Develop Reference

How to encode a URL using Asp.net?

I have the following line of aspx link that I would like to encode:
Response.Redirect("countriesAttractions.aspx?=");
I have tried the following method:
Response.Redirect(Encoder.UrlPathEncode("countriesAttractions.aspx?="));
This is another method that I tried:
var encoded = Uri.EscapeUriString("countriesAttractions.aspx?=");
Response.Redirect(encoded);
Both redirects to the page without the URL being encoded:
http://localhost:52595/countriesAttractions?=
I tried this third method:
Response.Redirect(Server.UrlEncode("countriesAttractions.aspx?="));
This time the url itself gets encoded:
http://localhost:52595/countriesAttractions.aspx%3F%3D
However I get an error from the UI saying:
HTTP Error 404.0 Not Found
The resource you are looking for has been removed, had its name changed, or
is temporarily unavailable.
Most likely causes:
-The directory or file specified does not exist on the Web server.
-The URL contains a typographical error.
-A custom filter or module, such as URLScan, restricts access to the file.
Also, I would like to encode another kind of URL that involves parsing of session strings:
Response.Redirect("specificServices.aspx?service=" +
Session["service"].ToString().Trim() + "&price=" +
Session["price"].ToString().Trim()));
The method I tried to include the encoding method into the code above:
Response.Redirect(Server.UrlEncode("specificServices.aspx?service=" +
Session["service"].ToString().Trim() + "&price=" +
Session["price"].ToString().Trim()));
The above encoding method I used displayed the same kind of results I received with my previous Server URL encode methods. I am not sure on how I can encode url the correct way without getting errors.
As well as encoding URL with CommandArgument:
Response.Redirect("specificAttractions.aspx?attraction=" +
e.CommandArgument);
I have tried the following encoding:
Response.Redirect("specificAttractions.aspx?attraction=" +
HttpUtility.HtmlEncode(Convert.ToString(e.CommandArgument)));
But it did not work.
Is there any way that I can encode the url without receiving this kind of error?
I would like the output to be something like my second result but I want to see the page itself and not the error page.
I have tried other methods I found on stackoverflow such as self-coded methods but those did not work either.
I am using AntiXSS class library in this case for the methods I tried, so it would be great if I can get solutions using AntiXSS library.
I need to encode URL as part of my school project so it would be great if I can get solutions. Thank you.

You can use the UrlEncode or UrlPathEncode methods from the HttpUtility class to achieve what you need. See documentation at https://msdn.microsoft.com/en-us/library/system.web.httputility.urlencode(v=vs.110).aspx
It's important to understand however, that you should not need to encode the whole URL string. It's only the parameter values - which may contain arbitrary data and characters which aren't valid in a URL - that you need to encode.
To explain this concept, run the following in a simple .NET console application:
string url = "https://www.google.co.uk/search?q=";
//string url = "http://localhost:52595/specificAttractions.aspx?country=";
string parm = "Bora Bora, French Polynesia";
Console.WriteLine(url + parm);
Console.WriteLine(url + HttpUtility.UrlEncode(parm), System.Text.Encoding.UTF8);
Console.WriteLine(url + HttpUtility.UrlPathEncode(parm), System.Text.Encoding.UTF8);
Console.WriteLine(HttpUtility.UrlEncode(url + parm), System.Text.Encoding.UTF8);
You'll get the following output:
https://www.google.co.uk/search?q=Bora Bora, French Polynesia
https://www.google.co.uk/search?q=Bora+Bora%2c+French+Polynesia
https://www.google.co.uk/search?q=Bora%20Bora,%20French%20Polynesia
https%3a%2f%2fwww.google.co.uk%2fsearch%3fq%3dBora+Bora%2c+French+Polynesia
By pasting these into a browser and trying to use them, you'll soon see what is a valid URL and what is not.
(N.B. when pasting into modern browsers, many of them will URL-encode automatically for you, if your parameter is not valid - so you'll find the first output works too, but if you tried to call it via some C# code for instance, it would fail.)
Working demo: https://dotnetfiddle.net/gqFsdK
You can of course alter the values you input to anything you like. They can be hard-coded strings, or the result of some other code which returns a string (e.g. fetching from the session, or a database, or a UI element, or anywhere else).
N.B. It's also useful to clarify that a valid URL is simply a string in the correct format of a URL. It is not the same as a URL which actually exists. A URL may be valid but not exist if you try to use it, or may be valid and really exist.

parsing base64 blob from tool output

I have a problem parsing base64 encoded blob from tool output.
I'm using this regex in c#: #"(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)"
Everything worked fine until the blob I receive looks like following (it does not have even one '='. according to wiki base64 string can have 0-2 "=" signs in the end/)
I cannot work with string before and after the blob because it can be muli-language
Provisioning the computer account... Successfully provisioned
[user-1009-1-] in the domain [testauto.sof]. Provisioning data was
saved successfully to
[C:\Users\user1\AppData\Local\Temp\user-1009-1-.blob]. Provisioning
string (2624l bytes):
ARAIAMzMzMzIAwAAAAAAAAAAAgABAAAAAQAAAAQAAgABAAAAAQAAAKADAAAIAAIAoAMAAAEQCADMzMzMkAMAAAAAAAAAAAIABAACAAgAAgAMAAIAFAAWABAAAgAcAB4AFAACABwAHgAYAAIA5pXFb5WfaEeEDMNZ4eUJVxwAAgAgAAIAJAACAAEAAADmlcVvlZ9oR4QMw1nh5QlXKAACACwAAgD8MQDgMAACADQAAgACAAAADwAAAAAAAAAPAAAAbQBpAHIAYQBnAGUAYQB1AHQAbwAuAHMAbwBmAAAAAAAQAAAAAAAAABAAAAB4AGkAcwBoAGUAbgBnAC0AMQAwADAAOQAtADEALQAAAHkAAAAAAAAAeQAAAF0APwAjAHkAWgBYADoAdwBgAGUANgB2AG8AJQBuAHkAIwBUAE4ALAAxAHUAOQBkAD4AdwA5AG8AaABgAHEAIwBhADYALABwAF0ALwBoAEgAIABqAHMATwA5AGwATgB5ADEAVQAhAE4ASwAiAEUAPQA8AGIAZQBAAC8ARgA1AGIAQAAiAG8AUgA6AGIAawAzAF4AVwBrACYATQA5AE8AdQBvAHYAZQA0AGMAKwBDAHMAUABrAGsAdQBAAF4AYAAgAFsAJQBgAGUAJwAuAG8AOwBBACgATQBuACIARgAlAG0ASwA1ADMAbQBJAHcAXQBkAAAAAAALAAAAAAAAAAoAAABNAEkAUgBBAEcARQBBAFUAVABPAA8AAAAAAAAADgAAAG0AaQByAGEAZwBlAGEAdQB0AG8ALgBzAG8AZgAPAAAAAAAAAA4AAABtAGkAcgBhAGcAZQBhAHUAdABvAC4AcwBvAGYABAAAAAEEAAAAAAAFFQAAAN0GKLrAxnxUyKGAThoAAAAAAAAAGgAAAFwAXABTAE8ARgAtAFEAQQAwADIALgBtAGkAcgBhAGcAZQBhAHUAdABvAC4AcwBvAGYAAAANAAAAAAAAAA0AAABcAFwAMQAwAC4AMgAzAC4ANwAyAC4AMgAAAAAADwAAAAAAAAAPAAAAbQBpAHIAYQBnAGUAYQB1AHQAbwAuAHMAbwBmAAAAAAAPAAAAAAAAAA8AAABtAGkAcgBhAGcAZQBhAHUAdABvAC4AcwBvAGYAAAAAABgAAAAAAAAAGAAAAEQAZQBmAGEAdQBsAHQALQBGAGkAcgBzAHQALQBTAGkAdABlAC0ATgBhAG0AZQAAABgAAAAAAAAAGAAAAEQAZQBmAGEAdQBsAHQALQBGAGkAcgBzAHQALQBTAGkAdABlAC0ATgBhAG0AZQAAAAAAAAAAAAAA
Computer account provisioning completed successfully. The operation
completed successfully.
Anyone can help me to fix the regex?
Here is regex calculator that I using:
http://regex101.com/r/wP3kP9/1

The following should work successfully:
^(?!$)(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?$
regex101
In my understanding, if no = is present, it's because the string length is a multiple of 4.
I also anchored it with ^...$and used the m option so only your base64 string matches. I added (?!$) so empty lines don't match (couldn't simply change the * to + because you may want to match short strings like aa==).

A socket message from Python to C# comes through garbled

I'm trying to set up a very basic ZeroMQ-based socket link between Python server and C# client using simplejson and Json.NET.
I try to send a dict from Python and read it into an object in C#. Python code:
message = {'MessageType':"None", 'ContentType':"None", 'Content':"OK"}
message_blob = simplejson.dumps(message).encode(encoding = "UTF-8")
alive_socket.send(message_blob)
The message is sent as normal UTF-8 string or, if I use UTF-16, as "'\xff\xfe{\x00"\x00..." etc.
Code in C# is where my problem is:
string reply = client.Receive(Encoding.UTF8);
The UTF-8 message is received as "≻潃瑮湥≴›..." etc.
I tried to use UTF-16 and the message comes through OK, but the first symbols are still the little-endian \xFF \xFE BOM so when I try to feed it to the deserializer,
PythonMessage replyMessage = JsonConvert.DeserializeObject<PythonMessage>(reply);
//PythonMessage is just a very simple class with properties,
//not relevant to the problem
I get an error (obviously occurring at the first symbol, \xFF):
Unexpected character encountered while parsing value: .
Something is obviously wrong in the way I'm using encoding. Can you please show me the right way to do this?

The byte-order-mark is obligatory in UTF-16. You can use UTF-16LE or UTF-16BE to assume a particular byte order and the BOM will not be generated. That is, use:
message_blob = simplejson.dumps(message).encode(encoding = "UTF-16le")

Parse JSON C# Error

I'm try to getting JSON data but getting Error.
Unexpected character encountered while parsing value: . Path '', line
0, position 0.
I'm using Net 4.5 and JSON.Net Framework
Here my code
WebClient net = new WebClient();
string str = await net.DownloadStringTaskAsync(url);
JObject o = JObject.Parse(str); // ERROR Here
And my code JSON Data View on Webservice
http://sv1.volcanosoft.com/test/index.php?area=ho-chi-minh
this site format index.php UTF-8 and header of php file
header('Content-Type:application/json; charset=utf-8');
echo '{"item":';
echo json_encode($data);
echo '}';

The downloaded string starts with two byte order marks (U+FEFF), which JSON.NET parser (correctly) doesn't understand.
The reason why the downloaded string contains two BOMs is because the data your service is sending contains 3 of them. The first one is removed automatically by UTF-8 encoding, but the two other remain.
BOM can be useful with files, where you can't store the charset used. But you are sending the charset used in a header, so you don't need to send BOM at all. And sending three of them is certainly incorrect.
I believe this is caused by BOMs in your PHP files, so you should probably remove them from there.

Google Translate Api and Special Characters

I've recently started using the google translate API inside a c# project. I am trying to translate some text from english to french. I am having issues with some special characters though.
For example the word Company comes thru as Société instead of Société as it should. Is there some way in code I can convert these to the correct special characters? ie (é to é)
Thanks
If you need anymore info let me know.

I ran into this same exact issue. If you're using the WebClient class to download the json response from google, try setting the Encoding property to UTF8.
using(var webClient = new WebClient { Encoding = Encoding.UTF8 })
{
string json = webClient.DownloadString(someUri);
...
}

I have reproduced your problem, and it looks like you are using the UTF7 encoding. UTF8 is the way you need to go.
I use Google's API by creating a WebRequest to get an HTTP response from the server, then I read the response stream with a StreamReader. StreamReader defaults to UTF8, but to reproduce your problem, I passed Encoding.UTF7 into the StreamReader's constructor.