/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE
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* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
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* add the following below this CDDL HEADER, with the fields enclosed
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* by brackets "[]" replaced with your own identifying * information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Portions Copyright 2006-2007 Sun Microsystems, Inc.
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*/
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package org.opends.server.protocols.asn1;
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import static org.opends.server.messages.MessageHandler.*;
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import static org.opends.server.messages.ProtocolMessages.*;
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import static org.opends.server.protocols.asn1.ASN1Constants.*;
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import static org.opends.server.util.ServerConstants.*;
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import static org.opends.server.util.StaticUtils.*;
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/**
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* This class defines the data structures and methods to use when interacting
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* with ASN.1 null elements.
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*/
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public class ASN1Null
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extends ASN1Element
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{
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/**
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* The serial version identifier required to satisfy the compiler because this
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* class implements the <CODE>java.io.Serializable</CODE> interface. This
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* value was generated using the <CODE>serialver</CODE> command-line utility
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* included with the Java SDK.
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*/
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private static final long serialVersionUID = 8921787912269145125L;
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/**
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* Creates a new ASN.1 null element with the default type.
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*/
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public ASN1Null()
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{
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super(UNIVERSAL_NULL_TYPE);
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}
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/**
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* Creates a new ASN.1 null element with the specified type.
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*
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* @param type The BER type to use for this ASN.1 null element.
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*/
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public ASN1Null(byte type)
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{
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super(type);
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}
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/**
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* Specifies the value for this ASN.1 null element.
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*
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* @param value The encoded value for this ASN.1 null element.
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*
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* @throws ASN1Exception If the provided array is not empty.
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*/
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public void setValue(byte[] value)
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throws ASN1Exception
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{
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if ((value != null) && (value.length != 0))
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{
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int msgID = MSGID_ASN1_NULL_SET_VALUE_INVALID_LENGTH;
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String message = getMessage(msgID, value.length);
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throw new ASN1Exception(msgID, message);
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}
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}
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/**
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* Decodes the provided ASN.1 element as a null element.
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*
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* @param element The ASN.1 element to decode as a null element.
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*
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* @return The decoded ASN.1 null element.
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*
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* @throws ASN1Exception If the provided ASN.1 element cannot be decoded as
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* a null element.
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*/
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public static ASN1Null decodeAsNull(ASN1Element element)
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throws ASN1Exception
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{
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if (element == null)
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{
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int msgID = MSGID_ASN1_NULL_DECODE_ELEMENT_NULL;
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String message = getMessage(msgID);
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throw new ASN1Exception(msgID, message);
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}
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byte[] value = element.value();
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if (value.length != 0)
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{
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int msgID = MSGID_ASN1_NULL_DECODE_ELEMENT_INVALID_LENGTH;
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String message = getMessage(msgID, value.length);
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throw new ASN1Exception(msgID, message);
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}
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return new ASN1Null(element.getType());
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}
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/**
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* Decodes the provided byte array as an ASN.1 null element.
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*
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* @param encodedElement The byte array to decode as an ASN.1 null element.
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*
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* @return The decoded ASN.1 null element.
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*
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* @throws ASN1Exception If the provided byte array cannot be decoded as an
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* ASN.1 null element.
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*/
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public static ASN1Null decodeAsNull(byte[] encodedElement)
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throws ASN1Exception
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{
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// First make sure that the array is not null and long enough to contain
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// a valid ASN.1 null element.
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if (encodedElement == null)
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{
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int msgID = MSGID_ASN1_NULL_DECODE_ARRAY_NULL;
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String message = getMessage(msgID);
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throw new ASN1Exception(msgID, message);
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}
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if (encodedElement.length < 2)
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{
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int msgID = MSGID_ASN1_SHORT_ELEMENT;
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String message = getMessage(msgID, encodedElement.length);
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throw new ASN1Exception(msgID, message);
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}
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// Next, decode the length. This allows multi-byte lengths with up to four
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// bytes used to indicate how many bytes are in the length.
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byte type = encodedElement[0];
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int length = (encodedElement[1] & 0x7F);
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int valueStartPos = 2;
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if (length != encodedElement[1])
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{
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int numLengthBytes = length;
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if (numLengthBytes > 4)
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{
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int msgID = MSGID_ASN1_INVALID_NUM_LENGTH_BYTES;
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String message = getMessage(msgID, numLengthBytes);
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throw new ASN1Exception(msgID, message);
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}
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else if (encodedElement.length < (2 + numLengthBytes))
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{
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int msgID = MSGID_ASN1_TRUNCATED_LENGTH;
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String message = getMessage(msgID, numLengthBytes);
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throw new ASN1Exception(msgID, message);
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}
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length = 0x00;
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valueStartPos = 2 + numLengthBytes;
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for (int i=0; i < numLengthBytes; i++)
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{
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length = (length << 8) | (encodedElement[i+2] & 0xFF);
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}
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}
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// Make sure that the number of bytes left is equal to the number of bytes
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// in the value.
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if ((encodedElement.length - valueStartPos) != length)
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{
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int msgID = MSGID_ASN1_LENGTH_MISMATCH;
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String message = getMessage(msgID, length,
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(encodedElement.length - valueStartPos));
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throw new ASN1Exception(msgID, message);
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}
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// Make sure that the decoded length is exactly zero byte.
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if (length != 0)
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{
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int msgID = MSGID_ASN1_NULL_DECODE_ARRAY_INVALID_LENGTH;
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String message = getMessage(msgID, length);
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throw new ASN1Exception(msgID, message);
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}
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// Copy the value and construct the element to return.
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return new ASN1Null(type);
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}
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/**
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* Appends a string representation of this ASN.1 null element to the provided
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* buffer.
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*
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* @param buffer The buffer to which the information should be appended.
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*/
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public void toString(StringBuilder buffer)
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{
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buffer.append("ASN1Null(type=");
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buffer.append(byteToHex(getType()));
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buffer.append(")");
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}
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/**
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* Appends a string representation of this protocol element to the provided
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* buffer.
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*
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* @param buffer The buffer into which the string representation should be
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* written.
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* @param indent The number of spaces that should be used to indent the
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* resulting string representation.
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*/
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public void toString(StringBuilder buffer, int indent)
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{
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StringBuilder indentBuf = new StringBuilder(indent);
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for (int i=0 ; i < indent; i++)
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{
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indentBuf.append(' ');
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}
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buffer.append(indentBuf);
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buffer.append("ASN.1 Null");
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buffer.append(EOL);
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buffer.append(indentBuf);
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buffer.append(" BER Type: ");
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buffer.append(byteToHex(getType()));
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buffer.append(EOL);
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}
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}
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