1 /*
2 * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package sun.security.x509;
27
28 import java.io.IOException;
29 import java.util.Locale;
30
31 import sun.security.util.*;
32
33 /**
34 * This class implements the DNSName as required by the GeneralNames
35 * ASN.1 object.
36 * <p>
37 * [RFC2459] When the subjectAltName extension contains a domain name service
38 * label, the domain name MUST be stored in the dNSName (an IA5String).
39 * The name MUST be in the "preferred name syntax," as specified by RFC
40 * 1034 [RFC 1034]. Note that while upper and lower case letters are
41 * allowed in domain names, no signifigance is attached to the case. In
42 * addition, while the string " " is a legal domain name, subjectAltName
43 * extensions with a dNSName " " are not permitted. Finally, the use of
44 * the DNS representation for Internet mail addresses (wpolk.nist.gov
45 * instead of wpolk@nist.gov) is not permitted; such identities are to
46 * be encoded as rfc822Name.
47 * <p>
48 * @author Amit Kapoor
49 * @author Hemma Prafullchandra
50 */
51 public class DNSName implements GeneralNameInterface {
52 private String name;
53
54 private static final String alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
55 private static final String digitsAndHyphen = "0123456789-";
56 private static final String alphaDigitsAndHyphen = alpha + digitsAndHyphen;
57
58 /**
59 * Create the DNSName object from the passed encoded Der value.
60 *
61 * @param derValue the encoded DER DNSName.
62 * @exception IOException on error.
63 */
64 public DNSName(DerValue derValue) throws IOException {
65 name = derValue.getIA5String();
66 }
67
68 /**
69 * Create the DNSName object with the specified name.
70 *
71 * @param name the DNSName.
72 * @throws IOException if the name is not a valid DNSName subjectAltName
73 */
74 public DNSName(String name) throws IOException {
75 if (name == null || name.length() == 0)
76 throw new IOException("DNS name must not be null");
77 if (name.indexOf(' ') != -1)
78 throw new IOException("DNS names or NameConstraints with blank components are not permitted");
79 if (name.charAt(0) == '.' || name.charAt(name.length() -1) == '.')
80 throw new IOException("DNS names or NameConstraints may not begin or end with a .");
81 //Name will consist of label components separated by "."
82 //startIndex is the index of the first character of a component
83 //endIndex is the index of the last character of a component plus 1
84 for (int endIndex,startIndex=0; startIndex < name.length(); startIndex = endIndex+1) {
85 endIndex = name.indexOf('.', startIndex);
86 if (endIndex < 0) {
87 endIndex = name.length();
88 }
89 if ((endIndex-startIndex) < 1)
90 throw new IOException("DNSName SubjectAltNames with empty components are not permitted");
91
92 //DNSName components must begin with a letter A-Z or a-z
93 if (alpha.indexOf(name.charAt(startIndex)) < 0)
94 throw new IOException("DNSName components must begin with a letter");
95 //nonStartIndex: index for characters in the component beyond the first one
96 for (int nonStartIndex=startIndex+1; nonStartIndex < endIndex; nonStartIndex++) {
97 char x = name.charAt(nonStartIndex);
98 if ((alphaDigitsAndHyphen).indexOf(x) < 0)
99 throw new IOException("DNSName components must consist of letters, digits, and hyphens");
100 }
101 }
102 this.name = name;
103 }
104
105 /**
106 * Return the type of the GeneralName.
107 */
108 public int getType() {
109 return (GeneralNameInterface.NAME_DNS);
110 }
111
112 /**
113 * Return the actual name value of the GeneralName.
114 */
115 public String getName() {
116 return name;
117 }
118
119 /**
120 * Encode the DNS name into the DerOutputStream.
121 *
122 * @param out the DER stream to encode the DNSName to.
123 * @exception IOException on encoding errors.
124 */
125 public void encode(DerOutputStream out) throws IOException {
126 out.putIA5String(name);
127 }
128
129 /**
130 * Convert the name into user readable string.
131 */
132 public String toString() {
133 return ("DNSName: " + name);
134 }
135
136 /**
137 * Compares this name with another, for equality.
138 *
139 * @return true iff the names are equivalent
140 * according to RFC2459.
141 */
142 public boolean equals(Object obj) {
143 if (this == obj)
144 return true;
145
146 if (!(obj instanceof DNSName))
147 return false;
148
149 DNSName other = (DNSName)obj;
150
151 // RFC2459 mandates that these names are
152 // not case-sensitive
153 return name.equalsIgnoreCase(other.name);
154 }
155
156 /**
157 * Returns the hash code value for this object.
158 *
159 * @return a hash code value for this object.
160 */
161 public int hashCode() {
162 return name.toUpperCase(Locale.ENGLISH).hashCode();
163 }
164
165 /**
166 * Return type of constraint inputName places on this name:<ul>
167 * <li>NAME_DIFF_TYPE = -1: input name is different type from name (i.e. does not constrain).
168 * <li>NAME_MATCH = 0: input name matches name.
169 * <li>NAME_NARROWS = 1: input name narrows name (is lower in the naming subtree)
170 * <li>NAME_WIDENS = 2: input name widens name (is higher in the naming subtree)
171 * <li>NAME_SAME_TYPE = 3: input name does not match or narrow name, but is same type.
172 * </ul>. These results are used in checking NameConstraints during
173 * certification path verification.
174 * <p>
175 * RFC2459: DNS name restrictions are expressed as foo.bar.com. Any subdomain
176 * satisfies the name constraint. For example, www.foo.bar.com would
177 * satisfy the constraint but bigfoo.bar.com would not.
178 * <p>
179 * draft-ietf-pkix-new-part1-00.txt: DNS name restrictions are expressed as foo.bar.com.
180 * Any DNS name that
181 * can be constructed by simply adding to the left hand side of the name
182 * satisfies the name constraint. For example, www.foo.bar.com would
183 * satisfy the constraint but foo1.bar.com would not.
184 * <p>
185 * RFC1034: By convention, domain names can be stored with arbitrary case, but
186 * domain name comparisons for all present domain functions are done in a
187 * case-insensitive manner, assuming an ASCII character set, and a high
188 * order zero bit.
189 * <p>
190 * @param inputName to be checked for being constrained
191 * @returns constraint type above
192 * @throws UnsupportedOperationException if name is not exact match, but narrowing and widening are
193 * not supported for this name type.
194 */
195 public int constrains(GeneralNameInterface inputName) throws UnsupportedOperationException {
196 int constraintType;
197 if (inputName == null)
198 constraintType = NAME_DIFF_TYPE;
199 else if (inputName.getType() != NAME_DNS)
200 constraintType = NAME_DIFF_TYPE;
201 else {
202 String inName =
203 (((DNSName)inputName).getName()).toLowerCase(Locale.ENGLISH);
204 String thisName = name.toLowerCase(Locale.ENGLISH);
205 if (inName.equals(thisName))
206 constraintType = NAME_MATCH;
207 else if (thisName.endsWith(inName)) {
208 int inNdx = thisName.lastIndexOf(inName);
209 if (thisName.charAt(inNdx-1) == '.' )
210 constraintType = NAME_WIDENS;
211 else
212 constraintType = NAME_SAME_TYPE;
213 } else if (inName.endsWith(thisName)) {
214 int ndx = inName.lastIndexOf(thisName);
215 if (inName.charAt(ndx-1) == '.' )
216 constraintType = NAME_NARROWS;
217 else
218 constraintType = NAME_SAME_TYPE;
219 } else {
220 constraintType = NAME_SAME_TYPE;
221 }
222 }
223 return constraintType;
224 }
225
226 /**
227 * Return subtree depth of this name for purposes of determining
228 * NameConstraints minimum and maximum bounds and for calculating
229 * path lengths in name subtrees.
230 *
231 * @returns distance of name from root
232 * @throws UnsupportedOperationException if not supported for this name type
233 */
234 public int subtreeDepth() throws UnsupportedOperationException {
235 // subtree depth is always at least 1
236 int sum = 1;
237
238 // count dots
239 for (int i = name.indexOf('.'); i >= 0; i = name.indexOf('.', i + 1)) {
240 ++sum;
241 }
242
243 return sum;
244 }
245
246 }