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mirror of https://github.com/trezor/trezor-firmware.git synced 2024-11-18 13:38:12 +00:00
trezor-firmware/trezorlib/stellar.py
2018-04-03 19:50:22 -06:00

290 lines
10 KiB
Python

import base64
import struct
import binascii
import xdrlib
def expand_path_or_default(client, address):
"""Uses client to parse address and returns an array of integers
If no address is specified, the default of m/44'/148'/0' is used
"""
if address:
return client.expand_path(address)
else:
return client.expand_path("m/44'/148'/0'")
def address_from_public_key(pk_bytes):
"""Returns the base32-encoded version of pk_bytes (G...)
"""
final_bytes = bytearray()
# version
final_bytes.append(6 << 3)
# public key
final_bytes.extend(pk_bytes)
# checksum
final_bytes.extend(struct.pack("<H", _crc16_checksum(final_bytes)))
return base64.b32encode(final_bytes)
def address_to_public_key(address_str):
"""Returns the raw 32 bytes representing a public key by extracting
it from the G... string
"""
final_bytes = bytearray()
decoded = base64.b32decode(address_str)
# skip 0th byte (version) and last two bytes (checksum)
return decoded[1:-2]
def parse_transaction_bytes(bytes):
"""Parses base64data into a StellarSignTx message
"""
parsed = {}
parsed["protocol_version"] = 1
parsed["operations"] = []
unpacker = xdrlib.Unpacker(bytes)
parsed["source_account"] = _xdr_read_address(unpacker)
parsed["fee"] = unpacker.unpack_uint()
parsed["sequence_number"] = unpacker.unpack_uhyper()
# Timebounds is an optional field
parsed["timebounds_start"] = 0
parsed["timebounds_end"] = 0
has_timebounds = unpacker.unpack_bool()
if has_timebounds:
max_timebound = 2**32-1 # max unsigned 32-bit int (trezor does not support the full 64-bit time value)
parsed["timebounds_start"] = unpacker.unpack_uhyper()
parsed["timebounds_end"] = unpacker.unpack_uhyper()
if parsed["timebounds_start"] > max_timebound or parsed["timebounds_start"] < 0:
raise ValueError("Starting timebound out of range (must be between 0 and " + max_timebound)
if parsed["timebounds_end"] > max_timebound or parsed["timebounds_end"] < 0:
raise ValueError("Ending timebound out of range (must be between 0 and " + max_timebound)
# memo type determines what optional fields are set
parsed["memo_type"] = unpacker.unpack_uint()
parsed["memo_text"] = None
parsed["memo_id"] = None
parsed["memo_hash"] = None
# text
if parsed["memo_type"] == 1:
parsed["memo_text"] = unpacker.unpack_string()
# id (64-bit uint)
if parsed["memo_type"] == 2:
parsed["memo_id"] = unpacker.unpack_uhyper()
# hash / return are the same structure (32 bytes representing a hash)
if parsed["memo_type"] == 3 or parsed["memo_type"] == 4:
parsed["memo+hash"] = unpacker.unpack_fopaque(32)
parsed["num_operations"] = unpacker.unpack_uint()
for opIdx in range(0, parsed["num_operations"]):
parsed["operations"].append(_parse_operation_bytes(unpacker))
return parsed
def _parse_operation_bytes(unpacker):
"""Returns a dictionary describing the next operation as read from
the byte stream in unpacker
"""
op = {
"source_account": None,
"type": None
}
has_source_account = unpacker.unpack_bool()
if has_source_account:
op["source_account"] = unpacker.unpack_fopaque(32)
op["type"] = unpacker.unpack_uint()
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L16
if op["type"] == 0:
op["new_account"] = _xdr_read_address(unpacker)
op["starting_balance"] = unpacker.unpack_hyper()
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L54
if op["type"] == 1:
op["destination_account"] = _xdr_read_address(unpacker)
op["asset"] = _xdr_read_asset(unpacker)
op["amount"] = unpacker.unpack_hyper()
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L72
if op["type"] == 2:
op["send_asset"] = _xdr_read_asset(unpacker)
op["send_max"] = unpacker.unpack_hyper()
op["destination_account"] = _xdr_read_address(unpacker)
op["destination_asset"] = _xdr_read_asset(unpacker)
op["destination_amount"] = unpacker.unpack_hyper()
op["paths"] = []
num_paths = unpacker.unpack_uint()
for i in range(0, num_paths):
op["paths"].append(_xdr_read_asset(unpacker))
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L93
if op["type"] == 3:
op["selling_asset"] = _xdr_read_asset(unpacker)
op["buying_asset"] = _xdr_read_asset(unpacker)
op["amount"] = unpacker.unpack_hyper()
op["price_n"] = unpacker.unpack_uint()
op["price_d"] = unpacker.unpack_uint()
op["offer_id"] = unpacker.unpack_uhyper()
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L111
if op["type"] == 4:
op["selling_asset"] = _xdr_read_asset(unpacker)
op["buying_asset"] = _xdr_read_asset(unpacker)
op["amount"] = unpacker.unpack_hyper()
op["price_n"] = unpacker.unpack_uint()
op["price_d"] = unpacker.unpack_uint()
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L129
if op["type"] == 5:
op["inflation_destination"] = None
op["clear_flags"] = None
op["set_flags"] = None
op["master_weight"] = None
op["low_threshold"] = None
op["medium_threshold"] = None
op["high_threshold"] = None
op["home_domain"] = None
op["signer_type"] = None
op["signer_key"] = None
op["signer_weight"] = None
op["has_inflation_destination"] = unpacker.unpack_bool()
if op["has_inflation_destination"]:
op["inflation_destination"] = _xdr_read_address(unpacker)
op["has_clear_flags"] = unpacker.unpack_bool()
if op["has_clear_flags"]:
op["clear_flags"] = unpacker.unpack_uint()
op["has_set_flags"] = unpacker.unpack_bool()
if op["has_set_flags"]:
op["set_flags"] = unpacker.unpack_uint()
op["has_master_weight"] = unpacker.unpack_bool()
if op["has_master_weight"]:
op["master_weight"] = unpacker.unpack_uint()
op["has_low_threshold"] = unpacker.unpack_bool()
if op["has_low_threshold"]:
op["low_threshold"] = unpacker.unpack_uint()
op["has_medium_threshold"] = unpacker.unpack_bool()
if op["has_medium_threshold"]:
op["medium_threshold"] = unpacker.unpack_uint()
op["has_high_threshold"] = unpacker.unpack_bool()
if op["has_high_threshold"]:
op["high_threshold"] = unpacker.unpack_uint()
op["has_home_domain"] = unpacker.unpack_bool()
if op["has_home_domain"]:
op["home_domain"] = unpacker.unpack_string()
op["has_signer"] = unpacker.unpack_bool()
if op["has_signer"]:
op["signer_type"] = unpacker.unpack_uint()
op["signer_key"] = unpacker.unpack_fopaque(32)
op["signer_weight"] = unpacker.unpack_uint()
# Change Trust
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L156
if op["type"] == 6:
op["asset"] = _xdr_read_asset(unpacker)
op["limit"] = unpacker.unpack_uhyper()
# Allow Trust
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L173
if op["type"] == 7:
op["trusted_account"] = _xdr_read_address(unpacker)
op["asset_type"] = unpacker.unpack_uint()
if op["asset_type"] == 1:
op["asset_code"] = unpacker.unpack_fstring(4)
if op["asset_type"] == 2:
op["asset_code"] = unpacker.unpack_fstring(12)
op["is_authorized"] = unpacker.unpack_bool()
# Merge Account
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L251
if op["type"] == 8:
op["destination_account"] = _xdr_read_address(unpacker)
# Inflation is not implemented since any account can send this operation
# Manage Data
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L218
if op["type"] == 10:
op["key"] = unpacker.unpack_string()
op["value"] = None
op["has_value"] = unpacker.unpack_bool()
if op["has_value"]:
op["value"] = unpacker.unpack_opaque()
# Bump Sequence
# see: https://github.com/stellar/stellar-core/blob/master/src/xdr/Stellar-transaction.x#L269
if op["type"] == 11:
op["bump_to"] = unpacker.unpack_uhyper()
return op
def _xdr_read_asset(unpacker):
"""Reads a stellar Asset from unpacker"""
asset = {
"type": unpacker.unpack_uint(),
"code": None,
"issuer": None
}
# alphanum 4
if asset["type"] == 1:
asset["code"] = unpacker.unpack_fstring(4)
asset["issuer"] = _xdr_read_address(unpacker)
if asset["type"] == 2:
asset["code"] = unpacker.unpack_fstring(12)
asset["issuer"] = _xdr_read_address(unpacker)
return asset
def _xdr_read_address(unpacker):
"""Reads a stellar address and returns the 32-byte
data representing the address
"""
# First 4 bytes are the address type
address_type = unpacker.unpack_uint()
if address_type != 0:
raise ValueError("Unsupported address type")
return unpacker.unpack_fopaque(32)
def _crc16_checksum(bytes):
"""Returns the CRC-16 checksum of bytearray bytes
Ported from Java implementation at: http://introcs.cs.princeton.edu/java/61data/CRC16CCITT.java.html
Initial value changed to 0x0000 to match Stellar configuration.
"""
crc = 0x0000
polynomial = 0x1021
for byte in bytes:
for i in range(0, 8):
bit = ((byte >> (7 - i) & 1) == 1)
c15 = ((crc >> 15 & 1) == 1)
crc <<= 1
if c15 ^ bit:
crc ^= polynomial
return crc & 0xffff