def validate_finished_header_block(
constants: ConsensusConstants,
sub_blocks: Dict[bytes32, SubBlockRecord],
header_block: HeaderBlock,
check_filter: bool,
expected_difficulty: uint64,
expected_sub_slot_iters: uint64,
) -> Tuple[Optional[uint64], Optional[ValidationError]]:
"""
Fully validates the header of a sub-block. A header block is the same as a full block, but
without transactions and transaction info. Returns (required_iters, error).
"""
unfinished_header_block = UnfinishedHeaderBlock(
header_block.finished_sub_slots,
header_block.reward_chain_sub_block.get_unfinished(),
header_block.challenge_chain_sp_proof,
header_block.reward_chain_sp_proof,
header_block.foliage_sub_block,
header_block.foliage_block,
header_block.transactions_filter,
)
required_iters, validate_unfinished_err = validate_unfinished_header_block(
constants,
sub_blocks,
unfinished_header_block,
check_filter,
expected_difficulty,
expected_sub_slot_iters,
False,
)
genesis_block = False
if validate_unfinished_err is not None:
return None, validate_unfinished_err
assert required_iters is not None
if header_block.sub_block_height == 0:
prev_sb: Optional[SubBlockRecord] = None
genesis_block = True
else:
prev_sb = sub_blocks[header_block.prev_header_hash]
new_sub_slot: bool = len(header_block.finished_sub_slots) > 0
ip_iters: uint64 = calculate_ip_iters(
constants,
expected_sub_slot_iters,
header_block.reward_chain_sub_block.signage_point_index,
required_iters,
)
if not genesis_block:
assert prev_sb is not None
# 27. Check sub-block height
if header_block.sub_block_height != prev_sb.sub_block_height + 1:
return None, ValidationError(Err.INVALID_HEIGHT)
# 28. Check weight
if header_block.weight != prev_sb.weight + expected_difficulty:
log.error(f"INVALID WEIGHT: {header_block} {prev_sb} {expected_difficulty}")
return None, ValidationError(Err.INVALID_WEIGHT)
else:
if header_block.sub_block_height != uint32(0):
return None, ValidationError(Err.INVALID_HEIGHT)
if header_block.weight != constants.DIFFICULTY_STARTING:
return None, ValidationError(Err.INVALID_WEIGHT)
# RC vdf challenge is taken from more recent of (slot start, prev_block)
if genesis_block:
cc_vdf_output = ClassgroupElement.get_default_element()
ip_vdf_iters = ip_iters
if new_sub_slot:
rc_vdf_challenge = header_block.finished_sub_slots[-1].reward_chain.get_hash()
else:
rc_vdf_challenge = constants.FIRST_RC_CHALLENGE
else:
assert prev_sb is not None
if new_sub_slot:
# slot start is more recent
rc_vdf_challenge = header_block.finished_sub_slots[-1].reward_chain.get_hash()
ip_vdf_iters = ip_iters
cc_vdf_output = ClassgroupElement.get_default_element()
else:
# Prev sb is more recent
rc_vdf_challenge = prev_sb.reward_infusion_new_challenge
ip_vdf_iters = uint64(header_block.reward_chain_sub_block.total_iters - prev_sb.total_iters)
cc_vdf_output = prev_sb.challenge_vdf_output
# 29. Check challenge chain infusion point VDF
if new_sub_slot:
cc_vdf_challenge = header_block.finished_sub_slots[-1].challenge_chain.get_hash()
else:
# Not first sub-block in slot
if genesis_block:
# genesis block
cc_vdf_challenge = constants.FIRST_CC_CHALLENGE
else:
assert prev_sb is not None
# Not genesis block, go back to first sub-block in slot
curr = prev_sb
while curr.finished_challenge_slot_hashes is None:
curr = sub_blocks[curr.prev_hash]
cc_vdf_challenge = curr.finished_challenge_slot_hashes[-1]
cc_target_vdf_info = VDFInfo(
cc_vdf_challenge,
ip_vdf_iters,
header_block.reward_chain_sub_block.challenge_chain_ip_vdf.output,
)
if header_block.reward_chain_sub_block.challenge_chain_ip_vdf != dataclasses.replace(
cc_target_vdf_info,
number_of_iterations=ip_iters,
):
expected = dataclasses.replace(
cc_target_vdf_info,
number_of_iterations=ip_iters,
)
log.error(f"{header_block.reward_chain_sub_block.challenge_chain_ip_vdf }. expected {expected}")
log.error(f"Block: {header_block}")
return None, ValidationError(Err.INVALID_CC_IP_VDF)
if not header_block.challenge_chain_ip_proof.is_valid(
constants,
cc_vdf_output,
cc_target_vdf_info,
None,
):
log.error(f"Did not validate, output {cc_vdf_output}")
log.error(f"Block: {header_block}")
return None, ValidationError(Err.INVALID_CC_IP_VDF)
# 30. Check reward chain infusion point VDF
rc_target_vdf_info = VDFInfo(
rc_vdf_challenge,
ip_vdf_iters,
header_block.reward_chain_sub_block.reward_chain_ip_vdf.output,
)
if not header_block.reward_chain_ip_proof.is_valid(
constants,
ClassgroupElement.get_default_element(),
header_block.reward_chain_sub_block.reward_chain_ip_vdf,
rc_target_vdf_info,
):
return None, ValidationError(Err.INVALID_RC_IP_VDF)
# 31. Check infused challenge chain infusion point VDF
if not genesis_block:
overflow = is_overflow_sub_block(constants, header_block.reward_chain_sub_block.signage_point_index)
deficit = calculate_deficit(
constants,
header_block.sub_block_height,
prev_sb,
overflow,
len(header_block.finished_sub_slots),
)
if header_block.reward_chain_sub_block.infused_challenge_chain_ip_vdf is None:
# If we don't have an ICC chain, deficit must be 4 or 5
if deficit < constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK - 1:
return None, ValidationError(Err.INVALID_ICC_VDF)
else:
assert header_block.infused_challenge_chain_ip_proof is not None
# If we have an ICC chain, deficit must be 0, 1, 2 or 3
if deficit >= constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK - 1:
return (
None,
ValidationError(
Err.INVALID_ICC_VDF,
f"icc vdf and deficit is bigger or equal to {constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK - 1}",
),
)
if new_sub_slot:
last_ss = header_block.finished_sub_slots[-1]
assert last_ss.infused_challenge_chain is not None
icc_vdf_challenge: bytes32 = last_ss.infused_challenge_chain.get_hash()
icc_vdf_input = ClassgroupElement.get_default_element()
else:
assert prev_sb is not None
if prev_sb.is_challenge_sub_block(constants):
icc_vdf_input = ClassgroupElement.get_default_element()
else:
icc_vdf_input = prev_sb.infused_challenge_vdf_output
curr = prev_sb
while curr.finished_infused_challenge_slot_hashes is None and not curr.is_challenge_sub_block(
constants
):
curr = sub_blocks[curr.prev_hash]
if curr.is_challenge_sub_block(constants):
icc_vdf_challenge = curr.challenge_block_info_hash
else:
assert curr.finished_infused_challenge_slot_hashes is not None
icc_vdf_challenge = curr.finished_infused_challenge_slot_hashes[-1]
icc_target_vdf_info = VDFInfo(
icc_vdf_challenge,
ip_vdf_iters,
header_block.reward_chain_sub_block.infused_challenge_chain_ip_vdf.output,
)
if not header_block.infused_challenge_chain_ip_proof.is_valid(
constants,
icc_vdf_input,
header_block.reward_chain_sub_block.infused_challenge_chain_ip_vdf,
icc_target_vdf_info,
):
return None, ValidationError(Err.INVALID_ICC_VDF, "invalid icc proof")
else:
if header_block.infused_challenge_chain_ip_proof is not None:
return None, ValidationError(Err.INVALID_ICC_VDF)
# 32. Check reward block hash
if header_block.foliage_sub_block.reward_block_hash != header_block.reward_chain_sub_block.get_hash():
return None, ValidationError(Err.INVALID_REWARD_BLOCK_HASH)
# 33. Check reward block is_block
if (header_block.foliage_sub_block.foliage_block_hash is not None) != header_block.reward_chain_sub_block.is_block:
return None, ValidationError(Err.INVALID_FOLIAGE_BLOCK_PRESENCE)
return required_iters, None
def validate_unfinished_header_block(
constants: ConsensusConstants,
sub_blocks: Dict[bytes32, SubBlockRecord],
header_block: UnfinishedHeaderBlock,
check_filter: bool,
expected_difficulty: uint64,
expected_sub_slot_iters: uint64,
skip_overflow_last_ss_validation: bool = False,
skip_vdf_is_valid: bool = False,
) -> Tuple[Optional[uint64], Optional[ValidationError]]:
"""
Validates an unfinished header block. This is a block without the infusion VDFs (unfinished)
and without transactions and transaction info (header). Returns (required_iters, error).
This method is meant to validate only the unfinished part of the sub-block. However, the finished_sub_slots
refers to all sub-slots that were finishes from the previous sub-block's infusion point, up to this sub-blocks
infusion point. Therefore, in the case where this is an overflow sub-block, and the last sub-slot is not yet
released, header_block.finished_sub_slots will be missing one sub-slot. In this case,
skip_overflow_last_ss_validation must be set to True. This will skip validation of end of slots, sub-epochs,
and lead to other small tweaks in validation.
"""
# 1. Check that the previous block exists in the blockchain, or that it is correct
prev_sb = sub_blocks.get(header_block.prev_header_hash, None)
genesis_block = prev_sb is None
if genesis_block and header_block.prev_header_hash != constants.GENESIS_PREV_HASH:
return None, ValidationError(Err.INVALID_PREV_BLOCK_HASH)
overflow = is_overflow_sub_block(constants, header_block.reward_chain_sub_block.signage_point_index)
if skip_overflow_last_ss_validation and overflow:
finished_sub_slots_since_prev = len(header_block.finished_sub_slots) + 1
else:
finished_sub_slots_since_prev = len(header_block.finished_sub_slots)
new_sub_slot: bool = finished_sub_slots_since_prev > 0
can_finish_se: bool = False
can_finish_epoch: bool = False
if genesis_block:
height: uint32 = uint32(0)
assert expected_difficulty == constants.DIFFICULTY_STARTING
assert expected_sub_slot_iters == constants.SUB_SLOT_ITERS_STARTING
else:
assert prev_sb is not None
height = uint32(prev_sb.sub_block_height + 1)
if prev_sb.sub_epoch_summary_included is not None:
can_finish_se, can_finish_epoch = False, False
else:
if new_sub_slot:
can_finish_se, can_finish_epoch = can_finish_sub_and_full_epoch(
constants,
prev_sb.sub_block_height,
prev_sb.deficit,
sub_blocks,
prev_sb.prev_hash,
False,
)
else:
can_finish_se = False
can_finish_epoch = False
# 2. Check finished slots that have been crossed since prev_sb
ses_hash: Optional[bytes32] = None
if new_sub_slot and not skip_overflow_last_ss_validation:
# Finished a slot(s) since previous block. The first sub-slot must have at least one sub-block, and all
# subsequent sub-slots must be empty
for finished_sub_slot_n, sub_slot in enumerate(header_block.finished_sub_slots):
# Start of slot challenge is fetched from SP
challenge_hash: bytes32 = sub_slot.challenge_chain.challenge_chain_end_of_slot_vdf.challenge
if finished_sub_slot_n == 0:
if genesis_block:
# 2a. check sub-slot challenge hash for genesis block
if challenge_hash != constants.FIRST_CC_CHALLENGE:
return None, ValidationError(Err.INVALID_PREV_CHALLENGE_SLOT_HASH)
else:
assert prev_sb is not None
curr: SubBlockRecord = prev_sb
while not curr.first_in_sub_slot:
curr = sub_blocks[curr.prev_hash]
assert curr.finished_challenge_slot_hashes is not None
# 2b. check sub-slot challenge hash for non-genesis block
if not curr.finished_challenge_slot_hashes[-1] == challenge_hash:
print(curr.finished_challenge_slot_hashes[-1], challenge_hash)
return None, ValidationError(Err.INVALID_PREV_CHALLENGE_SLOT_HASH)
else:
# 2c. check sub-slot challenge hash for empty slot
if (
not header_block.finished_sub_slots[finished_sub_slot_n - 1].challenge_chain.get_hash()
== challenge_hash
):
return None, ValidationError(Err.INVALID_PREV_CHALLENGE_SLOT_HASH)
if genesis_block:
# 2d. Validate that genesis block has no ICC
if sub_slot.infused_challenge_chain is not None:
return None, ValidationError(Err.SHOULD_NOT_HAVE_ICC)
else:
assert prev_sb is not None
icc_iters_committed: Optional[uint64] = None
icc_iters_proof: Optional[uint64] = None
icc_challenge_hash: Optional[bytes32] = None
icc_vdf_input = None
if prev_sb.deficit < constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK:
# There should be no ICC chain if the last sub block's deficit is 16
# Prev sb's deficit is 0, 1, 2, 3, or 4
if finished_sub_slot_n == 0:
# This is the first sub slot after the last sb, which must have deficit 1-4, and thus an ICC
curr = prev_sb
while not curr.is_challenge_sub_block(constants) and not curr.first_in_sub_slot:
curr = sub_blocks[curr.prev_hash]
if curr.is_challenge_sub_block(constants):
icc_challenge_hash = curr.challenge_block_info_hash
icc_iters_committed = uint64(prev_sb.sub_slot_iters - curr.ip_iters(constants))
else:
assert curr.finished_infused_challenge_slot_hashes is not None
icc_challenge_hash = curr.finished_infused_challenge_slot_hashes[-1]
icc_iters_committed = prev_sb.sub_slot_iters
icc_iters_proof = uint64(prev_sb.sub_slot_iters - prev_sb.ip_iters(constants))
if prev_sb.is_challenge_sub_block(constants):
icc_vdf_input = ClassgroupElement.get_default_element()
else:
icc_vdf_input = prev_sb.infused_challenge_vdf_output
else:
# This is not the first sub slot after the last sub block, so we might not have an ICC
if (
header_block.finished_sub_slots[finished_sub_slot_n - 1].reward_chain.deficit
< constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK
):
finished_ss = header_block.finished_sub_slots[finished_sub_slot_n - 1]
assert finished_ss.infused_challenge_chain is not None
# Only sets the icc iff the previous sub slots deficit is 4 or less
icc_challenge_hash = finished_ss.infused_challenge_chain.get_hash()
icc_iters_committed = prev_sb.sub_slot_iters
icc_iters_proof = icc_iters_committed
icc_vdf_input = ClassgroupElement.get_default_element()
# 2e. Validate that there is not icc iff icc_challenge hash is None
assert (sub_slot.infused_challenge_chain is None) == (icc_challenge_hash is None)
if sub_slot.infused_challenge_chain is not None:
assert icc_vdf_input is not None
assert icc_iters_proof is not None
assert icc_challenge_hash is not None
assert sub_slot.proofs.infused_challenge_chain_slot_proof is not None
# 2f. Check infused challenge chain sub-slot VDF
# Only validate from prev_sb to optimize
target_vdf_info = VDFInfo(
icc_challenge_hash,
icc_iters_proof,
sub_slot.infused_challenge_chain.infused_challenge_chain_end_of_slot_vdf.output,
)
if sub_slot.infused_challenge_chain.infused_challenge_chain_end_of_slot_vdf != dataclasses.replace(
target_vdf_info,
number_of_iterations=icc_iters_committed,
):
return None, ValidationError(Err.INVALID_ICC_EOS_VDF)
if not skip_vdf_is_valid and not sub_slot.proofs.infused_challenge_chain_slot_proof.is_valid(
constants, icc_vdf_input, target_vdf_info, None
):
return None, ValidationError(Err.INVALID_ICC_EOS_VDF)
if sub_slot.reward_chain.deficit == constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK:
# 2g. Check infused challenge sub-slot hash in challenge chain, deficit 16
if (
sub_slot.infused_challenge_chain.get_hash()
!= sub_slot.challenge_chain.infused_challenge_chain_sub_slot_hash
):
return None, ValidationError(Err.INVALID_ICC_HASH_CC)
else:
# 2h. Check infused challenge sub-slot hash not included for other deficits
if sub_slot.challenge_chain.infused_challenge_chain_sub_slot_hash is not None:
return None, ValidationError(Err.INVALID_ICC_HASH_CC)
# 2i. Check infused challenge sub-slot hash in reward sub-slot
if (
sub_slot.infused_challenge_chain.get_hash()
!= sub_slot.reward_chain.infused_challenge_chain_sub_slot_hash
):
return None, ValidationError(Err.INVALID_ICC_HASH_RC)
else:
# 2j. If no icc, check that the cc doesn't include it
if sub_slot.challenge_chain.infused_challenge_chain_sub_slot_hash is not None:
return None, ValidationError(Err.INVALID_ICC_HASH_CC)
# 2k. If no icc, check that the cc doesn't include it
if sub_slot.reward_chain.infused_challenge_chain_sub_slot_hash is not None:
return None, ValidationError(Err.INVALID_ICC_HASH_RC)
if sub_slot.challenge_chain.subepoch_summary_hash is not None:
assert ses_hash is None # Only one of the slots can have it
ses_hash = sub_slot.challenge_chain.subepoch_summary_hash
# 2l. check sub-epoch summary hash is None for empty slots
if finished_sub_slot_n != 0:
if sub_slot.challenge_chain.subepoch_summary_hash is not None:
return None, ValidationError(Err.INVALID_SUB_EPOCH_SUMMARY_HASH)
if can_finish_epoch and sub_slot.challenge_chain.subepoch_summary_hash is not None:
# 2m. Check new difficulty and ssi
if sub_slot.challenge_chain.new_sub_slot_iters != expected_sub_slot_iters:
return None, ValidationError(Err.INVALID_NEW_SUB_SLOT_ITERS)
if sub_slot.challenge_chain.new_difficulty != expected_difficulty:
return None, ValidationError(Err.INVALID_NEW_DIFFICULTY)
else:
# 2n. Check new difficulty and ssi are None if we don't finish epoch
if sub_slot.challenge_chain.new_sub_slot_iters is not None:
return None, ValidationError(Err.INVALID_NEW_SUB_SLOT_ITERS)
if sub_slot.challenge_chain.new_difficulty is not None:
return None, ValidationError(Err.INVALID_NEW_DIFFICULTY)
# 2o. Check challenge sub-slot hash in reward sub-slot
if sub_slot.challenge_chain.get_hash() != sub_slot.reward_chain.challenge_chain_sub_slot_hash:
return (
None,
ValidationError(
Err.INVALID_CHALLENGE_SLOT_HASH_RC,
"sub-slot hash in reward sub-slot mismatch",
),
)
eos_vdf_iters: uint64 = expected_sub_slot_iters
cc_start_element: ClassgroupElement = ClassgroupElement.get_default_element()
cc_eos_vdf_challenge: bytes32 = challenge_hash
if genesis_block:
if finished_sub_slot_n == 0:
# First block, one empty slot. prior_point is the initial challenge
rc_eos_vdf_challenge: bytes32 = constants.FIRST_RC_CHALLENGE
cc_eos_vdf_challenge = constants.FIRST_CC_CHALLENGE
else:
# First block, but have at least two empty slots
rc_eos_vdf_challenge = header_block.finished_sub_slots[
finished_sub_slot_n - 1
].reward_chain.get_hash()
else:
assert prev_sb is not None
if finished_sub_slot_n == 0:
# No empty slots, so the starting point of VDF is the last reward block. Uses
# the same IPS as the previous block, since it's the same slot
rc_eos_vdf_challenge = prev_sb.reward_infusion_new_challenge
eos_vdf_iters = uint64(prev_sb.sub_slot_iters - prev_sb.ip_iters(constants))
cc_start_element = prev_sb.challenge_vdf_output
else:
# At least one empty slot, so use previous slot hash. IPS might change because it's a new slot
rc_eos_vdf_challenge = header_block.finished_sub_slots[
finished_sub_slot_n - 1
].reward_chain.get_hash()
# 2p. Check end of reward slot VDF
target_vdf_info = VDFInfo(
rc_eos_vdf_challenge,
eos_vdf_iters,
sub_slot.reward_chain.end_of_slot_vdf.output,
)
if not skip_vdf_is_valid and not sub_slot.proofs.reward_chain_slot_proof.is_valid(
constants,
ClassgroupElement.get_default_element(),
sub_slot.reward_chain.end_of_slot_vdf,
target_vdf_info,
):
return None, ValidationError(Err.INVALID_RC_EOS_VDF)
# 2q. Check challenge chain sub-slot VDF
partial_cc_vdf_info = VDFInfo(
cc_eos_vdf_challenge,
eos_vdf_iters,
sub_slot.challenge_chain.challenge_chain_end_of_slot_vdf.output,
)
if genesis_block:
cc_eos_vdf_info_iters = constants.SUB_SLOT_ITERS_STARTING
else:
assert prev_sb is not None
if finished_sub_slot_n == 0:
cc_eos_vdf_info_iters = prev_sb.sub_slot_iters
else:
cc_eos_vdf_info_iters = expected_sub_slot_iters
# Check that the modified data is correct
if sub_slot.challenge_chain.challenge_chain_end_of_slot_vdf != dataclasses.replace(
partial_cc_vdf_info,
number_of_iterations=cc_eos_vdf_info_iters,
):
return None, ValidationError(Err.INVALID_CC_EOS_VDF, "wrong challenge chain end of slot vdf")
# Pass in None for target info since we are only checking the proof from the temporary point,
# but the challenge_chain_end_of_slot_vdf actually starts from the start of slot (for light clients)
if not skip_vdf_is_valid and not sub_slot.proofs.challenge_chain_slot_proof.is_valid(
constants, cc_start_element, partial_cc_vdf_info, None
):
return None, ValidationError(Err.INVALID_CC_EOS_VDF)
if genesis_block:
# 2r. Check deficit (MIN_SUB.. deficit edge case for genesis block)
if sub_slot.reward_chain.deficit != constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK:
return (
None,
ValidationError(
Err.INVALID_DEFICIT,
f"genesis, expected deficit {constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK}",
),
)
else:
assert prev_sb is not None
if prev_sb.deficit == 0:
# 2s. If prev sb had deficit 0, resets deficit to MIN_SUB_BLOCK_PER_CHALLENGE_BLOCK
if sub_slot.reward_chain.deficit != constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK:
log.error(
constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK,
)
return (
None,
ValidationError(
Err.INVALID_DEFICIT,
f"expected deficit {constants.MIN_SUB_BLOCKS_PER_CHALLENGE_BLOCK}, saw "
f"{sub_slot.reward_chain.deficit}",
),
)
else:
# 2t. Otherwise, deficit stays the same at the slot ends, cannot reset until 0
if sub_slot.reward_chain.deficit != prev_sb.deficit:
return None, ValidationError(Err.INVALID_DEFICIT, "deficit is wrong at slot end")
# 3. Check sub-epoch summary
# Note that the subepoch summary is the summary of the previous subepoch (not the one that just finished)
if not skip_overflow_last_ss_validation:
if ses_hash is not None:
# 3a. Check that genesis block does not have sub-epoch summary
if genesis_block:
return (
None,
ValidationError(
Err.INVALID_SUB_EPOCH_SUMMARY_HASH,
"genesis with sub-epoch-summary hash",
),
)
assert prev_sb is not None
# 3b. Check that we finished a slot and we finished a sub-epoch
if not new_sub_slot or not can_finish_se:
return (
None,
ValidationError(
Err.INVALID_SUB_EPOCH_SUMMARY_HASH,
f"new sub-slot: {new_sub_slot} finishes sub-epoch {can_finish_se}",
),
)
# 3c. Check the actual sub-epoch is correct
expected_sub_epoch_summary = make_sub_epoch_summary(
constants,
sub_blocks,
uint32(prev_sb.sub_block_height + 1),
sub_blocks[prev_sb.prev_hash],
expected_difficulty if can_finish_epoch else None,
expected_sub_slot_iters if can_finish_epoch else None,
)
expected_hash = expected_sub_epoch_summary.get_hash()
if expected_hash != ses_hash:
log.error(f"{expected_sub_epoch_summary}")
return (
None,
ValidationError(
Err.INVALID_SUB_EPOCH_SUMMARY,
f"expected ses hash: {expected_hash} got {ses_hash} ",
),
)
elif new_sub_slot and not genesis_block:
# 3d. Check that we don't have to include a sub-epoch summary
if can_finish_se or can_finish_epoch:
return (
None,
ValidationError(
Err.INVALID_SUB_EPOCH_SUMMARY,
"block finishes sub-epoch but ses-hash is None",
),
)
# 4. Check if the number of sub-blocks is less than the max
if not new_sub_slot and not genesis_block:
assert prev_sb is not None
num_sub_blocks = 2 # This includes the current sub-block and the prev sub-block
curr = prev_sb
while not curr.first_in_sub_slot:
num_sub_blocks += 1
curr = sub_blocks[curr.prev_hash]
if num_sub_blocks > constants.MAX_SUB_SLOT_SUB_BLOCKS:
return None, ValidationError(Err.TOO_MANY_SUB_BLOCKS)
# If sub_block state is correct, we should always find a challenge here
# This computes what the challenge should be for this sub-block
challenge = get_block_challenge(
constants,
header_block,
sub_blocks,
genesis_block,
overflow,
skip_overflow_last_ss_validation,
)
# 5a. Check proof of space
if challenge != header_block.reward_chain_sub_block.pos_ss_cc_challenge_hash:
log.error(f"Finished slots: {header_block.finished_sub_slots}")
log.error(
f"Data: {genesis_block} {overflow} {skip_overflow_last_ss_validation} {header_block.total_iters} "
f"{header_block.reward_chain_sub_block.signage_point_index}"
f"Prev: {prev_sb}"
)
log.error(f"Challenge {challenge} provided {header_block.reward_chain_sub_block.pos_ss_cc_challenge_hash}")
return None, ValidationError(Err.INVALID_CC_CHALLENGE)
# 5b. Check proof of space
if header_block.reward_chain_sub_block.challenge_chain_sp_vdf is None:
# Edge case of first sp (start of slot), where sp_iters == 0
cc_sp_hash: bytes32 = challenge
else:
cc_sp_hash = header_block.reward_chain_sub_block.challenge_chain_sp_vdf.output.get_hash()
q_str: Optional[bytes32] = header_block.reward_chain_sub_block.proof_of_space.verify_and_get_quality_string(
constants, challenge, cc_sp_hash
)
if q_str is None:
return None, ValidationError(Err.INVALID_POSPACE)
# 6. check signage point index
# no need to check negative values as this is uint 8
if header_block.reward_chain_sub_block.signage_point_index >= constants.NUM_SPS_SUB_SLOT:
return None, ValidationError(Err.INVALID_SP_INDEX)
# Note that required iters might be from the previous slot (if we are in an overflow sub-block)
required_iters: uint64 = calculate_iterations_quality(
q_str,
header_block.reward_chain_sub_block.proof_of_space.size,
expected_difficulty,
cc_sp_hash,
)
# 7. check signage point index
# no need to check negative values as this is uint8. (Assumes types are checked)
if header_block.reward_chain_sub_block.signage_point_index >= constants.NUM_SPS_SUB_SLOT:
return None, ValidationError(Err.INVALID_SP_INDEX)
# 8a. check signage point index 0 has no cc sp
if (header_block.reward_chain_sub_block.signage_point_index == 0) != (
header_block.reward_chain_sub_block.challenge_chain_sp_vdf is None
):
return None, ValidationError(Err.INVALID_SP_INDEX)
# 8b. check signage point index 0 has no rc sp
if (header_block.reward_chain_sub_block.signage_point_index == 0) != (
header_block.reward_chain_sub_block.reward_chain_sp_vdf is None
):
return None, ValidationError(Err.INVALID_SP_INDEX)
sp_iters: uint64 = calculate_sp_iters(
constants,
expected_sub_slot_iters,
header_block.reward_chain_sub_block.signage_point_index,
)
ip_iters: uint64 = calculate_ip_iters(
constants,
expected_sub_slot_iters,
header_block.reward_chain_sub_block.signage_point_index,
required_iters,
)
if header_block.reward_chain_sub_block.challenge_chain_sp_vdf is None:
# Blocks with very low required iters are not overflow blocks
assert not overflow
# 9. Check no overflows in the first sub-slot of a new epoch
# (although they are OK in the second sub-slot), this is important
if overflow and can_finish_epoch:
if finished_sub_slots_since_prev < 2:
return None, ValidationError(Err.NO_OVERFLOWS_IN_FIRST_SUB_SLOT_NEW_EPOCH)
# 10. Check total iters
if genesis_block:
total_iters: uint128 = uint128(expected_sub_slot_iters * finished_sub_slots_since_prev)
else:
assert prev_sb is not None
if new_sub_slot:
total_iters = prev_sb.total_iters
# Add the rest of the slot of prev_sb
total_iters = uint128(total_iters + prev_sb.sub_slot_iters - prev_sb.ip_iters(constants))
# Add other empty slots
total_iters = uint128(total_iters + (expected_sub_slot_iters * (finished_sub_slots_since_prev - 1)))
else:
# Slot iters is guaranteed to be the same for header_block and prev_sb
# This takes the beginning of the slot, and adds ip_iters
total_iters = uint128(prev_sb.total_iters - prev_sb.ip_iters(constants))
total_iters = uint128(total_iters + ip_iters)
if total_iters != header_block.reward_chain_sub_block.total_iters:
return (
None,
ValidationError(
Err.INVALID_TOTAL_ITERS,
f"expected {total_iters} got {header_block.reward_chain_sub_block.total_iters}",
),
)
sp_total_iters: uint128 = uint128(total_iters - ip_iters + sp_iters - (expected_sub_slot_iters if overflow else 0))
if overflow and skip_overflow_last_ss_validation:
dummy_vdf_info = VDFInfo(
bytes32([0] * 32),
uint64(1),
ClassgroupElement.get_default_element(),
)
dummy_sub_slot = EndOfSubSlotBundle(
ChallengeChainSubSlot(dummy_vdf_info, None, None, None, None),
None,
RewardChainSubSlot(dummy_vdf_info, bytes32([0] * 32), None, uint8(0)),
SubSlotProofs(VDFProof(uint8(0), b""), None, VDFProof(uint8(0), b"")),
)
sub_slots_to_pass_in = header_block.finished_sub_slots + [dummy_sub_slot]
else:
sub_slots_to_pass_in = header_block.finished_sub_slots
(
cc_vdf_challenge,
rc_vdf_challenge,
cc_vdf_input,
rc_vdf_input,
cc_vdf_iters,
rc_vdf_iters,
) = get_signage_point_vdf_info(
constants,
sub_slots_to_pass_in,
overflow,
prev_sb,
sub_blocks,
sp_total_iters,
sp_iters,
)
# 11. Check reward chain sp proof
if sp_iters != 0:
assert (
header_block.reward_chain_sub_block.reward_chain_sp_vdf is not None
and header_block.reward_chain_sp_proof is not None
)
target_vdf_info = VDFInfo(
rc_vdf_challenge,
rc_vdf_iters,
header_block.reward_chain_sub_block.reward_chain_sp_vdf.output,
)
if not skip_vdf_is_valid and not header_block.reward_chain_sp_proof.is_valid(
constants,
rc_vdf_input,
header_block.reward_chain_sub_block.reward_chain_sp_vdf,
target_vdf_info,
):
return None, ValidationError(Err.INVALID_RC_SP_VDF)
rc_sp_hash = header_block.reward_chain_sub_block.reward_chain_sp_vdf.output.get_hash()
else:
# Edge case of first sp (start of slot), where sp_iters == 0
assert overflow is not None
if header_block.reward_chain_sub_block.reward_chain_sp_vdf is not None:
return None, ValidationError(Err.INVALID_RC_SP_VDF)
if new_sub_slot:
rc_sp_hash = header_block.finished_sub_slots[-1].reward_chain.get_hash()
else:
if genesis_block:
rc_sp_hash = constants.FIRST_RC_CHALLENGE
else:
assert prev_sb is not None
curr = prev_sb
while not curr.first_in_sub_slot:
curr = sub_blocks[curr.prev_hash]
assert curr.finished_reward_slot_hashes is not None
rc_sp_hash = curr.finished_reward_slot_hashes[-1]
# 12. Check reward chain sp signature
if not AugSchemeMPL.verify(
header_block.reward_chain_sub_block.proof_of_space.plot_public_key,
rc_sp_hash,
header_block.reward_chain_sub_block.reward_chain_sp_signature,
):
return None, ValidationError(Err.INVALID_RC_SIGNATURE)
# 13. Check cc sp vdf
if sp_iters != 0:
assert header_block.reward_chain_sub_block.challenge_chain_sp_vdf is not None
assert header_block.challenge_chain_sp_proof is not None
target_vdf_info = VDFInfo(
cc_vdf_challenge,
cc_vdf_iters,
header_block.reward_chain_sub_block.challenge_chain_sp_vdf.output,
)
if header_block.reward_chain_sub_block.challenge_chain_sp_vdf != dataclasses.replace(
target_vdf_info,
number_of_iterations=sp_iters,
):
return None, ValidationError(Err.INVALID_CC_SP_VDF)
if not skip_vdf_is_valid and not header_block.challenge_chain_sp_proof.is_valid(
constants, cc_vdf_input, target_vdf_info, None
):
return None, ValidationError(Err.INVALID_CC_SP_VDF)
else:
assert overflow is not None
if header_block.reward_chain_sub_block.challenge_chain_sp_vdf is not None:
return None, ValidationError(Err.INVALID_CC_SP_VDF)
# 14. Check cc sp sig
if not AugSchemeMPL.verify(
header_block.reward_chain_sub_block.proof_of_space.plot_public_key,
cc_sp_hash,
header_block.reward_chain_sub_block.challenge_chain_sp_signature,
):
return None, ValidationError(Err.INVALID_CC_SIGNATURE, "invalid cc sp sig")
# 15. Check is_block
if genesis_block:
if header_block.foliage_sub_block.foliage_block_hash is None:
return None, ValidationError(Err.INVALID_IS_BLOCK, "invalid genesis")
else:
assert prev_sb is not None
# Finds the previous block
curr = prev_sb
while not curr.is_block:
curr = sub_blocks[curr.prev_hash]
# The first sub-block to have an sp > the last block's infusion iters, is a block
if overflow:
our_sp_total_iters: uint128 = uint128(total_iters - ip_iters + sp_iters - expected_sub_slot_iters)
else:
our_sp_total_iters = uint128(total_iters - ip_iters + sp_iters)
if (our_sp_total_iters > curr.total_iters) != (header_block.foliage_sub_block.foliage_block_hash is not None):
return None, ValidationError(Err.INVALID_IS_BLOCK)
if (our_sp_total_iters > curr.total_iters) != (
header_block.foliage_sub_block.foliage_block_signature is not None
):
return None, ValidationError(Err.INVALID_IS_BLOCK)
# 16. Check foliage sub block signature by plot key
if not AugSchemeMPL.verify(
header_block.reward_chain_sub_block.proof_of_space.plot_public_key,
header_block.foliage_sub_block.foliage_sub_block_data.get_hash(),
header_block.foliage_sub_block.foliage_sub_block_signature,
):
return None, ValidationError(Err.INVALID_PLOT_SIGNATURE)
# 17. Check foliage block signature by plot key
if header_block.foliage_sub_block.foliage_block_hash is not None:
if not AugSchemeMPL.verify(
header_block.reward_chain_sub_block.proof_of_space.plot_public_key,
header_block.foliage_sub_block.foliage_block_hash,
header_block.foliage_sub_block.foliage_block_signature,
):
return None, ValidationError(Err.INVALID_PLOT_SIGNATURE)
# 18. Check unfinished reward chain sub block hash
if (
header_block.reward_chain_sub_block.get_hash()
!= header_block.foliage_sub_block.foliage_sub_block_data.unfinished_reward_block_hash
):
return None, ValidationError(Err.INVALID_URSB_HASH)
# 19. Check pool target max height
if (
header_block.foliage_sub_block.foliage_sub_block_data.pool_target.max_height != 0
and header_block.foliage_sub_block.foliage_sub_block_data.pool_target.max_height < height
):
return None, ValidationError(Err.OLD_POOL_TARGET)
# 20a. Check pre-farm puzzle hash for genesis sub-block.
if genesis_block:
if (
header_block.foliage_sub_block.foliage_sub_block_data.pool_target.puzzle_hash
!= constants.GENESIS_PRE_FARM_POOL_PUZZLE_HASH
):
log.error(
f"Pool target {header_block.foliage_sub_block.foliage_sub_block_data.pool_target} hb {header_block}"
)
return None, ValidationError(Err.INVALID_PREFARM)
else:
# 20b. Check pool target signature. Should not check this for genesis sub-block.
if not AugSchemeMPL.verify(
header_block.reward_chain_sub_block.proof_of_space.pool_public_key,
bytes(header_block.foliage_sub_block.foliage_sub_block_data.pool_target),
header_block.foliage_sub_block.foliage_sub_block_data.pool_signature,
):
return None, ValidationError(Err.INVALID_POOL_SIGNATURE)
# 21. Check extension data if applicable. None for mainnet.
# 22. Check if foliage block is present
if (header_block.foliage_sub_block.foliage_block_hash is not None) != (header_block.foliage_block is not None):
return None, ValidationError(Err.INVALID_FOLIAGE_BLOCK_PRESENCE)
if (header_block.foliage_sub_block.foliage_block_signature is not None) != (header_block.foliage_block is not None):
return None, ValidationError(Err.INVALID_FOLIAGE_BLOCK_PRESENCE)
if header_block.foliage_block is not None:
# 23. Check foliage block hash
if header_block.foliage_block.get_hash() != header_block.foliage_sub_block.foliage_block_hash:
return None, ValidationError(Err.INVALID_FOLIAGE_BLOCK_HASH)
if genesis_block:
# 24a. Check prev block hash for genesis
if header_block.foliage_block.prev_block_hash != bytes([0] * 32):
return None, ValidationError(Err.INVALID_PREV_BLOCK_HASH)
else:
assert prev_sb is not None
# 24b. Check prev block hash for non-genesis
curr_sb: SubBlockRecord = prev_sb
while not curr_sb.is_block:
curr_sb = sub_blocks[curr_sb.prev_hash]
if not header_block.foliage_block.prev_block_hash == curr_sb.header_hash:
log.error(
f"Prev BH: {header_block.foliage_block.prev_block_hash} {curr_sb.header_hash} curr sb: {curr_sb}"
)
return None, ValidationError(Err.INVALID_PREV_BLOCK_HASH)
# 25. The filter hash in the Foliage Block must be the hash of the filter
if check_filter:
if header_block.foliage_block.filter_hash != std_hash(header_block.transactions_filter):
return None, ValidationError(Err.INVALID_TRANSACTIONS_FILTER_HASH)
# 26. The timestamp in Foliage Block must comply with the timestamp rules
if prev_sb is not None:
last_timestamps: List[uint64] = []
curr_sb = sub_blocks[header_block.foliage_block.prev_block_hash]
assert curr_sb.timestamp is not None
while len(last_timestamps) < constants.NUMBER_OF_TIMESTAMPS:
last_timestamps.append(curr_sb.timestamp)
fetched: Optional[SubBlockRecord] = sub_blocks.get(curr_sb.prev_block_hash, None)
if not fetched:
break
curr_sb = fetched
if len(last_timestamps) != constants.NUMBER_OF_TIMESTAMPS:
# For blocks 1 to 10, average timestamps of all previous blocks
assert curr_sb.sub_block_height == 0
prev_time: uint64 = uint64(int(sum(last_timestamps) // len(last_timestamps)))
if header_block.foliage_block.timestamp <= prev_time:
return None, ValidationError(Err.TIMESTAMP_TOO_FAR_IN_PAST)
if header_block.foliage_block.timestamp > int(time.time() + constants.MAX_FUTURE_TIME):
return None, ValidationError(Err.TIMESTAMP_TOO_FAR_IN_FUTURE)
return required_iters, None # Valid unfinished header block