opencard.opt.iso.fs
Class CardFilePath

java.lang.Object
  opencard.opt.iso.fs.CardFilePath

All Implemented Interfaces:

SecurityDomain

public class CardFilePath
extends java.lang.Object
implements SecurityDomain

CardFilePath encapsulates the various ways of addressing files on a smart card:

• File ID paths: A sequence of two byte file IDs as defined in ISO 7816-4
• Short File ID: One byte short file ID (0..31) for selecting EFs.
• Application ID: 5-16 bytes for selecting applications as defined by ISO 7816-4/5
• Symbolic paths: A sequence of symbolic names

Note that CardFilePath is a mutable object like StringBuffer.

Version:

$Id: CardFilePath.java,v 1.2 1999/11/03 12:37:17 damke Exp $

Author:

Dirk Husemann (hud@zurich.ibm.com), Reto Hermann (rhe@zurich.ibm.com)

See Also:

CardFile

Field Summary

static java.lang.String	APPID_PREFIX
protected CardFilePathComponent[]	components CardFilePath array containing the path components.
static java.lang.String	FID_SEPARATOR
static java.lang.String	PARTIALAPPID_POSTFIX
static java.lang.String	ROOTFILEID
static java.lang.String	SYM_SEPARATOR There are two kinds of path component separators: SYM_SEPARATOR used for symbolic paths (for example "/wuff/oink") FID_SEPARATOR used for file ID paths (for example ":CAFF:EEBA:BE00") Although represented as a string, both separators really are just one character long.

Constructor Summary

CardFilePath(byte[] bites)
Instantiate a CardFilePath from an array of bytes.

CardFilePath(CardFilePath path)
Clone the path object.

CardFilePath(java.lang.String path)
Create a CardFilePath from a String.

Method Summary

CardFilePath	append(CardFilePath path) Append to this CardFilePath object.
CardFilePath	append(CardFilePathComponent comp) Append to this CardFilePath object.
CardFilePath	chompPrefix(CardFilePath prefix) Chomp of the prefix of this path.
boolean	chompTail() Chomp off the last component of the path.
int	commonPrefixLength(CardFilePath path) Return the length of the common CardFilePath prefix (if at all).
java.util.Enumeration	components() Return an enumeration of the components of this CardFilePath.
boolean	equals(java.lang.Object filePath) Check whether this CardFilePath is equal to another.
CardFilePath	greatestCommonPrefix(CardFilePath path) Return the longest commmon prefix with another CardFilePath.
int	hashCode() Overrides Object.hashCode() since we already provide equals().
int	numberOfComponents() Return the number components in this path.
boolean	startsWith(CardFilePath prefix) Check whether this path starts with prefix.
CardFilePathComponent	tail() Return the last CardFilePathComponent of this CardFilePath object.
java.lang.String	toString() Return a string representation of this object.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

SYM_SEPARATOR

public static final java.lang.String SYM_SEPARATOR

There are two kinds of path component separators:

• SYM_SEPARATOR used for symbolic paths (for example "/wuff/oink")
• FID_SEPARATOR used for file ID paths (for example ":CAFF:EEBA:BE00")

Although represented as a string, both separators really are just one character long.

See Also:

Constant Field Values

FID_SEPARATOR

public static final java.lang.String FID_SEPARATOR

See Also:

Constant Field Values

APPID_PREFIX

public static final java.lang.String APPID_PREFIX

See Also:

Constant Field Values

PARTIALAPPID_POSTFIX

public static final java.lang.String PARTIALAPPID_POSTFIX

See Also:

Constant Field Values

ROOTFILEID

public static final java.lang.String ROOTFILEID

See Also:

Constant Field Values

components

protected CardFilePathComponent[] components

CardFilePath array containing the path components.

Constructor Detail

CardFilePath

public CardFilePath(java.lang.String path)
             throws CardIOException

Create a CardFilePath from a String. The string representation uses the following notation:

:XXYY:ZZAA

A path of file IDs; always starts with a colon (':'); always uses two bytes (with leading 0 if necessary); individual file IDs are separated by colons (':') as well

:ZZ or :XXYY:ZZ

A short file ID or a path ending in a short file ID; short file IDs can only occur at the end of path

#AABBCCDDEE..QQ

A 5-16 byte application ID as a sequence of bytes; must start with a hash ('#')

Some string

A 5-16 byte application ID as a string; can contain at most 16 characters

#AABB*

A partial application ID as a sequence of bytes

some string*

A partial application ID as a string.

/some/path/using/symbolic/names

A sequence of symbolic names started and separated by slashes ('/')

Special characters [:/*#] need to be escaped by repeating them.

Parameters:

path - The string representation of the path.

Throws:

CardIOException - Thrown either when the path has a silly format (e.g., file ID components followed by an application ID) or when the path contains malformed components (e.g., a short file ID containing just one nibble instead of a full byte) or when the path is empty

CardFilePath

public CardFilePath(byte[] bites)

Instantiate a CardFilePath from an array of bytes. Gobble up two bytes at a time and turn them into a two byte file ID. A remaining byte is turned into a short file ID.

Parameters:

bites - An array of bytes containing file IDs; the lowest pair (bites[0] and bites[1]) form the first path component; bites[0] is the high order byte and bites[1] is the low order byte.

CardFilePath

public CardFilePath(CardFilePath path)

Clone the path object.

Parameters:

path - The CardFilePath object to clone.

Method Detail

components

public java.util.Enumeration components()

Return an enumeration of the components of this CardFilePath.

Returns:

An Enumeration of CardFilePathComponent objects.

append

public CardFilePath append(CardFilePath path)

Append to this CardFilePath object.

Parameters:

path - The CardFilePath object to append.

append

public CardFilePath append(CardFilePathComponent comp)

Append to this CardFilePath object.

Parameters:

comp - The CardFilePathComponent object to append.

startsWith

public boolean startsWith(CardFilePath prefix)

Check whether this path starts with prefix. Note that prefix must be a true prefix of this path (i.e., after chompPrefix(prefix) this path would not be empty).

Parameters:

prefix - The potentially common prefix.

Returns:

True if this path starts with prefix

equals

public boolean equals(java.lang.Object filePath)

Check whether this CardFilePath is equal to another.

Overrides:

equals in class java.lang.Object

Parameters:

filePath - The path to compare with.

Returns:

True if both paths are equal.

commonPrefixLength

public int commonPrefixLength(CardFilePath path)

Return the length of the common CardFilePath prefix (if at all). prefix.

Parameters:

path - The other CardFilePath to check against.

Returns:

The length of the common prefix (0 indicates that only the MF is common).

greatestCommonPrefix

public CardFilePath greatestCommonPrefix(CardFilePath path)

Return the longest commmon prefix with another CardFilePath.

Parameters:

path - The other CardFilePath.

Returns:

A new CardFilePath object containing the longest common prefix.

Throws:

java.lang.IllegalArgumentException - Thrown when both paths do not share a common prefix.

chompPrefix

public CardFilePath chompPrefix(CardFilePath prefix)

Chomp of the prefix of this path.

Parameters:

prefix - The prefix to chomp off.

Returns:

The chomped path.

Throws:

java.lang.IllegalArgumentException - Thrown when the prefix is not.

chompTail

public boolean chompTail()

Chomp off the last component of the path. This is a no-op if the path consists of a single component.

Returns:

True if chomping succeeded.

tail

public CardFilePathComponent tail()

Return the last CardFilePathComponent of this CardFilePath object.

Returns:

The last CardFilePathComponent of this CardFilePath.

numberOfComponents

public int numberOfComponents()

Return the number components in this path.

Returns:

The number of CardFilePathComponents in this CardFilePath.

hashCode

public int hashCode()

Overrides Object.hashCode() since we already provide equals().

Overrides:

hashCode in class java.lang.Object

Returns:

The hash code.

toString

public java.lang.String toString()

Return a string representation of this object.

Overrides:

toString in class java.lang.Object

Returns:

A string representing this object.