1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 /** 19 * @author Vladimir N. Molotkov, Stepan M. Mishura 20 * @version $Revision$ 21 */ 22 23 package org.apache.harmony.security.asn1; 24 25 import java.io.IOException; 26 27 /** 28 * This class represents ASN.1 Bitstring type. 29 * 30 * @see <a href="http://asn1.elibel.tm.fr/en/standards/index.htm">ASN.1</a> 31 */ 32 33 public class ASN1BitString extends ASN1StringType { 34 35 // default implementation 36 private static final ASN1BitString ASN1 = new ASN1BitString(); 37 38 /** 39 * Constructs ASN.1 Bitstring type 40 * 41 * The constructor is provided for inheritance purposes 42 * when there is a need to create a custom ASN.1 Bitstring type. 43 * To get a default implementation it is recommended to use 44 * getInstance() method. 45 */ 46 public ASN1BitString() { 47 super(TAG_BITSTRING); 48 } 49 50 /** 51 * Returns ASN.1 Bitstring type default implementation 52 * 53 * The default implementation works with encoding 54 * that is represented as BitString object. 55 * 56 * @return ASN.1 Bitstring type default implementation 57 * @see org.apache.harmony.security.asn1.BitString 58 */ 59 public static ASN1BitString getInstance() { 60 return ASN1; 61 } 62 63 // 64 // 65 // Decode 66 // 67 // 68 69 public Object decode(BerInputStream in) throws IOException { 70 71 in.readBitString(); 72 73 if (in.isVerify) { 74 return null; 75 } 76 return getDecodedObject(in); 77 } 78 79 /** 80 * Extracts BitString object from BER input stream. 81 * 82 * @param in - BER input stream 83 * @return BitString object 84 */ 85 public Object getDecodedObject(BerInputStream in) throws IOException { 86 byte[] bytes = new byte[in.length - 1]; 87 System.arraycopy(in.buffer, in.contentOffset + 1, bytes, 0, 88 in.length - 1); 89 return new BitString(bytes, in.buffer[in.contentOffset]); 90 } 91 92 // 93 // Encode 94 // 95 96 public void encodeContent(BerOutputStream out) { 97 out.encodeBitString(); 98 } 99 100 public void setEncodingContent(BerOutputStream out) { 101 out.length = ((BitString) out.content).bytes.length + 1; 102 } 103 104 // 105 // 106 // Named Bit List 107 // 108 // 109 110 /** 111 * Default implementation for ASN.1 Named Bitstring type 112 * 113 * The default implementation works with encoding 114 * that is mapped to array of boolean. 115 */ 116 public static class ASN1NamedBitList extends ASN1BitString { 117 118 private static final byte[] SET_MASK = { (byte) 128, 64, 32, 16, 8, 4, 119 2, 1 }; 120 121 private static final BitString emptyString = new BitString( 122 new byte[] {}, 0); 123 124 private static final int INDEFINITE_SIZE = -1; 125 126 private final int minBits; 127 128 private final int maxBits; 129 130 public ASN1NamedBitList() { 131 this.minBits = INDEFINITE_SIZE; 132 this.maxBits = INDEFINITE_SIZE; 133 } 134 135 public ASN1NamedBitList(int minBits) { 136 this.minBits = minBits; 137 this.maxBits = INDEFINITE_SIZE; 138 } 139 140 public ASN1NamedBitList(int minBits, int maxBits) { 141 this.minBits = minBits; 142 this.maxBits = maxBits; 143 } 144 145 public Object getDecodedObject(BerInputStream in) throws IOException { 146 147 boolean[] value = null; 148 149 int unusedBits = in.buffer[in.contentOffset]; 150 int bitsNumber = (in.length - 1) * 8 - unusedBits; 151 152 if (maxBits == INDEFINITE_SIZE) { 153 if (minBits == INDEFINITE_SIZE) { 154 value = new boolean[bitsNumber]; 155 } else { 156 if (bitsNumber > minBits) { 157 value = new boolean[bitsNumber]; 158 } else { 159 value = new boolean[minBits]; 160 } 161 } 162 } else { 163 if (bitsNumber > maxBits) { 164 throw new ASN1Exception("ASN.1 Named Bitstring: size constraints"); 165 } 166 value = new boolean[maxBits]; 167 } 168 169 if (bitsNumber == 0) { 170 // empty bit string 171 return value; 172 } 173 174 int i = 1; 175 int j = 0; 176 byte octet = in.buffer[in.contentOffset + i]; 177 for (int size = in.length - 1; i < size; i++) { 178 179 for (int k = 0; k < 8; k++, j++) { 180 value[j] = (SET_MASK[k] & octet) != 0; 181 } 182 i++; 183 octet = in.buffer[in.contentOffset + i]; 184 } 185 186 // final octet 187 for (int k = 0; k < (8 - unusedBits); k++, j++) { 188 value[j] = (SET_MASK[k] & octet) != 0; 189 } 190 191 return value; 192 } 193 194 public void setEncodingContent(BerOutputStream out) { 195 196 boolean[] toEncode = (boolean[]) out.content; 197 198 int index = toEncode.length - 1; 199 while (index > -1 && !toEncode[index]) { 200 index--; 201 } 202 203 if (index == -1) { 204 out.content = emptyString; 205 out.length = 1; 206 } else { 207 int unusedBits = 7 - index % 8; 208 byte[] bytes = new byte[index / 8 + 1]; 209 210 int j = 0; 211 index = bytes.length - 1; 212 for (int i = 0; i < index; i++) { 213 for (int k = 0; k < 8; k++, j++) { 214 if (toEncode[j]) { 215 bytes[i] = (byte) (bytes[i] | SET_MASK[k]); 216 } 217 } 218 } 219 220 //final octet 221 for (int k = 0; k < (8 - unusedBits); k++, j++) { 222 if (toEncode[j]) { 223 bytes[index] = (byte) (bytes[index] | SET_MASK[k]); 224 } 225 } 226 227 out.content = new BitString(bytes, unusedBits); 228 out.length = bytes.length + 1; 229 } 230 } 231 } 232 } 233