31 lines
871 B
Python
31 lines
871 B
Python
from .hash_function import hash
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zerohashes = [b'\x00' * 32]
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for layer in range(1, 32):
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zerohashes.append(hash(zerohashes[layer - 1] + zerohashes[layer - 1]))
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# Compute a Merkle root of a right-zerobyte-padded 2**32 sized tree
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def calc_merkle_tree_from_leaves(values):
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values = list(values)
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tree = [values[::]]
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for h in range(32):
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if len(values) % 2 == 1:
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values.append(zerohashes[h])
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values = [hash(values[i] + values[i + 1]) for i in range(0, len(values), 2)]
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tree.append(values[::])
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return tree
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def get_merkle_root(values):
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return calc_merkle_tree_from_leaves(values)[-1][0]
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def get_merkle_proof(tree, item_index):
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proof = []
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for i in range(32):
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subindex = (item_index // 2**i) ^ 1
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proof.append(tree[i][subindex] if subindex < len(tree[i]) else zerohashes[i])
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return proof
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