net.i2p.data
Class RoutingKeyGenerator

java.lang.Object
  extended by net.i2p.data.RoutingKeyGenerator

public class RoutingKeyGenerator
extends java.lang.Object

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!


Constructor Summary
RoutingKeyGenerator(I2PAppContext context)
           
 
Method Summary
 void generateDateBasedModData()
          Update the current modifier data with some bytes derived from the current date (yyyyMMdd in GMT)
static RoutingKeyGenerator getInstance()
           
 long getLastChanged()
           
 byte[] getModData()
           
 Hash getRoutingKey(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, *then* This makes Sybil's job a lot harder, as she needs to essentially take over the whole keyspace.
static void main(java.lang.String[] args)
           
 void setModData(byte[] modData)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

RoutingKeyGenerator

public RoutingKeyGenerator(I2PAppContext context)
Method Detail

getInstance

public static RoutingKeyGenerator getInstance()

getModData

public byte[] getModData()

getLastChanged

public long getLastChanged()

setModData

public void setModData(byte[] modData)

generateDateBasedModData

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


getRoutingKey

public Hash getRoutingKey(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, *then* This makes Sybil's job a lot harder, as she needs to essentially take over the whole keyspace.

Throws:
java.lang.IllegalArgumentException - if origKey is null

main

public static void main(java.lang.String[] args)