Get string from Server.UrlEncode as uppercase

Question

I want its output as uppercase. This is what I get on Server.UrlEncode("http://"):

http%3a%2f%2f

but I need:

http%3A%2F%2F

Is there built-in solution in C#?

The url encoded shall serve as signature base string (input to signature algorithm) to create digest (hash). The hash will then be verified by other system (java,php,etc), so they need to recreate the hash by signature reconstruction first.

This matters for something like OAuth where the difference between `%2f` and `%2F` is enough to make your signature invalid - http://oauth.net/core/1.0/#encoding_parameters — Nathan Friedly, Jul 06 '13 at 00:00

score 32 · Accepted Answer · edited May 15 '13 at 11:30

32

This will uppercase all escaped characters in your string.

string url = "http://whatever.com/something";
string lower = Server.UrlEncode(url);
Regex reg = new Regex(@"%[a-f0-9]{2}");
string upper = reg.Replace(lower, m => m.Value.ToUpperInvariant());

edited May 15 '13 at 11:30

salle55

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answered Jun 16 '11 at 11:37

agent-j

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that's its agent-j, but without extra ")", Thanks! – lax Jun 16 '11 at 12:45
thanks for this. For some reason Twitter's OAuth requires the escaped characters to be in uppercase or else it'll give you 401 unauthorized – SAGExSDX Jun 12 '13 at 20:54
Thanks! (BTW, the reason this is necessary for OAuth is that the entire URL ("http://" and all) is URLEncoded and then signed. The OAuth 1.0 spec requires uppercase hexadicemal for encoded characters, but the .net UrlEncode produces lowercase - the difference causes the signatures to not match.) – Nathan Friedly Jul 06 '13 at 00:04
@SAGExSDX: I have uppercase the url that needed to create the oauth_signature. But it still give me the 401 error. If you have the C# code, can you share it me please ? – Cham Oct 13 '15 at 10:48
@user1457039 var lower = HttpUtility.UrlEncode(strText); var reg = new Regex(@"%[a-f0-9]{2}"); return reg.Replace(lower, m => m.Value.ToUpperInvariant()); It's the same as the above answer. – SAGExSDX Oct 17 '15 at 06:26

score 24 · Answer 2 · answered Jan 17 '18 at 12:54

24

Uri.EscapeDataString("http://")

This code return

http%3A%2F%2F

answered Jan 17 '18 at 12:54

PlushEngineCell

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my favorite. Why use regex when you can use this? – Jon Kump May 16 '18 at 22:02
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This the correct answer: If you had used HttpUtility.UrlEncode('http://'); to encode it would incorrectly return lowercase encode letters, which I was incorrectly using for signatures in Oauth http requests. – Mr Rowe May 14 '19 at 06:54
This doesn't escape square brackets: [] – Stack Man Apr 25 '20 at 16:17

score 3 · Answer 3 · answered Feb 19 '15 at 11:39

3

This is very easy

Regex.Replace( encodedString, @"%[a-f\d]{2}", m => m.Value.ToUpper() )

I.e. replace all hex letter-digit combinations to upper case

answered Feb 19 '15 at 11:39

SeregaKa

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score 3 · Answer 4 · answered Nov 26 '20 at 11:18

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I encountered the same problem, I found the answer in this link:

WebUtility.UrlEncode or HttpUtility.UrlEncode

in-short you can use:

System.Net.WebUtility.UrlEncode

which encodes into uppercase hex values

answered Nov 26 '20 at 11:18

Saed Swedan

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score 0 · Answer 5 · answered Jun 16 '11 at 11:34

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Assuming "http" is always the first four characters then you simply split the string after "http", UrlEncode that part and then call ToUpper() on it. Then join back together with "http" as your prefix.

answered Jun 16 '11 at 11:34

Dan Diplo

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Get string from Server.UrlEncode as uppercase

5 Answers5

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