net.i2p.crypto

Class SHA1Hash

java.lang.Object

net.i2p.data.SimpleDataStructure

net.i2p.crypto.SHA1Hash

All Implemented Interfaces:

DataStructure

Direct Known Subclasses:

InfoHash, NID, TokenKey

public class SHA1Hash
extends SimpleDataStructure

I2P data structure for SHA-1 hash values. This class provides a SimpleDataStructure wrapper for 20-byte SHA-1 hashes used throughout I2P for data integrity and identification purposes. It extends SimpleDataStructure to support I2P's serialization framework and provides efficient caching of hash codes.

Common uses include:

• Router and destination identifiers
• Message integrity verification
• Data structure indexing and lookup

Field Summary

Fields

Modifier and Type	Field and Description
static int	HASH_LENGTH

Fields inherited from class net.i2p.data.SimpleDataStructure

_data

Constructor Summary

Constructors

Constructor and Description
SHA1Hash()
SHA1Hash(byte[] data)

Method Summary

Modifier and Type	Method and Description
int	hashCode() a Hash is a hash, so just use the first 4 bytes for speed
int	length() The legal length of the byte array in this data structure
void	readBytes(InputStream in) Sets the data.
void	setData(byte[] data) Sets the data.

Methods inherited from class net.i2p.data.SimpleDataStructure

calculateHash, equals, fromBase64, fromByteArray, getData, read, toBase64, toByteArray, toString, writeBytes

Methods inherited from class java.lang.Object

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

Field Detail

HASH_LENGTH

public static final int HASH_LENGTH

See Also:

Constant Field Values

Constructor Detail

SHA1Hash

public SHA1Hash()

SHA1Hash

public SHA1Hash(byte[] data)

Throws:

IllegalArgumentException - if data is not 20 bytes (null is ok)

Method Detail

hashCode

public int hashCode()

a Hash is a hash, so just use the first 4 bytes for speed

Overrides:

hashCode in class SimpleDataStructure

length

public int length()

Description copied from class: SimpleDataStructure

The legal length of the byte array in this data structure

Specified by:

length in class SimpleDataStructure

readBytes

public void readBytes(InputStream in)
               throws DataFormatException,
                      IOException

Description copied from class: SimpleDataStructure

Sets the data.

Specified by:

readBytes in interface DataStructure

Overrides:

readBytes in class SimpleDataStructure

Parameters:

in - the stream to read

Throws:

DataFormatException - if the data is improperly formatted

IOException - if there was a problem reading the stream

setData

public void setData(byte[] data)

Description copied from class: SimpleDataStructure

Sets the data.

Overrides:

setData in class SimpleDataStructure

Parameters:

data - of correct length, or null

Throws:

IllegalArgumentException - if data is not 20 bytes (null is ok)