = new DeflateStream(memCompress, CompressionMode.Decompress);
	var msDecompress = new MemoryStream();
	csStream.CopyTo(msDecompress);
	var bDecompressed = msDecompress.ToArray();
	return bDecompressed;
}

I would really love if someone could implement this from first principles also, but the process is very very complicated, and it just fried my head trying to understand it.

So, with this in place, here is the loop I used to extract every file in the archive;

static void Main(string[] args)
{
	var file = "hello3.zip";
	var bFile = File.ReadAllBytes(file);
	var nextOffset = 0;
	do
	{
		var entry = new ZipEntry(bFile, nextOffset);
		if (!entry.IsValid) break;
		var content = Encoding.UTF8.GetString(entry.Decompressed);
		Console.WriteLine(entry.FileName);
		Console.WriteLine(content);
		nextOffset = entry.NextOffset;
	} while (true);
}

So, you could perhaps use this code to try to repair a corrupt zip file, or maybe optimize the extraction, so you extract on certain data from a large zip – or whatever.