Add IPv6 support for isLocal checks (#1592)

* Add IPv6 support for isLocal checks * Replace magic values like 127.0.0.1 and use our utility * Support for IPv6 local adresses in IPv6 only or dual stack environments * Loopback [::1] * Site-Local fc00::/7 * Link-local fe80::/10 * Introduce extra method for loopback addresses * Use public IP for passMaxLogin check * Use non-local IP addresses in test after change in verification
2018-07-04 02:05:17 +02:00
parent fc07ad3df1
commit 0227cb3f74
6 changed files with 104 additions and 30 deletions
@@ -1,16 +1,13 @@
 package fr.xephi.authme.util;

-import java.util.regex.Pattern;
+import java.net.InetAddress;
+import java.net.UnknownHostException;

 /**
 * Utility class about the InternetProtocol
 */
 public final class InternetProtocolUtils {

-    private static final Pattern LOCAL_ADDRESS_PATTERN =
-        Pattern.compile("(^127\\.)|(^(0)?10\\.)|(^172\\.(0)?1[6-9]\\.)|(^172\\.(0)?2[0-9]\\.)"
-            + "|(^172\\.(0)?3[0-1]\\.)|(^169\\.254\\.)|(^192\\.168\\.)");
-
    // Utility class
    private InternetProtocolUtils() {
    }
@@ -19,10 +16,57 @@ public final class InternetProtocolUtils {
     * Checks if the specified address is a private or loopback address
     *
     * @param address address to check
-     *
-     * @return true if the address is a local or loopback address, false otherwise
+     * @return true if the address is a local (site and link) or loopback address, false otherwise
     */
    public static boolean isLocalAddress(String address) {
-        return LOCAL_ADDRESS_PATTERN.matcher(address).find();
+        try {
+            InetAddress inetAddress = InetAddress.getByName(address);
+
+            // Examples: 127.0.0.1, localhost or [::1]
+            return isLoopbackAddress(address)
+                    // Example: 10.0.0.0, 172.16.0.0, 192.168.0.0, fec0::/10 (deprecated)
+                    // Ref: https://en.wikipedia.org/wiki/IP_address#Private_addresses
+                    || inetAddress.isSiteLocalAddress()
+                    // Example: 169.254.0.0/16, fe80::/10
+                    // Ref: https://en.wikipedia.org/wiki/IP_address#Address_autoconfiguration
+                    || inetAddress.isLinkLocalAddress()
+                    // non deprecated unique site-local that java doesn't check yet -> fc00::/7
+                    || isIPv6UniqueSiteLocal(inetAddress);
+        } catch (UnknownHostException e) {
+            return false;
+        }
+    }
+
+    /**
+     * Checks if the specified address is a loopback address. This can be one of the following:
+     * <ul>
+     * <li>127.0.0.1</li>
+     * <li>localhost</li>
+     * <li>[::1]</li>
+     * </ul>
+     *
+     * @param address address to check
+     * @return true if the address is a loopback one
+     */
+    public static boolean isLoopbackAddress(String address) {
+        try {
+            InetAddress inetAddress = InetAddress.getByName(address);
+            return inetAddress.isLoopbackAddress();
+        } catch (UnknownHostException e) {
+            return false;
+        }
+    }
+
+    private static boolean isLoopbackAddress(InetAddress address) {
+        return address.isLoopbackAddress();
+    }
+
+    private static boolean isIPv6UniqueSiteLocal(InetAddress address) {
+        // ref: https://en.wikipedia.org/wiki/Unique_local_address
+
+        // currently undefined but could be used in the near future fc00::/8
+        return (address.getAddress()[0] & 0xFF) == 0xFC
+                // in use for unique site-local fd00::/8
+                || (address.getAddress()[0] & 0xFF) == 0xFD;
    }
 }