CODEWITHSUNDEEP
c#visual-studio-2010encoding
Bob
Bob

Reputation: 3084

Decode a string with nested encodes

strong textGiven a string that has been encoded n times, how can I decode the string to give me the plain unencoded string if I don't know the value of n.

To clarify:

Initial : /unencoded?string/

Encoded Once : %2Funencoded%3Fstring%2F

Encoded Twice: %252Funencoded%253Fstring%252F

Encoded Three Times: %25252Funencoded%25253Fstring%25252F

How do I get from %25252Funencoded%25253Fstring%25252F to /unencoded?string/ without knowing it's been encoded three times?

I know I can use HttpServerUtility.UrlDecode or similar, but this only decodes once.

Upvotes: 1

Views: 707

Answers (2)

Dan
Dan

Reputation: 157

Updated .NET version of hometoast's answer below.

Essentially just swap HttpServerUtility.UrlDecode with HttpUtility.UrlDecode

string encodedString = "....";
string temp = string.Empty;
string decodedString = HttpUtility.UrlDecode(encodedString);
while (decodedString != temp)
{
    temp=decodedString;
    decodedString = HttpUtility.UrlDecode(temp);
}

Upvotes: 2

hometoast
hometoast

Reputation: 11782

decode it until decoding doesn't change it any more.

string encodedString = "....";
string temp = string.Empty;
string decodedString = HttpServerUtility.UrlDecode(encodedString);
while (decodedString != temp)
{
    temp=decodedString;
    decodedString = HttpServerUtility.UrlDecode(temp);
}

Upvotes: 4

Related Questions