org.bitcoinj.crypto

Class ChildNumber

java.lang.Object

org.bitcoinj.crypto.ChildNumber

All Implemented Interfaces:

java.lang.Comparable<ChildNumber>

public class ChildNumber
extends java.lang.Object
implements java.lang.Comparable<ChildNumber>

This is just a wrapper for the i (child number) as per BIP 32 with a boolean getter for the most significant bit and a getter for the actual 0-based child number. A List of these forms a path through a DeterministicHierarchy. This class is immutable.

Field Summary

Fields

Modifier and Type	Field and Description
static int	HARDENED_BIT The bit that's set in the child number to indicate whether this key is "hardened".
static ChildNumber	ONE
static ChildNumber	ONE_HARDENED
static ChildNumber	ZERO
static ChildNumber	ZERO_HARDENED

Constructor Summary

Constructors

Constructor and Description
ChildNumber(int i)
ChildNumber(int childNumber, boolean isHardened)

Method Summary

Modifier and Type	Method and Description
int	compareTo(ChildNumber other)
boolean	equals(java.lang.Object o)
int	getI() Returns the uint32 encoded form of the path element, including the most significant bit.
int	hashCode()
int	i() Returns the uint32 encoded form of the path element, including the most significant bit.
boolean	isHardened()
int	num() Returns the child number without the hardening bit set (i.e.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

HARDENED_BIT

public static final int HARDENED_BIT

The bit that's set in the child number to indicate whether this key is "hardened". Given a hardened key, it is not possible to derive a child public key if you know only the hardened public key. With a non-hardened key this is possible, so you can derive trees of public keys given only a public parent, but the downside is that it's possible to leak private keys if you disclose a parent public key and a child private key (elliptic curve maths allows you to work upwards).

See Also:

Constant Field Values

ZERO

public static final ChildNumber ZERO

ZERO_HARDENED

public static final ChildNumber ZERO_HARDENED

ONE

public static final ChildNumber ONE

ONE_HARDENED

public static final ChildNumber ONE_HARDENED

Constructor Detail

ChildNumber

public ChildNumber(int childNumber,
                   boolean isHardened)

ChildNumber

public ChildNumber(int i)

Method Detail

getI

public int getI()

Returns the uint32 encoded form of the path element, including the most significant bit.

i

public int i()

Returns the uint32 encoded form of the path element, including the most significant bit.

isHardened

public boolean isHardened()

num

public int num()

Returns the child number without the hardening bit set (i.e. index in that part of the tree).

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

compareTo

public int compareTo(ChildNumber other)

Specified by:

compareTo in interface java.lang.Comparable<ChildNumber>