Java tutorial
/* * Copyright (c) 1997, 2019, 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.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.access.JavaIOFilePermissionAccess; import jdk.internal.access.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; /** * Use the platform's default file system to avoid recursive initialization * issues when the VM is configured to use a custom file system provider. */ private static final java.nio.file.FileSystem builtInFS = DefaultFileSystemProvider.theFileSystem(); 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 = EMPTY_PATH; // 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 = EMPTY_PATH; } 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 * {@systemProperty 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 iff p2 has no "..". Since // 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 iff 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); } } }