As long as the problem lies in %2F being unescaped to "/" there are solutions out there. One involving a hack and for newer versions of .Net, an app.config setting. Check here: How to make System.Uri not to unescape %2f (slash) in path?
However I have still to figure out how to prevent it unescaping some specifically escaped characters, like '(' and ')' (%28 and %29). I have tried all the settings and hacks that I found out there to prevent the Uri class from delivering a partially unescaped path for the WebRequest. The solutions will happily prevent %2F being unescaped, but not %28 and %29 and possible most of the other chars being specifically escaped.
It seems like the WebRequest is specifically asking for 1 value from the Uri object to create the "GET /path HTTP/1.1" syntax: Uri.PathAndQuery which again calls its UriParser.GetComponents.
If you want to download from mediafire and it contains the chars %28 and %29 you will get into a infinite redirect loop as .Net keeps changing %28 and %29 to '(' and ')' and following the redirect (exception: "Too many automatic redirections were attempted").
So this is a solution for those who are stuck and have not been able to find a way to prevent the unescape of some characters.
The only way I have found to override this (currenly using .Net 4.6) and deliver my own PathAndQuery has been a combination of inherting UriParser and hacking its use.
public sealed class MyUriParser : System.UriParser
{
private UriParser _originalParser;
private MethodInfo _getComponentsMethod;
public MyUriParser(UriParser originalParser) : base()
{
if (_originalParser == null)
{
_originalParser = originalParser;
_getComponentsMethod = typeof(UriParser).GetMethod("GetComponents", BindingFlags.NonPublic | BindingFlags.Instance);
if (_getComponentsMethod == null)
{
throw new MissingMethodException("UriParser", "GetComponents");
}
}
}
private static Regex rx = new Regex(@"^(?<Scheme>[^:]+):(?://((?<User>[^@/]+)@)?(?<Host>[^@:/?#]+)(:(?<Port>\d+))?)?(?<Path>([^?#]*)?)?(\?(?<Query>[^#]*))?(#(?<Fragment>.*))?$",RegexOptions.Compiled | RegexOptions.ExplicitCapture | RegexOptions.Singleline);
private Match m = null;
protected override string GetComponents(Uri uri, UriComponents components, UriFormat format)
{
var original = (string)_getComponentsMethod.Invoke(_originalParser, BindingFlags.InvokeMethod, null, new object[] { uri, components, format }, null);
if (components == UriComponents.PathAndQuery)
{
var reg = rx.Match(uri.OriginalString);
var path = reg.Groups["Path"]?.Value;
var query = reg.Groups["Query"]?.Value;
if (path != null && query != null) return $"{path}?{query}";
if (query == null) return $"{path}";
return $"{path}";
}
return original;
}
}
And then hacking it into the Uri instance by replacing its UriParser with this one.
public static Uri CreateUri(string url)
{
var uri = new Uri(url);
if (url.Contains("%28") || url.Contains("%29"))
{
var originalParser = ReflectionHelper.GetValueByReflection(uri, "m_Syntax") as UriParser;
var parser = new MyUriParser(originalParser);
ReflectionHelper.SetValueByReflection(parser, "m_Scheme", "http");
ReflectionHelper.SetValueByReflection(parser, "m_Port", 80);
ReflectionHelper.SetValueByReflection(uri, "m_Syntax", parser);
}
return uri;
}
Due to the way UriParser works, it normally needs to register to have its port and scheme name set, so these 2 values has to be set by reflection as we are not registering it the correct way. I have not found a way to register "http" as it already exist. The ReflectionHelper is just a class I have but can be quickly replaced with normal reflection code.
Then call it like this:
HttpWebRequest dataRequest = (HttpWebRequest)WebRequest.Create(CreateUri(serviceURL));
