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Diffstat (limited to 'test/functional/test_framework/script_util.py')
| -rwxr-xr-x | test/functional/test_framework/script_util.py | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/test/functional/test_framework/script_util.py b/test/functional/test_framework/script_util.py new file mode 100755 index 0000000000..5ef67226c4 --- /dev/null +++ b/test/functional/test_framework/script_util.py @@ -0,0 +1,25 @@ +#!/usr/bin/env python3 +# Copyright (c) 2019 The Bitcoin Core developers +# Distributed under the MIT software license, see the accompanying +# file COPYING or http://www.opensource.org/licenses/mit-license.php. +"""Useful Script constants and utils.""" +from test_framework.script import CScript + +# To prevent a "tx-size-small" policy rule error, a transaction has to have a +# non-witness size of at least 82 bytes (MIN_STANDARD_TX_NONWITNESS_SIZE in +# src/policy/policy.h). Considering a Tx with the smallest possible single +# input (blank, empty scriptSig), and with an output omitting the scriptPubKey, +# we get to a minimum size of 60 bytes: +# +# Tx Skeleton: 4 [Version] + 1 [InCount] + 1 [OutCount] + 4 [LockTime] = 10 bytes +# Blank Input: 32 [PrevTxHash] + 4 [Index] + 1 [scriptSigLen] + 4 [SeqNo] = 41 bytes +# Output: 8 [Amount] + 1 [scriptPubKeyLen] = 9 bytes +# +# Hence, the scriptPubKey of the single output has to have a size of at +# least 22 bytes, which corresponds to the size of a P2WPKH scriptPubKey. +# The following script constant consists of a single push of 21 bytes of 'a': +# <PUSH_21> <21-bytes of 'a'> +# resulting in a 22-byte size. It should be used whenever (small) fake +# scriptPubKeys are needed, to guarantee that the minimum transaction size is +# met. +DUMMY_P2WPKH_SCRIPT = CScript([b'a' * 21]) |