This code is an example how to resolve anonymouse authoritative Namecoin .bit domains into an anonymous I2P network destination addresses.

Author:		Pentarh Udi <pentarh@gmail.com>
URL:		http://i2psupport.org/
License:	GPLv3 http://www.gnu.org/licenses/gpl-3.0.html
Using libs:	org.json https://github.com/douglascrockford/JSON-java

NOTE: This is not the end way of NameCoin integration, but a kickstart
NOTE: This is the proof-of-concept way to get fully anonymized internet services work with authoritative user-friendly name resolution
NOTE: It is still complex to set it up. It is beta and a lot of work is in a track

1. Background

Build instructions are in the bottom of this document

1.1 NameCoin

Namecoin is a distributed naming system based on bitcoin technology (a cryptocurrency).
It can be used to store any data that use a name (or a key) associated with a value like domain names (DNS), 
user identities, hash of documents to prove date of creation, etc:

[Name] => [Value]
domain_name => domain_zone_configuration
user_name => user_public_identity (email, name, gpg key, etc)
document_hash => document_infos (name, hash, owner, etc)

To register a name, you must own some namecoins (NMC, the internal cryptocurrency used by the software).

1.2 I2P

I2P is an anonymouse network, offering a simple layer that identity-sensitive 
applications can use to securely communicate. All data is wrapped with several 
layers of encryption, and the network is both distributed and dynamic, with no
trusted parties.

Many applications are available that interface with I2P, including mail, peer-peer, IRC chat, and others.

2. The Problem

NameCoin was designed as decentralized authoritative name resolution network with  record
digital signatures. So the NameCoin domains are authoritative and only owner can change his domain attributes.
NameCoin has no any central authority and works on P2P basis, being anonymous authoritative P2P domain provider. 
Owning NameCoin domain will not disclose any your private data to public if you do not want it.

NameCoin domains can be resolved into IP addresses, Tor addresses and I2P destinations.

When you configure your domain to resolve to regular IP4/IP6 addresses or delegate it to
a regular nameservers, you can expirence privacy data leak. Your server is not anonymous
in this case and can be shut down with 3rd party companies.

So there is no sense in anonymous domain when you use public IP protocol which is not anonymous 
by default.

Problem 1: NameCoin needs an anonymous P2P Network

I2P provides an Internet overlay anonymous network, where destination address is a hash with no 
correspondence with any IP addresses and private data.

I2P has its own domain name system (.i2p domains). But there is a serious problems with getting domain
available to public without using hardcore tricks. .i2p zone has several central registars and single
.i2p domain can conflict in resolving on different clients:
- Different registars can register the same domain for different persons
- To use Nth registar data, client must find its website and subscribe for its updates
- Also every client has several local address books, where records might conflict with 
registars' provided data

This makes .i2p zone not authoritative and opposed to user.

.i2p has athoritative .b32.i2p zone, but those names are just long hashes and also not user friendly.

Problem 2: I2P needs an authoritative anonymous domain name system, which provides user-friendly domain names
and their authoritative resolution into I2P destination anonymous addresses.

3. The Resolution

Summary:

Problem 1: NameCoin needs an anonymous P2P Network
Problem 2: I2P needs an authoritative anonymous domain name system, which provides user-friendly domain names
and their authoritative resolution into I2P destination anonymous addresses.

The resolution is to integrate NameCoin support into I2P Network.

4. NameCoin-I2P-Resolver project

This project provides example java classes to support .bit zone resolution into i2p destination hashes in I2P software.

All classes are in src/
Example patches are in patches/


==== Build instructions

1. Download and extract i2p sources

# wget http://mirror.i2p2.de/i2psource_0.8.12.tar.bz2
# tar xjf i2psource_0.8.12.tar.bz2 

2. Dowload Git Patches

# git clone http://github.com/pentarh/NameCoin-I2P-Resolver.git

3. Copy the src/org and src/net to i2pmodified/core/java/src

# cp -R NameCoin-I2P-Resolver/src/net i2p-0.8.12/core/java/src
# cp -R NameCoin-I2P-Resolver/src/org i2p-0.8.12/core/java/src

4. Apply patches

# cd i2p-0.8.12
# patch -p1 < ../NameCoin-I2P-Resolver/patches/I2PAppContext.java.patch
# patch -p1 < ../NameCoin-I2P-Resolver/patches/I2PTunnelHTTPClient.java.patch

5. Build

# ant distclean
# ant updater

You should get i2pudate.zip file. Stop your i2p router, extract contents of i2pupdate.zip into i2p installation dir replacing original files.

6. Installing namecoind

Get latest namecoind for your system at http://dot-bit.org/Main_Page

Create directory ~/.namecoin
Create config file ~/.namecoin/bitcoin.conf with example config:

rpcuser=namecoin
rpcpassword=nmpassword
rpcport=8335
gen=0
daemon=1
server=1
rpcallowip=127.0.0.1
rpcallowip=192.168.1.33

Note: rpcallowip should contain IP address of your I2P router to accept queries.
Note: rpcuser, rpcpassword, rpcport will be used in i2prouter namecoin.config

Run namecoind:
# ./namecoind -daemon

Wait until namecoind syncronized with network (first-run only step). It can take from 10s minutes to few hours.
To determine client is in sync, run

# ./namecoind getinfo

Look into "blocks" variable. It is increasing from zero at first run and should reach the latest block id at http://explorer.dot-bit.org/

Once it have reached latest network block id, its database will be up to date and you may start using it.

6. Configure I2P router <-> namecoind communication

Create a file ~/.i2p/namecoin.config with example contents:

enabled=1
host=127.0.0.1
port=8335
user=btc
password=Aks93kl1

Where
    host - is a namecoind IP
    port,user,password are from ~/.namecoin/bitcoinf.conf (configured in previous step)

7. Finally

Start your i2p router, configure your web browser to use router proxy at router ip and port 4444

Browse example .bit domain configured for i2p:

http://i2psupport.bit


References:
http://dot-bit.org/Main_Page - NameCoin decentralized domain system and cryptocurrency
http://dot-bit.org/HowToRegisterAndConfigureBitDomains - Registering NameCoin Domains
http://dot-bit.org/Domain_names - Using NameCoin domains
http://www.i2p2.de/ - I2P: Internet Invisible Project, anonymous network
https://bitcointalk.org/ - General community of all Bitcoin-based projects
https://bitcointalk.org/index.php?topic=60879.0 - Original thread of integration purposes NameCoin into I2P
https://bitcointalk.org/index.php?topic=61486.msg719109#msg719109 - Russian version
http://i2psupport.org/ - This project home page
http://i2psupport.bit/ - Mirror in anonymous .bit zone (need patched i2p router proxy to enter)