Function CheckBlock

bitcoin/core/__init__.py:872–948

Context independent CBlock checks. CheckBlockHeader() is called first, which may raise a CheckBlockHeader exception, followed the block tests. CheckTransaction() is called for every transaction. fCheckPoW - Check proof-of-work. fCheckMerkleRoot - Check merkle root and w

(block, fCheckPoW = True, fCheckMerkleRoot = True, cur_time=None)

def CheckBlock(block, fCheckPoW = True, fCheckMerkleRoot = True, cur_time=None):
    """Context independent CBlock checks.

    CheckBlockHeader() is called first, which may raise a CheckBlockHeader
    exception, followed the block tests. CheckTransaction() is called for every
    transaction.

    fCheckPoW        - Check proof-of-work.

    fCheckMerkleRoot - Check merkle root and witness merkle root matches transactions.
                     - Check witness commitment in coinbase

    cur_time         - Current time. Defaults to time.time()
    """

    # Block header checks
    CheckBlockHeader(block.get_header(), fCheckPoW=fCheckPoW, cur_time=cur_time)

    # Size limits
    if not block.vtx:
        raise CheckBlockError("CheckBlock() : vtx empty")
    if len(block.serialize(dict(include_witness=False))) > MAX_BLOCK_SIZE:
        raise CheckBlockError("CheckBlock() : block larger than MAX_BLOCK_SIZE")

    if block.GetWeight() > MAX_BLOCK_WEIGHT:
        raise CheckBlockError("CheckBlock() : block larger than MAX_BLOCK_WEIGHT")

    # First transaction must be coinbase
    if not block.vtx[0].is_coinbase():
        raise CheckBlockError("CheckBlock() : first tx is not coinbase")

    # Check rest of transactions. Note how we do things "all at once", which
    # could potentially be a consensus failure if there was some obscure bug.

    # For unique txid uniqueness testing. If coinbase tx is included twice
    # it'll be caught by the "more than one coinbase" test.
    unique_txids = set()
    nSigOps = 0
    for tx in block.vtx[1:]:
        if tx.is_coinbase():
            raise CheckBlockError("CheckBlock() : more than one coinbase")

        CheckTransaction(tx)

        txid = tx.GetTxid()
        if txid in unique_txids:
            raise CheckBlockError("CheckBlock() : duplicate transaction")
        unique_txids.add(txid)

        nSigOps += GetLegacySigOpCount(tx)
        if nSigOps > MAX_BLOCK_SIGOPS:
            raise CheckBlockError("CheckBlock() : out-of-bounds SigOpCount")

    # Check merkle root
    if fCheckMerkleRoot:
        if block.hashMerkleRoot != block.calc_merkle_root():
            raise CheckBlockError("CheckBlock() : hashMerkleRoot mismatch")
        if len(block.vWitnessMerkleTree):