net.i2p.data.router

Class RouterKeyGenerator

java.lang.Object

net.i2p.data.RoutingKeyGenerator

net.i2p.data.router.RouterKeyGenerator

public class RouterKeyGenerator
extends net.i2p.data.RoutingKeyGenerator

Component to manage the munging of hashes into routing keys - given a hash, perform some consistent transformation against it and return the result. This transformation is fed by the current "mod data". Right now the mod data is the current date (GMT) as a string: "yyyyMMdd", and the transformation takes the original hash, appends the bytes of that mod data, then returns the SHA256 of that concatenation. Do we want this to simply do the XOR of the SHA256 of the current mod data and the key? does that provide the randomization we need? It'd save an SHA256 op. Bah, too much effort to think about for so little gain. Other algorithms may come into play layer on about making periodic updates to the routing key for data elements to mess with Sybil. This may be good enough though. Also - the method generateDateBasedModData() should be called after midnight GMT once per day to generate the correct routing keys!

Since:

0.9.16 moved from net.i2p.data.RoutingKeyGenerator..

Constructor Summary

Constructors

Constructor and Description
RouterKeyGenerator(net.i2p.I2PAppContext context)

Method Summary

Modifier and Type	Method and Description
boolean	generateDateBasedModData() Update the current modifier data with some bytes derived from the current date (yyyyMMdd in GMT)
long	getLastChanged()
byte[]	getModData() The current (today's) mod data.
byte[]	getNextModData() Tomorrow's mod data.
net.i2p.data.Hash	getNextRoutingKey(net.i2p.data.Hash origKey) Get the routing key using tomorrow's modData, not today's
net.i2p.data.Hash	getRoutingKey(net.i2p.data.Hash origKey) Generate a modified (yet consistent) hash from the origKey by generating the SHA256 of the targetKey with the current modData appended to it This makes Sybil's job a lot harder, as she needs to essentially take over the whole keyspace.
net.i2p.data.Hash	getRoutingKey(net.i2p.data.Hash origKey, long time) Get the routing key for the specified date, not today's
long	getTimeTillMidnight() How long until midnight (ms)
static void	main(String[] args)

Methods inherited from class net.i2p.data.RoutingKeyGenerator

getInstance

Methods inherited from class java.lang.Object

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

Constructor Detail

RouterKeyGenerator

public RouterKeyGenerator(net.i2p.I2PAppContext context)

Method Detail

getModData

public byte[] getModData()

The current (today's) mod data. Warning - not a copy, do not corrupt.

Returns:

non-null, 8 bytes

getNextModData

public byte[] getNextModData()

Tomorrow's mod data. Warning - not a copy, do not corrupt. For debugging use only.

Returns:

non-null, 8 bytes

Since:

0.9.10

getLastChanged

public long getLastChanged()

Specified by:

getLastChanged in class net.i2p.data.RoutingKeyGenerator

getTimeTillMidnight

public long getTimeTillMidnight()

How long until midnight (ms)

Returns:

could be slightly negative

Since:

0.9.10 moved from UpdateRoutingKeyModifierJob

generateDateBasedModData

public boolean generateDateBasedModData()

Update the current modifier data with some bytes derived from the current date (yyyyMMdd in GMT)

Returns:

true if changed

getRoutingKey

public net.i2p.data.Hash getRoutingKey(net.i2p.data.Hash origKey)

Generate a modified (yet consistent) hash from the origKey by generating the SHA256 of the targetKey with the current modData appended to it This makes Sybil's job a lot harder, as she needs to essentially take over the whole keyspace.

Specified by:

getRoutingKey in class net.i2p.data.RoutingKeyGenerator

Throws:

IllegalArgumentException - if origKey is null

getNextRoutingKey

public net.i2p.data.Hash getNextRoutingKey(net.i2p.data.Hash origKey)

Get the routing key using tomorrow's modData, not today's

Since:

0.9.10

getRoutingKey

public net.i2p.data.Hash getRoutingKey(net.i2p.data.Hash origKey,
                                       long time)

Get the routing key for the specified date, not today's

Parameters:

time - Java time

Since:

0.9.28

main

public static void main(String[] args)

Since:

0.9.29