dotnet/Documentation/compatibility/WCF-PipeConnection.GetHashAlgorithm-now-uses-SHA256.md

##WCF PipeConnection.GetHashAlgorithm now uses SHA256

###Scope Minor ###Version Introduced .NET Framework 4.7.1 ###Source Analyzer Status NotPlanned ###Change Description In .NET Framework 4.7 and earlier versions, WCF generated random NamedPipe names by creating a SHA1 hash. Starting with .NET 4.7.1, WCF will use a SHA256 to generate the name for the NamedPipe. ###Recommended Action: If you run into compatibility issue with this change on .Net 4.7.1 or later version, you may opt-out the change by adding the following configuration in App config file:

<configuration>
    <runtime>
	    <AppContextSwitchOverrides value="Switch.System.ServiceModel.UseSha1InPipeConnectionGetHashAlgorithm=true" />
	</runtime> 
</configuration>

##Affected APIs

• Not detectable via API analysis