Namehash Algorithm from EIP137 - Ethereum Name Service

namehash.py

import codecs

# pip install pysha3==1.0.2
from sha3 import keccak_256


def sha3(text):
    return keccak_256(text).digest()


def namehash(name):
    if name == '':
        return b'\x00' * 32
    label, _, remainder = name.partition('.')
    return sha3(namehash(remainder) + sha3(label.encode()))


def hex(c):
    return '0x' + codecs.encode(c, 'hex').decode()


if __name__ == '__main__':
    print(hex(namehash('')))  # 0x0000000000000000000000000000000000000000000000000000000000000000
    print(hex(namehash('eth')))  # 0x93cdeb708b7545dc668eb9280176169d1c33cfd8ed6f04690a0bcc88a93fc4ae
    print(hex(namehash('foo.eth')))  # 0xde9b09fd7c5f901e23a3f19fecc54828e9c848539801e86591bd9801b019f84f