partial bitcoin#26341: add BIP158 false-positive element check in rpc_scanblocks.py

excludes:
- fa54d3011ed0cbb7bcdc76548423ba41f0042832
This commit is contained in:
Kittywhiskers Van Gogh 2022-10-19 18:57:09 +02:00 committed by pasta
parent eab94ac07b
commit d033cd55be
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2 changed files with 78 additions and 27 deletions

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@ -0,0 +1,49 @@
#!/usr/bin/env python3
# Copyright (c) 2022 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Helper routines relevant for compact block filters (BIP158).
"""
from .siphash import siphash
def bip158_basic_element_hash(script_pub_key, N, block_hash):
""" Calculates the ranged hash of a filter element as defined in BIP158:
'The first step in the filter construction is hashing the variable-sized
raw items in the set to the range [0, F), where F = N * M.'
'The items are first passed through the pseudorandom function SipHash, which takes a
128-bit key k and a variable-sized byte vector and produces a uniformly random 64-bit
output. Implementations of this BIP MUST use the SipHash parameters c = 2 and d = 4.'
'The parameter k MUST be set to the first 16 bytes of the hash (in standard
little-endian representation) of the block for which the filter is constructed. This
ensures the key is deterministic while still varying from block to block.'
"""
M = 784931
block_hash_bytes = bytes.fromhex(block_hash)[::-1]
k0 = int.from_bytes(block_hash_bytes[0:8], 'little')
k1 = int.from_bytes(block_hash_bytes[8:16], 'little')
return (siphash(k0, k1, script_pub_key) * (N * M)) >> 64
def bip158_relevant_scriptpubkeys(node, block_hash):
""" Determines the basic filter relvant scriptPubKeys as defined in BIP158:
'A basic filter MUST contain exactly the following items for each transaction in a block:
- The previous output script (the script being spent) for each input, except for
the coinbase transaction.
- The scriptPubKey of each output, aside from all OP_RETURN output scripts.'
"""
spks = set()
for tx in node.getblock(blockhash=block_hash, verbosity=3)['tx']:
# gather prevout scripts
for i in tx['vin']:
if 'prevout' in i:
spks.add(bytes.fromhex(i['prevout']['scriptPubKey']['hex']))
# gather output scripts
for o in tx['vout']:
if o['scriptPubKey']['type'] != 'nulldata':
spks.add(bytes.fromhex(o['scriptPubKey']['hex']))
return spks

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@ -1,15 +1,17 @@
#!/usr/bin/env python3
# Copyright (c) 2016 The Bitcoin Core developers
# Copyright (c) 2016-2022 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Specialized SipHash-2-4 implementations.
"""SipHash-2-4 implementation.
This implements SipHash-2-4 for 256-bit integers.
This implements SipHash-2-4. For convenience, an interface taking 256-bit
integers is provided in addition to the one accepting generic data.
"""
def rotl64(n, b):
return n >> (64 - b) | (n & ((1 << (64 - b)) - 1)) << b
def siphash_round(v0, v1, v2, v3):
v0 = (v0 + v1) & ((1 << 64) - 1)
v1 = rotl64(v1, 13)
@ -27,37 +29,37 @@ def siphash_round(v0, v1, v2, v3):
v2 = rotl64(v2, 32)
return (v0, v1, v2, v3)
def siphash256(k0, k1, h):
n0 = h & ((1 << 64) - 1)
n1 = (h >> 64) & ((1 << 64) - 1)
n2 = (h >> 128) & ((1 << 64) - 1)
n3 = (h >> 192) & ((1 << 64) - 1)
def siphash(k0, k1, data):
assert(type(data) == bytes)
v0 = 0x736f6d6570736575 ^ k0
v1 = 0x646f72616e646f6d ^ k1
v2 = 0x6c7967656e657261 ^ k0
v3 = 0x7465646279746573 ^ k1 ^ n0
v3 = 0x7465646279746573 ^ k1
c = 0
t = 0
for d in data:
t |= d << (8 * (c % 8))
c = (c + 1) & 0xff
if (c & 7) == 0:
v3 ^= t
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0 ^= t
t = 0
t = t | (c << 56)
v3 ^= t
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0 ^= n0
v3 ^= n1
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0 ^= n1
v3 ^= n2
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0 ^= n2
v3 ^= n3
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0 ^= n3
v3 ^= 0x2000000000000000
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0 ^= 0x2000000000000000
v2 ^= 0xFF
v0 ^= t
v2 ^= 0xff
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
return v0 ^ v1 ^ v2 ^ v3
def siphash256(k0, k1, num):
assert(type(num) == int)
return siphash(k0, k1, num.to_bytes(32, 'little'))