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<schemeSettings> Element (Uri Settings)

Specifies how a Uri will be parsed for specific schemes.

<configuration> Element
  <Uri> Element (Uri Settings)
    <schemeSettings> Element (Uri Settings)

<schemeSettings> 
</schemeSettings>

Attributes and Elements

The following sections describe attributes, child elements, and parent elements.

Attributes

None

Child Elements

Element

Description

add

Adds a scheme setting for a scheme name.

clear

Clears all existing scheme settings.

remove

Removes a scheme setting for a scheme name.

Parent Elements

Element

Description

uri

Contains settings that specify how the .NET Framework handles web addresses expressed using uniform resource identifiers (URIs).

Remarks

By default, the System.Uri class un-escapes percent encoded path delimiters before executing path compression. This was implemented as a security mechanism against attacks like the following:

https://www.contoso.com/..%2F..%2F/Windows/System32/cmd.exe?/c+dir+c:\\

If this URI gets passed down to modules not handling percent encoded characters correctly, it could result in the following command being executed by the server:

c:\Windows\System32\cmd.exe /c dir c:\

For this reason, System.Uri class first un-escapes path delimiters and then applies path compression. The result of passing the malicious URL above to System.Uri class constructor results in the following URI:

https://www.microsoft.com/Windows/System32/cmd.exe?/c+dir+c:\\

This default behavior can be modified to not un-escape percent encoded path delimiters using the schemeSettings configuration option for a specific scheme.

Configuration Files

This element can be used in the application configuration file or the machine configuration file (Machine.config).

Example

The following code example shows a configuration used by the Uri class to support not escaping percent-encoded path delimiters for the http scheme.

<configuration>
  <uri>
    <schemeSettings>
      <add name="http" genericUriParserOptions="DontUnescapePathDotsAndSlashes"/>
    </schemeSettings>
  </uri>
</configuration>

Element Information

Namespace

System

Schema Name

Validation File

Can be Empty

See Also

Reference

Network Settings Schema

System.Configuration.SchemeSettingElement

System.Configuration.SchemeSettingElementCollection

System.Configuration.UriSection

UriSection.SchemeSettings

System.GenericUriParserOptions

System.Uri