/*
* Adito
*
* Copyright (C) 2003-2006 3SP LTD. All Rights Reserved
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package com.maverick.crypto.asn1;
import java.io.ByteArrayInputStream;
import java.io.EOFException;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* Don't use this class. It will eventually disappear, use ASN1InputStream.
* <br>
* This class is scheduled for removal.
*/
public class DERInputStream
extends FilterInputStream implements DERTags
{
public DERInputStream(
InputStream is)
{
super(is);
}
protected int readLength()
throws IOException
{
int length = read();
if (length < 0)
{
throw new IOException("EOF found when length expected");
}
if (length == 0x80)
{
return -1; // indefinite-length encoding
}
if (length > 127)
{
int size = length & 0x7f;
length = 0;
for (int i = 0; i < size; i++)
{
int next = read();
if (next < 0)
{
throw new IOException("EOF found reading length");
}
length = (length << 8) + next;
}
}
return length;
}
protected void readFully(
byte[] bytes)
throws IOException
{
int left = bytes.length;
if (left == 0)
{
return;
}
while (left > 0)
{
int l = read(bytes, bytes.length - left, left);
if (l < 0)
{
throw new EOFException("unexpected end of stream");
}
left -= l;
}
}
/**
* build an object given its tag and a byte stream to construct it
* from.
*/
protected DERObject buildObject(
int tag,
byte[] bytes)
throws IOException
{
switch (tag)
{
case NULL:
return null;
case SEQUENCE | CONSTRUCTED:
ByteArrayInputStream bIn = new ByteArrayInputStream(bytes);
BERInputStream dIn = new BERInputStream(bIn);
DERConstructedSequence seq = new DERConstructedSequence();
try
{
for (;;)
{
DERObject obj = dIn.readObject();
seq.addObject(obj);
}
}
catch (EOFException ex)
{
return seq;
}
case SET | CONSTRUCTED:
bIn = new ByteArrayInputStream(bytes);
dIn = new BERInputStream(bIn);
ASN1EncodableVector v = new ASN1EncodableVector();
try
{
for (;;)
{
DERObject obj = dIn.readObject();
v.add(obj);
}
}
catch (EOFException ex)
{
return new DERConstructedSet(v);
}
case BOOLEAN:
return new DERBoolean(bytes);
case INTEGER:
return new DERInteger(bytes);
case ENUMERATED:
return new DEREnumerated(bytes);
case OBJECT_IDENTIFIER:
return new DERObjectIdentifier(bytes);
case BIT_STRING:
int padBits = bytes[0];
byte[] data = new byte[bytes.length - 1];
System.arraycopy(bytes, 1, data, 0, bytes.length - 1);
return new DERBitString(data, padBits);
case UTF8_STRING:
return new DERUTF8String(bytes);
case PRINTABLE_STRING:
return new DERPrintableString(bytes);
case IA5_STRING:
return new DERIA5String(bytes);
case T61_STRING:
return new DERT61String(bytes);
case VISIBLE_STRING:
return new DERVisibleString(bytes);
case UNIVERSAL_STRING:
return new DERUniversalString(bytes);
case GENERAL_STRING:
return new DERGeneralString(bytes);
case BMP_STRING:
return new DERBMPString(bytes);
case OCTET_STRING:
return new DEROctetString(bytes);
case UTC_TIME:
return new DERUTCTime(bytes);
case GENERALIZED_TIME:
return new DERGeneralizedTime(bytes);
default:
//
// with tagged object tag number is bottom 5 bits
//
if ((tag & TAGGED) != 0)
{
if ((tag & 0x1f) == 0x1f)
{
throw new IOException("unsupported high tag encountered");
}
if (bytes.length == 0) // empty tag!
{
if ((tag & CONSTRUCTED) == 0)
{
return new DERTaggedObject(false, tag & 0x1f, new DERNull());
}
else
{
return new DERTaggedObject(false, tag & 0x1f, new DERConstructedSequence());
}
}
//
// simple type - implicit... return an octet string
//
if ((tag & CONSTRUCTED) == 0)
{
return new DERTaggedObject(false, tag & 0x1f, new DEROctetString(bytes));
}
bIn = new ByteArrayInputStream(bytes);
dIn = new BERInputStream(bIn);
DEREncodable dObj = dIn.readObject();
//
// explicitly tagged (probably!) - if it isn't we'd have to
// tell from the context
//
if (dIn.available() == 0)
{
return new DERTaggedObject(tag & 0x1f, dObj);
}
//
// another implicit object, we'll create a sequence...
//
seq = new DERConstructedSequence();
seq.addObject(dObj);
try
{
for (;;)
{
dObj = dIn.readObject();
seq.addObject(dObj);
}
}
catch (EOFException ex)
{
// ignore --
}
return new DERTaggedObject(false, tag & 0x1f, seq);
}
return new DERUnknownTag(tag, bytes);
}
}
public DERObject readObject()
throws IOException
{
int tag = read();
if (tag == -1)
{
throw new EOFException();
}
int length = readLength();
byte[] bytes = new byte[length];
readFully(bytes);
return buildObject(tag, bytes);
}
}