davmail.ldap

Class BerDecoder

java.lang.Object

davmail.ldap.Ber

davmail.ldap.BerDecoder

public final class BerDecoder
extends Ber

A BER decoder. Contains methods to parse a BER buffer.

Author:

Jagane Sundar, Vincent Ryan

Field Summary

Fields inherited from class davmail.ldap.Ber

ASN_APPLICATION, ASN_BIT_STRING, ASN_BOOLEAN, ASN_CONSTRUCTOR, ASN_CONTEXT, ASN_ENUMERATED, ASN_INTEGER, ASN_NULL, ASN_OBJECT_ID, ASN_OCTET_STR, ASN_PRIMITIVE, ASN_PRIVATE, ASN_SEQUENCE, ASN_SET, ASN_SIMPLE_STRING, ASN_UNIVERSAL, buf, bufsize, offset

Constructor Summary

Constructors

Constructor and Description
BerDecoder(byte[] buf, int offset, int bufsize) Creates a BER decoder that reads bytes from the specified buffer.

Method Summary

Modifier and Type	Method and Description
int	bytesLeft() Returns the number of unparsed bytes in this BER buffer.
int	getParsePosition() Returns the current parse position.
boolean	parseBoolean() Parses an ASN_BOOLEAN tagged integer from this BER buffer.
int	parseByte() Parses the next byte in this BER buffer.
int	parseEnumeration() Parses an ASN_ENUMERATED tagged integer from this BER buffer.
int	parseInt() Parses an ASN_INTEGER tagged integer from this BER buffer.
protected int	parseIntWithTag(int tag) Parses an integer that's preceded by a tag.
int	parseLength() Parses a possibly variable length field.
byte[]	parseOctetString(int tag, int[] rlen) Parses an octet string of a given type(tag) from this BER buffer.
int	parseSeq(int[] rlen) Parses the next sequence in this BER buffer.
String	parseString(boolean decodeUTF8) Parses a string.
String	parseStringWithTag(int tag, boolean decodeUTF8, int[] rlen) Parses a string of a given tag from this BER buffer.
int	peekByte() Returns the next byte in this BER buffer without consuming it.
void	reset() Resets this decode to start parsing from the initial offset (ie., same state as after calling the constructor).

Methods inherited from class davmail.ldap.Ber

dumpBER

Methods inherited from class java.lang.Object

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

Constructor Detail

BerDecoder

public BerDecoder(byte[] buf,
                  int offset,
                  int bufsize)

Creates a BER decoder that reads bytes from the specified buffer.

Method Detail

reset

public void reset()

Resets this decode to start parsing from the initial offset (ie., same state as after calling the constructor).

getParsePosition

public int getParsePosition()

Returns the current parse position. It points to the byte that will be parsed next. Useful for parsing sequences.

parseLength

public int parseLength()
                throws davmail.ldap.Ber.DecodeException

Parses a possibly variable length field.

Throws:

davmail.ldap.Ber.DecodeException

parseSeq

public int parseSeq(int[] rlen)
             throws davmail.ldap.Ber.DecodeException

Parses the next sequence in this BER buffer.

Parameters:

rlen - An array for returning size of the sequence in bytes. If null, the size is not returned.

Returns:

The sequence's tag.

Throws:

davmail.ldap.Ber.DecodeException

parseByte

public int parseByte()
              throws davmail.ldap.Ber.DecodeException

Parses the next byte in this BER buffer.

Returns:

The byte parsed.

Throws:

davmail.ldap.Ber.DecodeException

peekByte

public int peekByte()
             throws davmail.ldap.Ber.DecodeException

Returns the next byte in this BER buffer without consuming it.

Returns:

The next byte.

Throws:

davmail.ldap.Ber.DecodeException

parseBoolean

public boolean parseBoolean()
                     throws davmail.ldap.Ber.DecodeException

Parses an ASN_BOOLEAN tagged integer from this BER buffer.

Returns:

true if the tagged integer is 0; false otherwise.

Throws:

davmail.ldap.Ber.DecodeException

parseEnumeration

public int parseEnumeration()
                     throws davmail.ldap.Ber.DecodeException

Parses an ASN_ENUMERATED tagged integer from this BER buffer.

Returns:

The tag of enumeration.

Throws:

davmail.ldap.Ber.DecodeException

parseInt

public int parseInt()
             throws davmail.ldap.Ber.DecodeException

Parses an ASN_INTEGER tagged integer from this BER buffer.

Returns:

The value of the integer.

Throws:

davmail.ldap.Ber.DecodeException

parseIntWithTag

protected int parseIntWithTag(int tag)
                       throws davmail.ldap.Ber.DecodeException

Parses an integer that's preceded by a tag.

 BER integer ::= tag length byte {byte}*

Throws:

davmail.ldap.Ber.DecodeException

parseString

public String parseString(boolean decodeUTF8)
                   throws davmail.ldap.Ber.DecodeException

Parses a string.

Throws:

davmail.ldap.Ber.DecodeException

parseStringWithTag

public String parseStringWithTag(int tag,
                                 boolean decodeUTF8,
                                 int[] rlen)
                          throws davmail.ldap.Ber.DecodeException

Parses a string of a given tag from this BER buffer.

BER simple string ::= tag length {byte}*

Parameters:

rlen - An array for holding the relative parsed offset; if null offset not set.

decodeUTF8 - If true, use UTF-8 when decoding the string; otherwise use ISO-Latin-1 (8859_1). Use true for LDAPv3; false for LDAPv2.

tag - The tag that precedes the string.

Returns:

The non-null parsed string.

Throws:

davmail.ldap.Ber.DecodeException

parseOctetString

public byte[] parseOctetString(int tag,
                               int[] rlen)
                        throws davmail.ldap.Ber.DecodeException

Parses an octet string of a given type(tag) from this BER buffer.

 BER Binary Data of type "tag" ::= tag length {byte}*

Parameters:

tag - The tag to look for.

rlen - An array for returning the relative parsed position. If null, the relative parsed position is not returned.

Returns:

A non-null array containing the octet string.

Throws:

DecodeException - If the next byte in the BER buffer is not tag, or if length specified in the BER buffer exceeds the number of bytes left in the buffer.

davmail.ldap.Ber.DecodeException

bytesLeft

public int bytesLeft()

Returns the number of unparsed bytes in this BER buffer.