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simplify read_wire_msg a bit

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Jan Pochyla 2016-07-20 15:33:42 +02:00 committed by Pavol Rusnak
parent f2c331d783
commit 3a69524c52
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1 changed files with 6 additions and 10 deletions
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src/trezor/wire.py
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@ -39,23 +39,19 @@ def _write_report(rep):
def read_wire_msg():
rep = yield from _read_report()
assert rep[0] == _HEADER_MAGIC, 'Incorrect report magic'
# Parse message header
sid, mtype, mlen = ustruct.unpack_from('>LLL', rep, 1) # Skip magic
magic, sid, mtype, mlen = ustruct.unpack('>BLLL', rep)
assert magic == _HEADER_MAGIC, 'Incorrect report magic'
assert mlen < _MAX_DATA_LEN, 'Message too large to read'
mlen += 4 # Account for the checksum
data = rep[13:][:mlen] # Skip magic and header, trim to data len
buffered = bytearray(data) # Resulting message data
remaining = mlen - len(buffered)
remaining = mlen - len(data)
buffered = bytearray(data) if remaining > 0 else data # Avoid the copy if we don't append
while remaining > 0:
rep = yield from _read_report()
assert rep[0] == _DATA_MAGIC, 'Incorrect report magic'
# Compare the session IDs
rsid = ustruct.unpack_from('>L', rep, 1)
magic, rsid = ustruct.unpack('>BL', rep)
assert magic == _DATA_MAGIC, 'Incorrect report magic'
assert rsid == sid, 'Session ID mismatch'
data = rep[5:][:remaining] # Skip magic and session ID, trim