tests: Calculate input weight more accurately

The external input test with specifying input weight would make a
pessimistic estimate of the input weight. However this would result in a
test failure as it is sometimes too pessimistic when an ECDSA signature
ends up being smaller than usual. To correct this, we can calculate the
input weight more accurately.

Github-Pull: #24454
Rebased-From: 8a04a386f7
This commit is contained in:
Andrew Chow 2022-03-01 09:09:10 -05:00 committed by fanquake
parent bd6d3ac8b7
commit 5fd25eb9cb
No known key found for this signature in database
GPG key ID: 2EEB9F5CC09526C1
2 changed files with 16 additions and 6 deletions

View file

@ -10,6 +10,10 @@ from itertools import product
from test_framework.descriptors import descsum_create
from test_framework.key import ECKey
from test_framework.messages import (
ser_compact_size,
WITNESS_SCALE_FACTOR,
)
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import (
assert_approx,
@ -655,10 +659,11 @@ class PSBTTest(BitcoinTestFramework):
break
psbt_in = dec["inputs"][input_idx]
# Calculate the input weight
# (prevout + sequence + length of scriptSig + 2 bytes buffer) * 4 + len of scriptwitness
# (prevout + sequence + length of scriptSig + scriptsig + 1 byte buffer) * WITNESS_SCALE_FACTOR + num scriptWitness stack items + (length of stack item + stack item) * N stack items + 1 byte buffer
len_scriptsig = len(psbt_in["final_scriptSig"]["hex"]) // 2 if "final_scriptSig" in psbt_in else 0
len_scriptwitness = len(psbt_in["final_scriptwitness"]["hex"]) // 2 if "final_scriptwitness" in psbt_in else 0
input_weight = ((41 + len_scriptsig + 2) * 4) + len_scriptwitness
len_scriptsig += len(ser_compact_size(len_scriptsig)) + 1
len_scriptwitness = (sum([(len(x) // 2) + len(ser_compact_size(len(x) // 2)) for x in psbt_in["final_scriptwitness"]]) + len(psbt_in["final_scriptwitness"]) + 1) if "final_scriptwitness" in psbt_in else 0
input_weight = ((40 + len_scriptsig) * WITNESS_SCALE_FACTOR) + len_scriptwitness
low_input_weight = input_weight // 2
high_input_weight = input_weight * 2

View file

@ -10,6 +10,10 @@ from itertools import product
from test_framework.authproxy import JSONRPCException
from test_framework.descriptors import descsum_create
from test_framework.key import ECKey
from test_framework.messages import (
ser_compact_size,
WITNESS_SCALE_FACTOR,
)
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import (
assert_equal,
@ -526,10 +530,11 @@ class WalletSendTest(BitcoinTestFramework):
break
psbt_in = dec["inputs"][input_idx]
# Calculate the input weight
# (prevout + sequence + length of scriptSig + 2 bytes buffer) * 4 + len of scriptwitness
# (prevout + sequence + length of scriptSig + scriptsig + 1 byte buffer) * WITNESS_SCALE_FACTOR + num scriptWitness stack items + (length of stack item + stack item) * N stack items + 1 byte buffer
len_scriptsig = len(psbt_in["final_scriptSig"]["hex"]) // 2 if "final_scriptSig" in psbt_in else 0
len_scriptwitness = len(psbt_in["final_scriptwitness"]["hex"]) // 2 if "final_scriptwitness" in psbt_in else 0
input_weight = ((41 + len_scriptsig + 2) * 4) + len_scriptwitness
len_scriptsig += len(ser_compact_size(len_scriptsig)) + 1
len_scriptwitness = (sum([(len(x) // 2) + len(ser_compact_size(len(x) // 2)) for x in psbt_in["final_scriptwitness"]]) + len(psbt_in["final_scriptwitness"]) + 1) if "final_scriptwitness" in psbt_in else 0
input_weight = ((40 + len_scriptsig) * WITNESS_SCALE_FACTOR) + len_scriptwitness
# Input weight error conditions
assert_raises_rpc_error(