/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @author Vladimir N. Molotkov, Stepan M. Mishura
* @version $Revision$
*/
/*
* Imported by CG 20090319 based on Apache Harmony ("enhanced") revision 476395.
*/
package org.apache.harmony.security.asn1;
import java.io.IOException;
/**
* This class represents ASN.1 Bitstring type.
*
* @see http://asn1.elibel.tm.fr/en/standards/index.htm
*/
public class ASN1BitString extends ASN1StringType {
// default implementation
private static final ASN1BitString ASN1 = new ASN1BitString();
/**
* Constructs ASN.1 Bitstring type
*
* The constructor is provided for inheritance purposes
* when there is a need to create a custom ASN.1 Bitstring type.
* To get a default implementation it is recommended to use
* getInstance() method.
*/
public ASN1BitString() {
super(TAG_BITSTRING);
}
/**
* Returns ASN.1 Bitstring type default implementation
*
* The default implementation works with encoding
* that is represented as BitString object.
*
* @return ASN.1 Bitstring type default implementation
* @see org.apache.harmony.security.asn1.BitString
*/
public static ASN1BitString getInstance() {
return ASN1;
}
//
//
// Decode
//
//
public Object decode(BerInputStream in) throws IOException {
in.readBitString();
if (in.isVerify) {
return null;
}
return getDecodedObject(in);
}
/**
* Extracts BitString object from BER input stream.
*
* @param in - BER input stream
* @return BitString object
*/
public Object getDecodedObject(BerInputStream in) throws IOException {
byte[] bytes = new byte[in.length - 1];
System.arraycopy(in.buffer, in.contentOffset + 1, bytes, 0,
in.length - 1);
return new BitString(bytes, in.buffer[in.contentOffset]);
}
//
// Encode
//
public void encodeContent(BerOutputStream out) {
out.encodeBitString();
}
public void setEncodingContent(BerOutputStream out) {
out.length = ((BitString) out.content).bytes.length + 1;
}
//
//
// Named Bit List
//
//
/**
* Default implementation for ASN.1 Named Bitstring type
*
* The default implementation works with encoding
* that is mapped to array of boolean.
*/
public static class ASN1NamedBitList extends ASN1BitString {
private static final byte[] SET_MASK = { (byte) 128, 64, 32, 16, 8, 4,
2, 1 };
private static final BitString emptyString = new BitString(
new byte[] {}, 0);
private static final int INDEFINITE_SIZE = -1;
private final int minBits;
private final int maxBits;
public ASN1NamedBitList() {
this.minBits = INDEFINITE_SIZE;
this.maxBits = INDEFINITE_SIZE;
}
public ASN1NamedBitList(int minBits) {
this.minBits = minBits;
this.maxBits = INDEFINITE_SIZE;
}
public ASN1NamedBitList(int minBits, int maxBits) {
this.minBits = minBits;
this.maxBits = maxBits;
}
public Object getDecodedObject(BerInputStream in) throws IOException {
boolean[] value = null;
int unusedBits = in.buffer[in.contentOffset];
int bitsNumber = (in.length - 1) * 8 - unusedBits;
if (maxBits == INDEFINITE_SIZE) {
if (minBits == INDEFINITE_SIZE) {
value = new boolean[bitsNumber];
} else {
if (bitsNumber > minBits) {
value = new boolean[bitsNumber];
} else {
value = new boolean[minBits];
}
}
} else {
if (bitsNumber > maxBits) {
throw new ASN1Exception(
"ASN.1 Named Bitstring: size contstrains"); //FIXME message
}
value = new boolean[maxBits];
}
if (bitsNumber == 0) {
// empty bit string
return value;
}
int i = 1;
int j = 0;
byte octet = in.buffer[in.contentOffset + i];
for (int size = in.length - 1; i < size; i++) {
for (int k = 0; k < 8; k++, j++) {
value[j] = (SET_MASK[k] & octet) != 0;
}
i++;
octet = in.buffer[in.contentOffset + i];
}
// final octet
for (int k = 0; k < (8 - unusedBits); k++, j++) {
value[j] = (SET_MASK[k] & octet) != 0;
}
return value;
}
public void setEncodingContent(BerOutputStream out) {
boolean[] toEncode = (boolean[]) out.content;
int index = toEncode.length - 1;
while (index > -1 && !toEncode[index]) {
index--;
}
if (index == -1) {
out.content = emptyString;
out.length = 1;
} else {
int unusedBits = 7 - index % 8;
byte[] bytes = new byte[index / 8 + 1];
int j = 0;
index = bytes.length - 1;
for (int i = 0; i < index; i++) {
for (int k = 0; k < 8; k++, j++) {
if (toEncode[j]) {
bytes[i] = (byte) (bytes[i] | SET_MASK[k]);
}
}
}
//final octet
for (int k = 0; k < (8 - unusedBits); k++, j++) {
if (toEncode[j]) {
bytes[index] = (byte) (bytes[index] | SET_MASK[k]);
}
}
out.content = new BitString(bytes, unusedBits);
out.length = bytes.length + 1;
}
}
}
}