Blockchain Resolver

Netki Blockchain (Namecoin) Resolver Library

General

A resolver library that resolves Blockchain-based (Namecoin) domain names and uses DNSSEC to validate the results of the query. Blockchain-based (Namecoin) domains currently reside in the .bit TLD. For more information about Namecoin, please visit the Namecoin WIKI.

Requirements

• Access to a Namecoin node (this module uses the name_show RPC call).

Python Modules

• dnspython - http://www.dnspython.org
• requests - http://docs.python-requests.org/en/latest/
• pyUnbound - https://www.unbound.net/documentation/pyunbound/

NOTE: pyUnbound is NOT available via pip. Please follow the instructions below to install and setup PyUnbound

PyUnbound Setup

This version of bcresolver has been tested with Unbound v1.4.22. (https://unbound.net/downloads/unbound-1.4.22.tar.gz)

Install via Repository

unbound-python is available via installation by yum and is available in the EPEL repository.

[user@host ~]$ yum install -y unbound-python

This will install unbound-python, compat-libevent, and unbound-libs packages.

Manual Download, Installation and Setup

When ./configure-ing unbound, make sure to use the --with-pyunbound flag. This will make pyunbound available after make and make install

Please refer to https://www.unbound.net/documentation/pyunbound/install.html for Unbound installation help.

Use the unbound-anchor tool to setup the ICANN-supplied DNSSEC Root Trust Anchor.

Make sure to set the PYTHON_VERSION environment variable if you have multiple Python versions installed, otherwise the module will be installed for the default system Python version.

[user@host ~]$ export set PYTHON_VERSION=2.7
[user@host ~]$ wget https://unbound.net/downloads/unbound-1.4.22.tar.gz
[user@host ~]$ tar -xzf unbound-1.4.22-py.tar.gz
[user@host ~]$ cd unbound-1.4.22
[user@host ~]$ ./configure --with-pyunbound
[user@host ~]$ make
[user@host ~]$ make install

Usage

blockchain-resolver provides the bcresolver.NamecoinResolver class which has the resolve(name, qtype) function available. This can be used to resolve a Namecoin-based DNS entry using Namecoin-stored NS and DS records and then chaining up to standard DNS+DNSSEC using that information as the trust anchor.

NOTE: We recommend setting the temp_dir parameter to a ramdisk-backed directory to prevent disk thrashing.

Success Example

>>> from bcresolver import NamecoinResolver
>>> nc_resolver = NamecoinResolver(
... host='127.0.0.1',
... user='namecoin',
... password='XXXXXXXXXXXXXXXX',
... port=8336,
... temp_dir=None)
>>> nc_resolver.resolve('_wallet.wallet.mattdavid.bit', 'TXT')
btc

>>> nc_resolver.resolve('www.mattdavid.bit', 'A')
108.162.204.31

>>> nc_resolver.resolve('www2.mattdavid.bit', 'CNAME')
www.mattdavid.bit.

>>> nc_resolver.resolve('mattdavid.bit', 'MX')
(10, 'mx.mattdavid.bit.')

>>> nc_resolver.resolve('_btc._wallet.sample.walletname.bit', 'TXT')
1CpLXM15vjULK3ZPGUTDMUcGATGR9xGitv

No DS Records in Namecoin Value Example

>>> from bcresolver import NamecoinResolver
>>> nc_resolver = NamecoinResolver(
... host='127.0.0.1',
... user='namecoin',
... password='XXXXXXXXXXXXXXXX',
... port=8336,
... temp_dir=None)
>>> nc_resolver.resolve('www.explorer.bit', 'A')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "bcresolver/__init__.py", line 162, in resolve
    raise NoDSRecordException()
bcresolver.NoDSRecordException

Additional Examples

See the examples/ directory for additional use examples for this module.