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Code Issues Releases Wiki Activity

enable crc32, update protocol, add session closing

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This commit is contained in:
Jan Pochyla 2016-09-21 16:51:17 +02:00
parent 531350d6ba
commit 80ffa27052
1 changed files with 23 additions and 18 deletions
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41
trezorlib/transport.py
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@ -1,5 +1,6 @@
import struct import struct
import mapping import mapping
import binascii
class NotImplementedException(Exception): class NotImplementedException(Exception):
pass pass
@ -156,7 +157,7 @@ class TransportV2(Transport):
data = bytearray(msg.SerializeToString()) data = bytearray(msg.SerializeToString())
# Convert to unsigned in python2 # Convert to unsigned in python2
checksum = 0 # binascii.crc32(data) & 0xffffffff checksum = binascii.crc32(data) & 0xffffffff
header1 = struct.pack(">L", self.session_id) header1 = struct.pack(">L", self.session_id)
header2 = struct.pack(">LL", mapping.get_type(msg), len(data)) header2 = struct.pack(">LL", mapping.get_type(msg), len(data))
@ -169,12 +170,12 @@ class TransportV2(Transport):
if first: if first:
# Magic character, header1, header2, data padded to 64 bytes # Magic character, header1, header2, data padded to 64 bytes
datalen = 63 - len(header1) datalen = 63 - len(header1)
chunk = b'!' + header1 + \ chunk = b'H' + header1 + \
data[:datalen] + b'\0' * (datalen - len(data[:datalen])) data[:datalen] + b'\0' * (datalen - len(data[:datalen]))
else: else:
# Magic character, header1, data padded to 64 bytes # Magic character, header1, data padded to 64 bytes
datalen = 63 - len(header1) datalen = 63 - len(header1)
chunk = b'#' + header1 + \ chunk = b'D' + header1 + \
data[:datalen] + b'\0' * (datalen - len(data[:datalen])) data[:datalen] + b'\0' * (datalen - len(data[:datalen]))
self._write_chunk(chunk) self._write_chunk(chunk)
@ -199,13 +200,16 @@ class TransportV2(Transport):
footer = data[-4:] footer = data[-4:]
data = data[:-4] data = data[:-4]
# csum = struct.unpack('>L', footer) csum, = struct.unpack('>L', footer)
# assert csum == binascii.crc32(data), "Checksum mismatch" csum_comp = binascii.crc32(data) & 0xffffffff
if csum != csum_comp:
raise Exception("Message checksum mismatch. Expected %d, got %d" %
(csum_comp, csum))
return (session_id, msg_type, data) return (session_id, msg_type, data)
def parse_first(self, chunk): def parse_first(self, chunk):
if chunk[0:1] != b"!": if chunk[0:1] != b"H":
raise Exception("Unexpected magic character") raise Exception("Unexpected magic character")
try: try:
@ -218,7 +222,7 @@ class TransportV2(Transport):
return (session_id, msg_type, datalen, data) return (session_id, msg_type, datalen, data)
def parse_next(self, chunk): def parse_next(self, chunk):
if chunk[0:1] != b"#": if chunk[0:1] != b"D":
raise Exception("Unexpected magic characters") raise Exception("Unexpected magic characters")
try: try:
@ -230,27 +234,28 @@ class TransportV2(Transport):
data = chunk[1 + headerlen:] data = chunk[1 + headerlen:]
return (session_id, data) return (session_id, data)
def parse_session(self, chunk): def parse_session_open(self, chunk):
if chunk[0:1] != b"!": if chunk[0:1] != b"O":
raise Exception("Unexpected magic character") raise Exception("Unexpected magic character")
try: try:
headerlen = struct.calcsize(">LL") headerlen = struct.calcsize(">L")
(null_session_id, new_session_id) = struct.unpack( (session_id,) = struct.unpack(">L", bytes(chunk[1:1 + headerlen]))
">LL", bytes(chunk[1:1 + headerlen]))
except: except:
raise Exception("Cannot parse header") raise Exception("Cannot parse header")
if null_session_id != 0: return session_id
raise Exception("Session response needs to use session ID 0")
return new_session_id
def _session_begin(self): def _session_begin(self):
self._write_chunk(b'!' + b'\0' * 63) self._write_chunk(b'O' + b'\0' * 63)
self.session_id = self.parse_session(self._read_chunk()) self.session_id = self.parse_session_open(self._read_chunk())
def _session_end(self): def _session_end(self):
pass header = struct.pack(">L", self.session_id)
self._write_chunk(b'C' + header + b'\0' * (63 - len(header)))
if self._read_chunk()[0] != ord('C'):
raise Exception("Expected session close")
self.session_id = None
''' '''
def read_headers(self, read_f): def read_headers(self, read_f):