mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-24 23:38:09 +00:00
313 lines
7.9 KiB
Python
313 lines
7.9 KiB
Python
# This file is part of the TREZOR project.
|
|
#
|
|
# Copyright (C) 2012-2016 Marek Palatinus <slush@satoshilabs.com>
|
|
# Copyright (C) 2012-2016 Pavol Rusnak <stick@satoshilabs.com>
|
|
#
|
|
# This library is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU Lesser General Public License as published by
|
|
# the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# This library is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU Lesser General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU Lesser General Public License
|
|
# along with this library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
'''
|
|
Extremely minimal streaming codec for a subset of protobuf. Supports uint32,
|
|
bytes, string, embedded message and repeated fields.
|
|
|
|
For de-sererializing (loading) protobuf types, object with `Reader`
|
|
interface is required:
|
|
|
|
>>> class Reader:
|
|
>>> def readinto(self, buffer):
|
|
>>> """
|
|
>>> Reads `len(buffer)` bytes into `buffer`, or raises `EOFError`.
|
|
>>> """
|
|
|
|
For serializing (dumping) protobuf types, object with `Writer` interface is
|
|
required:
|
|
|
|
>>> class Writer:
|
|
>>> def write(self, buffer):
|
|
>>> """
|
|
>>> Writes all bytes from `buffer`, or raises `EOFError`.
|
|
>>> """
|
|
'''
|
|
|
|
from io import BytesIO
|
|
|
|
_UVARINT_BUFFER = bytearray(1)
|
|
|
|
|
|
def load_uvarint(reader):
|
|
buffer = _UVARINT_BUFFER
|
|
result = 0
|
|
shift = 0
|
|
byte = 0x80
|
|
while byte & 0x80:
|
|
if reader.readinto(buffer) == 0:
|
|
raise EOFError
|
|
byte = buffer[0]
|
|
result += (byte & 0x7F) << shift
|
|
shift += 7
|
|
return result
|
|
|
|
|
|
def dump_uvarint(writer, n):
|
|
buffer = _UVARINT_BUFFER
|
|
shifted = True
|
|
while shifted:
|
|
shifted = n >> 7
|
|
buffer[0] = (n & 0x7F) | (0x80 if shifted else 0x00)
|
|
writer.write(buffer)
|
|
n = shifted
|
|
|
|
|
|
class UVarintType:
|
|
WIRE_TYPE = 0
|
|
|
|
|
|
class Sint32Type:
|
|
WIRE_TYPE = 0
|
|
|
|
|
|
class BoolType:
|
|
WIRE_TYPE = 0
|
|
|
|
|
|
class BytesType:
|
|
WIRE_TYPE = 2
|
|
|
|
|
|
class UnicodeType:
|
|
WIRE_TYPE = 2
|
|
|
|
|
|
class MessageType:
|
|
WIRE_TYPE = 2
|
|
FIELDS = {}
|
|
|
|
def __init__(self, **kwargs):
|
|
for kw in kwargs:
|
|
setattr(self, kw, kwargs[kw])
|
|
self._fill_missing()
|
|
|
|
def __eq__(self, rhs):
|
|
return (self.__class__ is rhs.__class__ and
|
|
self.__dict__ == rhs.__dict__)
|
|
|
|
def __repr__(self):
|
|
d = {}
|
|
for key, value in self.__dict__.items():
|
|
if value is None or value == []:
|
|
continue
|
|
d[key] = value
|
|
return '<%s: %s>' % (self.__class__.__name__, d)
|
|
|
|
def __iter__(self):
|
|
return self.__dict__.__iter__()
|
|
|
|
def __getattr__(self, attr):
|
|
if attr.startswith('_add_'):
|
|
return self._additem(attr[5:])
|
|
|
|
if attr.startswith('_extend_'):
|
|
return self._extenditem(attr[8:])
|
|
|
|
raise AttributeError(attr)
|
|
|
|
def _extenditem(self, attr):
|
|
def f(param):
|
|
try:
|
|
l = getattr(self, attr)
|
|
except AttributeError:
|
|
l = []
|
|
setattr(self, attr, l)
|
|
|
|
l += param
|
|
|
|
return f
|
|
|
|
def _additem(self, attr):
|
|
# Add new item for repeated field type
|
|
for v in self.FIELDS.values():
|
|
if v[0] != attr:
|
|
continue
|
|
if not (v[2] & FLAG_REPEATED):
|
|
raise AttributeError
|
|
|
|
try:
|
|
l = getattr(self, v[0])
|
|
except AttributeError:
|
|
l = []
|
|
setattr(self, v[0], l)
|
|
|
|
item = v[1]()
|
|
l.append(item)
|
|
return lambda: item
|
|
|
|
raise AttributeError
|
|
|
|
def _fill_missing(self):
|
|
# fill missing fields
|
|
for fname, ftype, fflags in self.FIELDS.values():
|
|
if not hasattr(self, fname):
|
|
if fflags & FLAG_REPEATED:
|
|
setattr(self, fname, [])
|
|
else:
|
|
setattr(self, fname, None)
|
|
|
|
def CopyFrom(self, obj):
|
|
self.__dict__ = obj.__dict__.copy()
|
|
|
|
def ByteSize(self):
|
|
data = BytesIO()
|
|
dump_message(data, self)
|
|
return len(data.getvalue())
|
|
|
|
|
|
class LimitedReader:
|
|
|
|
def __init__(self, reader, limit):
|
|
self.reader = reader
|
|
self.limit = limit
|
|
|
|
def readinto(self, buf):
|
|
if self.limit < len(buf):
|
|
raise EOFError
|
|
else:
|
|
nread = self.reader.readinto(buf)
|
|
self.limit -= nread
|
|
return nread
|
|
|
|
|
|
class CountingWriter:
|
|
|
|
def __init__(self):
|
|
self.size = 0
|
|
|
|
def write(self, buf):
|
|
nwritten = len(buf)
|
|
self.size += nwritten
|
|
return nwritten
|
|
|
|
|
|
FLAG_REPEATED = 1
|
|
|
|
|
|
def load_message(reader, msg_type):
|
|
fields = msg_type.FIELDS
|
|
msg = msg_type()
|
|
|
|
while True:
|
|
try:
|
|
fkey = load_uvarint(reader)
|
|
except EOFError:
|
|
break # no more fields to load
|
|
|
|
ftag = fkey >> 3
|
|
wtype = fkey & 7
|
|
|
|
field = fields.get(ftag, None)
|
|
|
|
if field is None: # unknown field, skip it
|
|
if wtype == 0:
|
|
load_uvarint(reader)
|
|
elif wtype == 2:
|
|
ivalue = load_uvarint(reader)
|
|
reader.readinto(bytearray(ivalue))
|
|
else:
|
|
raise ValueError
|
|
continue
|
|
|
|
fname, ftype, fflags = field
|
|
if wtype != ftype.WIRE_TYPE:
|
|
raise TypeError # parsed wire type differs from the schema
|
|
|
|
ivalue = load_uvarint(reader)
|
|
|
|
if ftype is UVarintType:
|
|
fvalue = ivalue
|
|
elif ftype is Sint32Type:
|
|
fvalue = (ivalue >> 1) ^ ((ivalue << 31) & 0xffffffff)
|
|
elif ftype is BoolType:
|
|
fvalue = bool(ivalue)
|
|
elif ftype is BytesType:
|
|
fvalue = bytearray(ivalue)
|
|
reader.readinto(fvalue)
|
|
elif ftype is UnicodeType:
|
|
fvalue = bytearray(ivalue)
|
|
reader.readinto(fvalue)
|
|
fvalue = fvalue.decode()
|
|
elif issubclass(ftype, MessageType):
|
|
fvalue = load_message(LimitedReader(reader, ivalue), ftype)
|
|
else:
|
|
raise TypeError # field type is unknown
|
|
|
|
if fflags & FLAG_REPEATED:
|
|
pvalue = getattr(msg, fname)
|
|
pvalue.append(fvalue)
|
|
fvalue = pvalue
|
|
setattr(msg, fname, fvalue)
|
|
|
|
return msg
|
|
|
|
|
|
def dump_message(writer, msg):
|
|
repvalue = [0]
|
|
mtype = msg.__class__
|
|
fields = mtype.FIELDS
|
|
|
|
for ftag in fields:
|
|
field = fields[ftag]
|
|
fname = field[0]
|
|
ftype = field[1]
|
|
fflags = field[2]
|
|
|
|
fvalue = getattr(msg, fname, None)
|
|
if fvalue is None:
|
|
continue
|
|
|
|
fkey = (ftag << 3) | ftype.WIRE_TYPE
|
|
|
|
if not fflags & FLAG_REPEATED:
|
|
repvalue[0] = fvalue
|
|
fvalue = repvalue
|
|
|
|
for svalue in fvalue:
|
|
dump_uvarint(writer, fkey)
|
|
|
|
if ftype is UVarintType:
|
|
dump_uvarint(writer, svalue)
|
|
|
|
elif ftype is Sint32Type:
|
|
dump_uvarint(writer, ((svalue << 1) & 0xffffffff) ^ (svalue >> 31))
|
|
|
|
elif ftype is BoolType:
|
|
dump_uvarint(writer, int(svalue))
|
|
|
|
elif ftype is BytesType:
|
|
dump_uvarint(writer, len(svalue))
|
|
writer.write(svalue)
|
|
|
|
elif ftype is UnicodeType:
|
|
if not isinstance(svalue, bytes):
|
|
svalue = svalue.encode('utf-8')
|
|
|
|
dump_uvarint(writer, len(svalue))
|
|
writer.write(svalue)
|
|
|
|
elif issubclass(ftype, MessageType):
|
|
counter = CountingWriter()
|
|
dump_message(counter, svalue)
|
|
dump_uvarint(writer, counter.size)
|
|
dump_message(writer, svalue)
|
|
|
|
else:
|
|
raise TypeError
|