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 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package java.io;

import java.security.*;
import java.util.Enumeration;
import java.util.List;
import java.util.ArrayList;
import java.util.Vector;
import java.util.Collections;
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. A pathname consisting of
 * the special token "&lt;&lt;ALL FILES&gt;&gt;" 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 "&lt;&lt;ALL FILES&gt;&gt;" 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 final static int EXECUTE = 0x1;
 /**
 * Write action.
 */
 private final static int WRITE = 0x2;
 /**
 * Read action.
 */
 private final static int READ = 0x4;
 /**
 * Delete action.
 */
 private final static int DELETE = 0x8;
 /**
 * Read link action.
 */
 private final static int READLINK = 0x10;

 /**
 * All actions (read,write,execute,delete,readlink)
 */
 private final static int ALL = READ|WRITE|EXECUTE|DELETE|READLINK;
 /**
 * No actions.
 */
 private final static 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. In the case of
 // directories, it is the name "/blah/*" or "/blah/-" without
 // the last character (the "*" or "-").

 private transient String cpath;

 // 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("***\n");
 sb.append("cpath = "+cpath+"\n");
 sb.append("mask = "+mask+"\n");
 sb.append("actions = "+getActions()+"\n");
 sb.append("directory = "+directory+"\n");
 sb.append("recursive = "+recursive+"\n");
 sb.append("***\n");
 return sb.toString();
 }
*/

 private static final long serialVersionUID = 7930732926638008763L;

 /**
 * 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 ((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<String>() {
 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
 * "&lt;&lt;ALL FILES&gt;&gt;" 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.
 *
 * @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>
 *
 * @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.
 */
 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 (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));
 }
 }

 /**
 * Checks two FilePermission objects for equality. Checks that <i>obj</i> is
 * a FilePermission, and has the same pathname and actions as this object.
 *
 * @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.
 */
 public boolean equals(Object obj) {
 if (obj == this)
 return true;

 if (! (obj instanceof FilePermission))
 return false;

 FilePermission that = (FilePermission) obj;

 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.
 */
 public int hashCode() {
 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) {
 StringBuilder sb = new StringBuilder();
 boolean comma = false;

 if ((mask & READ) == READ) {
 comma = true;
 sb.append("read");
 }

 if ((mask & WRITE) == WRITE) {
 if (comma) sb.append(',');
 else comma = true;
 sb.append("write");
 }

 if ((mask & EXECUTE) == EXECUTE) {
 if (comma) sb.append(',');
 else comma = true;
 sb.append("execute");
 }

 if ((mask & DELETE) == DELETE) {
 if (comma) sb.append(',');
 else comma = true;
 sb.append("delete");
 }

 if ((mask & READLINK) == READLINK) {
 if (comma) sb.append(',');
 else comma = true;
 sb.append("readlink");
 }

 return sb.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.
 */
 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.
 */
 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));
 }
}

/**
 * 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 List<Permission> perms;

 /**
 * Create an empty FilePermissionCollection object.
 */
 public FilePermissionCollection() {
 perms = new ArrayList<>();
 }

 /**
 * 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
 */
 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");

 synchronized (this) {
 perms.add(permission);
 }
 }

 /**
 * 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.
 */
 public boolean implies(Permission permission) {
 if (! (permission instanceof FilePermission))
 return false;

 FilePermission fp = (FilePermission) permission;

 int desired = fp.getMask();
 int effective = 0;
 int needed = desired;

 synchronized (this) {
 int len = perms.size();
 for (int i = 0; i < len; i++) {
 FilePermission x = (FilePermission) perms.get(i);
 if (((needed & x.getMask()) != 0) && x.impliesIgnoreMask(fp)) {
 effective |= x.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.
 */
 public Enumeration<Permission> elements() {
 // Convert Iterator into Enumeration
 synchronized (this) {
 return Collections.enumeration(perms);
 }
 }

 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.size());
 synchronized (this) {
 permissions.addAll(perms);
 }

 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 ArrayList<>(permissions.size());
 for (Permission perm : permissions) {
 perms.add(perm);
 }
 }
}