def check_pow(
block_number: int,
mining_hash: Hash32,
mix_hash: Hash32,
nonce: bytes,
difficulty: int,
) -> None:
if len(mix_hash) != 32:
raise ValidationError(f"Wrong length: mix_hash={mix_hash.hex()}")
elif len(mining_hash) != 32:
raise ValidationError(f"Wrong length: mining_hash={mining_hash.hex()}")
elif len(nonce) != 8:
raise ValidationError(f"Wrong length: nonce={nonce.hex()}")
cache = get_cache(block_number)
mining_output = hashimoto_light(block_number, cache, mining_hash,
int.from_bytes(nonce, "big"))
mix_digest = mining_output[b"mix digest"]
if mix_digest != mix_hash:
raise ValidationError(
f"Invalid POW: expected={mix_digest.hex()} "
f"actual={mix_hash.hex()}. "
f"Mix hash calculated from block #{block_number}, "
f"mine hash {mining_hash.hex()}, nonce {nonce.hex()}"
f", difficulty {difficulty}, cache hash {keccak(cache).hex()}")
result = int.from_bytes(mining_output[b"result"], "big")
if result > 2**256 // difficulty:
raise ValidationError(
f"Insufficient difficulty: actual={result} required={difficulty}")
def check_pow(block_number: int, mining_hash: Hash32, mix_hash: Hash32,
nonce: bytes, difficulty: int) -> None:
cache = get_cache(block_number) #we get cache by block number
mining_output = hashimoto_light(
block_number, cache, mining_hash, big_endian_to_int(
nonce)) # MISTAKE not int_to_big_endian but the other way around
#big_endian_to_int(nonce)
#int_to_big_endian(nonce)) #this is the hashimoto light mining output. It takes block_number, cache, mining_hash, int_to_big_endian(nonce) and hash it
print("MIX Digest: ", mining_output[b'mix digest'])
print("MIX HASH: ", w3.eth.getBlock(block_number).mixHash.hex())
print("RESULT: ", mining_output[b'result'])
print("CONDITION: ", (2**256) // difficulty)
if mining_output[
b'mix digest'] != mining_hash: #this is to say that if the mining digest is not equal to the mix hash, then...
return False
elif int_to_big_endian(mining_output[b'result']) <= (
2**256 // difficulty
): #to convert the result int integer and check if it meets the condition of being less or equal to 2^256 divided by the difficulty
return False
else:
return True #if it returns true, then all good! We could do more checks but this is enough for now. For additional checks see here https://github.com/ethereum/py-evm/blob/d553bd405bbf41a1da0c227a614baba7b43e9449/eth/consensus/pow.py
def hashimoto(
block_number: int,
full_size: int,
cache: Union[List[List[int]], bytes],
mining_hash: bytes,
bin_nonce: bytes,
):
return pyethash.hashimoto_light(block_number, cache, mining_hash,
big_endian_to_int(bin_nonce))
def mine_pow_nonce(block_number: int, mining_hash: Hash32, difficulty: int) -> Tuple[bytes, bytes]:
cache = get_cache(block_number)
for nonce in range(MAX_TEST_MINE_ATTEMPTS):
mining_output = hashimoto_light(block_number, cache, mining_hash, nonce)
result = big_endian_to_int(mining_output[b'result'])
result_cap = 2**256 // difficulty
if result <= result_cap:
return nonce.to_bytes(8, 'big'), mining_output[b'mix digest']
raise Exception("Too many attempts at POW mining, giving up")
def check_pow(block_number, mining_hash, mix_hash, nonce, difficulty):
validate_length(mix_hash, 32)
validate_length(mining_hash, 32)
validate_length(nonce, 8)
cache = get_cache(block_number)
mining_output = hashimoto_light(block_number, cache, mining_hash,
big_endian_to_int(nonce))
if mining_output[b'mix digest'] != mix_hash:
raise ValidationError("mix hash mistmatch; {0} != {1}".format(
encode_hex(mining_output[b'mix digest']), encode_hex(mix_hash)))
result = big_endian_to_int(mining_output[b'result'])
validate_lte(result, 2**256 // difficulty)
def check_pow(block_number, mining_hash, mix_hash, nonce, difficulty):
validate_length(mix_hash, 32, title="Mix Hash")
validate_length(mining_hash, 32, title="Mining Hash")
validate_length(nonce, 8, title="POW Nonce")
cache = get_cache(block_number)
mining_output = hashimoto_light(
block_number, cache, mining_hash, big_endian_to_int(nonce))
if mining_output[b'mix digest'] != mix_hash:
raise ValidationError("mix hash mismatch; {0} != {1}".format(
encode_hex(mining_output[b'mix digest']), encode_hex(mix_hash)))
result = big_endian_to_int(mining_output[b'result'])
validate_lte(result, 2**256 // difficulty, title="POW Difficulty")
def check_pow(block_number: int, mining_hash: Hash32, mix_hash: Hash32,
nonce: bytes, difficulty: int) -> None:
validate_length(mix_hash, 32, title="Mix Hash")
validate_length(mining_hash, 32, title="Mining Hash")
validate_length(nonce, 8, title="POW Nonce")
cache = get_cache(block_number)
mining_output = hashimoto_light(block_number, cache, mining_hash,
big_endian_to_int(nonce))
if mining_output[b'mix digest'] != mix_hash:
raise ValidationError("mix hash mismatch; {0} != {1}".format(
encode_hex(mining_output[b'mix digest']), encode_hex(mix_hash)))
result = big_endian_to_int(mining_output[b'result'])
validate_lte(result, 2**256 // difficulty, title="POW Difficulty")
def test_light_and_full_agree():
cache = pyethash.mkcache_bytes(1024, "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~")
full_size = 1024 * 32
header = "~~~~~X~~~~~~~~~~~~~~~~~~~~~~~~~~"
light_result = pyethash.hashimoto_light(full_size, cache, header, 0)
dataset = pyethash.calc_dataset_bytes(full_size, cache)
full_result = pyethash.hashimoto_full(dataset, header, 0)
assert light_result["mix digest"] != None
assert len(light_result["mix digest"]) == 32
assert light_result["mix digest"] == full_result["mix digest"]
assert light_result["result"] != None
assert len(light_result["result"]) == 32
assert light_result["result"] == full_result["result"]
def test_light_and_full_agree():
cache = pyethash.mkcache_bytes(
1024,
"~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~")
full_size = 1024 * 32
header = "~~~~~X~~~~~~~~~~~~~~~~~~~~~~~~~~"
light_result = pyethash.hashimoto_light(full_size, cache, header, 0)
dataset = pyethash.calc_dataset_bytes(full_size, cache)
full_result = pyethash.hashimoto_full(dataset, header, 0)
assert light_result["mix digest"] != None
assert len(light_result["mix digest"]) == 32
assert light_result["mix digest"] == full_result["mix digest"]
assert light_result["result"] != None
assert len(light_result["result"]) == 32
assert light_result["result"] == full_result["result"]
def mine_pow_nonce(block_number: int, mining_hash: Hash32,
difficulty: int) -> Tuple[bytes, bytes]:
cache = get_cache(block_number)
# VDF input
mining_input = hashimoto_light(block_number, cache, mining_hash)
vdf_input_integer = big_endian_to_int(mining_input[b'result'])
# Calculate VDF Steps needed.
# Adding VRF (WIP)
node_vrf_seed_b64 = self.vrf.get_seed_b64(vdf_input_integer)
vdf_steps = hashimoto_light(DEFAULT_DEBUG_STAKE, TOTAL_COINS,
node_vrf_seed_b64)
vdf_difficulty = big_endian_to_int(vdf_steps[b'result'])
print('VDF Difficulty = %d' % vdf_difficulty)
print("DEBUG: Mining sequential VDF (Sloth) ...")
# nonce = vdf_execute(vdf_input_integer,node_vdf_steps) # VRF version
nonce = vdf_execute(vdf_input_integer, vdf_difficulty)
print("DEBUG: Generated NONCE = %d" % nonce)
return nonce, node_vrf_seed_b64, self.vrf.get_pem_public_key(
) # , node_vrf_seed # with this
def check_pow(block_number: int, mining_hash: Hash32, mix_hash: Hash32,
nonce: bytes, difficulty: int) -> None:
validate_length(mix_hash, 32, title="Mix Hash")
validate_length(mining_hash, 32, title="Mining Hash")
validate_length(nonce, 8, title="POW Nonce")
cache = get_cache(block_number)
mining_output = hashimoto_light(block_number, cache, mining_hash,
big_endian_to_int(nonce))
if mining_output[b'mix digest'] != mix_hash:
raise ValidationError(
f"mix hash mismatch; expected: {encode_hex(mining_output[b'mix digest'])} "
f"!= actual: {encode_hex(mix_hash)}. "
f"Mix hash calculated from block #{block_number}, "
f"mine hash {encode_hex(mining_hash)}, nonce {encode_hex(nonce)}"
f", difficulty {difficulty}, cache hash {encode_hex(keccak(cache))}"
)
result = big_endian_to_int(mining_output[b'result'])
validate_lte(result, 2**256 // difficulty, title="POW Difficulty")
from repoze.lru import lru_cache
else:
ETHASH_LIB = 'ethash'
from functools import lru_cache
if ETHASH_LIB == 'ethash':
mkcache = ethash.mkcache
EPOCH_LENGTH = ethash_utils.EPOCH_LENGTH
hashimoto_light = ethash.hashimoto_light
elif ETHASH_LIB == 'pyethash':
import pyethash
mkcache = pyethash.mkcache_bytes
EPOCH_LENGTH = pyethash.EPOCH_LENGTH
hashimoto_light = lambda s, c, h, n: \
pyethash.hashimoto_light(s, c, h, utils.big_endian_to_int(n))
else:
raise Exception("invalid ethash library set")
TT64M1 = 2**64 - 1
cache_seeds = ['\x00' * 32]
cache_by_seed = OrderedDict()
cache_by_seed.max_items = 10
def get_cache(block_number):
while len(cache_seeds) <= block_number // EPOCH_LENGTH:
cache_seeds.append(sha3.sha3_256(cache_seeds[-1]).digest())
seed = cache_seeds[block_number // EPOCH_LENGTH]
if seed in cache_by_seed:
c = cache_by_seed.pop(seed) # pop and append at end
def hashimoto_light(s, c, h, n): return \ pyethash.hashimoto_light(s, c, h, utils.big_endian_to_int(n)) else:
def pow_hash(block_number, header, nonce) -> Tuple[bytes, bytes]:
"""search for hash result using hashimoto_light."""
cache_bytes = get_cache(block_number)
hash_ret = hashimoto_light(block_number, cache_bytes, header, nonce)
return hash_ret[b"mix digest"], hash_ret[b"result"]