blue-loader-python/ledgerblue/ledgerWrapper.py

108 lines
3.5 KiB
Python

"""
*******************************************************************************
* Ledger Blue
* (c) 2016 Ledger
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
********************************************************************************
"""
import struct
from .commException import CommException
def wrapCommandAPDU(channel, command, packetSize, ble=False):
if packetSize < 3:
raise CommException("Can't handle Ledger framing with less than 3 bytes for the report")
sequenceIdx = 0
offset = 0
if not ble:
result = struct.pack(">H", channel)
extraHeaderSize = 2
else:
result = ""
extraHeaderSize = 0
result += struct.pack(">BHH", 0x05, sequenceIdx, len(command))
sequenceIdx = sequenceIdx + 1
if len(command) > packetSize - 5 - extraHeaderSize:
blockSize = packetSize - 5 - extraHeaderSize
else:
blockSize = len(command)
result += command[offset : offset + blockSize]
offset = offset + blockSize
while offset <> len(command):
if not ble:
result += struct.pack(">H", channel)
result += struct.pack(">BH", 0x05, sequenceIdx)
sequenceIdx = sequenceIdx + 1
if (len(command) - offset) > packetSize - 3 - extraHeaderSize:
blockSize = packetSize - 3 - extraHeaderSize
else:
blockSize = len(command) - offset
result += command[offset : offset + blockSize]
offset = offset + blockSize
if not ble:
while (len(result) % packetSize) <> 0:
result += "\x00"
return bytearray(result)
def unwrapResponseAPDU(channel, data, packetSize, ble=False):
sequenceIdx = 0
offset = 0
if not ble:
extraHeaderSize = 2
else:
extraHeaderSize = 0
if ((data is None) or (len(data) < 5 + extraHeaderSize + 5)):
return None
if not ble:
if struct.unpack(">H", str(data[offset : offset + 2]))[0] <> channel:
raise CommException("Invalid channel")
offset += 2
if data[offset] <> 0x05:
raise CommException("Invalid tag")
offset += 1
if struct.unpack(">H", str(data[offset : offset + 2]))[0] <> sequenceIdx:
raise CommException("Invalid sequence")
offset += 2
responseLength = struct.unpack(">H", str(data[offset : offset + 2]))[0]
offset += 2
if len(data) < 5 + extraHeaderSize + responseLength:
return None
if responseLength > packetSize - 5 - extraHeaderSize:
blockSize = packetSize - 5 - extraHeaderSize
else:
blockSize = responseLength
result = data[offset : offset + blockSize]
offset += blockSize
while (len(result) <> responseLength):
sequenceIdx = sequenceIdx + 1
if (offset == len(data)):
return None
if not ble:
if struct.unpack(">H", str(data[offset : offset + 2]))[0] <> channel:
raise CommException("Invalid channel")
offset += 2
if data[offset] <> 0x05:
raise CommException("Invalid tag")
offset += 1
if struct.unpack(">H", str(data[offset : offset + 2]))[0] <> sequenceIdx:
raise CommException("Invalid sequence")
offset += 2
if (responseLength - len(result)) > packetSize - 3 - extraHeaderSize:
blockSize = packetSize - 3 - extraHeaderSize
else:
blockSize = responseLength - len(result)
result += data[offset : offset + blockSize]
offset += blockSize
return bytearray(result)