Fix issue #5371 to correctly handle Request IP Addresses

[davidjrh]

Fixes issue #5371.

Summary

Added code to correctly parse the request IP Address when original IP Address comes in the request header "X-Forwarded-For" (i.e. when using an ARR like in an Azure App Service) by removing the port.

[valadas]

Hmm, not sure if it's an issue or not but what about IPv6 addresses that use : as a separator ?

[bdukes]

That's a great point @valadas. I think we need to try calling this.ValidateIP(userIPAddress, ipFamily) and only if it fails do we try cutting off after the colon.

[davidjrh]

Good point @valadas. I've moved the check to the this.ValidateIP(userIPAddress, ipFamily) methods as @bdukes suggested. Need to to it beforeIPAddress.TryParse(ipString, out address) because that method fails if contains an IPv4 with colons.

[davidjrh]

Finnally brought back the port removal outside the ValidateIP method since it must return the IP without the port (returning the IP with the port is not for what the method is currently used)

[valadas]

That looks better, it only leaves the possibility of an IPv6 with a port which would look like
http://[1fff:0:a88:85a3::ac1f]:8001/index.html which is a bit more of a pickle because the [] are optional and only needed if a port is specified.
So I guess if it's IPv6 we could check if there is a ], if so we split on it and remove the first character [ or something like that.

[valadas]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[davidjrh]

Hi @valadas, I've added code to handle the same situation for IPv6 addresses, following your thoughts.

[valadas]

That looks awesome