[SSHD-1234] Rooted file system can leak informations

sshd-common/src/main/java/org/apache/sshd/common/file/root/RootedDirectoryStream.java

@@ -0,0 +1,63 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sshd.common.file.root;
+
+import java.io.IOException;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Path;
+import java.util.Iterator;
+
+/**
+ * secure directory stream proxy for a {@link RootedFileSystem}
+ *
+ * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
+ */
+public class RootedDirectoryStream implements DirectoryStream<Path> {
+    protected final RootedFileSystem rfs;
+    protected final DirectoryStream<Path> delegate;
+
+    public RootedDirectoryStream(RootedFileSystem rfs, DirectoryStream<Path> delegate) {
+        this.rfs = rfs;
+        this.delegate = delegate;
+    }
+
+    @Override
+    public Iterator<Path> iterator() {
+        return root(rfs, delegate.iterator());
+    }
+
+    @Override
+    public void close() throws IOException {
+        delegate.close();
+    }
+
+    protected Iterator<Path> root(RootedFileSystem rfs, Iterator<Path> iter) {
+        return new Iterator<Path>() {
+            @Override
+            public boolean hasNext() {
+                return iter.hasNext();
+            }
+
+            @Override
+            public Path next() {
+                return rfs.provider().root(rfs, iter.next());
+            }
+        };
+    }
+}

sshd-common/src/main/java/org/apache/sshd/common/file/root/RootedFileSystem.java

@@ -94,6 +94,11 @@ public Iterable<FileStore> getFileStores() {
         return rootFs.getFileStores();
     }
 
+    @Override
+    protected boolean hostFsHasWindowsSeparator() {
+        return "\\".equals(getRoot().getFileSystem().getSeparator());
+    }
+
     @Override
     public String toString() {
         return rootPath.toString();