org.ldaptive.asn1
Class DERParser

java.lang.Object
  org.ldaptive.asn1.DERParser

public class DERParser
extends Object

This class provides a SAX-like parsing facility for DER-encoded data where elements of interest in the parse tree may be registered to handlers via the registerHandler(java.lang.String, org.ldaptive.asn1.ParseHandler) methods. DERPath strings are used to map handlers to elements of interest.

Version:

$Revision: 3050 $ $Date: 2014-09-04 14:24:42 -0400 (Thu, 04 Sep 2014) $

Author:

Middleware Services

See Also:

DERPath

Field Summary

protected org.slf4j.Logger

logger Logger for this class.

Constructor Summary

DERParser()

Method Summary

void	parse(ByteBuffer encoded) Parse a DER-encoded data structure by calling registered handlers when points of interest are encountered in the parse tree.
int	readLength(ByteBuffer encoded) Reads the length of a DER-encoded value from the given byte buffer.
DERTag	readTag(ByteBuffer encoded) Reads a DER tag from a single byte at the current position of the given buffer.
void	registerHandler(DERPath path, ParseHandler handler) Registers the supplied handler to fire when the supplied path is encountered.
void	registerHandler(String path, ParseHandler handler) See registerHandler(DERPath, ParseHandler).

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final org.slf4j.Logger logger

Logger for this class.

Constructor Detail

DERParser

public DERParser()

Method Detail

registerHandler

public void registerHandler(String path,
                            ParseHandler handler)

See registerHandler(DERPath, ParseHandler).

Parameters:

path - to register

handler - to associate with the path

registerHandler

public void registerHandler(DERPath path,
                            ParseHandler handler)

Registers the supplied handler to fire when the supplied path is encountered.

Parameters:

path - to register

handler - to associate with the path

parse

public void parse(ByteBuffer encoded)

Parse a DER-encoded data structure by calling registered handlers when points of interest are encountered in the parse tree.

Parameters:

encoded - DER-encoded bytes.

readTag

public DERTag readTag(ByteBuffer encoded)

Reads a DER tag from a single byte at the current position of the given buffer. The buffer position is naturally advanced one byte in this operation.

Parameters:

encoded - Buffer containing DER-encoded bytes positioned at tag.

Returns:

Tag or null if no universal tag or application-specific tag is known that matches the byte read in.

readLength

public int readLength(ByteBuffer encoded)

Reads the length of a DER-encoded value from the given byte buffer. The buffer is expected to be positioned at the byte immediately following the tag byte, which is where the length byte(s) begin(s). Invocation of this method has two generally beneficial side effects:

1. Buffer is positioned at start of value bytes.
2. Buffer limit is set to the end of value bytes.

Parameters:

encoded - buffer containing DER-encoded bytes positioned at start of length byte(s).

Returns:

number of bytes occupied by tag value.