| /* |
| * Copyright (c) 2000, 2011, 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 com.sun.jndi.dns; |
| |
| |
| import java.util.ArrayList; |
| import java.util.Comparator; |
| import java.util.Enumeration; |
| |
| import javax.naming.*; |
| |
| |
| /** |
| * <tt>DnsName</tt> implements compound names for DNS as specified by |
| * RFCs 1034 and 1035, and as updated and clarified by RFCs 1123 and 2181. |
| * |
| * <p> The labels in a domain name correspond to JNDI atomic names. |
| * Each label must be less than 64 octets in length, and only the |
| * optional root label at the end of the name may be 0 octets long. |
| * The sum of the lengths of all labels in a name, plus the number of |
| * non-root labels plus 1, must be less than 256. The textual |
| * representation of a domain name consists of the labels, escaped as |
| * needed, dot-separated, and ordered right-to-left. |
| * |
| * <p> A label consists of a sequence of octets, each of which may |
| * have any value from 0 to 255. |
| * |
| * <p> <em>Host names</em> are a subset of domain names. |
| * Their labels contain only ASCII letters, digits, and hyphens, and |
| * none may begin or end with a hyphen. While names not conforming to |
| * these rules may be valid domain names, they will not be usable by a |
| * number of DNS applications, and should in most cases be avoided. |
| * |
| * <p> DNS does not specify an encoding (such as UTF-8) to use for |
| * octets with non-ASCII values. As of this writing there is some |
| * work going on in this area, but it is not yet finalized. |
| * <tt>DnsName</tt> currently converts any non-ASCII octets into |
| * characters using ISO-LATIN-1 encoding, in effect taking the |
| * value of each octet and storing it directly into the low-order byte |
| * of a Java character and <i>vice versa</i>. As a consequence, no |
| * character in a DNS name will ever have a non-zero high-order byte. |
| * When the work on internationalizing domain names has stabilized |
| * (see for example <i>draft-ietf-idn-idna-10.txt</i>), <tt>DnsName</tt> |
| * may be updated to conform to that work. |
| * |
| * <p> Backslash (<tt>\</tt>) is used as the escape character in the |
| * textual representation of a domain name. The character sequence |
| * `<tt>\DDD</tt>', where <tt>DDD</tt> is a 3-digit decimal number |
| * (with leading zeros if needed), represents the octet whose value |
| * is <tt>DDD</tt>. The character sequence `<tt>\C</tt>', where |
| * <tt>C</tt> is a character other than <tt>'0'</tt> through |
| * <tt>'9'</tt>, represents the octet whose value is that of |
| * <tt>C</tt> (again using ISO-LATIN-1 encoding); this is particularly |
| * useful for escaping <tt>'.'</tt> or backslash itself. Backslash is |
| * otherwise not allowed in a domain name. Note that escape characters |
| * are interpreted when a name is parsed. So, for example, the character |
| * sequences `<tt>S</tt>', `<tt>\S</tt>', and `<tt>\083</tt>' each |
| * represent the same one-octet name. The <tt>toString()</tt> method |
| * does not generally insert escape sequences except where necessary. |
| * If, however, the <tt>DnsName</tt> was constructed using unneeded |
| * escapes, those escapes may appear in the <tt>toString</tt> result. |
| * |
| * <p> Atomic names passed as parameters to methods of |
| * <tt>DnsName</tt>, and those returned by them, are unescaped. So, |
| * for example, <tt>(new DnsName()).add("a.b")</tt> creates an |
| * object representing the one-label domain name <tt>a\.b</tt>, and |
| * calling <tt>get(0)</tt> on this object returns <tt>"a.b"</tt>. |
| * |
| * <p> While DNS names are case-preserving, comparisons between them |
| * are case-insensitive. When comparing names containing non-ASCII |
| * octets, <tt>DnsName</tt> uses case-insensitive comparison |
| * between pairs of ASCII values, and exact binary comparison |
| * otherwise. |
| |
| * <p> A <tt>DnsName</tt> instance is not synchronized against |
| * concurrent access by multiple threads. |
| * |
| * @author Scott Seligman |
| */ |
| |
| |
| public final class DnsName implements Name { |
| |
| // If non-null, the domain name represented by this DnsName. |
| private String domain = ""; |
| |
| // The labels of this domain name, as a list of strings. Index 0 |
| // corresponds to the leftmost (least significant) label: note that |
| // this is the reverse of the ordering used by the Name interface. |
| private ArrayList<String> labels = new ArrayList<>(); |
| |
| // The number of octets needed to carry this domain name in a DNS |
| // packet. Equal to the sum of the lengths of each label, plus the |
| // number of non-root labels, plus 1. Must remain less than 256. |
| private short octets = 1; |
| |
| |
| /** |
| * Constructs a <tt>DnsName</tt> representing the empty domain name. |
| */ |
| public DnsName() { |
| } |
| |
| /** |
| * Constructs a <tt>DnsName</tt> representing a given domain name. |
| * |
| * @param name the domain name to parse |
| * @throws InvalidNameException if <tt>name</tt> does not conform |
| * to DNS syntax. |
| */ |
| public DnsName(String name) throws InvalidNameException { |
| parse(name); |
| } |
| |
| /* |
| * Returns a new DnsName with its name components initialized to |
| * the components of "n" in the range [beg,end). Indexing is as |
| * for the Name interface, with 0 being the most significant. |
| */ |
| private DnsName(DnsName n, int beg, int end) { |
| // Compute indexes into "labels", which has least-significant label |
| // at index 0 (opposite to the convention used for "beg" and "end"). |
| int b = n.size() - end; |
| int e = n.size() - beg; |
| labels.addAll(n.labels.subList(b, e)); |
| |
| if (size() == n.size()) { |
| domain = n.domain; |
| octets = n.octets; |
| } else { |
| for (String label: labels) { |
| if (label.length() > 0) { |
| octets += (short) (label.length() + 1); |
| } |
| } |
| } |
| } |
| |
| |
| public String toString() { |
| if (domain == null) { |
| StringBuilder buf = new StringBuilder(); |
| for (String label: labels) { |
| if (buf.length() > 0 || label.length() == 0) { |
| buf.append('.'); |
| } |
| escape(buf, label); |
| } |
| domain = buf.toString(); |
| } |
| return domain; |
| } |
| |
| /** |
| * Does this domain name follow <em>host name</em> syntax? |
| */ |
| public boolean isHostName() { |
| for (String label: labels) { |
| if (!isHostNameLabel(label)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| public short getOctets() { |
| return octets; |
| } |
| |
| public int size() { |
| return labels.size(); |
| } |
| |
| public boolean isEmpty() { |
| return (size() == 0); |
| } |
| |
| public int hashCode() { |
| int h = 0; |
| for (int i = 0; i < size(); i++) { |
| h = 31 * h + getKey(i).hashCode(); |
| } |
| return h; |
| } |
| |
| public boolean equals(Object obj) { |
| if (!(obj instanceof Name) || (obj instanceof CompositeName)) { |
| return false; |
| } |
| Name n = (Name) obj; |
| return ((size() == n.size()) && // shortcut: do sizes differ? |
| (compareTo(obj) == 0)); |
| } |
| |
| public int compareTo(Object obj) { |
| Name n = (Name) obj; |
| return compareRange(0, size(), n); // never 0 if sizes differ |
| } |
| |
| public boolean startsWith(Name n) { |
| return ((size() >= n.size()) && |
| (compareRange(0, n.size(), n) == 0)); |
| } |
| |
| public boolean endsWith(Name n) { |
| return ((size() >= n.size()) && |
| (compareRange(size() - n.size(), size(), n) == 0)); |
| } |
| |
| public String get(int pos) { |
| if (pos < 0 || pos >= size()) { |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| int i = size() - pos - 1; // index of "pos" component in "labels" |
| return labels.get(i); |
| } |
| |
| public Enumeration<String> getAll() { |
| return new Enumeration<String>() { |
| int pos = 0; |
| public boolean hasMoreElements() { |
| return (pos < size()); |
| } |
| public String nextElement() { |
| if (pos < size()) { |
| return get(pos++); |
| } |
| throw new java.util.NoSuchElementException(); |
| } |
| }; |
| } |
| |
| public Name getPrefix(int pos) { |
| return new DnsName(this, 0, pos); |
| } |
| |
| public Name getSuffix(int pos) { |
| return new DnsName(this, pos, size()); |
| } |
| |
| public Object clone() { |
| return new DnsName(this, 0, size()); |
| } |
| |
| public Object remove(int pos) { |
| if (pos < 0 || pos >= size()) { |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| int i = size() - pos - 1; // index of element to remove in "labels" |
| String label = labels.remove(i); |
| int len = label.length(); |
| if (len > 0) { |
| octets -= (short) (len + 1); |
| } |
| domain = null; // invalidate "domain" |
| return label; |
| } |
| |
| public Name add(String comp) throws InvalidNameException { |
| return add(size(), comp); |
| } |
| |
| public Name add(int pos, String comp) throws InvalidNameException { |
| if (pos < 0 || pos > size()) { |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| // Check for empty labels: may have only one, and only at end. |
| int len = comp.length(); |
| if ((pos > 0 && len == 0) || |
| (pos == 0 && hasRootLabel())) { |
| throw new InvalidNameException( |
| "Empty label must be the last label in a domain name"); |
| } |
| // Check total name length. |
| if (len > 0) { |
| if (octets + len + 1 >= 256) { |
| throw new InvalidNameException("Name too long"); |
| } |
| octets += (short) (len + 1); |
| } |
| |
| int i = size() - pos; // index for insertion into "labels" |
| verifyLabel(comp); |
| labels.add(i, comp); |
| |
| domain = null; // invalidate "domain" |
| return this; |
| } |
| |
| public Name addAll(Name suffix) throws InvalidNameException { |
| return addAll(size(), suffix); |
| } |
| |
| public Name addAll(int pos, Name n) throws InvalidNameException { |
| if (n instanceof DnsName) { |
| // "n" is a DnsName so we can insert it as a whole, rather than |
| // verifying and inserting it component-by-component. |
| // More code, but less work. |
| DnsName dn = (DnsName) n; |
| |
| if (dn.isEmpty()) { |
| return this; |
| } |
| // Check for empty labels: may have only one, and only at end. |
| if ((pos > 0 && dn.hasRootLabel()) || |
| (pos == 0 && hasRootLabel())) { |
| throw new InvalidNameException( |
| "Empty label must be the last label in a domain name"); |
| } |
| |
| short newOctets = (short) (octets + dn.octets - 1); |
| if (newOctets > 255) { |
| throw new InvalidNameException("Name too long"); |
| } |
| octets = newOctets; |
| int i = size() - pos; // index for insertion into "labels" |
| labels.addAll(i, dn.labels); |
| |
| // Preserve "domain" if we're appending or prepending, |
| // otherwise invalidate it. |
| if (isEmpty()) { |
| domain = dn.domain; |
| } else if (domain == null || dn.domain == null) { |
| domain = null; |
| } else if (pos == 0) { |
| domain += (dn.domain.equals(".") ? "" : ".") + dn.domain; |
| } else if (pos == size()) { |
| domain = dn.domain + (domain.equals(".") ? "" : ".") + domain; |
| } else { |
| domain = null; |
| } |
| |
| } else if (n instanceof CompositeName) { |
| n = (DnsName) n; // force ClassCastException |
| |
| } else { // "n" is a compound name, but not a DnsName. |
| // Add labels least-significant first: sometimes more efficient. |
| for (int i = n.size() - 1; i >= 0; i--) { |
| add(pos, n.get(i)); |
| } |
| } |
| return this; |
| } |
| |
| |
| boolean hasRootLabel() { |
| return (!isEmpty() && |
| get(0).equals("")); |
| } |
| |
| /* |
| * Helper method for public comparison methods. Lexicographically |
| * compares components of this name in the range [beg,end) with |
| * all components of "n". Indexing is as for the Name interface, |
| * with 0 being the most significant. Returns negative, zero, or |
| * positive as these name components are less than, equal to, or |
| * greater than those of "n". |
| */ |
| private int compareRange(int beg, int end, Name n) { |
| if (n instanceof CompositeName) { |
| n = (DnsName) n; // force ClassCastException |
| } |
| // Loop through labels, starting with most significant. |
| int minSize = Math.min(end - beg, n.size()); |
| for (int i = 0; i < minSize; i++) { |
| String label1 = get(i + beg); |
| String label2 = n.get(i); |
| |
| int j = size() - (i + beg) - 1; // index of label1 in "labels" |
| // assert (label1 == labels.get(j)); |
| |
| int c = compareLabels(label1, label2); |
| if (c != 0) { |
| return c; |
| } |
| } |
| return ((end - beg) - n.size()); // longer range wins |
| } |
| |
| /* |
| * Returns a key suitable for hashing the label at index i. |
| * Indexing is as for the Name interface, with 0 being the most |
| * significant. |
| */ |
| String getKey(int i) { |
| return keyForLabel(get(i)); |
| } |
| |
| |
| /* |
| * Parses a domain name, setting the values of instance vars accordingly. |
| */ |
| private void parse(String name) throws InvalidNameException { |
| |
| StringBuilder label = new StringBuilder(); // label being parsed |
| |
| for (int i = 0; i < name.length(); i++) { |
| char c = name.charAt(i); |
| |
| if (c == '\\') { // found an escape sequence |
| c = getEscapedOctet(name, i++); |
| if (isDigit(name.charAt(i))) { // sequence is \DDD |
| i += 2; // consume remaining digits |
| } |
| label.append(c); |
| |
| } else if (c != '.') { // an unescaped octet |
| label.append(c); |
| |
| } else { // found '.' separator |
| add(0, label.toString()); // check syntax, then add label |
| // to end of name |
| label.delete(0, i); // clear buffer for next label |
| } |
| } |
| |
| // If name is neither "." nor "", the octets (zero or more) |
| // from the rightmost dot onward are now added as the final |
| // label of the name. Those two are special cases in that for |
| // all other domain names, the number of labels is one greater |
| // than the number of dot separators. |
| if (!name.equals("") && !name.equals(".")) { |
| add(0, label.toString()); |
| } |
| |
| domain = name; // do this last, since add() sets it to null |
| } |
| |
| /* |
| * Returns (as a char) the octet indicated by the escape sequence |
| * at a given position within a domain name. |
| * @throws InvalidNameException if a valid escape sequence is not found. |
| */ |
| private static char getEscapedOctet(String name, int pos) |
| throws InvalidNameException { |
| try { |
| // assert (name.charAt(pos) == '\\'); |
| char c1 = name.charAt(++pos); |
| if (isDigit(c1)) { // sequence is `\DDD' |
| char c2 = name.charAt(++pos); |
| char c3 = name.charAt(++pos); |
| if (isDigit(c2) && isDigit(c3)) { |
| return (char) |
| ((c1 - '0') * 100 + (c2 - '0') * 10 + (c3 - '0')); |
| } else { |
| throw new InvalidNameException( |
| "Invalid escape sequence in " + name); |
| } |
| } else { // sequence is `\C' |
| return c1; |
| } |
| } catch (IndexOutOfBoundsException e) { |
| throw new InvalidNameException( |
| "Invalid escape sequence in " + name); |
| } |
| } |
| |
| /* |
| * Checks that this label is valid. |
| * @throws InvalidNameException if label is not valid. |
| */ |
| private static void verifyLabel(String label) throws InvalidNameException { |
| if (label.length() > 63) { |
| throw new InvalidNameException( |
| "Label exceeds 63 octets: " + label); |
| } |
| // Check for two-byte characters. |
| for (int i = 0; i < label.length(); i++) { |
| char c = label.charAt(i); |
| if ((c & 0xFF00) != 0) { |
| throw new InvalidNameException( |
| "Label has two-byte char: " + label); |
| } |
| } |
| } |
| |
| /* |
| * Does this label conform to host name syntax? |
| */ |
| private static boolean isHostNameLabel(String label) { |
| for (int i = 0; i < label.length(); i++) { |
| char c = label.charAt(i); |
| if (!isHostNameChar(c)) { |
| return false; |
| } |
| } |
| return !(label.startsWith("-") || label.endsWith("-")); |
| } |
| |
| private static boolean isHostNameChar(char c) { |
| return (c == '-' || |
| c >= 'a' && c <= 'z' || |
| c >= 'A' && c <= 'Z' || |
| c >= '0' && c <= '9'); |
| } |
| |
| private static boolean isDigit(char c) { |
| return (c >= '0' && c <= '9'); |
| } |
| |
| /* |
| * Append a label to buf, escaping as needed. |
| */ |
| private static void escape(StringBuilder buf, String label) { |
| for (int i = 0; i < label.length(); i++) { |
| char c = label.charAt(i); |
| if (c == '.' || c == '\\') { |
| buf.append('\\'); |
| } |
| buf.append(c); |
| } |
| } |
| |
| /* |
| * Compares two labels, ignoring case for ASCII values. |
| * Returns negative, zero, or positive as the first label |
| * is less than, equal to, or greater than the second. |
| * See keyForLabel(). |
| */ |
| private static int compareLabels(String label1, String label2) { |
| int min = Math.min(label1.length(), label2.length()); |
| for (int i = 0; i < min; i++) { |
| char c1 = label1.charAt(i); |
| char c2 = label2.charAt(i); |
| if (c1 >= 'A' && c1 <= 'Z') { |
| c1 += 'a' - 'A'; // to lower case |
| } |
| if (c2 >= 'A' && c2 <= 'Z') { |
| c2 += 'a' - 'A'; // to lower case |
| } |
| if (c1 != c2) { |
| return (c1 - c2); |
| } |
| } |
| return (label1.length() - label2.length()); // the longer one wins |
| } |
| |
| /* |
| * Returns a key suitable for hashing a label. Two labels map to |
| * the same key iff they are equal, taking possible case-folding |
| * into account. See compareLabels(). |
| */ |
| private static String keyForLabel(String label) { |
| StringBuilder sb = new StringBuilder(label.length()); |
| for (int i = 0; i < label.length(); i++) { |
| char c = label.charAt(i); |
| if (c >= 'A' && c <= 'Z') { |
| c += 'a' - 'A'; // to lower case |
| } |
| sb.append(c); |
| } |
| return sb.toString(); |
| } |
| |
| |
| /** |
| * Serializes only the domain name string, for compactness and to avoid |
| * any implementation dependency. |
| * |
| * @serialdata The domain name string. |
| */ |
| private void writeObject(java.io.ObjectOutputStream s) |
| throws java.io.IOException { |
| s.writeObject(toString()); |
| } |
| |
| private void readObject(java.io.ObjectInputStream s) |
| throws java.io.IOException, ClassNotFoundException { |
| try { |
| parse((String) s.readObject()); |
| } catch (InvalidNameException e) { |
| // shouldn't happen |
| throw new java.io.StreamCorruptedException( |
| "Invalid name: " + domain); |
| } |
| } |
| |
| private static final long serialVersionUID = 7040187611324710271L; |
| } |