NightMiner

A very simple pure Python implementation of a CryptoCurrency stratum CPU mining client. Currently supports scrypt (litecoin) and SHA256d (bitcoin).

At a Glance

• Simple, one file
• Supports Scrypt (litecoin, dogecoin, etc) and SHA256d (bitcoin, namecoin, etc)
• Stratum (and only stratum)
• Zero dependencies (beyond standard Python libraries)
• 100% pure Python implementation
• Attempts to detect faster implementations of scrypt (pure Python is SLOW)
• Enable protocol chatter (-P) to see messages to and from the server

Command Line Interface

python nightminer.py [-h] [-o URL] [-u USERNAME] [-p PASSWORD]
                     [-O USERNAME:PASSWORD] [-a {scrypt,sha256d}] [-B] [-q]
                     [-P] [-d] [-v]

-o URL, --url=              stratum mining server url
-u USERNAME, --user=        username for mining server
-p PASSWORD, --pass=        password for mining server
-O USER:PASS, --userpass=   username:password pair for mining server

-a, --algo                  hashing algorithm to use for proof of work (scrypt, sha256d)

-B, --background            run in the background as a daemon

-q, --quiet                 suppress non-errors
-P, --dump-protocol         show all JSON-RPC chatter
-d, --debug                 show extra debug information

-h, --help                  show the help message and exit
-v, --version               show program's version number and exit


Example:
    python nightminer.py -o stratum+tcp://foobar.com:3333 -u user -p passwd

API

The API can be used by anyone wishing to create their own modified miner to learn more about the protocol, test their own pool or experiment with new algorithms.

import nightminer

Selecting a scrypt implementation (optional)

By default, the fastest detected library will be used; but if you wish to force a specific implementation:

nightminer.set_scrypt_library(library = nightminer.SCRYPT_LIBRARY_AUTO)
print nightminer.SCRYPT_LIBRARY

Subscription

After connecting to a stratum server, there is a small level of handshaking and then occasional messages to maintain state. The Subscription class manages this subscription state with the server.

Properties:

• id - The subscription ID
• worker_name - The name of the authenticated worker
• difficulty, target - The result of the proof of work must be less than target
• extranounce1 - The extranounce1
• extranounce2_size - The size of the binary extranounce2 (in bytes)

set_subscription(subscription_id, extranounce1, extranounce2_size) Sets up the subscription details. Reply from the server to mining.subscribe.

set_difficulty(difficulty) Sets the current difficulty. Sent from the server as a mining.set_difficulty message.

set_worker_name(worker_name) Sets the worker's name after the server has authenticated the username/password. Reply from the server to mining.authorize.

create_job(job_id, prevhash, coinb1, coinb2, merkle_branches, version, nbits, ntime) Creates a new job. Sent from the server as a mining.notify message.

Job

When the server has a new job to work on it sends a mining.notiffy message. The Job class manages all the paameters required to perform work and performs the actual mining.

Properties:

• id - The job ID
• prevhash - The previous hash
• coinb, coinb2 - The coinbase prefix and suffix
• merkle_branches - The Merkle branches
• version - The version
• nbits, ntime - The network bits and network time
• target, extranounce, extranounce2_size - See Subscription class above
• hashrate - The rate this miner has been hashing at

merkle_root_bin(extranounce2_bin) Calculate the Merkle root, as a binary string.

mine(nounce_start = 0, nounce_stride = 1) Iterates over all solutions for this job. This will run for an extrememly long time, likely far longer than ntime would be valid, so you will likely call stop() at some point and start on a new job.

stop() Causes the mine() method to finish immediately for any thread inside.

Miner

This is a sub-class of SimpleJsonRpcClient which connects to the stratum server and processes work requests from the server updating a Subscription object.

Properties:

• url - The stratum server URL
• username, password - The provided username and password

serve_forever() Connect to the server, handshake and block forever while handling work from the server.

Use Cases

Create a standard miner

miner = Miner('stratum+tcp://foobar.com:3333', 'username', 'password')
miner.server_forever()

Experimenting with a new algorithm...

For this example, we will create a CryptoCoin based on MD5.

import hashlib

# Create the Subscription object (proof-of-work should be 32 bytes long)
class SubscriptionMd5(nightminer.Subscription):
  def ProofOfWork(self, header):
    return hashlib.md5(header).digest() + ('0' * 16)

If you wish to manually find a few valid shares:

# Create a subscription (and fill it in a bit with what a proper server would give us)
subs = SubscriptionMd5()
subs.set_subscription('my_subs_id', '00000000', 4)
subs.set_difficulty(1.0 / (2 ** 16))
subs.set_worker_name('my_fake_worker')

# Create a job
job = subs.create_job('my_job', ('0' * 64), ('0' * 118), ('0' * 110), [ ], '00000002', 'deadbeef', '01234567')

# Search for 5 shares
share_count = 0
for valid_share in job.mine():
  print "Found a valid share:", valid_share
  share_count += 1
  if share_count == 5: break

print "Hashrate:", job.hashrate

Or if you already have a server ready to go with your algorithm:

# Register the Subscription
SubscriptionByAlgorithm['my_algo'] = SubscriptionMd5

# Start a miner
miner = Miner('stratum+tcp://localhost:3333', 'username', 'password', 'my_algo')
miner.server_forever()

FAQ

Why would you do this? I was trying to tinker around with Litecoin, but found it difficult to find a simple, complete example of how to decode the endianness of the provided parameters and build the block header. So, the obvious next step is to create a full client to experiment with.

Why is this so slow? It is written in Python. It is not meant to be fast, more of a reference solution or something that can be easily hacked into to test your own pool.

On my MacBook Air, with one thread I get around 3,000 hashes/s using the ltc_scrypt libary but less than 2 hashes/s using the built-in pure Python scrypt.

What is this ltc_scrypt you speak of? It is a Python C-binding for a C implementation of scrypt found in p2pool (https://github.com/forrestv/p2pool). To add to your own system:

> # Download the source
> curl -L https://github.com/forrestv/p2pool/archive/13.4.tar.gz > p2pool-13.4.tar.gz

> # Untar
> tar -xzf p2pool-13.4.tar.gz

> # Build and install
> cd p2pool-13.4/litecoin_scrypt/
> python setup.py build
> sudo python setup.py install

After this is installed, this miner will be about 2,000 times faster.

Why am I am only getting rejected shares? Make sure you are using the correct algoithm, that means --algo=scrypt (the default) for Litecoin or --algo=sha256d for Bitcoin.

How do I get a question I have added? E-mail me at [email protected] with any questions, suggestions, comments, et cetera.

Can I give you my money? Umm... Ok? :-)

Bitcoin - 1LNdGsYtZXWeiKjGba7T997qvzrWqLXLma Litecoin - LXths3ddkRtuFqFAU7sonQ678bSGkXzh5Q Namecoin - N6JLCggCyYcpcUq3ydJtLxv67eEJg4Ntk2