org.jasn
Class DerDecoder

java.lang.Object
  org.jasn.BerDecoder
      org.jasn.DerDecoder

All Implemented Interfaces:

Asn1Decoder

public class DerDecoder

extends BerDecoder

A decoder for parsing DER encoded ASN.1 value from an input stream.

Author:

Nicolas Vraux

To do:

implements decodeUTF8 with its own decoding method, implements decodeGeneralizedTime

Constructor Summary

DerDecoder(InputStream in)
Creates a decoder for parsing BER encoded ASN.1 values from the specified input stream.

DerDecoder(InputStream in, int bufSize)
Creates a decoder for parsing BER encoded ASN.1 values from the specified input stream.

Method Summary

BitString	decodeBitString(BitString set) Decodes an ASN.1 BIT STRING value from the underlying stream and appends its bit values to the specified BitString.
boolean	decodeBoolean() Decodes an ASN.1 BOOLEAN value from the underlying stream and returns it as a boolean value.

Methods inherited from class org.jasn.BerDecoder

decodeAny, decodeAny, decodeBitString, decodeBMPString, decodeBMPString, decodeChoice, decodeConstructed, decodeEndOf, decodeEnumerated, decodeEnumeratedAsInt, decodeEnumeratedAsLong, decodeExplicit, decodeGeneralizedTime, decodeIA5String, decodeIA5String, decodeImplicit, decodeInteger, decodeIntegerAsInt, decodeIntegerAsLong, decodeNull, decodeNumericString, decodeNumericString, decodeObjectIdentifier, decodeOctetString, decodeOctetString, decodePrintableString, decodePrintableString, decodeSequence, decodeSequenceOf, decodeSet, decodeSetOf, decodeString, decodeTeletexString, decodeTeletexString, decodeUTCTime, decodeUTF8String, decodeUTF8String, decodeVisibleString, decodeVisibleString, endOf, isNextConstructed, isNextTag, matchTag, setInputStream, skipNext

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DerDecoder

public DerDecoder(InputStream in,
                  int bufSize)

Creates a decoder for parsing BER encoded ASN.1 values from the specified input stream. An internal buffer array of length bufSize will be used for decoding.

Parameters:

in - the underlying input stream.

DerDecoder

public DerDecoder(InputStream in)

Creates a decoder for parsing BER encoded ASN.1 values from the specified input stream.

Parameters:

in - the underlying input stream.

Method Detail

decodeBoolean

public boolean decodeBoolean()
                      throws IOException

Decodes an ASN.1 BOOLEAN value from the underlying stream and returns it as a boolean value.

Specified by:

decodeBoolean in interface Asn1Decoder

Overrides:

decodeBoolean in class BerDecoder

Returns:

the decoded boolean value.

Throws:

IOException - if an I/O error occurs.

DecodingException - if the bytes read do not represent a valid BER encoded BOOLEAN value.

decodeBitString

public BitString decodeBitString(BitString set)
                          throws IOException

Decodes an ASN.1 BIT STRING value from the underlying stream and appends its bit values to the specified BitString. The first bit of the decode BIT STRING value corresponds to the bit at index set.length() + 1 of the BitString.

The total number of bit contained in the decoded BIT STRING may be retrieved by invoking the length method of the returned BitString.

Specified by:

decodeBitString in interface Asn1Decoder

Overrides:

decodeBitString in class BerDecoder

Parameters:

set - the BitString to which the decoded bits are appended.

Returns:

a BitString instance representing the content of the decoded BIT STRING.

Throws:

IOException - if an I/O error occurs.

DecodingException - if the bytes read do not represent a valid BER encoded BIT STRING value.