BPL lib

A simple Python package for the Blockpool Blockchain

This is an easy-to-use Python package for interacting with a Blockpool Blockchain. This package provided the majority of the functionality provided by BPL-JS

Features

Address

• from_secret
• from_public_key
• from_private_key
• validate

Network

• use
• use_custom
• get_begin_epoch
• get_version

Transaction Entity

• generate
• get_id
• get_hash
• sign
• second_sign
• to_bytes
• to_dict
• from_dict
• verify
• second_verify

Transaction Types

• Transfer Transaction
• Vote Transaction
• Second Signature Transaction
• Multi-Signature Transaction
• Delegate Transaction
• IPFS Transaction

Time

• get_time
• get_real_time
• get_slot_number
• get_slot_time

Installation

python -m pip install --no-cache-dir --index-url https://test.pypi.org/simple/ bpl-lib

Note: package has been uploaded to test.pypi. Some dependencies might not be able to be install (e.g. base58) due to this. If this occurs use:

pip install base58
pip install ecdsa

Then

python -m pip install --no-cache-dir --index-url https://test.pypi.org/simple/ bpl-lib

Usage

There are 6 main sub-packages in bpl-lib:

• bpl_lib.address
• bpl_lib.crypto
• bpl_lib.helpers
• bpl_lib.network
• bpl_lib.time
• bpl_lib.transactions

---

Addresses

Generating an Address

There are currently 2 methods for generating an address:

• from_public_key
• from_secret

Note: Addresses are dependent on the version of the network, therefore to generate an address you must first select a network (see network section).

from_public_key

To generate a unique Blockpool address from a given public key:

from bpl_lib.address import Address
from bpl_lib.network import Network

Network.use("mainnet")
public_key = "03aacac6c98daaf3d433fe90e9295ce380916946f850bcdc6f6880ae6503ca1e40"
address = Address.from_public_key(public_key)

print(address)

Printing:

b'AdzCBJt2F2Q2RYL7vnp96QhTeGdDZNZGeJ'

from_secret

To generate a unique Blockpool address from a given secret passphrase:

from bpl_lib.address import Address
from bpl_lib.network import Network

Network.use("mainnet")
address = Address.from_secret("secret passphrase")

print(address)

Printing:

b'AdzCBJt2F2Q2RYL7vnp96QhTeGdDZNZGeJ'

Validation

Note: Addresses are dependent on the version of the network, therefore to validate an address you must first select a network (see network section).

from bpl_lib.address import Address
from bpl_lib.network import Network

Network.use("mainnet")
address = "AdzCBJt2F2Q2RYL7vnp96QhTeGdDZNZGeJ"
is_valid = Address.validate(address)

print(is_valid)

Printing:

True

---

Cryptography

Generating Keys

from bpl_lib.crypto import Keys

keys = Keys("secret passphrase").to_dict()

print(keys)

Printing:

{
    "public_key": "03aacac6c98daaf3d433fe90e9295ce380916946f850bcdc6f6880ae6503ca1e40",
    "private_key": "b6a2b12beb4179538bfb42423cce2e98ccdebcc684145ba977f2f80630eb278e"
}

Signatures

from bpl_lib.crypto import Signature, sha256

message = sha256("message".encode())
signature = Signature("secret passphrase").sign(message)["signature"]

print(signature)

Printing:

"30440220622b8edf8fc5cf4522a13489a9b710b1bf94b6e37722d2278a0069ae3c67088b0220206e202dcad8e4ee2100716ce0d2c7d08a685f983c21dfbccdd6ecec50268b6f"

Hashing

The crypto sub-package also provides common hashing algorithms such as:

• sha1(bytes)
• sha256(bytes)
• ripemd160(bytes)
• hash160(bytes)
• hash256(bytes)

---

Helpers

The helpers package contains useful contains and classes:

• TRANSACTION_TYPE - Enum Class containing all 6 transaction types
• TRANSACTION_FEES - Transaction fees depending on TRANSACTION_TYPE
• NETWORKS_DB - Networks database file location

---

Network

The networks sub-package is an interface for network configurations. The networks sub-package makes use of a local SQLite database, which stores the network identifier, begin epoch time and network version. These setting / fields are require for calculations such as addresses and timestamps.

Using a network

There are current 2 methods that allows a client to use a network:

• use
• use_custom

use

The use method requires a network identifier and queries the local network database for the specified configuration. The method then stores the configuration in memory.

from bpl_lib.network import Network

Network.use("mainnet")

print(Network.get_begin_epoch())
print(Network.get_version())

Printing:

"2017-03-21 13:00:00"
23

use_custom

The use_custom method requires a network identifier, begin_epoch and version. The method first inserts this custom configuration into the local network database, this will allow you to make use of the custom configuration in other applications. After that the method stores the custom configuration in memory.

Note: identifier is used as the primary key in the database, this implies that the identifier for the network must be unique. If the identifier is not unique a BPLNetworkException is raised.

from datetime import datetime 

from bpl_lib.network import Network

identifier = "test_use_custom_method"
begin_epoch = datetime.strptime("2018-07-25 15:30:00", "%Y-%m-%d %H:%M:%S")
version = 0x19

Network.use_custom(identifier, begin_epoch, version)

print(Network.get_begin_epoch())
print(Network.get_version())

Printing:

"2018-07-25 15:30:00"
25

Accessing the current configuration

After loading a network configuration into memory, there are 2 settings that can be accessed via the Network interface:

• begin_epoch
• version

Accessing begin_epoch

To access begin_epoch the Network.get_begin_epoch method must be used.

from bpl_lib.network import Network

Network.use("testnet")

print(Network.get_begin_epoch())

Printing:

"2017-03-21 13:00:00"

Accessing version

To access version the Network.get_version method must be used.

from bpl_lib.network import Network

Network.use("testnet")

print(Network.get_version())

Printing:

82

---

Time

The time sub-package contains 4 methods:

• get_time - returns the timestamp for the blockchain
• get_real_time - converts blockchain timestamp to datetime
• get_slot_number - converts blockchain timestamp to slot number
• get_slot_time - converts slot number to blockchain timestamp

get_time

The get_time method converts a datetime object to a blockchain timestamp. The method has an optional argument time. If time is not provided then the current time will be used. (See code)

from bpl_lib.time import Time

print(Time.get_time())

Printing:

42429391

get_real_time

The get_real_time method converts a blockchain timestamp into a datetime object. The method has an optional argument timestamp. If timestamp is not provided then the current timestamp will be used. (See code)

from bpl_lib.time import Time

print(Time.get_real_time(42429391))

Printing:

"2018-07-25 14:56:31"

get_slot_number

The get_slot_number method converts a blockchain timestamp into a slot number. The method has an optional argument timestamp. If timestamp is not provided then the current timestamp will be used. (See code)

from bpl_lib.time import Time

print(Time.get_slot_number())

Printing:

5303721

get_slot_time

The get_slot_time method converts a slot number into a blockchain timestamp. The method has an optional argument slot_number. If slot_number is not provided then the current slot number will be used. (See code)

from bpl_lib.time import Time

print(Time.get_slot_time(5303721))

Printing:

42429768

---

Transactions

Each transaction is built from the Transaction Entity (See Features). There are 2 currently possible ways of building a BPL transaction:

• Transaction.generate
• Transaction.from_dict

Buidling a transaction using generate

Transaction.generate automatically calculates the timestamp for the transaction, therefore a network must be selected before a transaction can be built. (See network)

from bpl_lib.transactions.Transfer import Transfer
from bpl_lib.network import Network

Network.use("mainnet")
transaction = Transfer.generate("BCU4rocsgw2GNihtnzAgFzRfx7XebZRpRi", 1000, "passphrase")

print(transaction.to_dict())

Printing:

{  
   'recipientId': 'BCU4rocsgw2GNihtnzAgFzRfx7XebZRpRi',
   'senderPublicKey': '02e012f0a7cac12a74bdc17d844cbc9f637177b470019c32a53cef94c7a56e2ea9',
   'type': "<TRANSACTION_TYPE.TRANSFER: 0>",
   'id': '9bfa3aee9ed984f856c6268b0b03dd908d3541c4c94f614fdae5c66c587560b2',
   'asset': {},
   'venderField': None,
   'fee': 10000000,
   'signature': '3045022100faf1e2bb7388caf0ba4ca26d6bddf9ea39197365d369f63efe271ad183745a77022047865c97baa925369ee099594010f7e7912772febbb83bcb9512f9b2759ac97d',
   'timestamp': 42430405,
   'amount': 1000,
   'signSignature': None
}

To see how each transaction is built see the documentation in the code.

---

Security or Errors

If you discover a security vulnerability or error within this package, please email me or message me on the BPL discord.

---

Credits

• Alistair O'Brien