com.novell.ldap.asn1.ASN1Length Maven / Gradle / Ivy
/* **************************************************************************
* $OpenLDAP$
*
* Copyright (C) 1999, 2000, 2001 Novell, Inc. All Rights Reserved.
*
* THIS WORK IS SUBJECT TO U.S. AND INTERNATIONAL COPYRIGHT LAWS AND
* TREATIES. USE, MODIFICATION, AND REDISTRIBUTION OF THIS WORK IS SUBJECT
* TO VERSION 2.0.1 OF THE OPENLDAP PUBLIC LICENSE, A COPY OF WHICH IS
* AVAILABLE AT HTTP://WWW.OPENLDAP.ORG/LICENSE.HTML OR IN THE FILE "LICENSE"
* IN THE TOP-LEVEL DIRECTORY OF THE DISTRIBUTION. ANY USE OR EXPLOITATION
* OF THIS WORK OTHER THAN AS AUTHORIZED IN VERSION 2.0.1 OF THE OPENLDAP
* PUBLIC LICENSE, OR OTHER PRIOR WRITTEN CONSENT FROM NOVELL, COULD SUBJECT
* THE PERPETRATOR TO CRIMINAL AND CIVIL LIABILITY.
******************************************************************************/
package com.novell.ldap.asn1;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
/**
* This class provides a means to manipulate ASN.1 Length's. It will
* be used by ASN1Encoder's and ASN1Decoder's by composition.
*/
public class ASN1Length {
/* Private variables
*/
private int length;
private int encodedLength;
/* Constructors for ASN1Length
*/
/**
* Constructs an empty ASN1Length. Values are added by calling reset
*/
public ASN1Length(){}
/**
* Constructs an ASN1Length
*/
public ASN1Length(int length)
{
this.length = length;
}
/**
* Constructs an ASN1Length object by decoding data from an
* input stream.
*
* @param in A byte stream that contains the encoded ASN.1
*
*/
public ASN1Length(InputStream in)
throws IOException
{
int r = in.read();
encodedLength++;
if(r == 0x80)
length = -1;
else if(r < 0x80)
length = r;
else {
length = 0;
for(r = r & 0x7F; r > 0; r--) {
int part = in.read();
encodedLength++;
if(part < 0)
throw new EOFException("BERDecoder: decode: EOF in ASN1Length");
length = (length << 8) + part;
}
}
}
/**
* Resets an ASN1Length object by decoding data from an
* input stream.
*
* Note: this was added for optimization of ASN1.LBERdecoder.decode()
*
* @param in A byte stream that contains the encoded ASN.1
*
*/
public final void reset(InputStream in)
throws IOException
{
encodedLength = 0;
int r = in.read();
encodedLength++;
if(r == 0x80)
length = -1;
else if(r < 0x80)
length = r;
else {
length = 0;
for(r = r & 0x7F; r > 0; r--) {
int part = in.read();
encodedLength++;
if(part < 0)
throw new EOFException("BERDecoder: decode: EOF in ASN1Length");
length = (length << 8) + part;
}
}
}
/**
* Returns the length of this ASN1Length.
*/
public final int getLength()
{
return length;
}
/**
* Returns the encoded length of this ASN1Length.
*/
public final int getEncodedLength()
{
return encodedLength;
}
}