crypto/ssh: use net.IP.Equal instead of bytes.Equal

A net.IP may be represented by both by a 4 as well as a 16 byte long
byte slice. Because of this, it is not safe to compare IP addresses
using bytes.Equal as the same IP address using a different internal
representation will produce mismatches.

Change-Id: I0d228771cf363ccfb9532f8bc2a2fc8eff61f6e9
Reviewed-on: https://go-review.googlesource.com/34450
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

ssh/server.go

@@ -242,7 +242,7 @@ func checkSourceAddress(addr net.Addr, sourceAddr string) error {
 	}
 
 	if allowedIP := net.ParseIP(sourceAddr); allowedIP != nil {
-		if bytes.Equal(allowedIP, tcpAddr.IP) {
+		if allowedIP.Equal(tcpAddr.IP) {
 			return nil
 		}
 	} else {