Develop Reference

Base64EncodedString does not include NewLines

I´m using a .NET core 3.0 project on Windows 10. I´m trying to encode a string to base64 with below code:
var stringvalue = "Row1" + Environment.NewLine + "\n\n" + "Row2";
var encodedString = Convert.ToBase64String(Encoding.UTF8.GetBytes(stringvalue));
encodedString has then below result:
Um93MQ0KCgpSb3cy
stringvalue is:
Row1\r\n\n\nRow2
However, if I´m passing the same value to this site (https://www.base64encode.org/), i´m getting another result:
Um93MVxyXG5cblxuUm93Mg==
In visual studio, I tried to resave the file with Unix lineendings, but without any luck:
I want the string to be encoded as how it´s done in https://www.base64encode.org. Any ideas how to get this done?

From the screenshot, I can see that you have entered a different string from the string you used in your C# code. The string you used in https://www.base64encode.org is represented as a C# string literal like this:
"Row1\\r\\n\n\\nRow2"
// or
#"Row1\r\n\n\nRow2"
So to answer your question:
I want the string to be encoded as how it´s done in https://www.base64encode.org. Any ideas how to get this done?
You should do:
var encodedString = Convert.ToBase64String(Encoding.UTF8.GetBytes("Row1\\r\\n\n\\nRow2"));
But that's probably not what you actually want. Your first attempt at the C# code is more likely to be desired, because that is actually a carriage return character, followed by 3 new line characters. The string you entered in https://www.base64encode.org is simply the backslash character followed by the letter r (or n).
You can't really make the output on https://www.base64encode.org match the C# output, because you can only choose one kind of line separator on there. You can only either encode Row1\r\n\r\n\r\nRow2 or Row\n\n\nRow2. Nevertheless, you can check that the C# result is correct by decoding the output using https://www.base64decode.org.

The \r\n will be encoded on the website, this is not a newline, these are 4 characters. There is this newline-separator-checkbox, to say you want the windows style, to convert your real world input value:
Row1
Row2.
I guess your \r\n\n\n is just a mistake, the website is prepared to convert it to \r\n\r\n only.

C# .NET: Problems with query strings with character references

I'm having problems creating a query string and sending it to another webpage.
The text I'm trying to send is long and has special characters. Here is an example:
Represent a fraction 1/𝘣 on a number line diagram by defining the interval from 0 to 1 as the whole and partitioning it into 𝘣 equal parts. Recognize that each part has size 1/𝘣 and that the endpoint of the part based at 0 locates the number 1/𝘣 on the number line.
I can send this just fine if I hand code it:
<a href="Default.cshtml?standardText=Represent a fraction 1/𝘣 on a number line diagram by defining the interval from 0 to 1 as the whole and partitioning it into 𝘣 equal parts. Recognize that each part has size 1/𝘣 and that the endpoint of the part based at 0 locates the number 1/𝘣 on the number line.">
Link Text
</a>
This goes through without any problems, and I can read the entire Query String on the other side.
But if I am creating the link programmatically, my query string gets cut off right before the first character reference. I am using the following setup in a helper function:
string url = "Default.cshtml";
url += "?standardText=" + standard.text;
Link Text
When I use this, I only get "Understand a Fraction as 1/" and then it stops.
When I look at the page source, the only difference in the links is that one has actual ampersands and the second is having those turned into &
<a href="Default.cshtml?standardText=Understand a fraction 1/&#120355; as the quantity formed by 1 part when a whole is partitioned into &#120355; equal parts; understand a fraction &#120354;/&#119887; as the quantity formed by &#120354; parts of size 1/&#120355;."
So the problem is not really the spaces, but the fact that the & is being interpreted as starting a new query string parameter.
I have tried various things [using HttpUtility.UrlEncode, HttpUtility.UrlEncodeUnicode, Html.Raw, trying to replace spaces with "+"], but the problem isn't with the spaces, its with how the character references are being handled. When I tried HttpUtility.urlEncode I got a double-encoding security error.
On the advice of OmG I tried replacing all the &s, #s, and /s using:
url = url.Replace("&","%26");
url = url.Replace("#","%23");
url = url.Replace("/","%2F");
This led to the following link:
All Items
And now when I click on the link I get a different security warning/error:
A potentially dangerous Request.QueryString value was detected from the client (standardText="...raction 1/𝘣 as the qua...").
I don't see why it is so hard to send character references through a QueryString. Is there a way to prevent Razor from converting all my &s to the &amp ; ? The address works fine when it is just plain "&"s.
Update: using URLDecode() on the string does not affect its character entity references, so when I try to decode the string then re-encode it, I still get the double-escape security warning.
Update: on the suggestion of #MikeMcCaughan, I tried using JS, but I am not very knowledgeable about mixing JS and Razor. I tried creating a link by dropping a script into the body like so:
<script type="text/javascript">
var a = document.createElement('a');
var linkText = document.createTextNode("my title text");
a.appendChild(linkText);
a.title = "my title text";
a.href = encodeURIComponent(#url);
document.body.appendChild(a);
</script>
But no link showed up, so I'm obviously doing it wrong.
For reference, when I try to use #Html.Raw(url),
Link Text
The &s are still turned into &amp ;s. the link renders as:
Link text

One simple solution is replacing the special characters by their encoding which can be accessed from here.
As you can find, replace in the string & with %26 using .replace for string. Also, replace / with %2F, # with %23, ; with %3B, and space with %20.
Also, You can do these in C# by the following function:
Server.URLEncode("<The Url>")
and in Javascript by the following function:
encodeURI("<The Url>")
Also, as you know the double-encoding is this. To prevent the double-encoding, you should have not encoded some part of the string before passing the string into the Server.URLEncode function.

Plus sign in query string

I have a webapp created using C# and asp.net. I placed a parameter value in the querystring with a plus(+) sign. But the plus sign disappear.
How can I include the plus sign(+) in the query string without disappearing?
Please advise.
Thanks.
Edit: added code with UrlEncode
string str = Server.UrlEncode(Requery.QueryString["new"]);

+ sign has a semantic meaning in the query string. It is used to represent a space. Another character that has semantic importance in the query string is & which is used to separate the various var=value pairs in the query string.
Most server side scripts would decode the query parameters before using them, so that a + gets properly converted to a space. Now, if you want a literal + to be present in the query string, you need to specify %2B instead.
+ sign in the query string is URL-decoded to a space. %2B in the query string is URL-decoded to a + sign.
See the difference between
http://www.google.com/search?q=foo+bar
and
http://www.google.com/search?q=foo%2Bbar
In the above examples, Google's server script is URL-decoding the query parameters and then using them to do the search.
URL-encoding is nothing but % sign followed by the hex-code of the special character. For example, we know that the hex code of A is 0x41 (decimal: 65). Try this:
http://www.google.com/search?q=%41
Hope this makes URL-encoding clear.
So, if you want the + sign to be preserved when a JavaScript is fetching a URL with + signs in its query parameters and a server side script would process the query parameters after URL-decoding it, you should URL-encode the query parameters in the URL before using issuing the HTTP get request so that all + signs are converted to %2B's when the request reaches the server side script. Now when the server side script URL-decodes the query string, all %2B's gets converted back to + signs which is what you want.
See Encode URL in JavaScript? to learn how to URL-encode the parameters using JavaScript. Short answer from the discussion there:
var encodedURL = "http://example.com/foo.php?var=" + encodeURIComponent(param);

You should URLEncode your query string values to make sure any special characters are not lost.

Look at HTML URL Encoding Reference
You need to Encode the + sign - It's value should be %2B

I alter my previous statement so no one gets confused!
Create your url using the Server.UrlEncode.
e.g.
string myUrl = "http://myurl?param1=" + Server.UrlEncode("my+param+1");

For the solution, I have applied:
Step 1:Use Server.UrlEncode method for encoding the URL parameter.
Response.Redirect("YourURL?parameter=Server.UrlEncode(parameterValue.ToString().Trim()");
step 2: on another side, you get a string with a plus(+) sign.
var parameter = Request.QueryString["parameterValue"].ToString().Trim();
This is the result: %2beH8 --> +eH8

Other simple way is, Request.Url.ToString().Substring(Request.Url.ToString().IndexOf("=") + 1) assuming that my URL is, http://localhost/MyApp/Activate.aspx?ActivationCode=cHbtqH9P2dDZkx/mYUgFFo7nrNqSFgqdPisAzzu5/nwlEYDOHI+CQw==

before send you parameter, you need check if the parameter contains plus sign, if have you need replace to one flag, for example:
the parameter is: klasjdlkasd+djid3223
can you replace: klasjdlkasdFLAGdjid3223
and when you go convert, you need replace angain
klasjdlkasd+djid3223

Try this, it works for me:
Request.QueryString["new"].Trim();

The solution is to ALWAYS include .Replace(" ", "+") when you request querystring
string s = Request.QueryString["id"].Trim().Replace(" ", "+");
source: http://www.webmasterworld.com/forum47/3238.htm

Add this line in Decrypt Funcation:
strText = strText.Replace(" ", "+");

C# string.Split() Matching Both Slashes?

I've got a .NET 3.5 web application written in C# doing some URL rewriting that includes a file path, and I'm running into a problem. When I call string.Split('/') it matches both '/' and '\' characters. Is that... supposed to happen? I assumed that it would notice that the ASCII values were different and skip it, but it appears that I'm wrong.
// url = 'someserver.com/user/token/files\subdir\file.jpg
string[] buffer = url.Split('/');
The above code gives a string[] with 6 elements in it... which seems counter intuitive. Is there a way to force Split() to match ONLY the forward slash? Right now I'm lucky, since the offending slashes are at the end of the URL, I can just concatenate the rest of the elements in the string[], but it's a lot of work for what we're doing, and not a great solution to the underlying problem.
Anyone run into this before? Have a simple answer? I appreciate it!
More Code:
url = HttpContext.Current.Request.Path.Replace("http://", "");
string[] buffer = url.Split('/');
Turns out, Request.Path and Request.RawUrl are both changing my slashes, which is ridiculous. So, time to research that a bit more and figure out how to get the URL from a function that doesn't break my formatting. Thanks everyone for playing along with my insanity, sorry it was a misleading question!

When I try the following:
string url = #"someserver.com/user/token/files\subdir\file.jpg";
string[] buffer = url.Split('/');
Console.WriteLine(buffer.Length);
... I get 4. Post more code.

Something else is happening, paste more code.
string str = "a\\b/c\\d";
string[] ts = str.Split('/');
foreach (string t in ts)
{
Console.WriteLine(t);
}
outputs
a\b
c\d
just like it should.
My guess is that you are converting / into \ somewhere.

You could use regex to convert all \ slashes to a temp char, split on /, then regex the temp chars back to \. Pain in the butt, but one option.

I suspect (without seeing your whole application) that the problem lies in the semantics of path delimiters in URLs. It sounds like you are trying to attach a semantic value to backslashes within your application that is contrary to the way HTTP protocols define and use backslashes.
This is just a guess, of course.
The best way to solve this problem might be modifying the application to encode the path in some other way (such as "%5C" for backslashes, maybe?).

those two functions are probably converting \ to / because \ is not a valid character in a URL (see Which characters make a URL invalid?). The browser (NOT C#, as you are inferring) is assuming that when you are using that invalid character, you mean /, so it is "fixing" it for you. If you want \ in your URL, you need to encode it first.
The browsers themselves are actually the ones that make that change in the request, even if it is behind the scenes. To verify this, just turn on fiddler and look at the URLs that are actually getting sent when you go to a URL like this. IE and Chrome actually change the \ to / in the URL field on the browser itself, FireFox doesn't, but the request goes through that way anyways.

Update:
How about this:
Regex.Split(url, "/");

Best way to escape javascript string? (json?)

Using C# .net I am parsing some data with some partial html/javascript inside it (i dont know who made that decision) and i need to pull a link. The link looks like this
http:\/\/fc0.site.net\/fs50\/i\/2009\/name.jpg
It came from this which i assume is javascript and looks like json
"name":{"id":"589","src":"http:\/\/fc0.site.net\/fs50\/i\/2009\/name.jpg"}
But anyways how should i escape the first link so i get
http://fc0.site.net/fs50/i/2009/name.jpg
In this case i could just replace '\' with '' since links dont contain \ nor " so i could do that but i am a fan of knowing the right solution and doing things properly. So how might i escape this. After looking at that link for a minute i thought is that valid? does java script or json escape / with \? It doesnt seem like it should?

In your case:
"name":{"id":"589","src":"http://fc0.site.net/fs50/i/2009/name.jpg"}
"/" is a valid escape sequence. However, it is not required that / be escaped. You may escape it if you need to. The reason JSON explicitly allows escaping of slash is because HTML does not allow a string in a to contain "...
Update:
Check out this post

Odd, it doesn’t look like any JavaScript/JSON escaping you’d expect. You can have forward slashes in JavaScript strings just fine.

Why dont you try a regex on the escaped slashes to replace them in the C# code...
String url = #"http:\/\/fc0.site.net\/fs50\/i\/2009\/name.jpg";
String pattern = #"\\/";
String cleanUrl = Regex.Replace(url, pattern, "/");
Hope it helps!

Actually you want to unescape the string. Answered in this question.