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move psbt_tmp256 to stack when needed

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Peter D. Gray 2024-02-23 11:21:29 -05:00
parent 8e8e103b0a
commit ddf02b5ea1
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1 changed files with 7 additions and 5 deletions
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12
shared/psbt.py
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@ -31,8 +31,6 @@ from public_constants import (
PSBT_IN_REQUIRED_HEIGHT_LOCKTIME, MAX_PATH_DEPTH, MAX_SIGNERS
)
psbt_tmp256 = bytearray(256)
# PSBT proprietary keytype
PSBT_PROPRIETARY = const(0xFC)
@ -137,16 +135,20 @@ def calc_txid(fd, poslen, body_poslen=None):
def get_hash256(fd, poslen, hasher=None):
# return the double-sha256 of a value, without loading it into memory
# - if hasher provided, just updates over region of file (not a sha256d)
pos, ll = poslen
rv = hasher or sha256()
tmp = bytearray(min(256, ll))
fd.seek(pos)
while ll:
here = fd.readinto(psbt_tmp256)
if not here: break
here = fd.readinto(tmp)
if not here:
raise ValueError
if here > ll:
here = ll
rv.update(memoryview(psbt_tmp256)[0:here])
rv.update(memoryview(tmp)[0:here])
ll -= here
if hasher: