src/java.base/share/classes/java/io/FilePermission.java
changeset 47216 71c04702a3d5
parent 44638 525862468d5a
child 47478 438e0c9f2f17
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/io/FilePermission.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,1266 @@
+/*
+ * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.io;
+
+import java.net.URI;
+import java.nio.file.*;
+import java.security.*;
+import java.util.Enumeration;
+import java.util.Objects;
+import java.util.StringJoiner;
+import java.util.Vector;
+import java.util.concurrent.ConcurrentHashMap;
+
+import jdk.internal.misc.JavaIOFilePermissionAccess;
+import jdk.internal.misc.SharedSecrets;
+import sun.nio.fs.DefaultFileSystemProvider;
+import sun.security.action.GetPropertyAction;
+import sun.security.util.FilePermCompat;
+import sun.security.util.SecurityConstants;
+
+/**
+ * This class represents access to a file or directory.  A FilePermission consists
+ * of a pathname and a set of actions valid for that pathname.
+ * <P>
+ * Pathname is the pathname of the file or directory granted the specified
+ * actions. A pathname that ends in "/*" (where "/" is
+ * the file separator character, <code>File.separatorChar</code>) indicates
+ * all the files and directories contained in that directory. A pathname
+ * that ends with "/-" indicates (recursively) all files
+ * and subdirectories contained in that directory. Such a pathname is called
+ * a wildcard pathname. Otherwise, it's a simple pathname.
+ * <P>
+ * A pathname consisting of the special token {@literal "<<ALL FILES>>"}
+ * matches <b>any</b> file.
+ * <P>
+ * Note: A pathname consisting of a single "*" indicates all the files
+ * in the current directory, while a pathname consisting of a single "-"
+ * indicates all the files in the current directory and
+ * (recursively) all files and subdirectories contained in the current
+ * directory.
+ * <P>
+ * The actions to be granted are passed to the constructor in a string containing
+ * a list of one or more comma-separated keywords. The possible keywords are
+ * "read", "write", "execute", "delete", and "readlink". Their meaning is
+ * defined as follows:
+ *
+ * <DL>
+ *    <DT> read <DD> read permission
+ *    <DT> write <DD> write permission
+ *    <DT> execute
+ *    <DD> execute permission. Allows <code>Runtime.exec</code> to
+ *         be called. Corresponds to <code>SecurityManager.checkExec</code>.
+ *    <DT> delete
+ *    <DD> delete permission. Allows <code>File.delete</code> to
+ *         be called. Corresponds to <code>SecurityManager.checkDelete</code>.
+ *    <DT> readlink
+ *    <DD> read link permission. Allows the target of a
+ *         <a href="../nio/file/package-summary.html#links">symbolic link</a>
+ *         to be read by invoking the {@link java.nio.file.Files#readSymbolicLink
+ *         readSymbolicLink } method.
+ * </DL>
+ * <P>
+ * The actions string is converted to lowercase before processing.
+ * <P>
+ * Be careful when granting FilePermissions. Think about the implications
+ * of granting read and especially write access to various files and
+ * directories. The {@literal "<<ALL FILES>>"} permission with write action is
+ * especially dangerous. This grants permission to write to the entire
+ * file system. One thing this effectively allows is replacement of the
+ * system binary, including the JVM runtime environment.
+ * <P>
+ * Please note: Code can always read a file from the same
+ * directory it's in (or a subdirectory of that directory); it does not
+ * need explicit permission to do so.
+ *
+ * @see java.security.Permission
+ * @see java.security.Permissions
+ * @see java.security.PermissionCollection
+ *
+ *
+ * @author Marianne Mueller
+ * @author Roland Schemers
+ * @since 1.2
+ *
+ * @serial exclude
+ */
+
+public final class FilePermission extends Permission implements Serializable {
+
+    /**
+     * Execute action.
+     */
+    private static final int EXECUTE = 0x1;
+    /**
+     * Write action.
+     */
+    private static final int WRITE   = 0x2;
+    /**
+     * Read action.
+     */
+    private static final int READ    = 0x4;
+    /**
+     * Delete action.
+     */
+    private static final int DELETE  = 0x8;
+    /**
+     * Read link action.
+     */
+    private static final int READLINK    = 0x10;
+
+    /**
+     * All actions (read,write,execute,delete,readlink)
+     */
+    private static final int ALL     = READ|WRITE|EXECUTE|DELETE|READLINK;
+    /**
+     * No actions.
+     */
+    private static final int NONE    = 0x0;
+
+    // the actions mask
+    private transient int mask;
+
+    // does path indicate a directory? (wildcard or recursive)
+    private transient boolean directory;
+
+    // is it a recursive directory specification?
+    private transient boolean recursive;
+
+    /**
+     * the actions string.
+     *
+     * @serial
+     */
+    private String actions; // Left null as long as possible, then
+                            // created and re-used in the getAction function.
+
+    // canonicalized dir path. used by the "old" behavior (nb == false).
+    // In the case of directories, it is the name "/blah/*" or "/blah/-"
+    // without the last character (the "*" or "-").
+
+    private transient String cpath;
+
+    // Following fields used by the "new" behavior (nb == true), in which
+    // input path is not canonicalized. For compatibility (so that granting
+    // FilePermission on "x" allows reading "`pwd`/x", an alternative path
+    // can be added so that both can be used in an implies() check. Please note
+    // the alternative path only deals with absolute/relative path, and does
+    // not deal with symlink/target.
+
+    private transient Path npath;       // normalized dir path.
+    private transient Path npath2;      // alternative normalized dir path.
+    private transient boolean allFiles; // whether this is <<ALL FILES>>
+    private transient boolean invalid;  // whether input path is invalid
+
+    // static Strings used by init(int mask)
+    private static final char RECURSIVE_CHAR = '-';
+    private static final char WILD_CHAR = '*';
+
+//    public String toString() {
+//        StringBuffer sb = new StringBuffer();
+//        sb.append("*** FilePermission on " + getName() + " ***");
+//        for (Field f : FilePermission.class.getDeclaredFields()) {
+//            if (!Modifier.isStatic(f.getModifiers())) {
+//                try {
+//                    sb.append(f.getName() + " = " + f.get(this));
+//                } catch (Exception e) {
+//                    sb.append(f.getName() + " = " + e.toString());
+//                }
+//                sb.append('\n');
+//            }
+//        }
+//        sb.append("***\n");
+//        return sb.toString();
+//    }
+
+    private static final long serialVersionUID = 7930732926638008763L;
+
+    /**
+     * Always use the internal default file system, in case it was modified
+     * with java.nio.file.spi.DefaultFileSystemProvider.
+     */
+    private static final java.nio.file.FileSystem builtInFS =
+            DefaultFileSystemProvider.create()
+                    .getFileSystem(URI.create("file:///"));
+
+    private static final Path here = builtInFS.getPath(
+            GetPropertyAction.privilegedGetProperty("user.dir"));
+
+    private static final Path EMPTY_PATH = builtInFS.getPath("");
+    private static final Path DASH_PATH = builtInFS.getPath("-");
+    private static final Path DOTDOT_PATH = builtInFS.getPath("..");
+
+    /**
+     * A private constructor that clones some and updates some,
+     * always with a different name.
+     * @param input
+     */
+    private FilePermission(String name,
+                           FilePermission input,
+                           Path npath,
+                           Path npath2,
+                           int mask,
+                           String actions) {
+        super(name);
+        // Customizables
+        this.npath = npath;
+        this.npath2 = npath2;
+        this.actions = actions;
+        this.mask = mask;
+        // Cloneds
+        this.allFiles = input.allFiles;
+        this.invalid = input.invalid;
+        this.recursive = input.recursive;
+        this.directory = input.directory;
+        this.cpath = input.cpath;
+    }
+
+    /**
+     * Returns the alternative path as a Path object, i.e. absolute path
+     * for a relative one, or vice versa.
+     *
+     * @param in a real path w/o "-" or "*" at the end, and not <<ALL FILES>>.
+     * @return the alternative path, or null if cannot find one.
+     */
+    private static Path altPath(Path in) {
+        try {
+            if (!in.isAbsolute()) {
+                return here.resolve(in).normalize();
+            } else {
+                return here.relativize(in).normalize();
+            }
+        } catch (IllegalArgumentException e) {
+            return null;
+        }
+    }
+
+    static {
+        SharedSecrets.setJavaIOFilePermissionAccess(
+            /**
+             * Creates FilePermission objects with special internals.
+             * See {@link FilePermCompat#newPermPlusAltPath(Permission)} and
+             * {@link FilePermCompat#newPermUsingAltPath(Permission)}.
+             */
+            new JavaIOFilePermissionAccess() {
+                public FilePermission newPermPlusAltPath(FilePermission input) {
+                    if (!input.invalid && input.npath2 == null && !input.allFiles) {
+                        Path npath2 = altPath(input.npath);
+                        if (npath2 != null) {
+                            // Please note the name of the new permission is
+                            // different than the original so that when one is
+                            // added to a FilePermissionCollection it will not
+                            // be merged with the original one.
+                            return new FilePermission(input.getName() + "#plus",
+                                    input,
+                                    input.npath,
+                                    npath2,
+                                    input.mask,
+                                    input.actions);
+                        }
+                    }
+                    return input;
+                }
+                public FilePermission newPermUsingAltPath(FilePermission input) {
+                    if (!input.invalid && !input.allFiles) {
+                        Path npath2 = altPath(input.npath);
+                        if (npath2 != null) {
+                            // New name, see above.
+                            return new FilePermission(input.getName() + "#using",
+                                    input,
+                                    npath2,
+                                    null,
+                                    input.mask,
+                                    input.actions);
+                        }
+                    }
+                    return null;
+                }
+            }
+        );
+    }
+
+    /**
+     * initialize a FilePermission object. Common to all constructors.
+     * Also called during de-serialization.
+     *
+     * @param mask the actions mask to use.
+     *
+     */
+    private void init(int mask) {
+        if ((mask & ALL) != mask)
+                throw new IllegalArgumentException("invalid actions mask");
+
+        if (mask == NONE)
+                throw new IllegalArgumentException("invalid actions mask");
+
+        if (FilePermCompat.nb) {
+            String name = getName();
+
+            if (name == null)
+                throw new NullPointerException("name can't be null");
+
+            this.mask = mask;
+
+            if (name.equals("<<ALL FILES>>")) {
+                allFiles = true;
+                npath = builtInFS.getPath("");
+                // other fields remain default
+                return;
+            }
+
+            boolean rememberStar = false;
+            if (name.endsWith("*")) {
+                rememberStar = true;
+                recursive = false;
+                name = name.substring(0, name.length()-1) + "-";
+            }
+
+            try {
+                // new File() can "normalize" some name, for example, "/C:/X" on
+                // Windows. Some JDK codes generate such illegal names.
+                npath = builtInFS.getPath(new File(name).getPath())
+                        .normalize();
+                // lastName should always be non-null now
+                Path lastName = npath.getFileName();
+                if (lastName != null && lastName.equals(DASH_PATH)) {
+                    directory = true;
+                    recursive = !rememberStar;
+                    npath = npath.getParent();
+                }
+                if (npath == null) {
+                    npath = builtInFS.getPath("");
+                }
+                invalid = false;
+            } catch (InvalidPathException ipe) {
+                // Still invalid. For compatibility reason, accept it
+                // but make this permission useless.
+                npath = builtInFS.getPath("-u-s-e-l-e-s-s-");
+                invalid = true;
+            }
+
+        } else {
+            if ((cpath = getName()) == null)
+                throw new NullPointerException("name can't be null");
+
+            this.mask = mask;
+
+            if (cpath.equals("<<ALL FILES>>")) {
+                directory = true;
+                recursive = true;
+                cpath = "";
+                return;
+            }
+
+            // store only the canonical cpath if possible
+            cpath = AccessController.doPrivileged(new PrivilegedAction<>() {
+                public String run() {
+                    try {
+                        String path = cpath;
+                        if (cpath.endsWith("*")) {
+                            // call getCanonicalPath with a path with wildcard character
+                            // replaced to avoid calling it with paths that are
+                            // intended to match all entries in a directory
+                            path = path.substring(0, path.length() - 1) + "-";
+                            path = new File(path).getCanonicalPath();
+                            return path.substring(0, path.length() - 1) + "*";
+                        } else {
+                            return new File(path).getCanonicalPath();
+                        }
+                    } catch (IOException ioe) {
+                        return cpath;
+                    }
+                }
+            });
+
+            int len = cpath.length();
+            char last = ((len > 0) ? cpath.charAt(len - 1) : 0);
+
+            if (last == RECURSIVE_CHAR &&
+                    cpath.charAt(len - 2) == File.separatorChar) {
+                directory = true;
+                recursive = true;
+                cpath = cpath.substring(0, --len);
+            } else if (last == WILD_CHAR &&
+                    cpath.charAt(len - 2) == File.separatorChar) {
+                directory = true;
+                //recursive = false;
+                cpath = cpath.substring(0, --len);
+            } else {
+                // overkill since they are initialized to false, but
+                // commented out here to remind us...
+                //directory = false;
+                //recursive = false;
+            }
+
+            // XXX: at this point the path should be absolute. die if it isn't?
+        }
+    }
+
+    /**
+     * Creates a new FilePermission object with the specified actions.
+     * <i>path</i> is the pathname of a file or directory, and <i>actions</i>
+     * contains a comma-separated list of the desired actions granted on the
+     * file or directory. Possible actions are
+     * "read", "write", "execute", "delete", and "readlink".
+     *
+     * <p>A pathname that ends in "/*" (where "/" is
+     * the file separator character, <code>File.separatorChar</code>)
+     * indicates all the files and directories contained in that directory.
+     * A pathname that ends with "/-" indicates (recursively) all files and
+     * subdirectories contained in that directory. The special pathname
+     * {@literal "<<ALL FILES>>"} matches any file.
+     *
+     * <p>A pathname consisting of a single "*" indicates all the files
+     * in the current directory, while a pathname consisting of a single "-"
+     * indicates all the files in the current directory and
+     * (recursively) all files and subdirectories contained in the current
+     * directory.
+     *
+     * <p>A pathname containing an empty string represents an empty path.
+     *
+     * @implNote In this implementation, the
+     * {@code jdk.io.permissionsUseCanonicalPath} system property dictates how
+     * the {@code path} argument is processed and stored.
+     * <P>
+     * If the value of the system property is set to {@code true}, {@code path}
+     * is canonicalized and stored as a String object named {@code cpath}.
+     * This means a relative path is converted to an absolute path, a Windows
+     * DOS-style 8.3 path is expanded to a long path, and a symbolic link is
+     * resolved to its target, etc.
+     * <P>
+     * If the value of the system property is set to {@code false}, {@code path}
+     * is converted to a {@link java.nio.file.Path} object named {@code npath}
+     * after {@link Path#normalize() normalization}. No canonicalization is
+     * performed which means the underlying file system is not accessed.
+     * If an {@link InvalidPathException} is thrown during the conversion,
+     * this {@code FilePermission} will be labeled as invalid.
+     * <P>
+     * In either case, the "*" or "-" character at the end of a wildcard
+     * {@code path} is removed before canonicalization or normalization.
+     * It is stored in a separate wildcard flag field.
+     * <P>
+     * The default value of the {@code jdk.io.permissionsUseCanonicalPath}
+     * system property is {@code false} in this implementation.
+     *
+     * @param path the pathname of the file/directory.
+     * @param actions the action string.
+     *
+     * @throws IllegalArgumentException
+     *          If actions is <code>null</code>, empty or contains an action
+     *          other than the specified possible actions.
+     */
+    public FilePermission(String path, String actions) {
+        super(path);
+        init(getMask(actions));
+    }
+
+    /**
+     * Creates a new FilePermission object using an action mask.
+     * More efficient than the FilePermission(String, String) constructor.
+     * Can be used from within
+     * code that needs to create a FilePermission object to pass into the
+     * <code>implies</code> method.
+     *
+     * @param path the pathname of the file/directory.
+     * @param mask the action mask to use.
+     */
+    // package private for use by the FilePermissionCollection add method
+    FilePermission(String path, int mask) {
+        super(path);
+        init(mask);
+    }
+
+    /**
+     * Checks if this FilePermission object "implies" the specified permission.
+     * <P>
+     * More specifically, this method returns true if:
+     * <ul>
+     * <li> <i>p</i> is an instanceof FilePermission,
+     * <li> <i>p</i>'s actions are a proper subset of this
+     * object's actions, and
+     * <li> <i>p</i>'s pathname is implied by this object's
+     *      pathname. For example, "/tmp/*" implies "/tmp/foo", since
+     *      "/tmp/*" encompasses all files in the "/tmp" directory,
+     *      including the one named "foo".
+     * </ul>
+     * <P>
+     * Precisely, a simple pathname implies another simple pathname
+     * if and only if they are equal. A simple pathname never implies
+     * a wildcard pathname. A wildcard pathname implies another wildcard
+     * pathname if and only if all simple pathnames implied by the latter
+     * are implied by the former. A wildcard pathname implies a simple
+     * pathname if and only if
+     * <ul>
+     *     <li>if the wildcard flag is "*", the simple pathname's path
+     *     must be right inside the wildcard pathname's path.
+     *     <li>if the wildcard flag is "-", the simple pathname's path
+     *     must be recursively inside the wildcard pathname's path.
+     * </ul>
+     * <P>
+     * {@literal "<<ALL FILES>>"} implies every other pathname. No pathname,
+     * except for {@literal "<<ALL FILES>>"} itself, implies
+     * {@literal "<<ALL FILES>>"}.
+     *
+     * @implNote
+     * If {@code jdk.io.permissionsUseCanonicalPath} is {@code true}, a
+     * simple {@code cpath} is inside a wildcard {@code cpath} if and only if
+     * after removing the base name (the last name in the pathname's name
+     * sequence) from the former the remaining part equals to the latter,
+     * a simple {@code cpath} is recursively inside a wildcard {@code cpath}
+     * if and only if the former starts with the latter.
+     * <p>
+     * If {@code jdk.io.permissionsUseCanonicalPath} is {@code false}, a
+     * simple {@code npath} is inside a wildcard {@code npath} if and only if
+     * {@code  simple_npath.relativize(wildcard_npath)} is exactly "..",
+     * a simple {@code npath} is recursively inside a wildcard {@code npath}
+     * if and only if {@code simple_npath.relativize(wildcard_npath)} is a
+     * series of one or more "..". This means "/-" implies "/foo" but not "foo".
+     * <p>
+     * An invalid {@code FilePermission} does not imply any object except for
+     * itself. An invalid {@code FilePermission} is not implied by any object
+     * except for itself or a {@code FilePermission} on
+     * {@literal "<<ALL FILES>>"} whose actions is a superset of this
+     * invalid {@code FilePermission}. Even if two {@code FilePermission}
+     * are created with the same invalid path, one does not imply the other.
+     *
+     * @param p the permission to check against.
+     *
+     * @return <code>true</code> if the specified permission is not
+     *                  <code>null</code> and is implied by this object,
+     *                  <code>false</code> otherwise.
+     */
+    @Override
+    public boolean implies(Permission p) {
+        if (!(p instanceof FilePermission))
+            return false;
+
+        FilePermission that = (FilePermission) p;
+
+        // we get the effective mask. i.e., the "and" of this and that.
+        // They must be equal to that.mask for implies to return true.
+
+        return ((this.mask & that.mask) == that.mask) && impliesIgnoreMask(that);
+    }
+
+    /**
+     * Checks if the Permission's actions are a proper subset of the
+     * this object's actions. Returns the effective mask iff the
+     * this FilePermission's path also implies that FilePermission's path.
+     *
+     * @param that the FilePermission to check against.
+     * @return the effective mask
+     */
+    boolean impliesIgnoreMask(FilePermission that) {
+        if (FilePermCompat.nb) {
+            if (this == that) {
+                return true;
+            }
+            if (allFiles) {
+                return true;
+            }
+            if (this.invalid || that.invalid) {
+                return false;
+            }
+            if (that.allFiles) {
+                return false;
+            }
+            // Left at least same level of wildness as right
+            if ((this.recursive && that.recursive) != that.recursive
+                    || (this.directory && that.directory) != that.directory) {
+                return false;
+            }
+            // Same npath is good as long as both or neither are directories
+            if (this.npath.equals(that.npath)
+                    && this.directory == that.directory) {
+                return true;
+            }
+            int diff = containsPath(this.npath, that.npath);
+            // Right inside left is good if recursive
+            if (diff >= 1 && recursive) {
+                return true;
+            }
+            // Right right inside left if it is element in set
+            if (diff == 1 && directory && !that.directory) {
+                return true;
+            }
+
+            // Hack: if a npath2 field exists, apply the same checks
+            // on it as a fallback.
+            if (this.npath2 != null) {
+                if (this.npath2.equals(that.npath)
+                        && this.directory == that.directory) {
+                    return true;
+                }
+                diff = containsPath(this.npath2, that.npath);
+                if (diff >= 1 && recursive) {
+                    return true;
+                }
+                if (diff == 1 && directory && !that.directory) {
+                    return true;
+                }
+            }
+
+            return false;
+        } else {
+            if (this.directory) {
+                if (this.recursive) {
+                    // make sure that.path is longer then path so
+                    // something like /foo/- does not imply /foo
+                    if (that.directory) {
+                        return (that.cpath.length() >= this.cpath.length()) &&
+                                that.cpath.startsWith(this.cpath);
+                    } else {
+                        return ((that.cpath.length() > this.cpath.length()) &&
+                                that.cpath.startsWith(this.cpath));
+                    }
+                } else {
+                    if (that.directory) {
+                        // if the permission passed in is a directory
+                        // specification, make sure that a non-recursive
+                        // permission (i.e., this object) can't imply a recursive
+                        // permission.
+                        if (that.recursive)
+                            return false;
+                        else
+                            return (this.cpath.equals(that.cpath));
+                    } else {
+                        int last = that.cpath.lastIndexOf(File.separatorChar);
+                        if (last == -1)
+                            return false;
+                        else {
+                            // this.cpath.equals(that.cpath.substring(0, last+1));
+                            // Use regionMatches to avoid creating new string
+                            return (this.cpath.length() == (last + 1)) &&
+                                    this.cpath.regionMatches(0, that.cpath, 0, last + 1);
+                        }
+                    }
+                }
+            } else if (that.directory) {
+                // if this is NOT recursive/wildcarded,
+                // do not let it imply a recursive/wildcarded permission
+                return false;
+            } else {
+                return (this.cpath.equals(that.cpath));
+            }
+        }
+    }
+
+    /**
+     * Returns the depth between an outer path p1 and an inner path p2. -1
+     * is returned if
+     *
+     * - p1 does not contains p2.
+     * - this is not decidable. For example, p1="../x", p2="y".
+     * - the depth is not decidable. For example, p1="/", p2="x".
+     *
+     * This method can return 2 if the depth is greater than 2.
+     *
+     * @param p1 the expected outer path, normalized
+     * @param p2 the expected inner path, normalized
+     * @return the depth in between
+     */
+    private static int containsPath(Path p1, Path p2) {
+
+        // Two paths must have the same root. For example,
+        // there is no contains relation between any two of
+        // "/x", "x", "C:/x", "C:x", and "//host/share/x".
+        if (!Objects.equals(p1.getRoot(), p2.getRoot())) {
+            return -1;
+        }
+
+        // Empty path (i.e. "." or "") is a strange beast,
+        // because its getNameCount()==1 but getName(0) is null.
+        // It's better to deal with it separately.
+        if (p1.equals(EMPTY_PATH)) {
+            if (p2.equals(EMPTY_PATH)) {
+                return 0;
+            } else if (p2.getName(0).equals(DOTDOT_PATH)) {
+                // "." contains p2 iif p2 has no "..". Since a
+                // a normalized path can only have 0 or more
+                // ".." at the beginning. We only need to look
+                // at the head.
+                return -1;
+            } else {
+                // and the distance is p2's name count. i.e.
+                // 3 between "." and "a/b/c".
+                return p2.getNameCount();
+            }
+        } else if (p2.equals(EMPTY_PATH)) {
+            int c1 = p1.getNameCount();
+            if (!p1.getName(c1 - 1).equals(DOTDOT_PATH)) {
+                // "." is inside p1 iif p1 is 1 or more "..".
+                // For the same reason above, we only need to
+                // look at the tail.
+                return -1;
+            }
+            // and the distance is the count of ".."
+            return c1;
+        }
+
+        // Good. No more empty paths.
+
+        // Common heads are removed
+
+        int c1 = p1.getNameCount();
+        int c2 = p2.getNameCount();
+
+        int n = Math.min(c1, c2);
+        int i = 0;
+        while (i < n) {
+            if (!p1.getName(i).equals(p2.getName(i)))
+                break;
+            i++;
+        }
+
+        // for p1 containing p2, p1 must be 0-or-more "..",
+        // and p2 cannot have "..". For the same reason, we only
+        // check tail of p1 and head of p2.
+        if (i < c1 && !p1.getName(c1 - 1).equals(DOTDOT_PATH)) {
+            return -1;
+        }
+
+        if (i < c2 && p2.getName(i).equals(DOTDOT_PATH)) {
+            return -1;
+        }
+
+        // and the distance is the name counts added (after removing
+        // the common heads).
+
+        // For example: p1 = "../../..", p2 = "../a".
+        // After removing the common heads, they become "../.." and "a",
+        // and the distance is (3-1)+(2-1) = 3.
+        return c1 - i + c2 - i;
+    }
+
+    /**
+     * Checks two FilePermission objects for equality. Checks that <i>obj</i> is
+     * a FilePermission, and has the same pathname and actions as this object.
+     *
+     * @implNote More specifically, two pathnames are the same if and only if
+     * they have the same wildcard flag and their {@code cpath}
+     * (if {@code jdk.io.permissionsUseCanonicalPath} is {@code true}) or
+     * {@code npath} (if {@code jdk.io.permissionsUseCanonicalPath}
+     * is {@code false}) are equal. Or they are both {@literal "<<ALL FILES>>"}.
+     * <p>
+     * When {@code jdk.io.permissionsUseCanonicalPath} is {@code false}, an
+     * invalid {@code FilePermission} does not equal to any object except
+     * for itself, even if they are created using the same invalid path.
+     *
+     * @param obj the object we are testing for equality with this object.
+     * @return <code>true</code> if obj is a FilePermission, and has the same
+     *          pathname and actions as this FilePermission object,
+     *          <code>false</code> otherwise.
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this)
+            return true;
+
+        if (! (obj instanceof FilePermission))
+            return false;
+
+        FilePermission that = (FilePermission) obj;
+
+        if (FilePermCompat.nb) {
+            if (this.invalid || that.invalid) {
+                return false;
+            }
+            return (this.mask == that.mask) &&
+                    (this.allFiles == that.allFiles) &&
+                    this.npath.equals(that.npath) &&
+                    Objects.equals(npath2, that.npath2) &&
+                    (this.directory == that.directory) &&
+                    (this.recursive == that.recursive);
+        } else {
+            return (this.mask == that.mask) &&
+                    this.cpath.equals(that.cpath) &&
+                    (this.directory == that.directory) &&
+                    (this.recursive == that.recursive);
+        }
+    }
+
+    /**
+     * Returns the hash code value for this object.
+     *
+     * @return a hash code value for this object.
+     */
+    @Override
+    public int hashCode() {
+        if (FilePermCompat.nb) {
+            return Objects.hash(
+                    mask, allFiles, directory, recursive, npath, npath2, invalid);
+        } else {
+            return 0;
+        }
+    }
+
+    /**
+     * Converts an actions String to an actions mask.
+     *
+     * @param actions the action string.
+     * @return the actions mask.
+     */
+    private static int getMask(String actions) {
+        int mask = NONE;
+
+        // Null action valid?
+        if (actions == null) {
+            return mask;
+        }
+
+        // Use object identity comparison against known-interned strings for
+        // performance benefit (these values are used heavily within the JDK).
+        if (actions == SecurityConstants.FILE_READ_ACTION) {
+            return READ;
+        } else if (actions == SecurityConstants.FILE_WRITE_ACTION) {
+            return WRITE;
+        } else if (actions == SecurityConstants.FILE_EXECUTE_ACTION) {
+            return EXECUTE;
+        } else if (actions == SecurityConstants.FILE_DELETE_ACTION) {
+            return DELETE;
+        } else if (actions == SecurityConstants.FILE_READLINK_ACTION) {
+            return READLINK;
+        }
+
+        char[] a = actions.toCharArray();
+
+        int i = a.length - 1;
+        if (i < 0)
+            return mask;
+
+        while (i != -1) {
+            char c;
+
+            // skip whitespace
+            while ((i!=-1) && ((c = a[i]) == ' ' ||
+                               c == '\r' ||
+                               c == '\n' ||
+                               c == '\f' ||
+                               c == '\t'))
+                i--;
+
+            // check for the known strings
+            int matchlen;
+
+            if (i >= 3 && (a[i-3] == 'r' || a[i-3] == 'R') &&
+                          (a[i-2] == 'e' || a[i-2] == 'E') &&
+                          (a[i-1] == 'a' || a[i-1] == 'A') &&
+                          (a[i] == 'd' || a[i] == 'D'))
+            {
+                matchlen = 4;
+                mask |= READ;
+
+            } else if (i >= 4 && (a[i-4] == 'w' || a[i-4] == 'W') &&
+                                 (a[i-3] == 'r' || a[i-3] == 'R') &&
+                                 (a[i-2] == 'i' || a[i-2] == 'I') &&
+                                 (a[i-1] == 't' || a[i-1] == 'T') &&
+                                 (a[i] == 'e' || a[i] == 'E'))
+            {
+                matchlen = 5;
+                mask |= WRITE;
+
+            } else if (i >= 6 && (a[i-6] == 'e' || a[i-6] == 'E') &&
+                                 (a[i-5] == 'x' || a[i-5] == 'X') &&
+                                 (a[i-4] == 'e' || a[i-4] == 'E') &&
+                                 (a[i-3] == 'c' || a[i-3] == 'C') &&
+                                 (a[i-2] == 'u' || a[i-2] == 'U') &&
+                                 (a[i-1] == 't' || a[i-1] == 'T') &&
+                                 (a[i] == 'e' || a[i] == 'E'))
+            {
+                matchlen = 7;
+                mask |= EXECUTE;
+
+            } else if (i >= 5 && (a[i-5] == 'd' || a[i-5] == 'D') &&
+                                 (a[i-4] == 'e' || a[i-4] == 'E') &&
+                                 (a[i-3] == 'l' || a[i-3] == 'L') &&
+                                 (a[i-2] == 'e' || a[i-2] == 'E') &&
+                                 (a[i-1] == 't' || a[i-1] == 'T') &&
+                                 (a[i] == 'e' || a[i] == 'E'))
+            {
+                matchlen = 6;
+                mask |= DELETE;
+
+            } else if (i >= 7 && (a[i-7] == 'r' || a[i-7] == 'R') &&
+                                 (a[i-6] == 'e' || a[i-6] == 'E') &&
+                                 (a[i-5] == 'a' || a[i-5] == 'A') &&
+                                 (a[i-4] == 'd' || a[i-4] == 'D') &&
+                                 (a[i-3] == 'l' || a[i-3] == 'L') &&
+                                 (a[i-2] == 'i' || a[i-2] == 'I') &&
+                                 (a[i-1] == 'n' || a[i-1] == 'N') &&
+                                 (a[i] == 'k' || a[i] == 'K'))
+            {
+                matchlen = 8;
+                mask |= READLINK;
+
+            } else {
+                // parse error
+                throw new IllegalArgumentException(
+                        "invalid permission: " + actions);
+            }
+
+            // make sure we didn't just match the tail of a word
+            // like "ackbarfaccept".  Also, skip to the comma.
+            boolean seencomma = false;
+            while (i >= matchlen && !seencomma) {
+                switch(a[i-matchlen]) {
+                case ',':
+                    seencomma = true;
+                    break;
+                case ' ': case '\r': case '\n':
+                case '\f': case '\t':
+                    break;
+                default:
+                    throw new IllegalArgumentException(
+                            "invalid permission: " + actions);
+                }
+                i--;
+            }
+
+            // point i at the location of the comma minus one (or -1).
+            i -= matchlen;
+        }
+
+        return mask;
+    }
+
+    /**
+     * Return the current action mask. Used by the FilePermissionCollection.
+     *
+     * @return the actions mask.
+     */
+    int getMask() {
+        return mask;
+    }
+
+    /**
+     * Return the canonical string representation of the actions.
+     * Always returns present actions in the following order:
+     * read, write, execute, delete, readlink.
+     *
+     * @return the canonical string representation of the actions.
+     */
+    private static String getActions(int mask) {
+        StringJoiner sj = new StringJoiner(",");
+
+        if ((mask & READ) == READ) {
+            sj.add("read");
+        }
+        if ((mask & WRITE) == WRITE) {
+            sj.add("write");
+        }
+        if ((mask & EXECUTE) == EXECUTE) {
+            sj.add("execute");
+        }
+        if ((mask & DELETE) == DELETE) {
+            sj.add("delete");
+        }
+        if ((mask & READLINK) == READLINK) {
+            sj.add("readlink");
+        }
+
+        return sj.toString();
+    }
+
+    /**
+     * Returns the "canonical string representation" of the actions.
+     * That is, this method always returns present actions in the following order:
+     * read, write, execute, delete, readlink. For example, if this FilePermission
+     * object allows both write and read actions, a call to <code>getActions</code>
+     * will return the string "read,write".
+     *
+     * @return the canonical string representation of the actions.
+     */
+    @Override
+    public String getActions() {
+        if (actions == null)
+            actions = getActions(this.mask);
+
+        return actions;
+    }
+
+    /**
+     * Returns a new PermissionCollection object for storing FilePermission
+     * objects.
+     * <p>
+     * FilePermission objects must be stored in a manner that allows them
+     * to be inserted into the collection in any order, but that also enables the
+     * PermissionCollection <code>implies</code>
+     * method to be implemented in an efficient (and consistent) manner.
+     *
+     * <p>For example, if you have two FilePermissions:
+     * <OL>
+     * <LI>  <code>"/tmp/-", "read"</code>
+     * <LI>  <code>"/tmp/scratch/foo", "write"</code>
+     * </OL>
+     *
+     * <p>and you are calling the <code>implies</code> method with the FilePermission:
+     *
+     * <pre>
+     *   "/tmp/scratch/foo", "read,write",
+     * </pre>
+     *
+     * then the <code>implies</code> function must
+     * take into account both the "/tmp/-" and "/tmp/scratch/foo"
+     * permissions, so the effective permission is "read,write",
+     * and <code>implies</code> returns true. The "implies" semantics for
+     * FilePermissions are handled properly by the PermissionCollection object
+     * returned by this <code>newPermissionCollection</code> method.
+     *
+     * @return a new PermissionCollection object suitable for storing
+     * FilePermissions.
+     */
+    @Override
+    public PermissionCollection newPermissionCollection() {
+        return new FilePermissionCollection();
+    }
+
+    /**
+     * WriteObject is called to save the state of the FilePermission
+     * to a stream. The actions are serialized, and the superclass
+     * takes care of the name.
+     */
+    private void writeObject(ObjectOutputStream s)
+        throws IOException
+    {
+        // Write out the actions. The superclass takes care of the name
+        // call getActions to make sure actions field is initialized
+        if (actions == null)
+            getActions();
+        s.defaultWriteObject();
+    }
+
+    /**
+     * readObject is called to restore the state of the FilePermission from
+     * a stream.
+     */
+    private void readObject(ObjectInputStream s)
+         throws IOException, ClassNotFoundException
+    {
+        // Read in the actions, then restore everything else by calling init.
+        s.defaultReadObject();
+        init(getMask(actions));
+    }
+
+    /**
+     * Create a cloned FilePermission with a different actions.
+     * @param effective the new actions
+     * @return a new object
+     */
+    FilePermission withNewActions(int effective) {
+        return new FilePermission(this.getName(),
+                this,
+                this.npath,
+                this.npath2,
+                effective,
+                null);
+    }
+}
+
+/**
+ * A FilePermissionCollection stores a set of FilePermission permissions.
+ * FilePermission objects
+ * must be stored in a manner that allows them to be inserted in any
+ * order, but enable the implies function to evaluate the implies
+ * method.
+ * For example, if you have two FilePermissions:
+ * <OL>
+ * <LI> "/tmp/-", "read"
+ * <LI> "/tmp/scratch/foo", "write"
+ * </OL>
+ * And you are calling the implies function with the FilePermission:
+ * "/tmp/scratch/foo", "read,write", then the implies function must
+ * take into account both the /tmp/- and /tmp/scratch/foo
+ * permissions, so the effective permission is "read,write".
+ *
+ * @see java.security.Permission
+ * @see java.security.Permissions
+ * @see java.security.PermissionCollection
+ *
+ *
+ * @author Marianne Mueller
+ * @author Roland Schemers
+ *
+ * @serial include
+ *
+ */
+
+final class FilePermissionCollection extends PermissionCollection
+    implements Serializable
+{
+    // Not serialized; see serialization section at end of class
+    private transient ConcurrentHashMap<String, Permission> perms;
+
+    /**
+     * Create an empty FilePermissionCollection object.
+     */
+    public FilePermissionCollection() {
+        perms = new ConcurrentHashMap<>();
+    }
+
+    /**
+     * Adds a permission to the FilePermissionCollection. The key for the hash is
+     * permission.path.
+     *
+     * @param permission the Permission object to add.
+     *
+     * @exception IllegalArgumentException - if the permission is not a
+     *                                       FilePermission
+     *
+     * @exception SecurityException - if this FilePermissionCollection object
+     *                                has been marked readonly
+     */
+    @Override
+    public void add(Permission permission) {
+        if (! (permission instanceof FilePermission))
+            throw new IllegalArgumentException("invalid permission: "+
+                                               permission);
+        if (isReadOnly())
+            throw new SecurityException(
+                "attempt to add a Permission to a readonly PermissionCollection");
+
+        FilePermission fp = (FilePermission)permission;
+
+        // Add permission to map if it is absent, or replace with new
+        // permission if applicable.
+        perms.merge(fp.getName(), fp,
+            new java.util.function.BiFunction<>() {
+                @Override
+                public Permission apply(Permission existingVal,
+                                        Permission newVal) {
+                    int oldMask = ((FilePermission)existingVal).getMask();
+                    int newMask = ((FilePermission)newVal).getMask();
+                    if (oldMask != newMask) {
+                        int effective = oldMask | newMask;
+                        if (effective == newMask) {
+                            return newVal;
+                        }
+                        if (effective != oldMask) {
+                            return ((FilePermission)newVal)
+                                    .withNewActions(effective);
+                        }
+                    }
+                    return existingVal;
+                }
+            }
+        );
+    }
+
+    /**
+     * Check and see if this set of permissions implies the permissions
+     * expressed in "permission".
+     *
+     * @param permission the Permission object to compare
+     *
+     * @return true if "permission" is a proper subset of a permission in
+     * the set, false if not.
+     */
+    @Override
+    public boolean implies(Permission permission) {
+        if (! (permission instanceof FilePermission))
+            return false;
+
+        FilePermission fperm = (FilePermission) permission;
+
+        int desired = fperm.getMask();
+        int effective = 0;
+        int needed = desired;
+
+        for (Permission perm : perms.values()) {
+            FilePermission fp = (FilePermission)perm;
+            if (((needed & fp.getMask()) != 0) && fp.impliesIgnoreMask(fperm)) {
+                effective |= fp.getMask();
+                if ((effective & desired) == desired) {
+                    return true;
+                }
+                needed = (desired ^ effective);
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Returns an enumeration of all the FilePermission objects in the
+     * container.
+     *
+     * @return an enumeration of all the FilePermission objects.
+     */
+    @Override
+    public Enumeration<Permission> elements() {
+        return perms.elements();
+    }
+
+    private static final long serialVersionUID = 2202956749081564585L;
+
+    // Need to maintain serialization interoperability with earlier releases,
+    // which had the serializable field:
+    //    private Vector permissions;
+
+    /**
+     * @serialField permissions java.util.Vector
+     *     A list of FilePermission objects.
+     */
+    private static final ObjectStreamField[] serialPersistentFields = {
+        new ObjectStreamField("permissions", Vector.class),
+    };
+
+    /**
+     * @serialData "permissions" field (a Vector containing the FilePermissions).
+     */
+    /*
+     * Writes the contents of the perms field out as a Vector for
+     * serialization compatibility with earlier releases.
+     */
+    private void writeObject(ObjectOutputStream out) throws IOException {
+        // Don't call out.defaultWriteObject()
+
+        // Write out Vector
+        Vector<Permission> permissions = new Vector<>(perms.values());
+
+        ObjectOutputStream.PutField pfields = out.putFields();
+        pfields.put("permissions", permissions);
+        out.writeFields();
+    }
+
+    /*
+     * Reads in a Vector of FilePermissions and saves them in the perms field.
+     */
+    private void readObject(ObjectInputStream in)
+        throws IOException, ClassNotFoundException
+    {
+        // Don't call defaultReadObject()
+
+        // Read in serialized fields
+        ObjectInputStream.GetField gfields = in.readFields();
+
+        // Get the one we want
+        @SuppressWarnings("unchecked")
+        Vector<Permission> permissions = (Vector<Permission>)gfields.get("permissions", null);
+        perms = new ConcurrentHashMap<>(permissions.size());
+        for (Permission perm : permissions) {
+            perms.put(perm.getName(), perm);
+        }
+    }
+}