Add a config option to redact remote IP addresses in logs. (#283)

* Add a config option to redact remote IP addresses in logs.

And other human-readable text.

* Don't redact relayed candidates; do redact relAddrs.

src/main/java/org/ice4j/TransportAddress.java

@@ -147,10 +147,42 @@ public byte[] getAddressBytes()
      */
     public String toString()
     {
-        String hostAddress = getHostAddress();
+        return toString(false);
+    }
+
+    public String toRedactedString()
+    {
+        return toString(true);
+    }
+
+    private String toString(boolean redact)
+    {
+        String hostAddress;
+        if (redact)
+        {
+            hostAddress = getRedactedAddress();
+            if (hostAddress == null)
+            {
+                String hostName = getHostName();
+                if (hostName != null)
+                {
+                    /* The transport address is an unresolved hostname.  Redact the hostname. */
+                    hostAddress = "xxxx.xxx";
+                }
+            }
+        }
+        else
+        {
+            hostAddress = getHostAddress();
+            if (hostAddress == null)
+            {
+                hostAddress = getHostName();
+            }
+        }
         if (hostAddress == null)
         {
-            hostAddress = getHostName();
+            // The address has neither a hostName nor a hostAddress.  Shouldn't happen, but don't NPE if it does. */
+            hostAddress = "null";
         }
 
         StringBuilder bldr = new StringBuilder(hostAddress);
@@ -181,6 +213,27 @@ public String getHostAddress()
         return addressStr;
     }
 
+    /* Return the host address, redacted if address redaction is enabled. */
+    public String getRedactedAddress()
+    {
+        if (AgentConfig.config.getRedactRemoteAddresses())
+        {
+            InetAddress addr = getAddress();
+            if (addr != null)
+            {
+                return toRedactedString(addr);
+            }
+            else
+            {
+                return null;
+            }
+        }
+        else
+        {
+            return getHostAddress();
+        }
+    }
+
     /**
      * The transport that this transport address is suggesting.
      *
@@ -288,4 +341,79 @@ public boolean canReach(TransportAddress dst)
 
         return true;
     }
+
+    public static String redact(InetAddress addr)
+    {
+        if (AgentConfig.config.getRedactRemoteAddresses())
+        {
+            return toRedactedString(addr);
+        }
+        else
+        {
+            return addr.getHostAddress();
+        }
+    }
+
+    public static String redact(SocketAddress addr)
+    {
+        if (addr instanceof InetSocketAddress && AgentConfig.config.getRedactRemoteAddresses())
+        {
+            InetSocketAddress iaddr = (InetSocketAddress)addr;
+            return toRedactedString(iaddr.getAddress()) + ":" + iaddr.getPort();
+        }
+        else if (addr == null)
+        {
+            return null;
+        }
+        else
+        {
+            return addr.toString();
+        }
+    }
+
+    /**
+     * Return a redacted form of an InetAddress, in a form preserving its IP address family
+     * and (for IPv6) its highest-level bytes.
+     */
+    public static String toRedactedString(InetAddress addr)
+    {
+        if (addr == null)
+        {
+            return null;
+        }
+        if (addr.isAnyLocalAddress() || addr.isLoopbackAddress())
+        {
+            return addr.getHostAddress();
+        }
+        if (addr instanceof Inet6Address)
+        {
+            StringBuilder sb = new StringBuilder();
+            byte[] addrBytes = addr.getAddress();
+            if ((addrBytes[0] & 0xe0) == 0x20)
+            {
+                /* Globally-routable IPv6 address; the second nybble can indicate the
+                 * RIR that allocated the address, so don't print it.
+                 */
+                sb.append("2xxx");
+            }
+            else if (addrBytes[0] != 0 || addrBytes[1] != 0)
+            {
+                /* Other IPv6 address; most common will be fc00:: unique-local and fe80:: link-local address where the
+                 * first 16 bits don't leak anything but the type; all others indicate something unexpected.
+                 */
+                sb.append(Integer.toHexString(((addrBytes[0]<<8) & 0xff00)
+                        | (addrBytes[1] & 0xff)));
+            }
+            sb.append("::xxx");
+            return sb.toString();
+        }
+        else if (addr instanceof Inet4Address)
+        {
+            return "xx.xx.xx.xx";
+        }
+        else
+        {
+            return addr.getHostAddress();
+        }
+    }
 }

src/main/java/org/ice4j/ice/Agent.java

@@ -1613,7 +1613,7 @@ protected void incomingCheckReceived(TransportAddress remoteAddress,
             = createCandidatePair(localCandidate, remoteCandidate);
 
         logger.debug(() -> "set use-candidate " + useCandidate + " for pair " +
-            triggeredPair.toShortString());
+            triggeredPair.toRedactedShortString());
         if (useCandidate)
         {
             triggeredPair.setUseCandidateReceived();
@@ -1635,7 +1635,7 @@ else if (state == IceProcessingState.FAILED)
             else //Running, Connected or Terminated.
             {
                 logger.debug(() -> "Received check from "
-                    + triggeredPair.toShortString() + " triggered a check.");
+                    + triggeredPair.toRedactedShortString() + " triggered a check.");
 
                 // We have been started, and have not failed (yet). If this is
                 // a new pair, handle it (even if we have already completed).
@@ -1725,7 +1725,7 @@ private void triggerCheck(CandidatePair triggerPair)
             //
             if (triggerPair.getParentComponent().getSelectedPair() == null)
                 logger.info("Add peer CandidatePair with new reflexive " +
-                        "address to checkList: " + triggerPair);
+                        "address to checkList: " + triggerPair.toRedactedString());
             parentStream.addToCheckList(triggerPair);
         }
 

src/main/java/org/ice4j/ice/Candidate.java

@@ -756,23 +756,54 @@ public TransportAddress getRelatedAddress()
      * @return a <tt>String</tt> representation of this <tt>Candidate</tt>.
      */
     @Override
-    public String toString()
+    public String toString() {
+        return toString(false);
+    }
+
+    /**
+     * Returns a <tt>String</tt> representation of this <tt>Candidate</tt>
+     * containing its <tt>TransportAddress</tt>, base, foundation, priority and
+     * whatever other properties may be relevant, but with its IP address redacted if
+     * redaction is enabled.
+     *
+     * @return a redacted <tt>String</tt> representation of this <tt>Candidate</tt>.
+     */
+    public String toRedactedString() {
+        return toString(true);
+    }
+
+    private String toString(boolean redacted)
     {
         StringBuilder buff = new StringBuilder("candidate:");
 
         buff.append(getFoundation());
         buff.append(" ").append(getParentComponent().getComponentID());
         buff.append(" ").append(getTransport());
         buff.append(" ").append(getPriority());
-        buff.append(" ").append(getTransportAddress().getHostAddress());
+        if (redacted && getType() != CandidateType.RELAYED_CANDIDATE)
+        {
+            buff.append(" ").append(getTransportAddress().getRedactedAddress());
+        }
+        else
+        {
+            buff.append(" ").append(getTransportAddress().getHostAddress());
+        }
         buff.append(" ").append(getTransportAddress().getPort());
         buff.append(" typ ").append(getType());
 
         TransportAddress relAddr = getRelatedAddress();
 
         if (relAddr != null)
         {
-            buff.append(" raddr ").append(relAddr.getHostAddress());
+            buff.append(" raddr ");
+            if (redacted)
+            {
+                buff.append(relAddr.getRedactedAddress());
+            }
+            else
+            {
+                buff.append(relAddr.getHostAddress());
+            }
             buff.append(" rport ").append(relAddr.getPort());
         }
 
@@ -788,6 +819,15 @@ public String toShortString()
         return getTransportAddress() + "/" + getType();
     }
 
+    public String toRedactedShortString()
+    {
+        if (getType() == CandidateType.RELAYED_CANDIDATE)
+        {
+            return toShortString();
+        }
+        return getTransportAddress().toRedactedString() + "/" + getType();
+    }
+
     /**
      * Returns an integer indicating the preference that this <tt>Candidate</tt>
      * should be considered with for becoming a default candidate.

src/main/java/org/ice4j/ice/CandidatePair.java

@@ -484,6 +484,20 @@ public String toString()
                 + "\n\tRemoteCandidate=" + getRemoteCandidate();
     }
 
+    /**
+     * Returns a String representation of this <tt>CandidatePair</tt>, with the remote
+     * candidate IP address redacted if redaction is enabled.
+     *
+     * @return a String representation of the object.
+     */
+    public String toRedactedString()
+    {
+        return
+                "CandidatePair (State=" + getState() + " Priority=" + getPriority()
+                        + "):\n\tLocalCandidate=" + getLocalCandidate()
+                        + "\n\tRemoteCandidate=" + getRemoteCandidate().toRedactedString();
+    }
+
     /**
      * Returns a short String representation of this <tt>CandidatePair</tt>.
      *
@@ -496,6 +510,19 @@ public String toShortString()
                 + " (" + getParentComponent().toShortString() + ")";
     }
 
+    /**
+     * Returns a short String representation of this <tt>CandidatePair</tt>,
+     * with the remote candidate IP address redacted if redaction is enabled.
+     *
+     * @return a redacted short String representation of the object.
+     */
+    public String toRedactedShortString()
+    {
+        return getLocalCandidate().toShortString()
+                + " -> " + getRemoteCandidate().toRedactedShortString()
+                + " (" + getParentComponent().toShortString() + ")";
+    }
+
     /**
      * A <tt>Comparator</tt> using the <tt>compareTo</tt> method of the
      * <tt>CandidatePair</tt>

src/main/java/org/ice4j/ice/CheckList.java

@@ -405,7 +405,7 @@ protected synchronized void handleNominationConfirmed(
 
         logger.info(
                 "Selected pair for stream " + cmp.toShortString() + ": "
-                    + nominatedPair.toShortString());
+                    + nominatedPair.toRedactedShortString());
 
         cmp.setSelectedPair(nominatedPair);
 

src/main/java/org/ice4j/ice/Component.java

@@ -326,7 +326,7 @@ public int getLocalCandidateCount()
     public void addRemoteCandidate(RemoteCandidate candidate)
     {
         logger.info("Add remote candidate for " + toShortString()
-                            + ": " + candidate.toShortString());
+                            + ": " + candidate.toRedactedShortString());
 
         synchronized(remoteCandidates)
         {
@@ -471,15 +471,15 @@ public void updateRemoteCandidates()
                     if (existingPair != null)
                     {
                         logger.info("existing Pair updated: " +
-                            existingPair.toShortString() +
-                            " to " + pair.toShortString() + ".");
+                            existingPair.toRedactedShortString() +
+                            " to " + pair.toRedactedShortString() + ".");
                         existingPair.setRemoteCandidate(pair.getRemoteCandidate());
                         existingPair.computePriority();
                     }
                     else
                     {
                         streamCheckList.add(pair);
-                        logger.info("new Pair added: " + pair.toShortString()
+                        logger.info("new Pair added: " + pair.toRedactedShortString()
                             + ".");
                     }
                 }
@@ -599,13 +599,22 @@ public String toString()
             buff.append("\n")
                 .append(remoteCandidatesCount)
                 .append(" Remote candidates:");
-            buff.append("\ndefault remote candidate: ")
-                .append(getDefaultRemoteCandidate());
+            Candidate<?> defaultRemoteCandidate = getDefaultRemoteCandidate();
+            buff.append("\ndefault remote candidate: ");
+            if (defaultRemoteCandidate != null)
+            {
+                buff.append(defaultRemoteCandidate.toRedactedString());
+            }
+            else
+            {
+                buff.append("null");
+            }
+
             synchronized(remoteCandidates)
             {
                 for (RemoteCandidate cand : remoteCandidates)
                 {
-                    buff.append("\n").append(cand);
+                    buff.append("\n").append(cand.toRedactedString());
                 }
             }
         }

src/main/java/org/ice4j/ice/ComponentSocket.java

@@ -96,7 +96,7 @@ private void addAuthorizedAddress(SocketAddress address)
                 return;
             }
 
-            logger.info("Adding allowed address: " + address);
+            logger.info("Adding allowed address: " + TransportAddress.redact(address));
 
             Set<SocketAddress> newSet = new HashSet<>();
             newSet.addAll(authorizedAddresses);