/*
* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*/
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 "<<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 "<<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 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
* "<<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.
*
* @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);
}
}
}